Enhanced position observer with a selective harmonic error eliminator and an error feed-forward compensator for sensor-less surface-mounted permanent magnet synchronous motor drives

In high-frequency (HF) pulsating voltage injection-based sensor-less surface-mounted permanent magnet synchronous motor (SPMSM) control, inverter nonlinearities and motor parameter asymmetries lead to harmonic errors in the estimated position. To eliminate these errors, the second-order generalized integrator (SOGI) is applied. An enhanced position observer with a selective harmonic error eliminator (SHEE) consisting of several SOGIs and an error feed-forward compensator (EFC) are proposed. The harmonic errors in the estimated position are effectively removed. The proposed strategy is verified by experimental results at a 1.5-kW SPMSM sensorless drive.