Sliding mode controller for current decreasing of permanent magnet synchronous motor with LC filter

In order to mitigate side effects of PWM (pulse width modulation) waves in motor control system, such as bearing currents and overvoltage, LC filter can be equipped between inverter and PMSM (permanent magnet synchronous motor). However, some new issues must be paid attention when LC filter is equipped. One of them is that motor phase currents cannot be measured, so they will not be controllable. It may result in unexpected power loss. The contribution of this paper is: a sliding mode current controller for PMSM with LC filter is propose! In order to control the current, a sliding mode controller embedded in conventional control algorithm is proposed. The state variables for motor current control are acquired by a Luenberger observer. The effectiveness is proved by simulation results.