A robust position sensorless control method of IPMSMs to magnetic non-linearity within over-modulation range

This paper proposes a novel position sensorless control system utilizing an inverter over-modulation range for IPMSMs with magnetic-nonlinearity by simple algorithms. Both position sensorless control and drive within inverter over-modulation range contribute cost reduction, however these schemes could destabilize closed loop current control system especially in high torque region because of (1) variation of q-axis inductance L_q due to magnetic saturation, (2) distortion of feedback currents within over-modulation range. Proposed control system apply the MTPA-oriented flux model and a comb filter to overcome these problems, and have confirmed that it can achieve (1) position sensorless drive, (2) robust maximum torque per ampere control with respect to magnetic-nonlinearity, (3) expanding the operation range.