Position Error Correction for Sensorless Control of PMSM Based on Robust Extended State Observer With Inductance Estimation

A conventional sensorless control method based on sliding mode observer (SMO) and type-2 phase-locked loop (PLL) is widely applied in permanent magnet synchronous motor (PMSM) drives due to its simplicity and effectiveness. However, the conventional method is easily affected by factors, such as parameter mismatch and dc bias, making it challenging to achieve satisfactory performance. Therefore, in this article, the conventional method is first accurately modeled to explore the mechanisms of position error generation from the switching function, PLL, and parameter mismatch. Subsequently, a general position error correction method is proposed based on a robust extended state observer (RESO) integrated with a simple inductance estimation method. The proposed RESO not only effectively eliminates various position errors, but also improves dynamic performance and enhances robustness. Finally, the effectiveness of the proposed method is validated through experimental comparisons with other methods on a 1.5-kW PMSM platform.