Electric Field Coupled Wireless Power Transmission Based on Three-Phase System

For the common capacitive coupling mechanism of single-phase quadrupole plate, an equivalent method is often used to simplify the six-capacitor into four-capacitor, which has become the most widely used capacitance equivalent model. Compared with the single-phase electric field coupled wireless power transmission system, in order to improve the output power, this paper refers to this method to design a three-phase input three-pair plate wireless power transmission system. By making every two pairs of plates take an equivalent method, the expression of the equivalent coupling capacitance value of the three pairs of plates is obtained. Then the equivalent three-phase system is simplified to a single-phase network, and the characteristics of the system with constant voltage and constant current output are derived. And the output power expression is obtained. It is proposed to control the system by controlling the system frequency to make the reactive power 0. Through the finite element simulation software Maxwell, the equivalent coupling capacitance values of the three pairs of plates are simulated and calculated. The three capacitance values are approximately equal, which verifies the feasibility of the equivalent method. After that, the proposed system is modeled and simulated. The two results verify each other, which proves the constant voltage output characteristics of the system and the characteristics of the resonant output at constant voltage, and also verifies the correctness of the formula derivation.