Repetitive Control-Based Extended State Observer for Current Fluctuation Suppression of PMSM Drives

Abstract

As the inner loop of the FOC system for permanent magnet synchronous motor (PMSM), the current loop determines the torque output and bandwidth of the overall system. However, there are aperiodic and periodic disturbances in the current loop due to the load changes, inverter dead zone, and motor flux harmonics. In order to estimate and suppress the above lumped disturbances, the paper presented a repetitive control-based extended state observer (ESO). By imbedding the repetitive control into the ESO, the aperiodic and periodic disturbances can be estimated simultaneously. Then, the lumped disturbances are applied as the feedforward compensation for the current loop. By contrast with the conventional PI and active disturbance rejection control, the studied method can suppress both aperiodic and periodic disturbances. The superiority of this method is confirmed on a 4.4kW PMSM experimental platform.