考虑站网协调的500kV终端变电站可靠性评估

500 kV Terminal Substation’s Reliability Assessment Considering Coordination Between Power Grid and Substation

针对500 kV终端变电站的特点提出一套工程化的可靠性评估方法,将500 kV终端变电站分为500 kV联络线、站内主接线、220 kV电网3个环节进行可靠性评估。基于马尔科夫模型,建立了500 kV终端变电站的全环节可靠性分析模型、方法和指标体系;采用根源分析方法,对500 kV终端变电站的可靠性影响因素进行了分析。最后,以广东电网某500 kV变电站的终端变电站改造方案作为算例进行了可靠性计算分析,验证了算法的实用性;结合算例进一步计算分析了500 kV联络线、主接线型式、220 kV电网网架结构、220 kV电源和负荷分布等因素对500 kV终端变电站可靠性的具体影响。研究表明:500 kV枢纽站改造为终端变电站后,其可靠性水平有所下降;但合理的终端变电站方案仍能够使可靠性满足工程应用要求;500 kV联络线和站内主接线是影响500 kV终端变电站可靠性的主要因素。

According to the features of 500kV terminal substation an engineering reliability assessment method is proposed,in which the 500 kV terminal substation is divided into three parts,namely the 500 kV tielines,main connection within the substation and 220 kV network,to perform the reliability assessment.Based on Markov model,a reliability analysis model for the whole substation as well as corresponding analysis method and index system are built.Utilizing root cause analysis（RCA）,the influencing factors affecting the reliability of 500 kV substation are analyzed.Taking the reconstruction scheme for a certain 500 kV terminal substation in Guangdong power grid as the case,the reliability of the case are calculated and analyzed to validate the practicality of the proposed algorithm.Combined with the case,concrete influences of factors such as 500 kV tielines,main connection within the substation,the structure of 220 kV network,220 kV power source and the distribution of load,on reliability of 500 kV terminal substation are analyzed.Research results show that when the 500kV hub substation is reconstructed to 500 kV terminal substation,its reliability level will be somewhat decreased.However,reasonable scheme for terminal substation can still make its reliability meet the demand of engineering application.The 500 kV tielines and main connection within the terminal substation are main factors affecting the reliability of 500 kV terminal substation.