双能式SF6高压断路器灭弧室结构设计及熄弧特性仿真研究

Structural Design of Arc Extinguisher for Dual-energy SF6 High Voltage Circuit Breaker and Simulation Research of Its Arc-extinguishing Characteristics

为满足现代电网快速切断和保护的需求,SF6高压断路器作为主要的一类线路保护装置,其灭弧性能有必要得到加强。针对目前自能式SF6高压断路器灭弧时存在反应时差,提出一种新型活塞助气双能式SF6高压断路器灭弧室结构,并以此为研究对象,在分析双能加强气流形成与灭弧机理的基础上,建立灭弧过程的气流场模型与电弧模型,采用Fluent软件对灭弧室内双能加强气流截断电弧时电弧耦合气流温度场变化过程进行仿真分析。仿真结果表明:提出的双能式灭弧室结构拟用于110 kV电压等级进行灭弧时具有良好的熄弧特性,能在5 ms时间内熄灭工频电弧并且可以在后续时间内有效抑制弧触头间二次燃弧。该灭弧室结构能够在电弧熄灭后继续保持灭弧通路内有冷态气流通过,可快速降低热膨胀室内的燃弧余温。通过该研究可以为提高SF6高压断路器开断能力提供技术参考。

To meet the requirements of rapid cut-off and protection of modern power grids,SF6 high-voltage circuit breakers are the main type of line protection devices,and their arc-extinguishing performance needs to be strengthened.Aiming at the reaction time difference of the current self-energizing SF6 high voltage circuit breaker during arc extinguishing,we proposed a new type of an arc-extinguishing chamber structure with piston-assisted air dual-energy SF6 high-voltage circuit breaker;moreover,taking the structure as a research object,on the basis of analyzing the formation and arc extinguishing mechanism of the dual-energy strengthening airflow,we established an airflow field model and arc model of the arc-extinguishing process.The Fluent software was used to simulate the temperature field of the arc-coupled airflow during the arc-enhanced airflow interception arc.The simulation results show that the dual-energy arc-extinguishing chamber structure proposed in this paper can extinguish the power-frequency arc within 5 ms when it is applied to the 110 kV voltage level for arc extinguishing,and can effectively suppress the secondary arcing between the arc contacts in the subsequent time.The arc extinguishing chamber structure can continue to maintain a cold airflow in the arc extinguishing passage after the arc is extinguished,and can quickly reduce the arcing residual temperature in the thermal expansion chamber.The research results in this paper can provide a technical reference for improving the breaking capacity of SF6 high voltage circuit breaker.