Constant voltage control of a secondary side controlled wireless power transfer converter using LC/S compensation

Abstract

In this study, constant voltage control of a secondary side controlled wireless power transfer (WPT) converter is evaluated based on efficiency. The LC/S compensation network which has perfect constant current characteristic is used in the design of the WPT converter. In order to improve the constant voltage performance of the LC/S compensation network, controlled rectifier is adapted to the converter. The phase shift modulation (PSM) control is applied to the switches of the rectifier as independent of the primary side. Thus, constant voltage regulation is achieved at constant operation frequency in a wide load range. The performance of the proposed converter is verified by a simulation work at 2.5 kW output power and 450 V output voltage. The efficiency values of the converter, as function of the load condition, is extracted by simulation and compared to frequency modulation control. In addition, power loss distribution and its comparison with frequency modulation is also discussed. The maximum efficiency of the converter is obtained 96.4% at full load condition.