阶段式保护原理性失效风险的概率评估方法

Probabilistic Assessment Method for Failure Risk of Stepped Protection Philosophy

继电保护对电力系统的安全稳定运行有着重大影响,其可靠性研究一直是电力工作者关注的课题。针对目前继电保护系统可靠性及风险评估方法存在难以反映保护原理特性、动作时序特性等不足,在保护元件原理性失效概率模型的基础上,确定了继电保护系统的风险评估指标,并制定了阶段式保护原理性失效风险评估的详细流程。最后分析了某实际电网中距离保护的原理性失效风险,结果表明该方法有助于寻找保护系统的薄弱环节、发现其他系统难以发现的问题,并能为保护定值校核等系统提供参考冗余信息。

Protection system has a significant impact on the stable operation of power system, its reliability has been an important topic concerned by power workers. In allusion to the deficiencies in reliability assessment of protection system, such as protection characteristic and sequential characteristic of protection action could not be described accurately in reliability assessment models, an instantaneous failure probabilistic model of protection elements was presented and a new risk probabilistic assessment flow was proposed after establishing reasonable risk indices. An application sample of distance protection risk assessment in an actual power network was given, the results show that the proposed method could be used to find weak links of protection system and detect protection problems that could not be reflected by other systems, as well as to supply redundant information for systems such as online verification and modification nf nrnt^c, ti.n ~f;~~,o