Position sensorless for IPMSM with heavy magnetic saturation based on pattern matching method

A pattern matching method for position sensorless control of IPMSM with heavy magnetic saturation in standstill and very low speed region has been proposed. The rotor position is estimated by comparing the feature values measured in a real-time with in beforehand. To measure feature values, high frequency signal must be injected. The operation region of pattern matching method is limited by amplitude of injectable signal. This paper presents the operating region that could utilize pattern matching method. Also to expand the operating region, a new signal injection method and matching method are proposed. By using the proposed method, the same sampling time interval for measuring feature values could be obtained even smaller signal is injected.