Vibration Monitoring of Converter Transformer On-load Tap-Changer Using Phase Space Reconstruction and Poincare Section

Vibration monitoring is thought as an effective tool for the condition monitoring of OLTC used in converter transformer, since the vibration signals are closely related to its mechanical switch-over process from one tap position to another position. Based on the vibration signals measured in some R type OLTC in converter station, phase space reconstruction is used to reconstruct the vibration signals with the calculated delay time and embedding dimension. Then Poincare section is drawn carefully to describe the distribution of phase points in X-Y plane with the proper index defined. Calculated resulted have shown that the features of phase points in Poincare section are further verified the chaotic characteristics of vibration signals of OLTC. The defined index of S1 and S2 are better illustrated the distribution patters of the phase points in Poincare section and then the good consistency of the measured OLTC during the switch-over process.