Modular Expansion Method for Wireless Power Transfer Systems With Arbitrary Topologies

Modular parallel inverter technology can enhance the power level and redundancy of wireless power transfer (WPT) systems, contributing to standardized production. It serves as an effective method for realizing high-power systems. However, inappropriate selection of compensation components can negatively affect the system's efficiency, power factor, and the flexibility of modularization. This paper analyzes two key properties of modular-parallel-inverter WPT (MPI-WPT) systems: module number flexibility and modular deviation suppression. Firstly, to assess the modular deviation suppression of the system, its definition and calculation method are provided. Secondly, the expansion condition to achieve modular flexibility is examined, highlighting that the modular system needs to be a fully resonant system. Subsequently, an expansion design methodology from a single WPT system to an MPI-WPT system is proposed, ensuring the preservation of the original properties of the system during its extension. Finally, the parallel characteristics of MPI-WPT systems were experimentally verified.