基于测量参数的距离保护运行风险分层评估方法

Hierarchical Risk Assessment Method of Power System Distance Protection Based on Measuring Parameters

距离保护的正确工作对电力系统的安全稳定运行意义重大。针对目前距离保护失效概率难以准确反映保护原理、难以计及保护之间配合关系对失效概率的影响且计算方法较为复杂等不足,首先结合阻抗继电器的动作特性,提出了基于启动截距和测量截距的距离保护失效概率计算方法。其次,通过确定保护失效的后果和风险评估指标,进一步制定了距离保护风险评估的详细流程。最后,以IEEE 3机9节点系统为例,分析了其距离保护原理性失效风险。分析结果表明,该方法能有效适应智能电网要求,可准确计算继电保护系统的失效概率和运行风险,并可发现保护系统的部分潜在风险。

Correct and reliable operation of distance protection is of great significance to both the safety and stability of the power system.In view of the fact that the calculation of current failure probability models of distance protection is usually complicated and unable to accurately reflect the protection principle and impact of protection coordination on relay failure probability,a new method of calculating the failure probability of distance protections based on start intercept and measuring intercept is proposed according to the action characteristics of impedance relays.A detailed flow of distance protection risk assessment taking the consequence of protection failure and risk indices into account is further determined.Finally,the distance protection risk assessment of an IEEE 9-bus system is given that shows the proposed method is effective in evaluating the operating risk of distance protection as well as analyzing the latent risk of the protection system. This work is supported by National Natural Science Foundation of China(No.51307059),Fundamental Research Funds for the Central Universities(No.2014MS86)and Hebei Provincial Natural Science Foundation of China(No.E2014502065).