Simulation And Analysis System For Transmission Line Relay Protection

Relay protection device is an important part of power system. It is also one of theimportant measures to ensure the safe and reliable operation of power system. Withthe enlargement of power grid scale, the requirements of relay protection device’sperformance are also getting higher and higher. In order to improve the reliability ofprotection, it is necessary to simulate and study the operation characteristics of relayprotection when a fault occurs, as well as to check and analysis accurately after theaccident. At present, the digital simulation technology of relay protection hasbecome the important method for relay protection device research and development.This paper deeply understand and study domestic and foreign digital simulationmethods of relay protection, and design the simulation and analysis system fortransmission line relay protection based on Matlab with the use of the relayprotection digital simulationtechnique. The system consists of three parts: systemcircuit model simulation, simulation of relay protection, and human-computerinteraction interface. The system circuit model simulation and simulation of variouscomplex protection module are based on Matlab/Simulink. The designment ofsystem interface are based on GUI which is the user interface developmentenvironment of Matlab. The designment of this system are according to the maincomponents of real microcomputer relay protection, and the system completelysimulates the execution sequence of various components: firstly set the systemcircuit model parameters through the human-computer interaction interface, then runthe simulation to obtain the system data, which is the input of simulation module ofline relay protection, finally the results of protection module simulation is output tothe interface, users can intuitively observe changes in the parameters and thedynamic process of relay protection. Therefore, the simulation system is closelyrelated to the real line relay protection.Based on stage current protection, distance protection and current comparisonpilot protection as examples, this paper introduces the develop process of thesimulation and analysis system for transmission line relay protection. Many kinds ofsimulation tests have be done, including fault simulation, protection action behaviorsimulation and other links. According to the experimental results, various lineprotection action behavior are validated and factors which may effect the accuracy of protect action are analyzed.The simulation results show that the simulation and analysis system can realizethe simulation and calculation of transmission line relay protection in various faulttypes. The user can directly observe changes in the parameters and the dynamicprocess of relay protection so that they can analyze the factors that impact theaccuracy of the protect action. This system has certain application value inprotection research and teaching.