Study On The Visual Relay Protection Setting Calculation System For Power Plant

The relay protection devices are important parts of the secondary electrical power system, and play extremely vital roles in guaranteeing the system's security, stability, economical operation, and so on. The domestic and foreign relay protection workers naturally pay more attention and research on how to enhance the rapidity and accuracy of setting and check to satisfy the request of the modern electrical power system's safe and stable operation.This paper researches the development, present questions and the limitation of the electrical power system relay protection setting calculation system, also considers its actual situations and characteristics, then proposes to develop a relay protection setting calculation system which is suitable for the power plant. Main work completed is as follows:(1) This paper first introduces the application of the visualization technology in electric power system because there is the visualization programming technology used in the software system.(2) It introduces the integrated design idea, divides the system into five main modules of the DBMS, graph modeling, fault analysis, setting calculation and fault simulation; and specifies every module's function.(3) It formats the database including equipments information, protection information, user information and fault information; it transfers data with other modules reversibly.(4) The breakdown calculation is a very important link. The paper introduces the mathematical model of each component, and design the procedure of the three-phase short-circuit and asymmetric short-circuit according to the needs of the relay protection setting calculation for power plant.(5) The article researches the graph modeling theory, and develops the graphic editor surface of the power plant. The user can edit, move, reproduce, delete, save, and so on. After the preservation, all attributes can be saved in the database.(6) It studies the general setting principles, compiles the setting calculation guide rules, and introduces the design thought, the principle characteristics, the mathematical models, the setting algorithm and the essential technology.(7) According to the formidable computation function of MATLAB and the friendly surface of VB, it proposes the design thought of fault simulation unifying the two. Two fault simulation methods are studied. Finally, the paper gives the flow chart of the fault information preview.