Study on operation voltage monitoring and electrothermal coupling simulation of electric multiple unit (EMU) roof arrester

Abstract

The roof arrester of electric multiple units (EMU) can efficiently limit the overvoltage, and ensure the safe operation of the EMU electrical equipment. In the process of high-speed operation, the traction power supply system is often affected by overvoltage. In addition, roof arrester explosion accidents occasionally occur. In this paper, the on-line voltage measurement system of the EMU arrester is developed. By analysing a large number of voltage waveforms, the abnormal voltage is divided into three categories: over-phase voltage, high harmonic voltage and steep impulse overvoltage. The characteristics of abnormal voltage waveforms are then summarised. The electrothermal coupling simulation model of the arrester is developed, and the current response and temperature distribution of the arrester under abnormal voltage are calculated. The impact of the impulse voltage energy on the arrester temperature is studied by applying a triangular wave voltage to the model. Finally, some suggestions are proposed for the operation and maintenance of the roof arrester.