A Method for Determining Resonant Elements Considering the Requirements of Double-LCC Circuits in Dynamic Wireless Power Transfer

Wireless power transfer technology is attracting attention as a means of charging electric vehicles while driving. Compared to the SS circuit, in which the coils and capacitors required for power transfer are connected in series and resonate, the Double-LCC circuit, in which capacitors are inserted in parallel on both the power transmitting and receiving sides, is more resistant to misalignment and has less standby loss. On the other hand, due to the complexity of the circuit and the increase in the degree of freedom, the optimization of the circuit has become very complicated and its determination method has not been established yet. In this study, when the coils to be used for transmitting and receiving power have already been determined, the optimal combination of resonant elements was determined considering all requirements such as allowable current, capacitor withstand voltage, required power transmission efficiency, required power, required secondary side power, etc. As a result, a resonant element was proposed that satisfies 98.0% efficiency and 31.2 kW of power, considering all requirements of the circuit in the simulated values. The validity of the proposed method was also shown by experiments.