Investigation of IPMSM´s Position Estimation in Low Speed Region with DC Link Current Detection

This paper presents a new method to estimate the pole position of an interior permanent magnet synchronous machine, IPMSM. The proposed method uses the three phase triangular carrier waves for the PWM signal generation and measures only the current of the DC link of the inverter. The DC link current can be measured with an inexpensive current sensor such as a shunt resistor. The proposed method enables to estimate the pole position at low speeds and standstill. In this paper, first, authors verify the validity of the proposed method by the experiment, and compensate the position estimation. The proposed method needs the current detection at tops and bottoms of carrier waves, precisely. So, the method is investigated in this theory about the effect of the current detection timing delay. And the ways to compensate the timing delay is explored.