高压自能式SF_(6)断路器空载分闸过程中阀运动特性的仿真分析

Simulation Analysis for Valve Motion Characteristics of High Voltage Self Blast SF_6 Circuit Breaker During No-load Opening Process

高压自能式SF_(6)断路器单向阀、回气阀和泄压阀的运动特性对灭弧室气流场计算结果的准确性具有重要影响。基于3个阀片实际的运动规律,运用牛顿第二定律,建立阀片运动的数学模型,并结合真实气体物性参数,对自能式SF_(6)断路器灭弧室冷态气流场进行仿真,准确获得了3个阀片的运动特性,同时分析了3个阀片的受力特性及阀片周围的压力分布。研究表明,空载情况下,单向阀将对拉杆产生相对运动,这是引起单向阀由闭合到开启状态变化的主要原因,而回气阀移动的主要原因是压气室压力的建立,泄压阀的开启时刻与位移取决于压气室压力与弹簧力值的大小。另外,单向阀与回气阀闭合或开启状态的转换伴随着阀片两侧受力的波动,而泄压阀的开启峰值要晚于压气室压力峰值。

The motion characteristics of non-return valve,return gas valve and pressure relief valve of high voltage self blast SF_6 circuit breaker have an important influence on the accuracy of calculation results of gas flow field of interrupter.Based on the actual motion of three valve discs,the Newton's Second Law is used to set up the mathematic models of valve disc motion.Then,the real physical property parameters of gas is combined to simulate the cold flow field of the interrupter of the self blast SF_6 cirucit breaker and the motion characteristics of the three valve discs are obtained accurately.At the same time,the stress characteristics of three valve discs and the pressure distribution around the valve discs are analyzed.The research shows that under no-load condition the non-return valve will produce relative motion against the pull rod,which is the main reason of the non-return valve changing from closing to opening condition.Howerver,the main reason of the motion of return gas valve is the set up of pressure of puffer chamber,the switching on instant and displacement of the pressure relief valve depend on the magnitude of the pressure of the puffer chamber and of the spring force.In addition,the switchover of the closing or opening status of the non-return valve and the return gas valve is accompanied by the the stressed fluctuation on both sides of the valve discs,while the peak of switching on of the pressure relief valve is later than that of the puffer chamber.