Sensorless control of synchronous reluctance motors based on an extended EMF model and initial position estimation

In this paper, we realize a sensorless control of synchronous reluctance motors based on a proposed extended EMF model. This proposed model can be used for all synchronous motors, so the estimation method applied for permanent magnet synchronous motors can be applied for synchronous reluctance motors without modification. At standstill state, since an amplitude of the extended EMF becomes zero, it is difficult to realize position estimation based on the extended EMF. In order to solve this problem, a system identification method for sensorless control is combined with it. Sensorless control of synchronous reluctance motors can be realized from standstill state to high-speed ranges by a combination of two methods.