ECCE-Asia 2021 1st author

J. Yoo and S. Sul, “Effect of Speed Estimation Error on Control Stability in Model-Based Sensorless PMSM Drives,” 2021 IEEE Energy Conversion Congress and Exposition - Asia (ECCE-Asia), 2021, pp. 531-536, doi: 10.1109/ECCE-Asia49820.2021.9479441.
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This paper analyzes the effect of low-pass filtering in the speed estimation of the position sensorless permanent-magnet synchronous motor (PMSM) drives. The rotor speed information is used in various ways in the drive, such as the decoupling term in the current regulator and the speed control loop. Moreover, since most sensorless observers are constructed at the estimated rotor reference frame (ERRF), the sensorless observer also requires the rotor speed information. Usually, the rotor speed information is obtained by applying a low-pass filter on the rotor position’s derivative term in order to attenuate the high-frequency noise. However, the low-pass filtered speed estimation may cause a discrepancy in the sensorless observer, and the instability could occur in the loaded condition at low speeds. To extend the torque capability in low-speed region, this paper proposes the separation of the speed estimation for the outer loop and that for the sensorless observer, which does not apply the low-pass filter for the sensorless observer. The proposed method is verified with the computer simulation and experimental test.