Research on a Three-level Three-bridge Switching Power Amplifier

The traditional power topology of magnetic levitation bearings generally adopts full-bridge or half-bridge, and for multi-degree-of-freedom magnetic levitation bearings have the disadvantages of large size, many switching devices and complex structure. In this paper, a three-level control strategy is proposed for a three-bridge-arm switching amplifier not only to reduce the number of switches, but also to reduce the degree of coupling between the bridge arms, so that both magnetic bearing coils are able to track the control signal accurately. Finally, two sets of sinusoidal signals with the same phase and phase difference of 90 degrees are used as inputs to verify the correctness of the conclusions using Pspice simulation software.