Comprehensive Analysis on the Current Imbalance in Modular IPOP WPT Systems with LCC Compensated Sub-modules

Modular series-parallel (MSP) systems with the superiority of easy scalability and high reliability, are widely used in high-power applications. In this paper, the MSP system configuration is implemented in wireless power transfer (WPT) applications. However, the current sharing issues of MSP WPT systems have not been investigated thoroughly. Especially the power transfer characteristics are more complex considering the cross-coupling between coils. Therefore, this paper focuses on the current sharing issues of the dual modular input-parallel-output-parallel (IPOP) configuration with LCC compensated sub-modules. The fundamental harmonic analysis method is used to obtain the system transfer characteristics of modular WPT systems, and then the current imbalance mechanism under four kinds of parameters mismatches is revealed. The correctness of the analysis is verified through experiments on a dual-module IPOP system.