Analysis and Design of Passive Damping for LC-Equipped Permanent-Magnet Synchronous Machine Drive System

The LC filter can be added between pulse width modulation (PWM) inverter and permanent-magnet synchronous machine (PMSM) to reduce the insulation stress and current harmonics. However, the LCL resonance can threaten the stability of the system. This paper focuses on the passive damping method for LC-equipped PMSM drive system to suppress the resonance without the need of additional sensors or changes in the control software. The inherent damping characteristic of the drive system is derived. Then, two kinds of passive damping schemes are investigated and compared. The analysis and design are validated with simulation results.