Position sensorless control method of IPMSM applying three shunt sensing PWM inverter using predictive current

In this paper, position sensorless control method of IPMSM applying three shunt sensing PWM inverter using predictive current for phase current reconstruction and EMF calculation is proposed. Considering the price and volume of the system, a motor drive system applied with shunt and sensorless has been recently studied. However, there is some area that cannot measure three phase current especially in high-speed motor operation where the MI (Modulation index) is increased. It deteriorates the control stability because of the phase current distortion in motor control. In this paper, the boundary where phase currents cannot be obtained is defined and the method for reconstructing the phases current are proposed by predicting phase current in the area which phase current measurement is impossible. Also, the EMF observer and synchronous voltage recalculation method are applied for sensorless control considering both linear area and over-modulated area.