Research On Relay Protection Virtual Simulation Experiment System

As the first line of defense for the safety and stability of the power system,relay protection plays a very important role in the stable operation of the power system and normal power supply.With the continuous development of computer network technology and virtual simulation technology,the use of virtual experiment system to achieve simulation simulation of relay protection experiments has become an effective means for electrical engineering students and engineering technicians to learn and study the principles of relay protection.This paper develops a set of relay protection virtual simulation experiment system for relay protection experiment teaching and training.The system integrates virtual instrument technology and power system digital simulation technology.Using the MIT module in Lab VIEW,the virtual instrument development software Lab VIEW and the simulation software MATLAB / Simulink are seamlessly connected and effectively combined to achieve joint simulation.Simulink is used for digital simulation calculation of primary system shortcircuit faults,and Lab VIEW is used for secondary system relay protection performance digital simulation and human-computer interaction interface design.Simulink simulation results can be dynamically displayed in Lab VIEW and can be automatically controlled to modify its simulation model parameter.Finally,connect to the SQL Server database,realize the system login module,and realize the network release of the system through the Web Server.Based on the system overall design,this paper studies the current protection and distance protection and the protection of the transformer differential protection of the three common experimental type,according to the working principle of the protection,composition,each module function in the algorithm simulation of relay protection device and its logic cooperate relationship,realize the dynamic performance of the virtual simulation of relay protection and action process visualization.In the design of current protection experiment,the full-wave Fourier algorithm of microcomputer relay protection is improved to eliminate the influence of attenuating dc component,reduce the error and make the experiment result more accurate;For distance protection,the research and design of the vibration blocking module,the phase selection module,the impedance relay module and the protection section discrimination module are emphasized;In the process of transformer differential protection simulation design,the design of ratio braking differential protection module,magnetizing inrush current identification module and differential speed break protection module are emphasized.The experiment principle learning,experiment parameter setting and experiment result display are realized.Through experimental tests,the virtual simulation experiment system for relay protection can simulate various fault conditions and observe the dynamic changes of the protection.At the same time,it can also simulate and analyze the factors that affect the correct action of the protection.The system has low development cost,short period,strong scalability,and friendly interactive interface,which is of great significance to the relay protection experiment teaching and training.