Development Of Relay Protection Experimental System

Relay protection is an important part of the power system and it plays a pivotal figure in ensuring the safe and stable operation of the power system. With the increasingly complex grid structure, relay protection is facing higher requirements. The simulation of relay protection based on computer technology is an effective method of researching the principles of relay protection to the electrical engineering professionals and students in related fields, which can reduce the experimental cost and risk and achieve realistic experimental simulation.In view of the existing shortcomings and lack of microprocessor-based relay protection tester and power system protection laboratory instruments, the research has developed a relay protection experimental system based on virtual instrument technology. MATLAB simulation model or dynamic simulation device is used to generate a variety of fault signals; and Lab VIEW used as an experimental system development platform achieves relay experimental system simulation.Distance protection and generator differential protection simulation systems are developed and the process of realizing the relay experiment is illustrated briefly. The distance protection function is divided into signal measurement module, start module, fault phase selector module, impedance relay module and oscillation blocking module. Distance protection carries out the measuring impedance, which has operating characteristics of Polygon. Based on achieving generator percentage differential protection, the generation, characteristics and identification of current transformer saturation are studied. The building of the relay model graphically and the visualization of action process on relay protection are realized in the paper. The relay protection experimental system is beneficial to study the new principles and algorithms, which can efficiently and accurately analysis the theories and action logic of relay protection.The practical result shows that this system is rich in the experimental function of relay protection and teaching demonstration feature, which provides a record and analysis tool for testing dynamic performance of power system fault, relay protection and automatic equipment. It has important reference value of research and teaching power system protection.