Comprehensive Analysis on the Imbalance of Voltage and Current in Multi-module Series-parallel WPT Systems

Abstract

Multi-module series-parallel (MMSP) power systems have the superiority of easy scalability and high reliability, and is the prospective candidate for high-power conversion. In this paper, the MMSP configuration is implemented in wireless power transfer (WPT) applications. However, the voltage and current sharing issues have not been analyzed precisely in existing researches. To obtain the inherent principle of voltage and current sharing in the MMSP WPT system, the dual-module series-parallel WPT systems with four configurations are studied as examples. By the fundamental harmonic analysis, the characteristics of a WPT module are obtained, and then the imbalance mechanism of voltage and current under four kinds of parameters mismatches are revealed. The results of circuit simulation verify the correctness of the theoretical analysis.