Analysis and design of a wireless closed-loop ICPT system working at ZVS mode

Based on the T-type equivalent circuit model of loosely coupled transformer, the theory of series-series (SS) resonant inductively coupled power transfer (ICPT) system was analyzed. By researching the principle of ICPT system working at zero voltage switch (ZVS) mode, the condition for realizing ZVS mode was got that the load resistance should be bigger than its critical value. According to the characteristic of open-loop ICPT system, a wireless voltage-feedback control for ICPT system working at ZVS mode was established. Based on the analysis above, An ICPT system prototype was built and tested, the maximum open-loop output power was 3.4 KW, overall efficiency was 90%; the closed-loop output voltage was stable at 260 V, and the maximum output power is 1.9 KW.