Research On Power Supply Of Contactless Power Transfer System

Contactless Power Transfer (CPT) technology is a new field of research in academia and engineering at home and abroad. It is based on electromagnetic induction or coupling resonance principles, synthetically utilizing power electronics, high power high frequency convertion technique and electromagnetic coupling technique, combined with modern control theory and methods, to transfer electric energy from stationary power systems to relative rest or moving electrical equipments via EM coupling between primary and secondary loops, meanwhile with no electrical contact. Compared with traditional power transmission mode, CPT eliminates a variety of safety risks, which are caused by exposed wires, mechanical wear, contact spark and so on. CPT also has the advantages of high security and good flexibility, and so it has vast application prospects and high practical value use in chemical industry, mine, underwater, power supply of human organs and other special occasions like aerospace, robotics, medical instruments, wireless charging of consumer electronics, lighting, transportation and other fields.Firstly this paper introduces the research background of CPT, summarizes the research situation of the literatures and existing research achievements. Further on a brief description of the basic principle of contactless power transmission, this paper gives analysis in detail of three key techniques:high-frequency conversion technology, electromagnetic coupling and resonance compensation, including commonly used converter topologies, different coupling mechanism forms, mutual inductance model, and power transmission characteristics with different compensation networks and so on. And then the paper focuses on CPT system based on class-E power amplifier. The operating principle, parameters designing and adjustment methods are given. Through simulation and experiment, the class-E amplifier is demonstrated high-efficiency property in CPT system. A new method for parameter designing based optimal load is proposed, and the experimental analysis of transmission power and efficiency versus load are done. In the end, this paper has an analysis of indirect AC-AC conversion topology based on voltage-fed full-bridge structure, which is further applied in long-distance, high-power CPT system. Taking a specific case, the parameters and experimental results are given, and then added with a brief discussion about control mode for voltage-fed full-bridge circuit.