Electric Vehicle Wireless Charging- Design and Analysis Using 1 MHz Circuit Capacitive Coupler

This research clarifies the horizontal and vertical alignment of the capacitive coupler to be used in electric vehicles for wireless power transfer. Using various compensation techniques, capacitive power transfer circuits were modeled and analyzed. For safety purposes, this concept is used to identify mutual capacitance and field emission around the charging system. The methodology of circuit formation for an effective coupler design was described. The output power of the compensation circuits implemented in the coupler design was obtained from mathematical analysis. The finite element analysis (FEA) method was used in the ANSYS Maxwell software package to find mutual capacitances and field emission area by the transmitter. The suitable compensation network was identified from various ways to calculate the output power. The coupler design with the alignment of the parallel plates in both vertical and horizontal orientations was proposed. The response of the mutual capacitance upon varying the length of the plates, air gap distance and misalignment positions were predicted. This paper contains suitable dimensions of capacitive plates and their respective capacitance value for different airgaps and misalignments of the plates placed on source and vehicle sides of the circuit. In addition to the modified-coupler design with the horizontally aligned plates, the coupler model with vertically aligned capacitive plates is proposed. This model is more suitable for wireless power transfer as it does not cause misalignment issues because of its symmetrical structure.