Low cost sensorless switched reluctance motor drives for automotive applications

The switched reluctance motor can be viable for various applications in the hostile environment of the automotive. The absence of shoot-through problems and simple unipolar power converter requirements give SRMs a definite edge over other type of motors. The absence of cogging torque in SRM is also a definite plus. A simple SRM drive system that can be used in automotive applications is presented. An indirect position sensing scheme that eliminates the need for discrete position sensors is the basis of this drive system. A frequency modulated (FM) encoder is developed to convert the inductance variation into a frequency encoded signal which is further processed in a microcontroller to generate the converter gating pulses