Mechanical sensorless drives of IPMSM with online parameter identification

The mechanical sensorless drive system for an interior permanent magnet synchronous motor (IPMSM), for which parameters including the inverter are identified, is proposed in this paper. The rotor position is estimated by a signal injection sensorless scheme at standstill. The resistance, including the on-resistance of the insulated gate bipolar transistor (IGBT), the voltage error caused by the dead time of the inverter, and the d-axis and q-axis inductances are identified. After the motor starts by the signal injection sensorless control, the sensorless scheme changes to a scheme based on the extended electromotive force (EMF) estimation, which uses the identified parameters. The magnet flux linkage is also identified for the sensorless operation. The effectiveness of the proposed method is verified by several experimental results.