Research on Vibration Signal of Transformer On- load Tap Changer Based on Kurtosis and Tunable Q-factor Wavelet Transform

The vibration signal of transformer on-load tap changer during switching can reflect the mechanical property of on-load tap changer. A new analysis method for vibration signal of transformer on-load tap changer based on kurtosis and tunable Q-factor wavelet transform is proposed. The vibration signal is divided into two segments: the rotating segment and the switching segment. For rotating segment, the kurtosis of vibration signal is calculated to diagnose the jam defect of on-load tap changer shaft. For switching segment, the intraclass correlation coefficient of different tap positions based on the results of tunable Q-factor wavelet transform are compared. The intraclass correlation coefficient can characterize whether mechanical defect is existing in on-load tap changer. The investigation results show that analysis of vibration signal based on kurtosis and tunable Q-factor wavelet transform can effectively evaluate the status of on-load tap changer, which provides important means for monitoring the mechanical condition of on-load tap changer.