A new scale-frequency method for inter-harmonic detection based on continuous wavelet transform

Inter-harmonic detection has been a major problem to improve power quality due to the invalid of traditional Fourier transform. Continuous wavelet transform is used in this paper. Based on analyzing the relationship between scale and frequency and by solving the wavelet transform coefficients extreme value, the characteristic scale can be determined and then the frequency corresponding to the characteristic scale can be solved, so inter-harmonics can be checked out. For the models with harmonics lower than 50Hz or containing a variety of inter-harmonics, MATLAB simulation experiments results show that the method proposed in this paper is reliable and accurate.