Adaptive filtering of the synchronizing reference signal and its application in an AC excited generation system

Based on the frequency-spectrum shifting principle, a kind of adaptive filtering technique of the synchronizing reference signal for power harmonic analysis and detection was proposed in the paper which does not need to use the phase locking technique and, therefore, especially fits the situation where the fundamental frequency is variable and the synchronizing reference signal is difficult to acquire. The principle of frequency spectrum shifting and adaptive filtering technique of the synchronizing reference signal are all discussed in detail. The effectiveness of the approach presented in the paper has been verified by the experiments in the harmonic detection and suppression of a prototype AC excited generation system