An Induced Voltage Source Model for Capacitive Power Transfer

Capacitive power transfer has been investigated as a constructive and significant alternative to the conventional inductive power transfer. It utilizes high-frequency electric field to realize wireless power transfer. However, the capacitive coupler is usually modeled by six coupling-dependent mutual capacitances. This model is hard for resonance analysis under the coupling variation. This paper explores an induced voltage source model for the capacitive coupler. It uses the two coupling-independent self-capacitances and a pair of induced voltage sources to represent the original six coupling-dependent capacitances. Such kind of modeling can well deal with the coupling variation and dramatically simplifies the resonance analysis. Both the finite-element-based simulation by Maxwell and real experiments are used to verify the proposed model. The results show that the self-capacitances are coupling-independent.