The Research Of Comprehensive Risk Index System Of Distribution System Under The Condition Of Wide-area Distributed Power Access

With the energy issues becoming more and more serious, a lot of distributed generation has been connected to power system, which however brings many problems to safe and stable operation of the power system. In order to effectively improve the monitoring technology and management of the electric power distribution system under the condition of wide-area distributed power access, build the risk index system is a hot research topic in the field of the current distribution network risk assessment.In this paper, we studied the load point reliability index and system reliability index starting with the reliability parameters of components in the distribution system. And we discussed the reliability model of distributed power, which laid the foundation for establishing the risk assessment system. Then, we researched the failure consequences severity index from two aspects: the power loss rate and the user number loss rate after system failure. What's more, we studied the influence of distributed power to the distribution system and deduced the failure consequences severity index of the distribution system containing distributed power and the distribution system with wide-area distributed power access. And on the basis of what we have done, we gave the risk index and made a classification, we established the risk index assessment system and assessment process. Finally, we took the IEEE 33 node network as an example and calculated the risk indexes of traditional distribution system, distribution system containing distributed power and distribution system with wide-area distributed power access. The calculation results showed that the access of distributed power can improve the risk level of distribution system, and the rationality and validity of the assessment system we established.