Research On Diagnosis Method Analysis Of Distribution Network Based On Power Supply Safety Standard

As a close link between power consumers and power generation and transmission systems,the running state of the power distribution system determines whether it can provide safe,reliable and continuous power supply for power consumers.With the development of modernization,power demand for rises sharply.Power consumers put forward higher requirements for safety and reliability of power supply.On the basis of meeting the safety and reliability of power supply,diagnosis of distribution network has important guiding significance for improving power grid construction efficiency and investment economy.According to mature guidance document,to select a quantitative and diverse index which could reflect the hierarchical structure of the grid and maintain the power supply to consumers at a certain security level,using main power grid safety indicators,such as the duration of power outage and the size of the power loss load,combined with diagnosis and analysis of distribution network based on operation mode related data,must be enforced.To this end,a diagnosis method of distribution network based on power supply safety standard is proposed in this thesis.First of all,the British ER P2/6 standards,Chinese electric-power industry standards,state grid standards and local standards represented by Jiangsu are compared.We laid special stress on analyzing the similarites and differences among these standards and their respective core elements and quantitative indicators requirements.Then,we further refine safety standard index and identificate the diagnostic indices of distribution network that can characterize the network structure of voltage classes,load transfer capability,level of distribution automation and level of operation and maintenancewe.Based on provisions for safety standards of power supply,we study overall assessment process of structure and security of distribution network and obtain the diagnosis method of distribution network based on power supply safety standard.Meanwhile,according to the characteristics of distribution network with large scale and complicated structure and various equipment,in order to quickly evaluate the security of distribution network,on the basis of existing security region theory of medium voltage distribution network,considering the high voltage substation and line,the security region verification model of full voltage rank sequence is constructed.Finally,the idea of analyzing the global power supply capability of distribution system from the angle of power supply blocking is put forward.A series of indicators and power supply bottleneck criteria for high and medium voltage distribution system are set up,which are used to measure the disparity of power supply capability of high voltage distribution system,and dig out the weak links that restrict the global power supply capability of distribution system.