Simulation test study on fatigue characteristics of circuit breaker insulation pull rod

The insulation pull rod is the main transmission mechanism of the circuit breaker. In addition to strong electrical performance, it should also have strong mechanical properties. Studying the dynamic characteristics and response insulation pull rods during opening and closing operation and exploring the changes in mechanical characteristics of insulation pull rods during multiple openings and closings are of great significance. In this paper, a 252kV GIS circuit breaker simulator is used to carry out an opening and closing impact fatigue test on an insulation pull rod. The strain signals of the insulation pull rod during the opening and closing stages are obtained. The strain distribution of insulation pulls rod and the influence of operation times on strain are analyzed. The results show that the force on the pull rod is uneven during operation. The force on the mechanism side and contact side is small, and the force on the rod body is large. Also, the pull rod is unstable and bent under pressure force. The impact response frequency is mainly distributed between 0∼1500Hz. With the increase in operation times, the low-frequency component of frequency response basically remains unchanged, while the high-frequency component decreases. After 10000 times opening and closing operations, there was no obvious mechanical loss on the pull rod, but the mechanical properties decreased. The research results can provide reference and basis for the formulation of the performance test method, and specifications of insulating rod materials.