icpt系统双acdcac型拓扑与控制策略研究-research on double acdc ac topology and control strategy of icpt system.docx

ABSTRACTAs a novel power transfer technology, inductively coupled power transfer(ICPT) technology has been widely researched and applied. Traditional AC-DC-AC type ICPT system has several drawbacks such as low system efficiency, control complexity and low power density, which restricts the popularization and application of wireless power transfer technology in practical system. Variation of load and operation randomness will degrade the performance and stability of ICPT system. Thus how to improve system stability with varying load is an critical and urgent problem to solve.This paper proposed a bi AC-DC-AC converter. The filter capacitor and rectifier could be reduced and conversion efficiency, power density and input power factor could be improved. Based on impedance analysis, the LCL-S type topology was analyzed, to obtain the output-input relation of primary resonant current. A steady primary resonant current control method was proposed to enhance the power transfer magnetic field stability against dynamic variation of primary resonant current caused by uncertain load. To deal with the application difficulty of feedback on RMS current, a waveform analysis was used to decrease the control complexity, and guarantee the stability of primary resonant current with varying load. Furthermore, to ensure the legality and safety of load, a useful unexpected load detection technique based on the measurement of resonant current peak was introduced.To satisfy various voltage level requirements, two output voltage adjustable control method, the equal pulse width chopping control and the resonant half-sine wave intermittent control, were proposed based on the characteristics of primary and secondary side. Moreover, how to choose between the soft-switching implementation method and intermittent method for the output voltage adjustable control were proposed in this paper.Based on MATLAB/SIMULINK and experimental study, the stability of controller were verified. The results indi