Sensorless wide speed range heavy-load starting method for switched reluctance motor

The invention discloses a sensorless wide speed range heavy-load starting method for a switched reluctance motor. According to the method, the magnitude of three-phase current is detected in real time; saturated incremental inductance of a conducting phase winding and unsaturated phase inductance of a non-conducting phase are calculated by an instantaneous current slope difference calculation method; estimation of the unsaturated phase inductance of a saturated conducting region is achieved by a method of converting the saturated incremental inductance into the unsaturated phase inductance; a full-period unsaturated phase inductance curve is constructed by combining the unsaturated phase inductance with the unsaturated phase inductance of a non-conducting region; and real-time rotor position information in heavy-load starting of the motor is estimated by an orthogonal coordinate transformation method of a three-phase unsaturated phase inductance vector, so that sensorless heavy-load starting of the switched reluctance motor is achieved. According to the sensorless wide speed range heavy-load starting method, the problem of heavy-load starting of the switched reluctance motor is effectively solved; meanwhile, the influences of motion counter electromotive force can be effectively eliminated by the instantaneous current slope difference calculation method; and the method can adapt to a wide speed operation range.