Design and control of a bidirectional wireless charging system using GaN devices

Most of the existing wireless power transfer system works in unidirectional with one-direction control signals. This paper presents a bidirectional wireless charging system with duplex communication method, which is not only able to achieve the two-way wireless power transmission, but also transfer control signals bi-directionally. The power circuit operation mode is actively controlled by using the wireless transceiver module which can duplex communication to deliver measured signals remotely. The operational principle is analytically studied in details and is verified by simulation. Finally, a prototype of the bidirectional charging system using GaN devices has been successfully designed and tested. In addition, the measured feedback signals are effectively transmitted to validate the control algorithm

IMPROVING EFFICIENCY OF WIRELESS POWER TRANSFER VIA MAGNETIC RESONANCE COUPLING

Described herein is wireless energy transmission via magnetic resonant coupling for author’s FYP project. The idea is based on two resonant coils, with one acting as transmitter, which consist of source and circuit, and the other as receiver connected to load, such as low power LED, having strong coupling electromagnetic resonant for wireless energy transmission from transmitter to receiver over a certain distance. The working principle operates as traditional inductance magnetic coupling devices, where Faradays’ Law states that, a time varying magnetic field of a coil of wire, voltage (emf) will be induced in the coil. However, these principles will limit the efficiency and distance transfer between transmitter and receiver. Thus, by applying resonant concept, which tunes both objects operating frequencies into resonant frequency, we can transfer energy wirelessly with greater efficiency and longer distance. This paper will emphasize on the fundamental principle in order to realize the concept until the design of the prototype itself. The basic theory such as magnetic induction, resonant frequency as well as magnetic resonant coupling will be further explained for better understanding and clarification. Apart from that, further analysis will also discussed and compared with the achievement and work done by others in comprehensive literature review chapter. In the design of prototype, a number of calculations have been done in order to get the resonance frequency which can be applied to both coils to function and the process of designing the circuit and building it through exclusive studies, will also be explained in detail. Last but not least, author will further analyze the circuit comprehensively by studying on three most important results, which are voltages, magnetic field intensities, and power with respect to different parameter setting. The author compared the finding by using theoretical calculation and measurement by using spectrum analyzer and multi-meter. All the measurement will be tabulated in tables and graphs

Wireless Power Transfer Technology for Electric Vehicle Charging

In the years 1884-1889, after Nicola Tesla invented "Tesla Coil", wireless power transfer (WPT) technology is in front of the world. WPT technologies can be categorized into three groups: inductive based WPT, magnetic resonate coupling (MRC) based WPT and electromagnetic radiation based WPT. MRC-WPT is advantageous with respect to its high safety and long transmission distance. Thus it plays an important role in the design of wireless electric vehicle (EV) charging systems. The most significant drawback of all WPT systems is the low efficiency of the energy transferred. Most losses happen during the transfer from coil to coil. This thesis proposes a novel coil design and adaptive hardware to improve power transfer efficiency (PTE) in magnetic resonant coupling WPT and mitigate coil misalignment, a crucial roadblock to the acceptance of WPT for EV. In addition, I do some analysis of multiple segmented transmitters design for dynamic wireless EVs charging and propose an adaptive renewable (wind) energy-powered dynamic wireless charging system for EV

A GaN-based wireless power and information transmission method using Dual-frequency Programmed Harmonic Modulation

Information transmission is often required in power transfer to implement control. In this paper, a Dual-Frequency Programmed Harmonic Modulation (DFPHM) method is proposed to transfer two frequencies carrying power and information with the single converter via a common inductive coil. The proposed method reduces the number of injection tightly coupled transformers used to transmit information, thereby simplifying the system structure and improving reliability. The performances of power and information transmission, and the method of information modulation and demodulation, as well as the principles of the control, are analyzed in detail. Then a simulation model is set up to verify the feasibility of the method. In addition, an experiment platform is established to verify that the single converter can transfer the power and information simultaneously via a common inductive coil without using tightly coupled transformers.Web of Science8498564984