500kV断路器灭弧室电寿命评估技术研究

Research on Evaluation Technology of Electrical Life of 500kV Circuit Breaker Interrupter

如果断路器开展投切操作的过程,出现电弧烧蚀的情况,由于电弧的影响,使得断路器的触头表面出现一定程度的损坏,造成变形、毛刺以及材料蒸发的现象。如果产生的电弧温度持续提高,那么对断路器的触头表面材料影响将加剧。为了有效降低电弧烧蚀的影响,断路器实际运行过程中,增加了灭弧室的功能,然而影响断路器灭弧室的电寿命主要有两个方面:弧触头和喷口。根据这两个方面的工作状态,提出了相应的试验检测技术和评估方法。通过大量的实验发现,当断路器开断电流不断累积的情况下,断路器的弧触头之间有效接触位移不断降低,形成的平均接触电阻逐渐提高,并且,断路器的有效接触位移随着累积开断能量的升高而呈指数降低的现象。

When the circuit breaker is switched on and off,the phenomenon of arc ablation will occur. Under the action of the arc,the contact surface of the circuit breaker is continuously damaged to a certain extent,resulting in deformation,burrs and the evaporation of materials. If the arc temperature continues to rise,the impact on the contact surface material of the circuit breaker will be intensified. In order to reduce the influence of arc ablation effectively,the function of arc extinguishing chamber is added in the actual operation of circuit breaker. However,two main aspects—arc contact and nozzle,affect the electrical life of the circuit breaker’s arcing chamber. This paper accords to the working status of these two aspects to put forward the corresponding testing technology and evaluation method. A large number of experiments find that the effective contact displacement between the arc contacts of the circuit breaker constantly decreases and the average contact resistance increases gradually when the breaking current of the circuit breaker accumulates,and that with the increase of accumulated breaking energy,the effective contact displacement of the circuit breaker decreases exponentially.