Efficiency optimization for LCC-LC compensated inductive coupling power transfer system with load-independent zero-phase-angle and constant voltage output

High-order compensation for the inductive coupling power transfer (ICPT) system is preferred due to its high design freedom and excellent coil current harmonics suppression capability. Especially, the good harmonics suppression capability is helpful to implement the synchronous wireless transfer of energy and data with a pair of data communication coils integrated into the energy transfer coils. Thus, on basis of THD1 and THD2 comparison for different high-order compensation topologies, the LCC-LC compensated ICPT system with load-independent zero phase angle (ZPA) and constant voltage output is discussed in this paper. Compared with other high-order compensation topologies with constant voltage output such as LC-LC, LC-LCC, and LCC-LCC, the LCC-LC has the advantages of ZPA operation with zero voltage switching and less secondary-side components. For a given magnetic coupler, infinite feasible combinations of compensation parameters can make the system accomplish ZPA and the same output characteristics. Thus, efficiency optimization of the LCC-LC compensated ICPT system can be investigated by configuring the optimal compensation parameters. To validate the theoretical analysis, especially the efficiency improvement, the experimental platform with 270 V input and 270 V/3 kW output is designed and built. The comparative experimental results for three different the compensation parameters show the optimized system can improve greatly conversion efficiency over the entire load range, especially under light load.