Research on the Service Life of High-Voltage Vacuum Circuit Breaker of High-speed Train

The vacuum circuit breaker (VCB) is an essential component of the high-speed train power supply system. The state of the high-voltage vacuum circuit breaker is critical to the safe and stable operation of the high-speed train. Due to the different special working conditions, the life characteristics of high-voltage vacuum circuit breakers for high-speed trains are different from those of ordinary high-voltage vacuum circuit breakers. The working principle, structure, and failure mechanism of vacuum circuit breakers are analyzed to solve this problem. A method based on the degradation trajectory is proposed to establish a performance degradation model. To study the service life of the vacuum circuit breaker, the opening and closing time test of the vacuum circuit breaker and the main circuit resistance value test experiment were carried out. According to the test results, the service life was predicted using its degradation model. The results show that under the current operating conditions of the mobile unit, the vacuum circuit breaker has reached the service life when the operating mileage is 4.717 820 million kilometers, which provides an important reference for the condition monitoring, maintenance, and repair of the high-voltage vacuum circuit breaker for the high-speed train.