Abstract
Various sensorless control methods in a low-speed region characterized by containing zero speed have been reported. In particular, a position sensorless control method using rotor saliency is difficult to apply to a PMSM that does not have rotor saliency. In addition, the method based on rotor saliency suffers from problems such as too much electromagnetic noise and increase in harmonic loss. A new position sensorless method has been developed for permanent magnet synchronous motor (PMSM) drives. This method utilizes the induced voltage caused by magnetic saturation (IVMS) of the PMSM. The sensitivity of the rotor position in IVMS depends on the magnetic saturation characteristic of the rotor. Moreover, we have developed mathematical models of the magnetic flux characteristics considering the magnetic saturation and cross-coupling effects for PMSMs. That is the motor models can express nonlinear characteristics. IVMS can be evaluated in the proposed simulations using the mathematical models. In this paper, a study of IVMS in the proposed simulations is discussed. The experimental results and simulated results using the proposed model and the behavior model are presented. The mode change threshold values required for sensorless control are identical to the values obtained in the proposed simulations.
