New sensorless rotor position detection technique of PMSM based on direct flux control

Abstract

Sensorless rotor position detection techniques have been gradually developed and proposed, which means that recently available methods can improperly work in some specific conditions. A proper and reliable method is needed. Consequently, a new sensorless rotor position detection technique of permanent magnetic synchronous machines (PMSMs) is proposed in this paper. The proposed method is achieved based on flux linkage signals with access to the neutral point of the machine, which is called direct flux control (DFC) method and it is unnecessary to measure the machine currents. Two simulation environments, MATLB/Simulink and a cooperative simulation with Simplorer and Maxwell, are investigated. The nonlinear magnetization curve (BH curve) is also taken into account, which is impossible to do in the synchronous frame, but possible to process by finite element methods (FEM) implemented in Maxwell. The PMSM model with the nonlinear BH curve can similarly operate as a real PMSM. Moreover, the calculated electric position, done by the proposed method, strongly confirms the possibility to acquire the rotor position for a wide range of speed, including standstill.