Speed detection based on STFT for no-coupling SACS motor testing

This paper analyzes the disadvantages of the testing system for the single-phase AC series-excited motor (SACSM) and points out the necessity of the study on the no-coupling motor testing system. Then, this paper studies on one of the basic problems of the no-coupling testing system, that is, the sensorless speed detection during the motor testing. The method to solve this problem based on STFT (short time Fourier transformation) is worked out, and the experiments show that, the results with high precision can be obtained within 15 seconds. The comparison between the methods using STFT and wavelet is also given out. The comparison shows that the method using STFT is better than that using wavelet both in calculation time and precision.