Detection and Analysis of Fault for HTS AMDT Cores by Magnetostriction-Induced Vibration

High-temperature superconductivity amorphous metal distribution transformer (HTS AMDT) exhibits superior properties in no-load losses compared with orientation silicon-steel transformer. However, how to reduce the audible noise level of HTS AMDT is a serious challenge for better performance. So far, few research works displayed the relationship between the noise and vibration. Vibration analysis on different positions of core surface plays a significant role in decreasing its noise, but the literatures about this are less. In this paper, a multi-channel vibration testing platform was set up and the experiments were conducted on one phase core of SCBH15-200/10 HTS AMDT in the laboratory. The positions of vibration sensors mounted on the core surface were determined according to the distribution of magnetic flux density by finite-element analysis. The vibration characteristics of different positions on core surface were investigated through time-domain and frequency-domain waveforms. Wavelet packet transform (WPT) was used to analyze the vibration frequency components more clearly. Experiment results indicate that the position in the middle of core yoke exhibits higher vibration amplitude. The method by calculating energy feature value based on WPT can be applied to detect the core vibration condition, which is helpful to on-line monitor the HTS AMDT.