万能式断路器保护动作值的计算分析

Calculation and Analysis of Protection Action Value for Open-Construction Circuit Breaker

介绍了低压万能式断路器过载长延时、短路短延时、短路瞬时、接地故障保护动作的特性和动作设定的阀值,并对某实际工程中变压器低压侧的断路器跳闸动作的原因进行了线路系统分析和数据的推导计算。结果表明,断路器保护动作值的合理设定,能有效避免事故的扩大,并能有选择地进行级联保护,有利于电网安全、稳定、可靠地运行。

Introduction was made to overload long-time delay,short-circuit short-time delay,short-circuit instant,characteristics of grounding fault protection action and threshold value for action setting of low-voltage open-construction circuit breaker,and line systematic analysis and data deduction and calculation were carried out for the causes of circuit breaker＇s tripping off at transformer＇s low-voltage side in a certain actual project.The results show that reasonable action value setting of circuit breaker protection can effectively avoid expanding accidents,carrying out cascade protection in choosing,which is favorable for safe,stable and reliable operation of power network.