This study presents the experimental study and analysis of double-LCL resonant compensation network based wireless power transfer (WPT) system for electric vehicles. The WPT system could accomplish both constant current and the unity-power-factor for the transmitting terminal and the receiving terminal. In addition, the transmitting terminal inverter can achieve zero-voltage-switching. The multi-physical characteristics of the transmitting and receiving terminals based on LCL resonant compensation network are analysed in detail. Finally, three-dimensional finite element analysis and an experimental system with circular pads is setup to verify the theoretical analysis under different loads and horizontal/vertical misalignment conditions. At the condition of 200 mm gap and no horizontal misalignment, the system can supply the maximum output power of about 7.36 kW having the maximum efficiency of 95.87%.

Inductive power transfer (IPT) systems have become increasingly popular in recharging electric vehicle (EV) batteries. This paper presents an investigation of a series parallel/series (SP/S) resonant compensation network based IPT system for EVs with further optimized circular pads (CPs). After the further optimization, the magnetic coupling coefficient and power transfer capacity of the CPs are significantly improved. In this system, based on a series compensation network on the secondary side, the constant output voltage, utilizing a simple yet effective control method (fixed-frequency control), is realized for the receiving terminal at a settled relative position under different load conditions. In addition, with a SP compensation network on the primary side, zero voltage switching (ZVS) of the inverter is universally achieved. Simulations and experiments have been implemented to validate the favorable applicability of the modified optimization of CPs and the proposed SP/S IPT system.