Wireless Power Transfer: Past and Future

1. Project Introduction

The concept of a Wireless Power Transfer System, commonly denoted as WPT, has attracted the attention of researchers and system developers in recent times. While the WPT is believed to have been around for almost a century, the industry recently received more attention. The number of publications on the WPT system is said to have increased by over 1200% in around ten years. The planet we live in now has so much wireless energy that the air we breathe is more enlightened than oxygen. This is also an age in which electro gadgets like mobile telephones, smartphones, MP3 players, notebook computers, and domestic robots operate next to old-fashioned electric wires and cumbersome batteries. Nikola Tesla (1890s), one of the leading electromagnet pioneers, had first intended to provide as cheap as possible electricity, then freshly discovered energy, to everyone. He dreamed that electrical energy could be transmitted wirelessly over long stretches with massive coupled electromagnetic resonators, which were most likely to be produced either by the ionosphere (which probably contains huge sparks) and the Earth itself (possibly via so-called Schumann resonances). The most emerging solutions are believed to have realized significant success across the marketplace following the diffusion of innovation. In the light of the WPT system, there has been a considerable focus on real-life applications, especially for the average users not limited to the engineering world. Wireless Power Transmission is heavily thought of as a method engaged in transmitting power from the source to the receiving end without the necessity of utilizing manmade conductors such as the copper wires, the twisted pair cable, and the co-axial cable.

It must also be noted that a wide variety of applications have drawn attention to the most essential WPT technologies. Tesla's main aim is to solve protection and performance at once. The technology has to be followed first. Recent research has mainly focused on the basic application of magnetic coupling. Nevertheless, Researchers have successfully lit a 60-watt light bulb through the air from the copper bob, which has been constructed specifically for the bulb and is attached seven feet from a second bobbin. Ultimately, to shrink the belt and to increase the gap between them so that the creator can control a space of rechargeable devices, each containing a tiny spiral. The base station was emitting "WiTricity." For more than a century, physicians have known that a moving magnetic field creates an electric field, and vice versa in a motor induction, which turns the engines on and enables you, say, to recharge the electric toothbrush in its base station. But usually, installation works only at very short distances, so the toothbrush and the base station have to touch.

Electricity has been the impossible cup of life in this failure of modernization and rejuvenation. An electric spell makes thoughts about the 21st-century citizen dry. The berth of orthodox electricity is by wiring. Luckily, however, a big discovery was carried about by rigorous and relentless research and development, which provides electricity without wires. This fantastic kid is called inductive charging. Dave Gerdingnow has been used as the inductive word by MIT researchers and everybody else today. The theory of an inductive loading transformer (a system that transfers energy through inductively coupled conductors from one circuit to another (Murray et al., 2017). In this rapidly increasing electronics world, several mobile devices have grown dramatically over the years.

In electronics, however, there are few sacrifices, including efficiency, easiness, or cost. The reliability issue involves the failure of the heating system and other storage and transmission energy losses. Some electronic systems are not available since high-cost, and high-tech logic circuits overcome the reliability problem, and the human efforts of their UIs are huge. One of the main issues is the comfort of mobile devices, such as cables and adapters for loading. Many people have several mobile devices already, and each has its battery adapter. Can wireless power transmission systems not be used effectively because we claim to live in a wireless environment? No! Mobile phones, smartphones, tablets, or other high-performance machines are inductively charged by themselves, eliminating the need to always connect them (Murray et al., 2017). Maybe better, due to inductive charging, some devices do not need batteries for operation. This powered spindle produces an electromagnetic field, which passes power immediately through electric currents when a second induction spindle is sufficiently close. When you install the second bulb in your unit, you can use the power to wirelessly unlock the device and charge batteries. It also produces electricity. Although most induction loaders only work at short distances and although a device and its basic unit do not need physical interactions for induction, they are usually the only way to get close enough to the created fields. Studies have shown that moderate power transfer efficiency can be achieved with just the smallest coupling coefficient. Some developers have nevertheless noted that resonant connectors are needed to reduce losses with high-Q resonators. Despite a small scale of research and implementations, this theory appeared a few years ago. In this context, the research would focus on the WPT system and its use in the lighting system.

2. Aims/Objectives and Scope of the Project

The WPT technology is said to have been used in people’s daily life as it is the case with dynamic electric vehicle charging, and the mobile phone chargers. The project, in this context, has its major aim centered on understanding the principle of WPT systems on the basis of the coils and the power electronic converters. In this context, a light bulb would serve as the key component for the case study thereby paving way for the simulation and the design of the low power WPT system in the light of demonstrating the functionality of the entire system. The aim would be supported by the following objectives including:

To explore the concept of Wireless Power Transfer (WPT)

To determine the building blocks of a Wireless Power Transfer (WPT) system

To examine the components and design elements for a typical WPT system

To design, simulate and demonstrate a low-power WPT system with a lighting bulb that is connected wirelessly

Equipment

Oscilloscope and probes, power supply, MATLAB Simulink

3. Deliverables

We have learned a range of valuable engineering lessons throughout this project and developed a sound understanding of power electronics, lighting, and integrated device architecture principles. The project deliverables include EAGLE PCB configuration for the board and power source control interface, EAGLE scheme of the board and power supply control interface, Content Report, design findings, and potential considerations. The finished design would be the basis for future innovations in LED lighting and electronics, and we will draw many valuable lessons in plans while developing this device. We were sitting some two meters outside a power outlet, the light bulb. The use of a straightforward installation, consisting essentially of two metal coils, proved, for the first time, that it is possible to send such power over a distance efficiently. This project related to experiments and collaboration from team members to achieve our aim. In this project, we used capacitors both un the transmitter end and the receiver.

Capacitive WPT is provided by generating an electric field between two condensers (the forward and return capacitors). The capacitors are built with two parallel and close plates between the transmitter and the receiver. These elements are generally in the order of several picofarads (Froiz-Míguez et al., 2018) in coupling capacitance. An electric field would be generated in an analog way when the plates are near, and an induced current is shown in the receiver. The power conversion is efficient as the condensers are attached to the battery. Although this is the most common type of layers, some variants provide (improved) improvements, such as the more lightweight, external capacity-reduced layers of the Stacked Structure; the induced current is proportional to the change in the electrical field, so power transformers are often used to maximize this variability in this kind of charger.

Conversely to resonant wireless carriers, capacitive WPT can efficiently transmit power even with metallic barriers (Froiz-Míguez et al., 2018). Capacitative wireless loaders are a competitive choice since the electrical sector is limited to the volume between the condensers' two surfaces. Compared with magnetic components, this limitation makes capacitive wireless chargers safer.

Other deliverables, including the inductive transmission of electricity, play an essential role in electronics since the system's operating frequency is closely connected with the capacity demands. Although prototypes operate at other frequency types, including 530 kHz (Abiri et al., 2020), 4 MHz (Shin,2020), and 13,56 MHz, most of the prototypes produced by literature use an operational frequency of 1 MHz (Arteaga et al., 2018). SiC MOSFETs are typically the chosen technologies because of their above-described advantages to handling these high-frequency values. Still, Gallium Nitride (GaN) is used at the highest frequencies due to lower switching losses (Bensenouci & Brahimi, 2017). A complete bridge inverter (most usual) (Hlaing et al., 2017) to convert DC to High-frequency alternating current (Sanusi et al., 2019), Class E to the converter (Froiz-Míguez et al., 2018), or Class α to converter (Hlaing et al., 2017) to a three-phase inverter (Froiz-Míguez et al., 2018) is used; however, a special six-plate topology is needed for the latter (Froiz-Míguez et al., 2018).

A WPT technology operating with a microwave is a far-reaching Microwave Power Transfer (MPT) system. This technology is based on the following. A magnet speed produced by a high voltage DC generator is the microwave. The microwave travels into a waveguide, and the receiving antenna is then radiated. The antenna transmitter should be built so that the radiated power can be oriented to the storage area (Froiz-Míguez et al., 2018). Therefore, the transmitter uses a phase-shifter array. The receiver then transforms the microwave signal into the DC signal by using a rectenna. The DC signal is attached to the EV battery, which allows the charging of this part. Power is normally 2.4 GHz or 5.8 GHz transmitted (Hlaing et al., 2017). In some recent works 28 GHz signals are also used (Gawłowicz et al., 2020).

Theree are some implementations for MPT (Gawłowicz et al., 2020), but the existing tests are constrained. Research in (Gawłowicz et al., 2020) constructs an electrical agricultural vehicle charging model with MPT. A prototype with a power level of 250 W achieves 44% in the DC conversion (Swan, 2019). The method demands a rigorous beamforming tracking algorithm since the MPT is sensitive to the relative misalignment of the transmitter with the receptor. To optimize energy transfer, the writers (Abiri et al., 2020) discuss the material most appropriate for the support of transmission antennas. With multiple meters separation from the power transmitter and the receipt, the applicability of MPT should also be geared towards aerospace rather than terrestrial vehicles. The William Brown group carried out the first pertinent MPT test on which a model aircraft was operated in 1964 (Sanusi et al., 2019). Space solar power/satellite was founded in 1968 by Peter Glazar (SSPS). The concept behind the green energy system is to absorb solar energy through a condenser from a geostationary satellite. Then this energy is converted by the solar arrays into electricity. It represents Earth's energy with an MPT circuit. In (Hlaing et al., 2017), you will find a more recent solution. In 1975, 450 kW was sent to a 1-mile microwave receiver from the transmitter (Abiri et al., 2020). In the 80s, a 5.4-GHz microwave provided small aircraft traveling at an altitude of 21 kilometers (Swan, 2019). They were part of the SHARP project, including telecommunication facilities offered by the aircraft (Hlaing et al., 2017). The aircraft was part of the SHARP project. MPT has currently been based on the drive of UAVs. To carry out power transmission, WPT technologies depend on electromagnetic fields. The flow of these fields as defined by the international organizations must be limited for health and safety purposes. Specifically, ICNIRP has released a guide to this subject that has been transposed into law for over 100 nations. ICNIRP is a non-ionization of radiation protection. It sets limitations for non-ionizing radiation, i.e., radiation derived from less than 10 eV photon energy and less than three frequencies. 1015, 1015 Hz (Swan, 2019). These limitations were established to ensure immunity from short- and long-term exposure to artificial electromagnetic fields for the general and working publics. The power transmission modules must also be made up of such control electronics and software to meet safety and operating specifications to obtain commercial WPT products (Swan, 2019). In order to incorporate the device successfully with other devices or infrastructures, some additional electronics and controls must additionally be used. In order to share data in a comfortable integration with the infrastructure, data communication is required (e.g., electrical grid or databases for vehicle identification) (Abiri et al., 2020).

4. Technical Background and Context

Karunanayake et al. (2019), in their article on the Resonant Frequency Splitting Problems, which occur in several applications, includes a display of power transfer from the resonant source belt to several resonant receivers. The resonant connection system is modeled using a relatively simple circuit of one or more recipients. The model takes into consideration the reciprocal connectivity of all coils and does not generally make approximation-related approaches. A study of the model reveals that a high-Q resonant connection is crucial to the system's productivity by an execution where the basic belt is inductively linked to the power supply, and the loads induce the receiving belt. The work produced will help to explain and apply the resonant connecting process to many mobile receivers. The authors point out that, concerning source coil and concerning each other, the key difficulty is adjusting the lumped capacities at the receptor terminals (Swan, 2019).

Mitra et al. (2018), concerning passive circuitry and device optimization parameters, the author demonstrated a fascinating system of magnetically coupled resonators. The authors showed a way to automatically tune the wireless power system. The optimum power transfer efficiency is achieved for almost any distance and/or orientation, as long as the receiver is within the transmitter operating range. Authors present a circuit model and derive loop principles like frequency division, maximal operating distance (critical coupling), and system behavior when it is uncoupled—validation of the historical model against calculated evidence. An adaptive frequency tuning technology is seen to offset the difference in efficiency in the distance and/or direction from the transmitter to the receiver. The system shown in this paper enables a fixed-load receiver to be shifted to almost any location and/or guidance in the transmitter's range and still achieves an almost constant efficiency in the 0–70 cm range of over 70%. The author also showed the ability to operate a commercial portfolio through their coupling resonator method. The magnetically coupled-resonator mechanism has supplied the laptop. The laptop battery was replaced during the laboratory experiments, and the wireless control system provided the power needed for regular laptop use. In the experiments, they achieved a 50 percent input reliability (Srinivasan et al., 2019).

The architecture considerations for inductive high energy links are outlined by the author of (Srinivasan et al., 2019). An inductive connection is a dc-dc converter constructed around a coupling transformer, which guarantees a steady output voltage after rectification. The main distinctions between low voltage and high power inductive relations are discussed here. The power transmission of 20 W is provided with an inductive connection over 1 cm of distance with an efficiency of 80%—diameters of 6 cm and a 2 mm thickness for an external and remote coil. In biomedical, industrial, and automotive applications, the central link drive is integrated. Nasir, (2019), it is possible to study the relationship between the maximum efficiency of air gap using identical circuits and to suggest calculations to obtain maximum efficiency for a certain air gap. This is consistent with the findings of the study and studies of the electromagnetic field. Applied electromagnetic field analyzes are investigated to vary the duration of the airgap between frequency and performance of Wireless Power Transfer. In electromagnetic field measurement, the system of moments is used.

A range of subject areas linked to the WPT system has attracted a range of publications interested in uncovering different areas linked to research areas. In this context, a refocus on the literature review focuses on discussing the published information attached to a more specific subject area covered within a specified period. Topic areas, which would be covered in this context, include the entire concept of WPT, building blocks of a typical WPT system and components, as well as elements of such a system. The main components of WPT are covered in this section. Figure 1.1 presents a block diagram for the system to be displayed.

5.The building blocks of a WPT system

The WPT system is vast and somehow complicated because developers are forced to define significant blocks that make up a typical system. Nasir (2019) noted that the WPT system could be defined in terms of the Near-Field electromagnetic PT and the Radiative Electromagnetic WPT. According to Jeong et al. (2018), the Near-Field system would have no definite boundary division across different regions. However, in some cases, boundary definition can depend on the maximum dimension of the operating frequency and the antenna. In this kind of system, there is a link between the H-field and the E-field. The fields are never radiative, implying that energy would stay at a proximal point of the source and would never leave it until an object is coupled to the prevailing source. On the other hand, the radiative electromagnetic WPT attracts the inductive coupling technique performed in a low-frequency range. In essence, designers developed an interest in boosting the carrier frequency, which would turn into delivering more power given the rate of the changes in terms of the incident magnetic field.

Rehman et al. (2019) equally noted a range of the building blocks of a typical WPT system. First, the researchers noted that coupled magnetic resonances form one of the fundamental blocks of the WPT system. Magnetic coupling is regarded as a key physical phenomenon that exists between the current-carrying coils. The electromagnetic field energy would tend flowing back and forth across the radiation sources in the near-field system. Notably, when two resonant objects are matched in a specific frequency, there would be substantial coupling, leading to energy transfer. In essence, the WPT technology would substantially take advantage of the resonance technology and magnetic coupling before realizing the wireless transmission of the power. Lu and Ma (2016) equally noted most of the state-of-art designs bear building blocks of the WPT systems in terms of the voltage regulation schemes, which play a focal role in eliminating the requirement and functionality of the post-conversion stage. One of such building blocks attached to the output voltage includes the primary-side non-linear power control. This block carries the local regulation blocks that are needed in responding to the load transient, especially on the receiving end. The receiving power demand signal is substantially acquired by comparing the receiving output voltage with the prevailing reference voltage.

In essence, the power demand signal is largely integrated with the help of the digital loop filter. Another block is that of the reconfigurable rectifier attached to the adaptive output. This block can facilitate the coarse regulation before extending the output power within a substantial range. This block is dominantly used across the low power applications with the hysteresis comparator utilized in comparing rectifier DC output voltage. The load resistor, under this block, is introduced to the primary side with the PA bearing equivalent output impedance. Giustiniano et al. (2018) also focused on the functionality of the pre-rectifier regulation, which has the primary-side power control and the regulating rectifier topologies meant for the output regulation. Another block is that of the multiple output operation and single multi-level inductor. In this context, it should be noted that different supply levels would be needed in the system for a range of functions. In this block, there is a need for one to make use of the bulky passive components across the converters, with some of them being utilized in time multiplexing. In some of the cases, the single-inductor multiple outputs, denoted as the SIMO architecture, are deployed when having a reduced number of the needed magnetic components.

6.1. History of Wireless Power Transmission

In a speech in 1820, when an electric current flowed on a wire cable, Han Oerested observed a needle deflection of the compass, demonstrating a magnetic, electric effect. Through his law on circuits, Andrie-Marie Ampere connected electric current and the magnetic field created by 1826. In Faraday's law of 1831, electromagnetic power could be induced by varying magnetic flows through a conductor. Heinrich Hertz reported in 1888 that the radiation was electromagnetic. In 1891, Nicola Tesla upgraded and patented Hertz's wireless transmitter (Gawłowicz et al., 2020).

The wireless power transfer patent for Hutin and Leblanc was granted in 1894 at 3 kHz (Kim et al., 2017). The same year, Tesla successfully powered a light lamp with a pair of coils (as shown in figure 2.1).

In 1895, with the electromagnetic wave, Jagdish Bose was able to ring a bell from 75 meters across a wall. In 1896, Marconi successfully transmitted 1.5 miles of radio transmission. Wireless power transmission performed by Tesla is 48 km away. In 1904, the prize was awarded for trying to drive a 0.1 hp air engine (75W) over a distance of at least 100feet (Akorede et al., 2017) with energy transmitted through space. Yagi and Uda invented their high-profit directional antenna in 1926. Then he published his article about microwave power transfer options and showed a model helicopter receiving the microwave beam (Akorede et al., 2017). Peter Glaser demonstrated the theory of satellite solar power in 1968 with his proposal to collect wireless energy transmitted from the sun. In 1973, electrodynamic induction was used to power the first passive Radio Frequency Identifying (RFID) device from a few meters away at the Los Alamos National Lab. In 2017, Professor Marin Soljacic presented a combination of resonance power transfer systems and his performance with the wireless power of a 60 W light bulb of 40% efficiency over 2 meters, which is known as "Witricity." In 2007, a research group at the Massachusetts Institute of Technology (MIT) was led by Professor Marin Soljacic. Intel recently replicated the experiment of the MIT team in 2008 and powered a light bulb on the wireless network at 75% efficiency but for a shorter distance. In 2015, Dr. Rim and his staff used inductivity transfer in a distance of 3-5m, with an output of 29 percent, 16 percent, 8 for 3m, 4m, and 5m, respectively, and were responsible for the transmission of inductive power. They used signals of 20 kHz. The report summarizes wireless power transfer literature from 2001 to 2013, citing over 50 articles. According to (Nayyef & Husein, 2018) are the most active authors. The U.S., South Korea, China, and Japan are also the top four successful countries.

6.2 History of Radiative Wireless Power Transfer

WPT's history via radio waves was traced back to the 1880s (with the intention of showing the presence and spread of electromagnetic waves in open space). Hertz used a spark-gap (equivalent to a dipole attain) transmitter in his experiment to produce high-frequency power and detect it at the receiving end, similar to a full WPT device. Several years later, in 1899, Nicola Tesla did his first experiment with the use of electricity without wires (Nayyef & Husein, 2018). Tesla produced an enormous spin in his experiment, which was fed at 150 kHz with 300 kW electricity. However, it was not clear if substantial amounts of power were obtained at any stage. Then Tesla launched the innovative Wardenclyffe Tower in 1901, with a massive wireless transmission station for messaging, telephony, and wireless control (Johnson, 2019). The project was not completed, however, because Tesla did not receive permanent funding. Work on WPT was almost dormant in the first half of the 20th century, and there was no development. During the Second World Krieg, with the significant progress in microwave technology, such as the invention of high-performance tubes for microwave generations and more sophisticated parabolic antennas for extremely direct radiation, the use of powerful WPT was realized, and thus the interest in WPT was rekindled. In 1964, after the invention of rectenna (Sathiyanarayanan et al., 2017), William C. Brown, the pioneer of modern WPT-based radiative technology, successfully proved a wireless helicopter (Sathiyanarayanan et al., 2017). The helicopter, which is flying about 18 m above the transmitting antenna with full power (about 270W), was tackled for the lateral positioning through a microwave beam of 2,45 GHz in this demonstration. In 1968, William Brown showed a helicopter with a beam positioning, using a microwave beam, to position the helicopter automatically over the beam center. In this demonstration, however, the helicopter was operated by an umbilical cable rather than by radiative WPT control. Unfortunately, because of financial problems, the most interesting device of a totally untreated helicopter driven and placed by a microwave beam was not further activity (Kapoor et al., 2020). in 1968, Peter Glaser suggested a PLC concept (Kapoor et al., 2020), which since then has greatly influenced radiative WPT science. The main purpose of the SPS is to absorb solar energy from a geostationary satellite and then to relay it to Earth via a microwave beam. During more than half a century, SPS was viewed in terms of the wide range of available and more stable solar energy in the geostationary orbit rather than in the ground as an important solution to resolving the energy scarcity and emissions problems of greenhouse gases (Zeng et al., 2020). In 1975, the Raytheon Laboratory achieved a WPT test with a 54% total D.C. to D.C. power transfer efficiency with the 1.7 m transmitted and antenna separated by a D.C. output of 495W (DHARANIRAJ, 2021). The WPT experiment was conducted.

This is considered to be the highest possible radiative WPT efficiency. William C. Brown and his colleagues performed another impressive radiative WPT experiment in 1975, called the Goldstone JPL (Jet Propulsion Laboratory) (Dharaniraj, 2021). In this experiment, the rectenna receptor, which was 1.54 km from the transmitter with a 2 388 GHz microwave beam, generated more than 30kW D.C. power, which strongly proved the feasibility of high power transmission through the microwave over a long distance. Three factors attributed to this achievement: high transmission capacity (450 kW), a high-efficiency rectenna (84 percent microwaving to D.C.) (70), (Saghaye-Polkoo et al., 2020), and massive transmitting and receiving antennas (26-meter transmitting antenna, 7.3 m rectenna array), are the key reasons why this is achieved. Such encouragement resulted in a thorough review of the SPS concept, completed in 1980 by NASA and the U.S. Department of Energies (DOE). It was not recommended that the production and implementation of the PLC system be carried out before the technology becomes adequately mature, even though it has a favorable conclusion on the PLC concept(Saghaye-Polkoo et al., 2020). The research on SPS has since been largely transferred to Japan. The first rocket experiment to test high-power microwave ionosphere transmission in Japan was launched in 1983, called the MINIX project (Microwave Ionosphere Nonlinear Interaction eXperiment). The MINIX experiment showed that a 2,45GHz microwave beam(Sharma et al., 2017) is used to transmit power from a daughter to a mother in a vacuum. In 1987 Canada showed the first wireless-flight aircraft to provide a long-lasting, low-cost aerial communication network in the program called the Stationary High Altitude Relay Platform (SHARP) ( Sharma et al., 2017). A 2.45GHz microwave beam was transmitted to power the aircraft 150m above ground level by a parabola antenna in a SHARP demonstration. 1992 was the first experiment to be conducted by the electronically steerable phased radiative power transmission device (ERDS) MILAX (Microwave Lifted Airplane eXperiment) ( Sharma et al., 2017).

6.3 Radiative Wireless Power Transfer: A Fresh New Look

As examined in the last subparagraph, radiative WPT was targeted primarily by the two attractive applications: Wireless aircraft and SPS for long-distance and high-power transmissions. This typically includes a very strong transmission power (e.g., 450 kW for the Goldstone JPL), massive transmission and receiving (e.g., a parabolic platter with a diameter of 26 meters) antennas, and a distinct load connection from the transmitter to the receiver. In recent years, there has been a significant interest in the supply of relatively low energy radiative WPTs (for example, from the microwatts to a few watts) over moderate distances (for example, a few meters up to hundreds of meters) (Sharma et al., 2017), thanks to the rapidly growing need for reliable and convenient WPT systems for remotely charging different low or medium-powered devices, such as RFID tags (Sharma et al., 2017). Although much less power is needed compared with ambitious wireless aircraft and SPS applications, there are many new challenges in design for future daily use WPT systems, including more compact transmitter/receiver devices, more complex propagation environment, mobility support needs, security and health concerns, and the potential impact on wireless services. In particular, the authors take stock of the important engineering criteria and the principal design challenges for potential WPT radiation systems.

Range: The future WPT systems can provide power over distances of a few meters. (e.g., for smartphone charges) hundreds of meters depending on the power demand and receiving sensitivities (e.g., for wireless sensor charging).

Efficiency: The overall efficiency of power transfer is paramount and, therefore, one of the toughest design aspects of radio-power transmission systems. An efficient WPT radiation device can achieve overall performance, depending on distance, from a fraction of a percent to a few percent. This includes an effective DC to RF transmission, high-level RF or air-beam formation, as well as an efficient RF to DC conversion at the recipient. A bottom-to-bottom design with an optimized transmitter and rectennas may need to be implemented in order to further boost performance.

Non-Radiative Power Transfer

The non-radio transfer of power, also known as near-field transfer technology, provides a very strong efficiency of 95%. The downside is that the distance between the recipient (r) and the wavelength of the signal is very short (Sharma et al., 2017).

Short Range

In short, the receiver distance r is less than the diameter of the coil d (r d), with wireless power transmission using the following two techniques.

Inductive Coupling

Inductive coupling is an old approach based on a basic theory. A source driving the different magnetic fields is linked with the primary spiral that induces tension in the secondary spiral recipient and transfers power transfer to load. For a distance of about 10cm, the frequency ranges from 20-40kHz.

Depending on the flux direction in relation to the loading surface, the inductive coupling can be divided into two groups: horizontal and vertical. Wirelessly loaded items like electronic toothbrushes and ribs have already entered the consumer market on the commercial side, and such power chargers have adopted a fixed positioning load receptor. To solve this problem, scientists add a very thin electromagnetic shield under a charging pad and over a receiving bob; usually, inductive charging causes Eddy current in metal which causes the risk of sparkling or arching. The authors also applied this technology to remove the external metal-contact electronic device by designing a high-performance, class-E power-transfer system with a frequency of 134 kHz and 295W power efficiency at 75%, which required forced air cooling.

An inductive charge device with the ability to move 20W power to 1cm with an efficiency of 80percent was proposed. This device is ideal for medical use. The same paper highly distinguishes between low power and high power inductive connection. MIT scientists recently revealed the invention of MagMIMO wireless charging technology to load a Wireless Unit up to 30 cm from a distance. MagMIMO can detect, throw, and even inside the bag a cone of energy into a telephone.

Capacitive Coupling

Energy is transmitted via an electric field in capacitive coupling between two electrodes. With the frequency, the sum of transferred energy is increased. It can transmit power through metal. This approach was used only for low-power devices because of dangerous problems if electrodes are supplied with high voltage. Many materials, including the human body, are often heavily influenced by powerful electrical fields. This results in limitations in biomedical applications using this technology. The two main circuit types for coupling are (Sharma et al., 2017) bipolar-structured transverse, where the boards should always be matched to the charge plates and unipolar or longitudinal style.

Medium Range

The mid-range transmission capacity, e.g. distances of 0.5m to 5m (d < r < 10d), is of high interest. The frequency of operation generally varies from 10kHz to 200MHz. Two spindles, three windings, and four winding systems were used (Aboualalaa et al., 2021). This method can be used in homes and offices to energize and move electricity. In this area, two methods are proposed: magnetic resonance coupling and inductive power transfer device. The resonant frequency was supported as it reduces the leakage, thereby allowing power to be transferred to distances. In (Aboualalaa et al., 2021), electromagnetic field analysis for various air gap lengths on a magnetic coupling circuit was used to study the relationship between the frequency (11MHz-17 MHz) power efficiency. The relationship between maximum efficiency and air gap duration was also investigated. Their findings show that a resonant frequency emerged for 49cm and 80cm, with the frequency 170cm and 357cm air gap. Figure 3.1 shows the results of peak efficiency versus various air gap lengths.

The magnetic resonance coupling procedure was discussed in the (Aboualalaa et al., 2021) MIT team for the transmission of power in this range. Two helical copper spindles (d=25cm) were also implemented in the same paper for transferring 60W light bulbs for 2m, with a 40 percent efficiency (4 times the spinal diameters) and a frequency of 9,9 MHz resonance. The source coil was used for Colpitts oscillators, and their schematic diagram is shown in Fig. 3.1. There were discussions about the availability to create a receiver coil for any portable system without reducing efficiency. They also proposed improving performance by the use of the silver plate coil and improved resonance object geometries.

The technological solution suggested was the magnetic resonance coupling. Still, when transferring energy over a greater distance, the induction combination method is not successful, and a significant amount of energy is being wasted in resistive losses. When the main and secondary spindles are active in the same frequency resonating loops, considerable control over that larger gap and lower losses can be transmitted (Shin, 2020). Indeed, N employed the resonant process. Tesla's work on energy conversion. When two resonant loops share power through the oscillations of their magnetic fields, the magnetic resonance pair occurs. In this case, all the impedances in the environment are even stronger than the positive and negative responses offset by the strong resonant coupling (Arteaga et al., 2018). Marin Soljac and other physicists from the Institute of Technology of Massachusetts (MIT) have shown that solid magnetic resonant connections can be implemented to transmit energy over large distances without wires by installing a facilité with two-tuned spindles at a distance.

6.4 Microwave power transmission

According to this technique, an energy beam with a microwave can be distributed well. The entire procedure involved three key pieces: a conversion system, a transmission antenna, a receiving and converting unit called a rectenna, from conventional energy to a microwave. Microwaves are sent with this approach at a significantly wider radius. The multi-receiver power is recorded with magnetic resonance couplings (Khalifa et al., 2018). Authors have created a single broad source resonance connector experiment for generating a signal with 8.3MHz frequency. Several resonant receptors have been generated by the use at the terminal of lumped condensers to match the resonant frequency. Their study found that the efficiency of the resonant coupling factor is improved. The authors have mentioned that the key challenge for future work will be to change the lumped capacitance at the receiving bow in terms of the source and all around. The experiment shows the removal of the laptop battery and the replacement of the battery with the magnetic resonant connecting mechanism. With a transmission power of 7,65MHz, the system has shown efficiency of 50 percent for 70cm reach. The technology for the inductive transfer of power in this range is also proposed (Jia et al., 2018). Condenser, inverter, rectifier, and loading device are included. The most appropriate frequency for this technique was 20kHz and 105kHz from models, analysis, and experiments (Yamagishi et al., 2018). An inductive 20kHz induction power transfer device has been utilized by a team of researchers from KAIST University (Jia et al., 2018). Dipolar coils have the long, narrow form of the ferrite core to be placed easily on the ceilings or corners of a room, and the overall configuration is presented in Fig. 4.1 Total power output was 1403W, 471W, and 209W for 3m, 4m and 5m for a frequency of 20 kHz. The performance was 29%, 16%, 8% respectively for each distance.

6.5 Radiative Power Transfer

Radiator transfer of power or remote power transmission technology uses long-distance (kilometer range) propagation of electromagnetic waves where r>2 is equally important. Directive and non-directive are two forms of radiative power transfers. For transmitting power from faraway fields, 300 MHz frequency microwave – 300 GHz and laser (ten micrometers to nanometer wavelength). Convert the received microwave signals to DC power for microwave propagation rectennas. In (Yamagishi et al., 2018), the use of a 2,45 GHz microwave for solar satellites was suggested. In this analysis, it has been demonstrated that the size of the transmitter antenna is 1 km and the rectenna at the receiver is not practical. The increased frequency was indicated that the antenna dimension could be minimized, but the disadvantage is the air absorption of the wave. Electric Vehicles (EVs) ( Khan et al.,2017) have recently been used for remote power with a microwave directive. The rectification of 10 kW power, with an 80 percent efficiency conversion into energizing EVs, was proposed to use a device that uses a power transmitter along the road leading to a rectenna receiver. Khan et al.,(2017) Commercialization of these systems depends heavily on the design and structure and electromagnetic compatibility for such systems. Delgado et al. (2018) advocate for the power of mobile devices in wireless networks, for example, through the use of high-frequency microwaves. However, further experimental evaluation is required for its practicality.

Omnidirectional RF transmission can also be used to pass power to portable devices for non-directive use. (Delgado et al., 2018) discusses the use of energy in a 10m range for powering ultra-high frequency RFID tags if the energy is being transmitted in the same way as a radio signal. Usually, low levels of efficiency using multidirectional technology for RF transmission. RF Beam can be used for wirelessly charged networks of sensors with power densities between 20-200μW/cm2 using non-directive RF charging. In (Jeong et al., 2021), the authors used transmitters from 1.79mW to 0.683mW for an ultra-low-power sensor platform with a method of 500kbps data. Similar work has been carried out by (Jeong et al., 2021) for wireless battery recharging sensors. The power can also be transferred to the photovoltaic cells via laser beam and stored in them. NASA flew the first laser-driven aircraft in 2003(Chiou et al., 2017).

RF energy collection also includes technology for RF radio waves converting from the atmosphere to DC, generally supplying power at a microwave level of milliwatts. It is used for powering electronic sensors and computers and low-power sensors. Some applications such as the TX91501 transmitter and the power harvester P2210 have been marketed, and further review of technology harvest may be found in (Zawawi et al., 2018). There are several types of ambient waves (Chiou et al., 2017). In (Tsai et al., 2017), authors were collecting energy by TV transmission. Tsai et al., (2017) The radio transmission were modulated in amplitude (AM). The (Zawawi et al., 2018) Global Mobile Communications System (GSM) band was applied to energy production with 900MHz and 1800MHz. WiFi is found in (Rahmani & Babakhani, 2020) routers. Cellular base stations are used, and (Chiou et al., 2017) electromagnetic waves of satellites are ultimately used for energy collection in base stations.

7.0 Standards

The safety norm for the architecture and electromagnetic interference and human radiation exposure should be considered when designing a wireless power transfer device. There are several requirements for protecting radiated emissions (Rahmani, & Babakhani, 2020), some of them: CISPR 11 or EN55011 Class B Category 2, CISPR 22 or EN55022 Class B, CISPR 14.2 and EN62233:2008, FCC part 15 Class B. More than 130 companies formed and launched a wireless power consortium. In 2010 "Qi" was announced for mobile electronic systems up to 5W, followed by an upgrade to Part 1 of the standard. This norm includes induced wireless loading, vertical flux approach, free positioning guidance, loading communication and loading pad communication, and load compatibility checks (Rahmani, & Babakhani, 2020). For low-power devices such as cell phones and laptops, this standard is helpful. There has also been another consortium to establish wireless power transfer standards: the Power Matters Alliance (PMA) and the Wireless Power Alliance (A4WP). A4WP focuses on how broad electromagnetic fields can be produced with magnetic resonance coupling. The Qi norm should be extended to include foreign artifacts, load detection, and means of increasing transmission distance. It will be useful to expand the Qi level to 120W rather than just 5W to cover large devices like laptops (Zhong & Wang, 2018).

7.1. Inductive Coupling Concept and Wireless Power Transfer Mode

There are two spindles called "primary" and "secondary" spindles in an IPT scheme. The machine model appears in Figure 6.1. Power transmission occurs as magnetic and electrical fields H and E produce the primary source trigger the voltage V on the secondary receiver.

The permeability of the transmitting medium is where ω is the working angular frequency, and μ is. The connection between binding is primarily determined by the magnetic flow connection between primary and secondary binding, according to (Zhong & Wang, 2018). Reduced distance between the primary and secondary transmitters while increasing the length of the coils contributes to increased magnetic flow. In the event of not well-aligned primary and secondary coils, effectiveness (η) will decrease, causing further energy loss. Figure 6.1 shows a diagram of a block of the power transmission mechanism for biomedical systems. The first portion is the power transmitter. This device has three parts. The transmitter is external to the body. It may, for example, even be placed in a space below the ground, in a chair, or in a remote bed. The Power Transmitter Circuit comprises a DC source, a DC-AC converter (this enables the transmission of the power at the proposed frequency), a tuner, an antenna for sending data and input from the implanted device (which allows the power transfer). The second component is the energy receiver, which is implanted underneath the tissue within the body. The receiver has the wireless control and has a secure potential for charge or off (Akpeghagha et al., 2019).

The receiver system consists of a secondary power antenna, a tuning circuit, an AC DC converter, a DCDC converter (regulator) and an implanted antenna control system. The third element is the center control transmitter. The portion is a third element for the resonator and power supply of the operating frequency. You may also wear it or put it on a receiver circuit beneath the human body. This part is not compulsory for all WPT systems architecture. Each WPT architecture is primarily designed to pass high-efficiency power and energy stabilization. There are five big problems here (Choudhary et al., 2011). Since the recipient is in the body, the size of the recipient is tiny. The first challenge is the receiver. This small size impacts the element of accuracy and thus decreases the connecting factor. The second challenge is the frequency of operations; with the rising frequency of operations, energy losses in human tissues are increasing and heat rises can be a protection concern.

The third problem is the proportion of the distance to the scale of the antennas. With increasing distance, η declines. The fourth factor is the misalignment of the side and angle of the transmitter with the antennas of the receiver that causes the coupling factor to decrease, which also reduces (Gowda et al., 2013). The fifth issue is the power level of the receiver. The main challenge in low-power applications is how to transfer power at high ̈ with reduced power efficiency. The concerns with high-power systems, instead, are avoiding the thermal problems at the coil side of the transmitter and how the body tissue can consume electromagnetic energy as low as possible (Akpeghagha et Al., 2019. )

7.2 Optimization Method for Transmitter and Receiver

To increase the coupling coefficient and decide the optimum frequency to boost μ, optimization procedures are used in order to determine size of the transmitting and receiving coil. Probably one of the major problems of biomedical wireless transfer is the size limits of devices. The devices are implanted in the layers of tissue. The scale varies between a few and decades mm. The receiver is usually in a small box. For instance, the capsules are endoscopies by mouth. The scale of this capsule is generally between 11 and 27 mm (Akpeghagha et al., 2019).The optimum antenna forms and dimensions should be predicted on the basis of the optimal operating frequency and gap range required to power this transmitter and receiver. In order to optimize the transmitter coil basically, the majority of the collected document can be started in two manners. The first considers that the distance of transfer is established (x is fixed and constant). This approach is ideal for medical applications where the device can be inserted under the skin and in tissue layers in a certain region.

7.3 Concept of Wireless Power Transfer

The principle of wireless communication, which refers to the transfer of energy over a long distance when the cables or wires are absent, is closely related (Choudhary et al., 2011). Most wireless activities, including long-haul communications, are supposed to offer space for service. Akpeghagha et al. (2019) have further emphasized that the wide range of wireless power transmission extends from the power source to the receiving end without using the interconnecting wires. Wireless transmission is said to be more advantageous, especially where the interconnecting wires are deemed inappropriate, impossible, and hazardous at the same time. The WPT concept regards efficiency as the most significant parameter observed while establishing the induction and coupling amid the energy transfer. The role played by the supportive principles in understanding the WPT structure was also noted by (Akpeghagha et al., 2019). Some of these ideas are never confined to the non-radiative elements, the magnet, and electric fields. Rahmani (2017) indicated that both magnetic and electrical sources would generate magnetic fields under the influence of both non-radiative and radiative elements. The proximity of the source is used to describe how components communicate with the available surrounding media in the transition, the far-field and near-field regions. In addition to this, (Akpeghagha et al., 2019) broadened the WPT definition by addressing the role of wireless power and resonance. Based on all these factors, the researchers argued that most household appliances like small magnetic fields. The latter has become a basis for the induction of short distances.

7.4 The building blocks of a WPT system

The WPT system is vast and somehow complicated because developers are forced to define significant blocks that make up a typical system. Rahmani (2017) noted that the WPT system could be defined in terms of the Near-Field electromagnetic PT and the Radiative Electromagnetic WPT. According to Rahmani (2017), the Near-Field system would have no definite boundary division across different regions. However, in some cases, boundary definition can depend on the maximum dimension of the operating frequency and the antenna. In this kind of system, there is a link between the H-field and the E-field. The fields are never radiative, implying that energy would stay at a proximal point of the source and would never leave it until an object is coupled to the prevailing source. On the other hand, the radiative electromagnetic WPT attracts the inductive coupling technique performed in a low-frequency range. In essence, designers developed an interest in boosting the carrier frequency, which would turn into delivering more power given the rate of the changes in terms of the incident magnetic field.

Gowda et al. (2013) equally noted a range of the building blocks of a typical WPT system. First, the researchers noted that coupled magnetic resonances form one of the fundamental blocks of the WPT system. Magnetic coupling is regarded as a key physical phenomenon that exists between the current-carrying coils. In the near-field system, the electromagnetic field energy would tend to flow back and forth across the radiation sources. Notably, when two resonant objects are matched in a specific frequency, there would be substantial coupling, leading to energy transfer. In essence, the WPT technology would substantially take advantage of the resonance technology and magnetic coupling before realizing the wireless transmission of the power. Lu and Ma (2016) equally noted most of the state-of-art designs bear building blocks of the WPT systems in terms of the voltage regulation schemes, which play a focal role in eliminating the requirement and functionality of the post-conversion stage. One of such building blocks attached to the output voltage includes the primary-side non-linear power control. This block carries the local regulation blocks that are needed in responding to the load transient, especially on the receiving end. The receiving power demand signal is substantially acquired by comparing the receiving output voltage with the prevailing reference voltage.

In essence, the power demand signal is largely integrated with the help of the digital loop filter. Another block is that of the reconfigurable rectifier attached to the adaptive output. This block can facilitate the coarse regulation before extending the output power within a substantial range. This block is dominantly used across the low power applications with the hysteresis comparator utilized in comparing rectifier DC output voltage. The load resistor, under this block, is introduced to the primary side with the PA bearing an equivalent output impedance. Lu and Ma (2016) also focused on the functionality of the pre-rectifier regulation, which has the primary-side power control and the regulating rectifier topologies meant for the output regulation. Another block is that of the multiple output operation and single multi-level inductor. In this context, it should be noted that different supply levels would be needed in the system for a range of functions. In this block, there is a need for one to make use of the bulky passive components across the converters, with some of them being utilized in time multiplexing. In some cases, the single-inductor multiple outputs, denoted as the SIMO architecture, are deployed when having a reduced number of the needed magnetic components.

7.5 Wireless Power Transfer Techniques

Radio Frequency (RF) Energy Harvesting

Capture RF and transform RF radiation into DC power is used as an energy harvest. In today's culture, RF signals are omnipresent and abundant (Khan et al., 2018). Some examples of RF outlets include cell phones, WiFi routers, and radio stations. These sources transmit RF signals in all directions, some of them being collected by receivers to transmit information, and some unused to move and attenuate until they vanish. RF energy harvesting aims to collect and use the energy to fuel these unused signals. There are many components to an RF energy harvesting system. Capture RF and transform RF radiation into DC power is used as an energy harvest. In today's culture, RF signals are omnipresent and abundant (Khan et al., 2018). Some examples of RF outlets include cell phones, WiFi routers, and radio stations. These sources transmit RF signals in all directions, some of them being collected by receivers to transmit information, and some unused to move and attenuate until they vanish. RF energy harvesting aims to collect and use the energy to fuel these unused signals. There are many components to an RF energy harvesting system.

8.0 Inductive Charging

The principle of electromagnetic induction is based on inductive charging. A wire spiral with a moving current produces a magnetic field. Similarly, when a wire spindle is put in a magnetic field that changes, a current starts flowing through the spiral. This principle can build a WPT device by attaching a belt to a constant energy source (such as a wall outlet or a DC power supply) and inserting a second belt inside the first. The magnetic field formed in the first spin by the stream induces a current in the second spin and wirelessly transfers the power (Rahmani et al., 2016). This phenomenon is shown in Figure 2.1.

As shown in figure 2.1, before entering the spindles, it is essential to convert the current into alternating current (AC). The current must be adjusted to direct current until moved to the second coil (DC). A shifting magnetic field can only induce the current in a belt; a static magnetic field cannot (Rahmani et al., 2020). The alternating current is then used to induce an ever-change magnetic field that then generates an alternating current in the second belt that has to be rectified to supply the system with electricity.

8.1 Power Management

A wireless power transfer system needs a properly functioning power management level. Power management aims to automatically track and control the flow of power from the transmission stage into the energy storage system. The power obtained by the power transfer stage will be delivered to the energy storage system directly and forever without this step. As energy storage technologies are very responsive and easy to harm if they are not loaded optimally, a power management system has been built for voltage, current, and temperature parameters with certain threshold values. If one of the parameters exists beyond an appropriate range, the power control system terminating charging instantly prevents damage to the energy storage devices described by these threshold values (Hassan et al., 2020).

8.2 Energy Storage Solution

The power obtained from an energy source is rarely at any given moment the same as that used by an appliance. This discrepancy leads to a loss of power (Kharel & Shabani, 2018). When less power than is needed by the load is received, all the electricity received is waste. When the power obtained exceeds the consumed power, the excess power usually becomes heat, sound, and vibrational energy unused. In these cases, for wasted capacity, a storage system like a battery is desirable. When necessary, the energy stored in the battery can be used later.

9.0 The components and design elements for the WPT system for a Lighting System

In designing a WPT system for lighting purposes, different studies have surfaced the ideal components and the design elements. Murray et al. (2017) noted that within a wide range of the applications believed to span the power levels, the wireless energy transfer, based on the HR-WPT, is the most common set of the functional blocks. In this system, the starting component is the input power, which is largely in the form of the wall power converted to DC within what is commonly referred to as the AC-DC rectifier block. In addition, the switching amplifier would be utilized in the process of converting the DC voltage into the RF voltage waveform. In some cases, designers would preferably use the Class D or Class E of the switching amplifier, which would need the inductive load impedance, which would yield the highest efficiency.

On the other hand, the IMN plays a central role in transforming the source resonator impedance into an impedance appropriate for the amplifying source. Other elements include the device resonators and the resonator couples known for generating the magnetic field, allowing energy to build up. Impedance matching would further be established through inductive coupling with the help of the device resonator and source resonator (Abiri et al., 2020).

A range of other components, including the inductors and capacitors, are equally arranged in different configurations to attain optimum efficiency. Shin (2020) also highlighted that the hardware design largely focuses on the transmitter and the receiver coils. In the light of the WPT system, the power source can essentially be connected to the inductive coupling system, which uses the magnetic fields in transferring energy. Notably, the coupling system is said to use both the receiving coil component and the transmitting coil component. A source is needed to supply power alongside the two components, which needs to be around 9V. A booster circuit is equally needed, especially for the DC-DC power converter that bears an output voltage more than the input voltage. This would have to be accompanied by the switched-mode power supply, which also contains a semiconductor and an energy storage element, inductor, and a capacitor. Another component needed in such a system is the transmitter coil which would be engaged in transmitting power wirelessly to the available receiving coil Kesler, (2013). Again, it is important to have the receiving coil due to its key role in receiving power from the transmitting coil. In essence, the half-wave rectifier would be of use when it comes to the conversions to DC while paving the way for measuring the voltage received by the receiving coil. The final element is the load, in which a lighting system would have an LED as a typical load. Other significant components that cannot be ignored in such a system include the transistor, the diode, and the turns. Circuits are essentially linked to either the circuit of the receiver or the circuit of the transmitter. The transmitting circuit is essentially linked to the boost converter, the power supply, and the copper coils, among other elements (Arteaga et al., 2018).

10. Challenges

While covering the literature review attached to the WPT system, a number of challenges could be established over the design process. Biological safety problems can be an issue, especially where there are instances of electromagnetic leakages. Based on research, the efficiency of power transmission cannot hit 100% due to internal and external factors.

11.0 Technical Approach

In designing a WPT system for lighting purposes, different studies have surfaced the ideal components and the design elements. Kesler (2013) noted that within a wide range of the applications believed to span the power levels, the wireless energy transfer, based on the HR-WPT, is the most common set of the functional blocks. In this system, the starting component is the input power, which is largely in the form of the wall power converted to DC within what is commonly referred to as the AC-DC rectifier block. In addition, the switching amplifier would be utilized in the process of converting the DC voltage into the RF voltage waveform. In some cases, designers would preferably use the Class D or Class E of the switching amplifier, which would need the inductive load impedance, which would yield the highest efficiency (Froiz-Míguez et al. 2018) .On the other hand, the IMN plays a central role in transforming the source resonator impedance into an impedance appropriate for the amplifying source. Other elements include the device resonators and the resonator couples known for generating the magnetic field, allowing energy to build up. Impedance matching would further be established through inductive coupling with the help of the device resonator and source resonator (Bensenouci & Brahimi, 2017). A range of other components, including the inductors and capacitors, are equally arranged in different configurations to attain optimum efficiency. Akpeghagha et al. (2019) also highlighted that the hardware design largely focuses on the transmitter and the receiver coils. In the light of the WPT system, the power source can essentially be connected to the inductive coupling system, which uses the magnetic fields in transferring energy. Notably, the coupling system is said to use both the receiving coil component and the transmitting coil component. Alongside the two components, a source is needed to supply power, which needs to be around 9V. A booster circuit is equally needed, especially for the DC-DC power converter that bears an output voltage more than the input voltage. This would have to be accompanied by the switched-mode power supply, which also contains a semiconductor and an energy storage element, inductor, and a capacitor. Another component needed in such a system is the transmitter coil which would be engaged in transmitting power wirelessly to the available receiving coil (Bensenouci & Brahimi, 2017). Again, it is important to have the receiving coil due to its key role in receiving power from the transmitting coil. In essence, the half-wave rectifier would be of use when it comes to the conversions to DC while paving the way for measuring the voltage received by the receiving coil. The final element is the load, in which a lighting system would have an LED as a typical load. Other significant components that cannot be ignored in such a system include the transistor, the diode, and the turns. Circuits are essentially linked to either the circuit of the receiver or the circuit of the transmitter. The transmitting circuit is essentially linked to the boost converter, the power supply, and the copper coils, among other elements (Bensenouci & Brahimi, 2017). MIT has shown that a light bulb can be installed about two meters from a power source. With an exceptionally easy configuration, consisting essentially of two metal spools, they first show that it is possible to send this much power efficiently over such a distance. It is possible. The trial paves the way for batteries to be charged wirelessly in smartphones, cell phones, and music players and for home equipment to be cut out. So, we focused essentially on MIT and other materials and what we explored in building a wireless power lighting bulb system (Sanusi et al., 2019). We will therefore produce a Wireless power lighting bulb system. As the name implies, wireless power transmission is a mechanism in which electric energy is transmitted without wiring or any physical interaction from one device to another but by electromagnetic waves. It can wirelessly illuminate a 3V bulb, and a collection of LEDs can be used. The transmitter and receiver project is split into two sections. By modifying the circuit, you can also use this project as a wireless charger for several devices. Wireless power transmission phenomena involve the inductive energy which passes through an oscillatory magnetic field from a transmitter coil to a recipient coil. The current supplied by an electricity source is converted into a high-frequency AC, which is done in this circuit's transmitter portion (Hlaing et al., 2017). We also winded a transmitter coil by using a plastic circle and an enameled knife thread. With a diameter of 16AWG, we have done about 280 turns. About 100 meters have been using the enameled loop wire. We have used it. Handmade inducers must be produced attentively because they are very sensitive. This is to guarantee that the same value of inductance is obtained. It is difficult for us to set the required frequency, which helps the transmission of wireless electrical power, since we do not have the actual inductance value (Murray et al., 2017). On top of it, the enameled coating wire is very thin. For a few seconds, the end of the wire was inserted in the fire to get this out. The sequence of 7.6pF and 50fF condensers then attached two ends of the coil. The next step-down transformer was attached to 240V AC voltage to supply the transmitter coil with 12V AC voltage. It was observed the Lead was linked to the receiver coil (Shin, 2020). Another means of rendering the receiver coil without creating a new receiver coil is a radial inductor. The move to build the transmitter coil into the "Normal Receiver Coil" method was taken. The radial inductor was used in the receptor coil with 800mH (Abiri et al., 2020). To match the transmitter coil, the frequency was determined. Then, without attaching the transmitter to the feature generator, the LED lamp was observed (Froiz-Míguez et al. 2018).

The setup is straightforward; the circuit has very few components and is very simple. The transmitter wire with a middle tap has ten turns. It is recommended that thick wires be used for the coil, with diameters of 60 centimeters, separated from each other by a distance of about two meters. It is recommended to use a heat sink can be used with the BD139 NPN Transistor; in our experiment, we acknowledged this; however, you can ignore this depending on the power output that you would select for the project. The transmitter of our setup circuit includes a condenser with a capacity of 4.7 nF and a 10-turn coil, much like a special frequency tank circuit. A capacitor is an electronic component that stores and discharges energy in a circuit. Alternating current often travels by without passing direct current. The receiver coil will have the same number of turns and thicknesses and a capacitor equal to the resonance frequency. A half-wave rectifier in the receiver circuit is used for the IN4148 diode or Schottky diode. This diode will effectively rectify the high-frequency alternating current. However, a standard diode (1N4007) can also be used, but it has a higher forward voltage drop, reducing the LED brightness slightly. In the setup, we will use a 9v battery to have a sufficient power transfer. The first wire loop electricity generates a magnetic field around the battery as it turns on voltage from the battery. The spiral attached to the lightbulb captures the magnetic field, creating power in the next bobbin, which turns the light on.

The transmitter and receiver system was designed. The first was the diameter of the coil, its inductance, and its resistor. The resonant frequency was then discovered, and the required resonance capacitance was adjusted. The frequency was obtained by using the main coil feature generator—the wave function of the sine wave function. In addition, an observation to detect the lights up of the LED was made by adding the LED to the receiving coil. The secondary coil was connected to the oscilloscope when the device was found to operate. To measure the distance, both coils recorded the voltage from the oscilloscope as closely as possible. The distance to record the voltages was then raised by half a centimeter for each distance until no voltage existed. The distances show the LED is no longer lit. The oscilloscope and formulas must define the voltage, current, frequency, and wavelength. Finally, the experiment results have been registered (Hlaing et al., 2017).

Transmitter coil

The transmitter was winded with two coils each with five turns.Then it is supposed to be tapeed and solderd. To increase the transmitting distance, play by adjusting the coils, capacitors and input voltages.

Wireless transmission reliability

The proposed system has a nearly 10% or even less reliability. Via ratio of output power to input power, efficiency can be determined.

10 Results and Discussion

The output voltage of the receiver coil was regarded as a major metric of the device. This is the main measure since the battery will obtain the power required if the voltage is adequate (if the respective current is sufficient). Many tests have been conducted to try to obtain satisfactory findings. Between each trial, changes were made to the rectenna while the remainder of the device remained unchanged. These tests and the changes between the trials are recorded in this part. According to our observation, the transmission of energy from point coil L1 to L2 was possible due to magnetic field attraction energy, allowing for the lighting to occur. The magnetic field is analyzed from the size and shape of the coils transmitted and received. It evaluates the magnetic field in the distance between the transmission and receiving coils and the induced current and stress in the receiving coil. In general, the transmitting (L1) and the receiving (L2) all use capacitors for simulating the resonance, while wireless power transfer is electromagnetic induction. L1 is connected to L2 in sequence, and L2 is connected to L1 in parallel. L1 and L2 reflect the overall transmitting resistance and receiving coils and circuits (Figures 10.1). The two circuits are magnetically coupled to the inductance of each coil and are present as a coupling coefficient that normalizes the reciprocal inductance. It is possible to quantify the performance of power transmission and the power transmitted to the charge of the receivers. The power transfer efficiency (η) is generally defined as follows and is commonly used to express the transfer of power performance:

This can be achieved by transmitting the PL power to the load of the loading circuit:

10.1ECG sensor simulation and checking

When the transmitting coil has an AC current of 13,56 MHz and the receiving coil is located at a certain distance from the z-axis, the magnetic field is transmitted (H-field). Figure below illustrates the effects of the calculation of the efficiency for the power transfer by the related locations of the transmission/reception coil and the generated magnetic field (Froiz-Míguez et al. 2018).

In case of maximum synchronization of the centers (zero misalignment), the magnitude changes for the receiving coil and the transmission coil; in the central ellipses, the transmission coil moves 5 mm to 25mm. If the receiving coil changes and the direction turns apart, the quality of transmission power changes on the main axis. In z axis orientation, currently the distance between sending and receiving coils is 5 mm. The transmission efficiency is approximately 1.85% in an adequately balanced state when the transmission efficiency is decreased by improved misalignment level. However, once the alignment is adjusted by around 10 mm, there is no noticeable difference in the transmission quality. The figure shows the magnetic field transition by rotating the transmission coil in the direction of the ellipse from 0 mm to 25 mm on the small axis. When the receiving coil is pushed in the uniaxial direction, the efficiency of the power transfer changes. The spacing between the transmitting and receiving coils is set at 5 mm in the z-axis direction, and the maximum transmission efficiency is precisely matched. The transmission efficiency could decline as the degree of misalignment increases. However, the transmission efficiency according to the figure below is no major variance:

The AC for the transmitting coil is 13.46 MHz and a certain distance from the z-axis where the transmitting coil lies is the location of the magnetic field. At a distance of 5 mm the propagation effectiveness is around 3.74 percent. Transmission/receipt of the resonance frequency should be accomplished with the optimal transmission efficiency, and the transmission efficiency is smaller at frequencies other than amplitude. If the centers of the receiving coil and transmitting coil are precisely aligned, the extent of the magnet field is modified (misalignment is zero). In the long-axis direction of the ellipse, the transfer spiral is moved 5 mm until it shifts by 25 mm. When the receiving coill is moved down the long axis, shorter ways, the power performance change and the direction are reversed. In the z-axis direction, the space between the sender and the receiving coil is set to 5mm. The transmission efficiency in a well-aligned state is approximately 1.85%. The level of misalignment will decrease (Froiz-Míguez et al. 2018). However, once the alignment is adjusted by around 10 mm, there is no noticeable difference in the transmission quality. The magnet field transformation allows the transmission path to have the highest transmission power, in perfectly aligned condition, as the alignment is changed from 0 to 25mm towards the ellipse. It is seen that when the orientation shift by approximately 15mm, there is no significant difference in transmission efficiency (Hlaing et al., 2017).

We performed actual experiments to monitor the wireless power transfer found in the simulations. The studies were also conducted using a cyclically transmitted 5-cm Diameter coil and a 30 mm receiver coil on the long/short axis. The coils for transmission and reception were covered with a diameter of 0.5m copper wire. The inductance was measured as 2.8 μH on the transmitted coil and 0.6 μH on the receiver. The resonant capacitance used for transmission and reception of coils at 13.56 MHz was 37 pF and 228 pF. (Table 1).

The transmitting coil voltage (using 1 k ton) was 8.3V, and the power was 26.6 mW while the gap between the transmitter and the receiver was 5 mm. The reception coil was 4,8V, 11,5mW and 1,5% respectively, for a wavelength of 20mm, for voltage, power and spread performance. As actual load is transmitted (including the IC Chipper for various amplifier) through a 9 V DC coil, the input produces 9 V DC when a full wave rectifier converts the induced AC voltage to DC voltage. In other words, if we are using the same coils like those used in this calculation, even though they are 2 cm apart, the transmit and receive coils will provide sufficient voltage and power. An experiment was performed in which the magnitude of the voltage received at the receiving coil will be determined when the distance between the coils is adjusted when the transmitter coil is maintained with the transmitter/receiver coil. The measurement results were obtained according to the distance between the coils by voltage and power from the receiving belt. As mentioned above, the efficiency of the power transmission was determined.

11. Discussion

This kind of energy transfer is like a well-known mechanism known as the magnetic inductive connection used in power transformers. HOWEVER, the MIT scheme is somewhat different since it is based on resonant connections. When they are centimeters apart, transformative coils can transmit electricity, and the magnetic fields cannot affect each other in the same way (Froiz-Míguez et al. 2018). Soljačić states that MIT researchers use rolling bows resonating at ten megahertz frequencies to reach the two-meter scale. The electrical flow through the first coil generates a magnetic field of 10 megahertz; the second coil can collect from relatively far out since it resonates at this frequency. The first coil energy would have been overlooked if the second coil resonated at a certain frequency (Froiz-Míguez et al. 2018). The method of researchers also makes the transition energy-efficient. If they emit antenna power similarly as information is distributed wirelessly, much power will be lost as it radiates in all directions. In reality, it would be difficult to send enough energy to power gadgets with the method used to transmit knowledge. In comparison, scientists use so-called non-radioactive electricity, which lies close to the coils. In this first demonstration, they demonstrated that the system would pass power to 45 percent efficiency. Hlaing et al. (2017) assume the system is safe for even those with embedded medical instruments, for example, pacemakers, based on estimates. If the scientists did not do thorough studies to assess how the device interferes with pacemakers, Froiz-Míguez et al. (2018) say that they are not expecting heavy interaction with artifacts that do not resonate at the same frequencies used to transmit electricity.

11.1 The power string era

The up-and-coming technology at the time was to move electrical power with wires from source to receiver. The classic power cord was required to work with all electrical systems, and to reach electricity, it had to be plugged into. But we couldn't be weighed down for too long by a power line. Rechargeable cableless systems have been omnipresent over the last few decades. However, an electrical touch must also be made to recharge these units.

11.2 Applications for wireless charge

Wireless charging is becoming highly prevalent commercially. As the Wireless Power Consortium (WPC) proposes and defines, Qi protocol is today the widest wireless charging standard. It is available in luxury smartphones and watches and equipment like shavers, lamps, and even controls instruments. In vehicles and chairs, Qi-conforming chargers can be used. Philips was the first member of the WPC and is a leading member of the WPC, and plays an important role in developing the various current and future Qi standards (Gawłowicz et al., 2020). Despite these advances, wireless energy still – generally speaking – is being used in its early stages for consumer use in real-time (i.e., without a battery) to power goods. When people get older and health care is growing, research on implantable medical devices is actively carried out and products with various functionalities are being launched. The electrical requirements of a human implantable medical device increase on the other hand, due to various functions, such that the main battery itself loses enough power. This thesis investigated wireless power transmission systems method. An implantable system's specifications are diversified, lowering power consumption times and reducing power replacement reoperation to maximize unnecessary expenses and psychological and physical pressures. The invention of a renewable control module that lowers the psychological and costly burdens of such additional operations is a basic technology that makes medical devices for the implantation of humans more practical (Gawłowicz et al., 2020). Due to population aging and healthcare programs, the demand for human implantable medical devices is increasing exponentially. Implantable medical devices are increasingly used in different fields of disease care to assist poor human functions, and power modules are increasingly required for active treatment by devices. With the WPT technologies, intense experimentation has attempted numerous items, such as electromagnetic induction technology or the solution of magnetic resonance sold as an artificial object, to implement a technique for a human injection method. However, the low-frequency electromagnetic waves in the human body have a low absorption rate, a short wavelength of propagation and a high absorption rate for electromagnetic waves in the human body that causes and limits the temperature of skin tissues to increase. The gap of transmission is very low. The wireless stimulation mechanism used in this research is electrically induced between the transmitter coil and the receiver coil. The receiving coil absorbs the magnetic field and produces electrical power when a magnetic field is induced in the transmitter coil. The transmission efficiency in this process is up to 90 percent or more. Still, the transmission distance is very short to few millimeters, and the transmission efficiency is considerably diminished by the failure to match the centers of spools. However, protection and reliability are considered among the most desirable applications in the medical field instead of the magnetic resonance method and electromagnetic wave method. The magnetic induction process can employ the findings of this analysis as a model for the power transmission mechanism like the human transplantation sensor. Power transmission is based on spindles, which rely on the distance between spindles, orientation, size of the bucket, spindles, turn number, magnet shielding, duty, and frequency. For optimal pairing and effective power transmission, the receiver and transmitter coils should be matched. The closer the distance between the two spindles is, the stronger the link. Therefore, the functional distance is set at less than 5mm, as set out in the WPC standard, concerning housing and interface surfaces. Shielding of both the transmitter and the receiver coils is applied to lead the magnetic field into the coupling area. Magnetic fields are not transmitting power outside the coupling zone. The security also includes wireless fields, which prevents connections to other neighboring components of the device.

11.3 Additional Technologies for EVs Wireless Charge

The power transmission modules must also be made up of such control electronics and software to meet safety and operating specifications to obtain commercial WPT products. Some additional electronics and controls must also be used to incorporate the device successfully with other devices or infrastructures. To conveniently integrate the charger with the infrastructure the data communication is required (for instance, electrical grid or databases for vehicle identification). In addition, the main and secondary sides of the wireless chargers need to swap such measures to ensure that the loading/unloading procedure is carried out properly, to make transmission/receiver alignment easier, or to detect loads (Swan, 2019). This should be carried out to extend the battery life since it must be charged regulated. In this way, ion-lithium batteries are normally charged with a continuous continuous-voltage system and are the most common batteries in EVs (Karunanayake et al., 2019). Therefore, according to the battery status, the main side must produce the electric signals. The primary side can determine, under certain cases, how power is received (Karunanayake et al., 2019). Still, the effects of certain measurements (current, voltage) need to be passed to the primary controller in a general sense. A wireless channel must be set for this purpose. It can be used in popular technology as IEEE 802.11, IEEE 802.16, 3G, and other applications. Some experimental designs take advantage of the mounted belt as contact components in magnetic resonant loaders and microwave-based WPT systems (Mitra et al., 2018). Any configuration parameters must be considered while the data and power systems depend on a shared channel. First, it is important to decide whether power and data can be simultaneously transmitted or timepieces can be set to separate the processes (they could even share the same carrier). Two separate carriers (one for the power transfer and another for the data transmission) would be the most often used implementation such that they do not Interfere (Mitra et al., 2018). In terms of data transmission, it is necessary to carefully choose the modulation technique and protocol to communicate effectively with the appropriate signal-to-notch ratio and the required bitrate for this Application (Mitra et al., 2018). The power recipient can be moved or randomly placed in certain WPT applications. In these cases, the product shall contain a receiver location algorithm to produce the electromagnetic wave in the right beam path. WPT wide-field controls the disparity in the current phase of the antennas. The transmitted power and regulation of the beamforming is usual in a range of antennas. To change the power transmission, near-field WPT techniques approximate the link between the transmitter and the receiver (Nasir,2019). The (Nasir 2019) project creates a stand-alone alignment framework for a wireless dynamic charge with a random receptor location. Intermediate items in the area between the transmitter and the receiver are particularly sensitive to magnetic resonant technologies and laser beams. Such artifacts may decrease performance or even unforeseen accidents because of the caused eddy currents or reflexes with resonant structures (with beam powering). The FOD algorithms can be designed to detect conditions in the intermediate zone between the transmitter and receiver in which certain objects and beings are located. Any suggestions can be found in (Nasir 2019) for this algorithm. The scheduling that controls and determines when the load or release occurs for a loader collection is an additional algorithm. Network structures and some optimization problems are provided. The objective of the issue of optimization can be to reduce peak burdens (Mitra et al., 2018) to reduce greenhouse emissions (Mitra et al., 2018), or to enhance the introduction of renewables (Mitra et al., 2018). Scheduling of routing can also be done. Thus drivers get guidelines on when and where their EVs should be charged and unloaded (Rehman et al., 2020). Wireless chargers are subject to few works on timing and/or routing. If we just take static wireless loaders into account, the programmable algorithms are like a small performance reduction. Nevertheless, quasi-dynamic and dynamic charge affects how recommendations on the method of loading/unloading are made. A new problem in the planning of algorithms is the dynamic load. The (Rehman et al., 2020) study suggests using buses to charge the electrically controlled cars while they are nearby. The algorithm is programmed to optimize the entire remaining energy that can be reached before a predefined deadline for all electrical equipment. To minimize the cost of charge ( Mitra et al., 2018), the works describe the timetable of online wireless buses. There is a problem of two-stage optimization, and the daily energy market is taken into consideration. As for routing, the complex wireless charge can be found in.

12. Conclusions and Recommendations for Further Work

Wireless transmission of electricity can transform this world in so many ways. If you're charging a mobile unit, wireless power transmission has a reply to change the impact of global warming on this planet. WVP by space microwave transmission is the most economically feasible application to address the impacts of global warming and the growing need for energy. This application would have endless Earth power and will also open up several potential space exploration possibilities. Emerging technology firms will enhance much of the small electronics capabilities, including mobile phones, PDAs, and mp3 players with WPT via resonance and inductive connectivity. Alternatives to highly polluting fossil fuel plants must be produced, with global warming having serious consequences on this planet by 2050. The future of Earth will depend entirely on the transmission of wireless electricity. Whilst there is no energy in the physical process, the changes to this planet are staggering. A few examples are the reduction in demand for less-polluting energy, a reduction in demand for fossil fuels, a solution to the oil crisis, improved protection forms, and electricity mobility everywhere. Currently, the most marketable and renewable solution to fossil power stations is digital energy transfers. A global wireless power transmission infrastructure is a possibility shortly with constant progress in the region. Now one day, we use wireless technologies, like the phone, but if we use wireless technology to use this system, then our contact will be smooth and strong. We addressed wireless power transfer and its numerous uses in our lives in this article. We have already spoken and spoken about how wireless power transmission technologies can be used to make our lives easier. This research has shown that this kind of technology can increase the transmission of energy, and magnetic resonance connection is the most workable way of transferring wireless energy. Furthermore, this technology will transform the way people live. This article has also shown that wireless energy can be transferred by the radial inductor without the presence of a control signal. The effect of various transmission distances on the voltage and the current of the receiver coil has been examined and reveals that the longer is the distance between two coils, the lower the voltage and the current of the receiver coil. Electric vehicles will benefit from the technology of wireless power transfer because it eases the process of charging and discharging. Four main innovations are used with wireless chargers when understanding the sense of electro mobility. They differ from one physical principle: induction, ability, radiofrequency, and laser. They differ from the other. Wireless power will contribute significantly to supplies of energy in the immediate future, according to researchers. The expression "wireless electricity" describes the transfer of energy from a power source through an air gap to an electric charge without connectors. Two coils – a transmitter and a Receiver coil – are the basis of a wireless power device. The transmitter coil is driven by the alternating current, which generates a magnetic field that induces a current in the recipient coil. To this end, dc provided by a power source is transformed utilizing the electronics incorporated into the transmitter into a high-frequency ac. The ac energizes a transmitter's copper wire coil, which produces a magnetic field. If a receiver spiral is positioned near the magnetic field, the field in the receiving spiral will cause ac. The receiver is then converted into a power available ac/dc by electronics. Many people have asked for a basic wireless power transmission project, which is why it is here. But this isn't an effective style, but fine for almost all small shows. Though WPT is already on the market, its applicability is more constrained. WPT's long-range marketing is ongoing. Multiple startups recently received financing for technology development in Silicon Valley. It uses ultrasound to vibrate the air efficiently into the receiver. One is uBeam. The recipient then returns the vibrations and loads the unit into electrical energy. A further startup is Reach Labs, which transmits power to receptors through radio waves, much like Wi-Fi. Fortunately, only the production of long-range WPT can speed up the private sector's interest. We can envision just some of the uses and effects of active WPT in the long run. Electronic batteries could be smaller as a continuous charge supply would be possible without plugging in which the need to build environmentally toxic fuel cells would be reduced. Solar panels could be put in space, and power could be streamed back to Earth, generating a green energy source that is virtually unlimited. Or the need to rest and refill power may be transmitted to drones or electric cars in order to ride or drive unhindered. We can see that electric planes could become the rule if we take that further. All in all, WPT has the potential to reduce our carbon emissions to 0: solar energy from space to electricity for all transport and machinery. Another WPT business is coupled. Coupled took a different approach from that of Powercast and used inductive coupling to transfer power. Power may be transferred between two same circuits via an inductive connection using the shared magnetic field. By allowed their connected power circuits to dynamically look for resonance to optimize the effectiveness of the transmitted charge, eCoupled has brought this technology up to a new stage. eCoupled uses very high frequencies to communicate between the transceivers without traditional to natural inductive connectivity. This allows one unit to be somewhat mobile. eCoupled claimed power losses of up to 2% and increased traditional inductive connections of more than 36%. The business circuits can be powered off by AC or DC and may either directly control machines or power a rechargeable circuit. The desire to "chat" with each other is exclusive to eCoupled. The transmitter can contact and relocate data within the inductive range with the entity it recharges. The circuits often relay over the audible spectrum at frequencies such that across the circuits, the signal from the broadcast energy is not attenuated.

The prototype has succeeded in wirelessly transmitting considerable electricity. The whole system is stable and operating. The enhanced components can be replaced or restored to the device without changing its performance as the individual component technology advances. This is crucial because certain modules develop and progress quickly. That has to be said. For example, improvements to LED performance will only improve the full functionality of the product. This thesis sets the groundwork for the use of consumer goods of wireless power transfer technologies. Laptops, mobile phones, etc., would probably gain wireless power one day.

13 Recommendations

Below are some tips to further enhance the performance and functionality of this initiative. By using higher quality copper wire, the frequency of the magnetic field can be increased. High-quality co-operation wire reduces radiation losses and increases cellular reliability in the transmission of electricity. In addition, the coil number and the source of the input current can be improved to boost the magnetic field power. More functions may be built-in to make the device more effective, such as measurement of distance or magnetic field measurement. It is proposed that a means be added to allow users to load their devices more distantly so as to make it versatile to use the lamp simultaneously while loading it. The automated warning or communication mechanism will in the future be instilled, and it will ensure that consumers will immediately be aware of whether their equipment will be low in power within a certain range of the transmitter unit. This can be done through NFC or Bluetooth. Improved architecture and reliability of rectenna would increase the efficiency of this device at greater distances. The reliability of the rectenna in this study was increased from initial output voltages in the millivolt range of the single-digit to high voltages. Further analysis in this field is believed to provide much better findings than those in this thesis. The device could certainly be transmitted to a multi-point rather than point by point if the efficiencies from rectenna were adequate. This will open a brand new wireless power transmission segment, which could charge devices like mobile phones and laptops, regardless of their location—research and development of the Voltage Regulation. The device is most immediately needed in this field of study. As the voltage can be adjusted to a constant 12 V from the rectenna, the output power can be collected and stored to power the light entirely. The magnet can also be used to increase and strengthen the magnetic field region around The coil by rolling the spindle around the magnet. Finally, this device may also be configured to reduce environmental harm by operating it with solar power.

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