A position sensorless control in standstill and very low speed region without sinusoidal inductance spatial distribution requirement of IPMSM based on pattern matching method

This paper presents a new position sensorless control method for high power density IPMSMs that has non-sinusoidal inductance spatial distribution. In standstill and low speed region, high-frequency signal injection method is generally utilized for rotor position estimation. However, to apply conventional method for high power density IPMSMs having non-sinusoidal inductance spatial distribution is difficult because the methods are using the value of phase inductance spatial distribution assumed to be sinusoidal. In order to realize position sensorless control with these IPMSMs, the position sensorless method based on pattern matching has been proposed [1], [2]. The pattern matching method has a limitation of operating region which is not clarified. This paper clearly presents the operating region that could utilize pattern matching method. Also a new method to estimate the rotor position is proposed in order to expand the operating region.