Starting method based on SVPWM for automotive applications

This paper presents a method to improve the starting performance for a sinusoidal PM machine by using low-resolution hall sensors. Generally, the position information can be obtained from highresolution sensors such as an incremental encoder or resolver mounted on a motor shaft. However, these sensors not only increase system cost, system size but also tend to reduce the system reliability. In most cases, only three discrete position signals are generated from three low-resolution hall sensors which are used to estimate rotor position. The sinusoidal control techniques for PM machines demands accurate position and speed feedback information. In order to overcome the low-resolution of the hall sensor, the position estimation using three discrete hall sensor signal is proposed in this paper. However, when the PM motor is started, it is difficult to estimate the rotor position due to the lack of hall signal information. In this paper, to overcome the problem of this initial operation, the PM machine is driven by square control at starting operation. After lots of commutation cycles is operated, the sinusoidal control is applied. The proposed method can be stably operated at the initial operation of the sinusoidal PM machine. Experimental results have been presented to prove the validity of the proposed method