Application of multi-switch in wireless power system

Abstract

In a traditional Inverter Circuit, using parallel power MOSFETs is a common practice to improve the performance of the circuit. However, in a wireless power transfer system using magnetic resonance coupling technique, the method of parallel MOSFET would cause a lot of problems: the speed of the MOSFET converter would decrease; the switching loss would increase. The worst situation is that the switch would not be able to meet the operating frequency of the Magnetic Resonance system. As a result, we introduce the Multi-switch Method to solve the problem above. From simulation, this method could reduce the loss of an individual switch. In this paper, we design a multi-switch circuit, and compare it with the traditional inverter circuit in a magnetic resonance system. Then we analyzed the individual switch loss in these two circuits by a comparative experiment to verify the effectiveness of this new circuit. The result suggests that, this multi-switch circuit improve the individual performance of the switch, and reduce the voltage oscillating waveform of the switch significantly.