Cascade sliding mode control of permanent magnet synchronous motors

In this paper a cascade sliding mode control (CSMC) system is proposed for the control of high performance permanent magnet synchronous motor (PMS) drives. An improved sliding mode control strategy is introduced first based on a modified control law in order to reduce chattering. It is then used in the CSMC system to improve system robustness and performance. The performance of a PMS motor under the proposed CSMC is evaluated by both simulation and DSP implementation. The simulation and experimental results show the superiority of the CSMC over a linear control and the conventional SMC under the load disturbance and parameter variations.