Dynamic monitoring of spring strain and fatigue in high voltage circuit breakers

Abstract The performance of high-voltage circuit breaker springs is crucial for the normal operation, safety performance, and equipment reliability of the circuit breaker. Their main functions include contact separation, rapid action, and load support. Therefore, it is required that the springs have good long-term stable performance and are not easily deformed or damaged. The circuit breaker spring may experience creep, fracture, and other conditions during use, resulting in abnormal working conditions of the circuit breaker and the inability to close. At present, the main maintenance methods adopt manual regular inspections and calibration of springs, which belong to post-control measures and cannot monitor the status of springs. This article studies the quantitative relationship between spring stress and strain, fatigue, and creep states, analyzes the changes in principal stress and shear stress during fatigue cracks, and monitors the status of springs by studying the optimal position of strain gauges.