混合断路器大电流开断过程中真空电弧与SF6电弧相互作用的仿真

真空断路器和SF6断路器串联的混合断路器,可有效利用真空和SF6气体两种介质不同的灭弧特性实现更大短路电流的分断。为研究两种电弧的相互任用,运用ATP软件及其TACS工具建立了系统实验仿真平台、12kV真空断路器与40.5kV SF6断路器的电弧模型;将仿真结果与实验波形结合通过数学方法分别求得实用的真空电弧和SF6电弧模型参数;搭建了实用真空电弧模型与SF6电弧模型串联的混合断路器模型。通过设定不同的系统仿真参数,研究开断过程中真空电弧和SF6电弧的相互作用及真空断路器与SF6断路器的分压关系;分析两断路器不同时刻分断的协同特性与介质恢复过程;量化研究混合断路器的断流容量增益特性。仿真结果证明,真空断口首先承担恢复电压有利于SF6断口的介质强度恢复;两断口间的电压分布关系主要由电弧电阻与断口间电容决定;在不增加SF6气体使用量的情况下混合断路器具有比SF6断路器更大的断流能力。研究结果为大容量混合断路器的设计提供了理论依据。

Simulation on Interaction of Vacuum Arc and SF6 Arc in Hybrid Circuit Breaker During High-current Interruption

Hybrid circuit breaker with vacuum interrupter and SF6 interrupter in series makes the best use of different arc extinguishing characteristics of vacuum arc and SF6 arc to achieve high-current interruption.To study the interaction between vacuum arc and SF6 arc,we established a system simulation platform,a vacuum arc model(12 kV),and a SF6 arc model(40.5 kV) by alternative transients program(ATP) and its transient analysis of control systems(TACS).Combining with the experimental oscillograph traces,we obtained practical model parameters of the vacuum arc and the SF6 arc;and established a hybrid circuit breaker model by connecting the vacuum arc model and the SF6 arc model in series.To study interactions and voltage distribution relations between vacuum arc and SF6 arc during current interruption process,we analyzed the dielectric recovery process and cooperative characteristics of two arc models at different moments,and quantitatively studied the gain characteristic of the breaking capacity of hybrid circuit breaker.Simulation results show that the vacuum interrupter firstly withstands the transient initial recovery voltage,which is helpful to the dielectric strength recovery of SF6 interrupter,the voltage distribution relationship is determined by arc resistance and capacitance of two breaks,and breaking capacity of hybrid circuit breaker is greater than that of SF6 circuit breaker without increasing the amount of SF6 gas.The results provide a theoretical basis for the design of large capacity hybrid circuit breaker.