计及继电保护装置可靠性评估的电网故障诊断方法

现代电网规模的扩大和互联性的增强,使电网故障诊断面临更加复杂的数据环境,提高了保证电网安全稳定运行的难度。针对电网发生故障特征不明显的复杂故障时,电网故障诊断不易得到准确结果的问题,提出了一种计及继电保护装置可靠性评估的电网故障诊断方法。利用与故障非强相关的告警信息,建立了保护可靠性的马尔可夫模型,用状态空间法求解保护拒动、误动的概率。将继电保护装置可靠性评估结果加入到基于解析模型的电网故障诊断方法的目标函数中,并使用变长度染色体遗传算法求解最优故障假说。用实际复杂故障案例验证了方法的可行性。

Fault Diagnosis Method of Power Grid Considering Reliability Assessment of Relay Protection Devices

The expansion of modern power grid scale and the enhancement of interconnection make the fault diagnosis of power system face more complex data environment, which improves the difficulty in guaranteeing the operation safety and stability of power grid. In order to solve the problem that power grid fault diagnosis method is not easy to get accurate results when complex fault with no obvious failure characteristics occurs, a fault diagnosis method of power grid considering reliability assessment of relay protection devices is proposed. Based on the alarm information which has weak correlation with failure, the Markov model of protection reliability is established, and the state space method is used to obtain the probability of refuse-to-operate failure and mis-operation failure. The results of protection reliability assessment are added to the objective function of the fault diagnosis method based on the analytical model. Variable length chromosome genetic algorithm is used to solve optimal fault hypothesis. The feasibility of the method is verified by the actual complex fault case.