Research on chaotic dynamic characteristics of onload tap changers

Abstract

Mechanical failure is the major failure type of on-load tap changers (OLTC) which makes the mechanical characteristic analysis of OLTC to be significant for fault diagnosis. Being different from traditional time and frequency domain analysis, vibration signals are analyzed from a new perspective in this paper based on the chaotic dynamic characteristic analysis. The key parameters of the analysis, namely the embedding dimension and delay time are obtained via chaotic methodology. Then the vibration signal is reconstructed successfully in multidimensional phase space and the maximum Lyapunov exponent is calculated to further verify the chaotic feature of vibration signal. Finally, the chaotic dynamic characteristics of OLTC vibration are illustrated with the Poincare section. Analyses of recorded data from field experiments shows that the apparent dynamic characteristic distinction is detected between vibrations of normal and fault condition which lays foundation for the effective OLTC fault diagnosis.