For the research of wireless power transfer, loosely coupled inductive power transfer (LCIPT) is one of the widely adopted technologies. There are already various researches focusing on development of high-efficiency LCIPT. However, when the transmission and receiver coils are misaligned, the power transfer efficiency will be significantly dropped. This article considers the change of mutual inductance when two induction coils are misaligned. A fuzzy control approach to solve for this problem by adaptively adjusting operational frequency is introduced. Experiments show that it can reduce the power transferring efficiency drop by 11% when two conduction coils are misaligned up to 50 mm. This research also supports adaptive maximum power transfer using tracking mechanism. Before conducting power transmission, the system can choose G2V or V2G according to the vehicle battery capacity via handshaking communication without the need of radio frequency links. In addition, the phase shift pulsewidth modulation technique is proposed for simultaneous data transmission enabling binary quadrature amplitude modulation for digital signal transmission. Fast over current protection is incorporated for power transfer safety when current overload happens. The transmission frequency of this article is controlled to meet the frequency specified by SAE TIR J2954.

Implementation of a multifunctional contactless bidirectional charging and discharging system with the aid of giant magnetoresistance (GMR) effect for car parking guidance is proposed. Traditional Hall effect sensors can detect magnetic flux changes. However, if the changes are not significant enough to induce detectable interference voltage, there will be error detection. To remedy, a GMR sensor may detect tiny changes in the magnetic field which will produce a larger change in resistance; this resistance is less susceptible to external noise influence while generating a relatively stable signal level. As a novel application, our research task combines a GMR sensor, a flexible magnetic stripe constituted by GMRs, a microprocessor and a wireless inductive power/data transfer module to realize a positioning control system for the parking lot's micro grid. Real-world experiments are conducted to verify the proposed approach.

This study first explored the effect of shading on the output characteristics of modules in a photovoltaic module array. Next, a modified particle swarm optimization (PSO) method was employed to track the maximum power point of the multiple-peak characteristic curve of the array. Through the optimization method, the weighting value and cognition learning factor decreased with an increasing number of iterations, whereas the social learning factor increased, thereby enhancing the tracking capability of a maximum power point tracker. In addition, the weighting value was slightly modified on the basis of the changes in the slope and power of the characteristic curve to increase the tracking speed and stability of the tracker. Finally, a PIC18F8720 microcontroller was coordinated with peripheral hardware circuits to realize the proposed PSO method, which was then adopted to track the maximum power point of the power–voltage (P–V) output characteristic curve of the photovoltaic module array under shading. Subsequently, tests were conducted to verify that the modified PSO method exhibited favorable tracking speed and accuracy.

Wireless power transmission (WPT) systems have been increasingly utilized for wireless charging of electric vehicles. However, most research efforts or commercial products only address wireless power transmission but not wireless data communication. In addition, limitation of the transmission range is always a gap obstructing its popularity. Accordingly, this study presents a novel WPT scheme incorporating both relay transmission and magnetic field data communication. For power transmission, a resonant inverter with pulse-width modulation was developed using relay coils to induce longer distance alternating current. For data transmission, a magnetic field communication system based on impedance changes and not reliant on extra radio frequency links was realized. Fuzzy compensation was used to stabilize the transmission of both power and data to counter changes in mutual inductance between coils. Phase-shift keying was utilized to generate digital signals for data transmission. Our experimental prototype was tested and verified to simultaneously transmit power and data in compliance with SAE TIR J2954 specifications using real-world experiments.

This invention proposes a novel light emitting diode (LED) lighting (dimmable) control scheme to transmit digital data through a magnetic field generated by a flyback driver that utilizes digitized data to adjust the brightness of LEDs for potential applications. This design would eliminate the cost of establishing wireless transmission hardware by simply relying on the magnetic field for communication to meet the management of the lighting control system. The method used a frequency-shift keying (FSK) technique on the secondary side of the system to send digitized data to the primary side. The primary side of the system interpreted the control commands by detecting the frequency change, and the corresponding lighting control was decoded. The inner communication connected the primary and secondary sides to the transformer through wirelessly transmitted data, which eliminated the requirements of optical coupling and peripheral circuits. For extended applications, the designed system can be combined with sensors at home for lighting management with the benefits of energy saving and potential emergency warnings.