Pulse-Injection-Based Sensorless Control Method with Improved Dynamic Current Response for PMSM

Sensorless control methods based on pulse injection are widely used in the standstill to low speed machine operation range. Generally, to achieve pulse-injection-based position estimation one or more switching periods for injection are dedicatedly needed, which results in reduced equivalent switching frequency, and consequently poor dynamic current response. In this paper, an improved pulse-injection-based method is proposed for sensorless drives of Permanent Magnet Synchronous Machine (PMSM) operating at standstill to low speed range. The proposed method can effectively increase the current dynamic response without increasing the control complexity. Meanwhile the current ripple could be reduced leading to lower torque ripple and acoustic noise. Experimental results are presented to validate the improved performance of the proposed sensorless method.

I. Introduction

For position, velocity or torque control in PMSM drives using Field Oriented Control (FOC) principle, the rotor position information is essential. To overcome the disadvantages of using a position sensor, many efforts have been dedicated to estimate the rotor position from the machines voltages and currents [1].