Optimization Research on a Switching Power Amplifier and a Current Control Strategy of Active Magnetic Bearing

Abstract

Active magnetic suspension bearing technology has been widely used in the field of high-speed motors because of its many technical advantages. A switching power amplifier is an important part of active magnetic bearing. This paper first analyzes the topology of a switching power amplifier and proposes an optimized switching power amplifier topology, which can significantly reduce the number of switches used in a power amplifier. Then, by studying the transfer function of the system, the boundary conditions of the power amplifier bandwidth, stiffness and damping, which maintain system stability, are obtained. Furthermore, an improved current control strategy is proposed, and this strategy can significantly improve the bandwidth of the switching power amplifier and improve the stability and dynamic performance of the system. Simulations and experiments verify the practicability and effectiveness of the topology and current control strategy proposed in this paper.