Synchronous Three-Level PWM Power Amplifier for Active Magnetic Bearings

The availability of low cost and high performance power amplifiers is essential for a widespread application of active magnetic bearings (AMB). In this paper, a new switching control pattern, referred to as synchronous three-level PWM (Pulse Width Modulation) scheme, is recommended for switching power amplifiers used in digitally controlled AMBs. This PWM control pattern allows it to work at a low switching frequency with low current harmonics. At the same time, the disturbance response is improved.