Abnormal vibration analysis of GIS based on time frequency detection

the stable operation of high voltage GIS equipment is very important to the safety of power grid. The abnormal vibration of GIS is a serious threat to the safety of equipment. In this paper, the abnormal vibration of 220 kV GIS equipment is detected by the wideband vibration measure system. By means of spectrum and continuous wavelet analysis of vibration signals, the time domain and frequency domain characteristics of the vibration signal are studied. The analysis results reveal the spectrum difference of the ultrasonic signal induced by partial discharge and the equipment vibration, and the propagation attenuation characteristics of the vibration signal on the GIS tube. In addition, the time delay of vibration signal is obtained by the wavelet entropy, therefore the vibration source is accurately located. It carried out on-site confirmation finally. It indicated that the time-frequency analysis can accurately locate the vibration source. It is conducive to the analysis of the causes of the abnormal vibration of GIS and the evaluation of the equipment operating conditions.