60 / 2024-04-07 14:48:59

An Influence of Ambient Temperature on Motor-energized Spring Operating Mechanisms in Serving High Voltage Circuit Breaker

high temperature,low temperature,High Voltage Circuit Breaker (HVCB),reliability,Spring Operation Mechanism

The failure mechanism of a serving high-voltage circuit breaker (CB) is usually indistinct, especially when it is exposed to ambient conditions like low- and high-temperature cycling, high humidity, salt atmosphere, ice coating, and so on. A motor-energizing spring operating mechanism is prevalently mounted in high-voltage circuit breakers (CBs), compared with a hydraulic, pneumatic, electromagnetic, or motor operating mechanism. The objective of this study is to investigate the influence of ambient temperature on the characteristics of a spring operating mechanism, which is always applied in 126-kV and 252-kV CBs. The test temperature ranges from -30 to 40 ℃, stepped by 10 ℃. The operating mechanism is arranged in an environmental test chamber and maintained for an idle time of 2 to 5.5 hours for each test temperature, respectively, followed by 30 opening and closing operations in atmosphere conditions at room temperature. Test results show that under a certain idle time, the opening and closing time at the first shot increases with the rising of the ambient temperature. The average opening and closing time of 30 operations present different tendency, i.e. the average opening time rises with the rising of test temperature, the closing time decays, inversely. The deviation of fist opening and closing operations after each idle time significantly increase with the decreasing of the ambient temperature.