The particularity of magnetic circuits of fractionalslot concentrated winding motor made the saturation of d and qaxis magnetic circuits more prominent. The frozen permeability method could be used to calculate the precise inductance of the motor when considering saturation. By using the finite element software, this method was applied to the 10pole 12slot fractionalslot concentrated winding prototype, and the results of this method are compared with those calculated by the traditional method. For the sensorless control of motor realized by high frequency signal injection method, the fundamental frequency inductances were used in the high frequency mathematical model. By using the frozen permeability method, the high frequency inductances in the highfrequency voltage mathematical equation were determined, and the fundamental frequency inductances were replaced by high frequency inductances to improve the accuracy of the sensorless control algorithm.