Research on an Improved Sliding Mode Observer for Speed Estimation in Permanent Magnet Synchronous Motor

Aimed at the problems of system chattering and large observation errors in sensorless control a permanent magnet synchronous motor (PMSM) based on traditional sliding mode observer (SMO), combined reaching law algorithm exponential arcsine saturation function is proposed to improve observer. An appropriate positive real number taken compared with product controller gain stator current error judge position motion. In early stage motion, utilized, then, latter stable stages used. The stability proved by Lyapunov theory. simulation experimental data show that speed reduced 80% observer, problem also improved.