On-line parameter identification of IPM motor using instantaneous reactive power for robust maximum torque per ampere control

The reluctance torque of an IPM motor can be effectively utilized by applying the maximum torque per ampere (MTPA) control algorithm, which improves the efficiency and the power density of the motor. However, the motor is unable to operate accurately on the MTPA curve due to the parameter mismatch caused by magnetic saturation and/or temperature variation. This paper proposes the d-axis inductance, the q-axis inductance, and the magnetic flux linkage identification strategy by using the instantaneous reactive power of the IPM motor. The key feature of the technique is robustness against the winding resistance variation. Several experimental tests have been conducted to verify the feasibility of the proposed technique, and it has been confirmed that every parameter identification can be achieved within 5 % error.