MISO configuration efficiency in inductive power transmission for supplying wireless sensors

The original intention of wireless power transmission was to make the power supply more flexible, but compared with wired transmission, its efficiency has always restricted its application. Therefore, the performance characteristics of wireless power transmission have always been a research focus in wireless power transmission. As for induction power transmission, its coupling mechanism is the key part of the transmission system, and its optimal design directly affects the power, efficiency and transmission distance of the system. The research results of the coupling mechanism of an inductive power transmission system in recent years are reviewed, and the effects of coil structure, coupling mechanism material and coil parameter design on efficiency characteristics are analyzed. This paper analyzes the existing optimization methods and existing problems, and points out the direction for the optimal design of the coupling mechanism of a wireless power transmission system.

Antennas play a very important role in wireless power transmission (WPT) systems using microwave since they affect the system transmission efficiency. General requirements for an antenna used for WPT systems are high directivity and narrow beamwidth. This paper presents the design, simulation and fabrication of microstrip patch antenna arrays for close-range WPT systems. Various antenna prototypes such as single patch, 2×2, 2×4, 4×8 and 8×8 microstrip patch antenna arrays working at 2.45 GHz are proposed. The 2×4 microstrip patch antenna array is fabricated and measured using Anritsu 37364D Vector Network Analyzer and NSI2000 Nearfield System. Measurement results show that the fabricated antenna obtains a directivity of 14.7 dBi and a 3 dB beamwidth of 23.2 degree. The experiment with the WPT system is carried out. This paper also presents structure of a WPT system and the role each building block in the system.

Every year more interest is focused on high frequencies (HF) communications for remote sensing platforms due to their capacity to establish links of more than 250 km without a line of sight and due to them being a low-cost alternative to satellite communications. In this article, we study the ionospheric ordinary and extraordinary waves to improve the applications of near vertical incidence skywave (NVIS) on a single input multiple output (SIMO) configuration. To obtain the results, we established a link of 95 km to test the diversity combining of ordinary and extraordinary waves by using selection combining (SC) and equal-gain combining (EGC) on a remote sensing platform. The testbench is based on digital modulation transmissions with power transmission between 3 and 100 W. The results show us the main energy per bit to noise spectral density ratio (Eb/N0) and the bit error rate (BER) differences between ordinary and extraordinary waves, SC, and EGC. To conclude, diversity techniques show us a decrease of the power transmission need, allowing for the use of compact antennas and increasing battery autonomy. Furthermore, we present three different improvement options for NVIS SIMO remote sensing platforms depending on the requirements of bitrate, power consumption, and efficiency of communication.

In inductive coupled power transmission system, at the same time of power transmission, signal transmission is necessary in order to realize the closed-loop control. Synchronous transmission of power and signal has advantages of high speed and stability. By using the method of capacitance modulation via changing capacitance, the working state of the resonator changes. The voltage across the coil appears certain changes. After step-down divider, demodulation, filtering, comparison and a series of signal processing, the transmitting signal will reproduce. The simulation and experiments show that the scheme is correct, the signal can be sent and extracted correctly, and the effect of power transmission is small. The synchronous transmission of signal in wireless power transmission system is realized

In the context of a smart grid, sensors act as real-time monitoring devices. They enable the continuous assessment of the performance index for high-voltage transmission lines. Compared with the traditional lithium battery energy supply system, wireless power transmission (WPT) systems not only ensure the safety but also reduce the maintenance schedule. In the process of energy transmission, traditional insulator-clamped WPT systems are susceptible to interference from metal connectors. Moreover, electromagnetic energy leakage can pose threats to the safety of personnel working with charged equipment and the stable operation of nearby conductive sensing devices. This study analyzes the general principles of energy flow in multicoil WPT systems based on the Poynting's theorem. We introduce the energy contraction coefficients to analyze the distribution of electromagnetic energy in the three-coil systems Achieving energy confinement in the system by adding the relay coils. Combined with an engineering background, we establish constraints and optimize the relay coil's radius and position. We clarify the relationship between relay coil parameters and system energy confinement. Through simulations and experiments, it is shown that with a constant system output power, the optimized three-coil systems improve the energy contraction coefficient by 20.9% compared to the initial two-coil system and increase the magnetic flux density contraction coefficient by 19.4%. This effectively enhances the stability of energy transfer and the safety of the external electromagnetic environment in insulator-clamped WPT systems.

In this paper are analyzed the main methods of wireless transmission of electrical energy, as well as their applications. For the beginning, there is a brief history of the development of the wireless electric power transmission technology. There are presented the principles of functioning of the main methods of wireless transmission of electrical energy, as well as the technical problems that need to be solved in the future. There are also presented the main applications of this technology, as well as the main companies that produce commercial wireless electrical power transmission equipment. Finally, we present the future opportunities of these wireless power transmission technologies and recommendations for future research topics in this field.

A wide variety of applications can benefit from near-field wireless power transfer using coupled inductive links, such as wireless sensors and implantable microelectronic devices. The use of inductive power transmission is expected to see an explosive growth over the next decade as engineers try to cut the last cord from mobile electronics, small home appliances, and even electric vehicles [1]. The inductive link power transfer efficiency (PTE) is highly dependent of the loading of the receiver (Rx) coil, referred to as R L . As shown in Fig. 12.7.1a, magnetic resonance-based power transmission in the form of a 3-coil link has been proposed to maximize PTE for any given R L by transforming it to an optimal load, using k 34 variable [2,3]. Alternatively, an off-chip matching circuit has been used to transform R L [4]. However, these methods need either an additional coil or a network of off-chip capacitors and inductors, which add to the size/cost of Rx. Moreover, in the above applications, R L can change drastically during operation and there is a need for Rx to dynamically compensate for a wide range of R L to maintain high PTE.

Charging of batteries in electric vehicles is the subject of several recent papers, which include conductive power transmission as well as inductive power transmission. Most research has been elaborated to address the limitations of inductive power transmission (IPT). IPT is the most recognized technique for electric vehicles at which power can be transferred from the source side to the load side with no physical contacts. By using this technique, charging can be carried out safely, comfortable and easily. This paper overviews theoretical and practical design of contactless power transmission systems and studies a frequency bifurcation phenomenon of a compensated IPT with a power factor correction (PFC). The research focuses on the serial compensated design with a resonance frequency adaptive frequency converter.

Compensation topologies for wireless power transmission system in medical implant applications: A review

Wireless technology opens a wide range of research opportunities in all areas of electrical science, particularly in the electrical power sector. Nonetheless, it grows richer with each addition and change made by scientists and researchers. This entire project is based on Wireless Power Transmission systems, whose ultimate purpose is to transmit power in a uniform gain in a registered region. To accomplish this purpose, first, a schematic diagram was designed which has two parts. The first part is for transferring the power and the second part is for receiving the power. The power transferring part is modified as Antenna and the receiver part is Rectenna and both the antenna and rectenna were designed in CST software. A receiver circuit was designed for delivering the power which was designed in ADS software. The receiver circuit was constructed in three individual sections. They are antenna circuit, rectifier circuit, and buck converter. The resonance frequency of the system is 2.4GHz and after completing the analysis we get the output of (5.655 to 4.95) V DC in rectangular shaped patch antenna and (5.573 to 4.86) V DC in circular shaped patch antenna in (2 to 60) meter. In addition, we tried to figure out which antenna provides better output by differentiate the shape of the antenna. The project’s primary goal is to transmit power to a focused area and also determine the estimated cost, health concerns, and repercussions in terms of social, political, and technological factors.

This paper presents a development of a low power wireless power transmission system. A phase shift phase-lock loop (PLL) control for WPT was also proposed. The proposed control strategy was used to optimize the phase offset between the fundamental primary side voltage and primary side current at all operating points. Then, the phase compensation can be achieved. In order to verify the proposed control scheme, a hardware prototype of the proposed wireless power transmission (WPT) system has been constructed. The coupling coefficient was measured at different air gaps and lateral offsets. Several simulations and experimental results such as voltage and current measurement of primary voltage and current were reported and discussed.

With the development of industrialization, more and more research topics have been focused on increasing the transmission power of wireless power transmission systems. This paper studies the parallel technology of the modular inductive wireless power transmission system, calculates the resonance compensation network of it. Next, the current sharing strategy is proposed to improve accuracy.Then we derive a simulation model. After that, we simulate under different load conditions and get the corresponding output voltage and current.The results show that the system can transmit power and obtain a relatively stable voltage, and this system can effectively balance the current between the modules.

This article describes a novel rectifying-antenna design with extended input power range operating at 2.4 GHz for both ambient wireless energy harvesting and wireless power transmission (WPT) systems. The rectenna consists of a 2 × 2 fractal antenna array and a rectifier circuit with a high-power conversion efficiency (PCE) in a wide input power range. This circuit contains two conversion stages based on two different Schottky diodes, and a third stage that dissipates the unconverted input power, which can disturb the harvesting process. These three stages are controlled by a power management block based on circulators, that direct the input power to the adequate stage according to its power range. A prototype of the proposed harvesting system is fabricated and experimentally validated. The measurement results confirm the wide input power range behavior of the designed rectenna with a relatively constant and high PCE (between 58% and 67%) for a power density ranging from 4 to 252 μW/cm2. The proposed solution can be successfully used for both ambient energy harvesting and WPT systems.

This paper observes impact of the various chokes on resonant frequency for the two different topologies of current-mode class-D (CMCD) amplifier used in the transmitter side of wireless power transmission (WPT) system. Both topologies are evaluated through measurements and simulations and the chokes with different inductance values were selected and applied to determine their impact on transmitter performance. In resonant WPT system, in particular transmitter subsystem, we suggest CMCD amplifier with center tapped transmitter coil. The most relevant features that are achieved, using CMCD amplifier with center tapped transmitter coil, in comparison to common CMCD amplifier are decreased choke voltage and significantly lower impact on resonant frequency.

An overall view of past, present and proposed wireless space power transmission projects is presented. Activities in the United States, Canada, France, the former Soviet Union and Japan are highlighted. The recent Japan-US space-to-space wireless power transmission demonstration ISYMETS is described as are the 1995 demonstrations of wireless power transmission systems in Kyoto, Japan, at the WPT 95 conference.