a method for commutation of a switched reluctance motor is disclosed that requires no rotor position sensor or detailed prior knowledge of the motor &# 39 ; s magnetic characteristics . the apparatus and method employs a calibration routine to learn the flux - current characteristics of each srm phase in its aligned position . from these characteristics , the flux - current characteristics at other appropriate switching angles are approximated . commutation is accomplished by estimating the flux in an active phase and comparing the estimate to the flux approximated for the switching angle . the apparatus and method is particularly well suited for relatively heavy duty loading applications , such as a fan .