Research On Relay Protection Setting Calculation Platform Of Distribution Network

With the development of national economy,higher requirements are put forward for the safety and reliability of distribution network.Misoperation or refusal of relay protection device in distribution network will seriously threaten the safe operation of distribution network.Improving the correctness and accuracy of protection setting value of distribution network is the main measure to reduce the misoperation or refusal of relay protection device.In addition,the penetration of distributed generation(DG)in the distribution network has increased significantly,which makes the traditional relay protection setting software unable to meet the requirements of modern distribution network.Therefore,the research and development of a new set of relay protection setting software with high accuracy,strong universality and high scalability is of great significance to improve the setting efficiency,reduce the burden of setting workers and meet the requirements of modern distribution network.In this paper,according to the user's requirements for the setting software,the setting software is analyzed and designed based on the object-oriented idea.The use case diagram is used to describe the functional requirements of the setting software,and the activity diagram and time sequence diagram are used to describe the dynamic behavior of the setting software during its operation.The functions of database information management,fault calculation and setting calculation in the setting software are mainly designed.According to the configuration and characteristics of relay setting calculation data,the database structure is given based on the analysis of database application requirements,and the equipment connection storage table,topology storage table and protection setting value storage table of the distribution network in the database are designed.In view of the problems brought by DG access to the traditional distribution network fault calculation method,based on the port compensation method to calculate the fault,a fault calculation method suitable for the distribution network with DG is proposed by studying the fault characteristics of DG.On this basis,the object-oriented idea is adopted to design the fault calculation component,and the object model and dynamic model of the fault calculation component are given.Through the radial distribution network to verify the fault calculation components,the calculation results prove the correctness of the fault calculation components.According to the protection configuration of distribution network,the protection setting method is summarized.In view of the lack of description of the secondary protection equipment by the protection package in the common information model(CIM),the protection package in CIM is extended by using the feature of polymorphism in object-oriented,and the protection setting method is extended.Based on the idea of object-oriented and protection zone setting calculation,the setting calculation component is designed,and the object model and dynamic model of the setting calculation component are given.The result shows that the calculation result of the setting system is accurate,and it has good expansibility and generality.