Wavelet Entropy-Based Traction Inverter Open Switch Fault Diagnosis in High-Speed Railways

Keting Hu,Shuangshuang Lin,Zhigang Liu

doi:10.3390/e18030078

Abstract

In this paper, a diagnosis plan is proposed to settle the detection and isolation problem of open switch faults in high-speed railway traction system traction inverters. Five entropy forms are discussed and compared with the traditional fault detection methods, namely, discrete wavelet transform and discrete wavelet packet transform. The traditional fault detection methods cannot efficiently detect the open switch faults in traction inverters because of the low resolution or the sudden change of the current. The performances of Wavelet Packet Energy Shannon Entropy (WPESE), Wavelet Packet Energy Tsallis Entropy (WPETE) with different non-extensive parameters, Wavelet Packet Energy Shannon Entropy with a specific sub-band (WPESE3,6), Empirical Mode Decomposition Shannon Entropy (EMDESE), and Empirical Mode Decomposition Tsallis Entropy (EMDETE) with non-extensive parameters in detecting the open switch fault are evaluated by the evaluation parameter. Comparison experiments are carried out to select the best entropy form for the traction inverter open switch fault detection. In addition, the DC component is adopted to isolate the failure Isolated Gate Bipolar Transistor (IGBT). The simulation experiments show that the proposed plan can diagnose single and simultaneous open switch faults correctly and timely.

Highlights

Vector controlled drive systems are widely adopted in the high-speed railways of China
Though WPESE3,6 has shown its good performance in detecting the fault legs without false alarms, it still has problems in identifying the fault Isolated Gate Bipolar Transistor (IGBT)
As WPESE3,6 is calculated by the absolute value, it cannot classify the direction

Summary

Introduction

Vector controlled drive systems are widely adopted in the high-speed railways of China. In this kind of drive system, the traction inverters are essential to meet the control demand. The traction inverters are prone to suffer failures because of their complex working environment and exposure to high stress [1]. These failures threaten the train’s operational safety. SPD failures include open switch faults and short switch faults. As for the open switch faults, the system can still run for a while, which may cause additional failures and damage the system. It is important to diagnose open switch faults in time

Results

Discussion

Conclusion