Analysis of Voltage Stress Dependencies Around the Coupler of a Capacitive Power Transfer System

This paper aims at addressing the dependencies of the voltages stresses around the coupler of a capacitive power transfer (CPT) system. CPT system with different compensation networks are summarized as a general topology, from which the voltage stresses are derived and analysed. A theoretical minimum voltage stress point that only depends on the output power, coupling capacitance and switching frequency is found, regardless of the compensation network type. Simulations as well as a 5W prototype with 150pF coupling capacitance, 2MHz switching frequency have been built and tested to validate the theoretical analysis.