Suppression of Common Mode EMI in Active Magnetic Bearings with Optimization for Current Ripples

The active magnetic bearing (AMB) is an advanced technology to suspend the high-speed rotating equipment. The power electronic converters used to drive the bearing will cause common mode (CM) EMI to the system, thus threaten the normal operation of the system. A novel modulation strategy based on the H-bridge topology is proposed in this paper to reduce the effect of the CM EMI. Also, this modulation scheme has been further optimized to decrease its introduced additional current ripples and power loss. Experiments have been done to validate the performance.