An Improved Relay Protection Simulation Method - Direction Distance Method

摘要

This paper briefly introduces the domestic and foreign status quo of protective relaying simulation technologies. It also summarizes the current problems and obvious drawbacks of three existing methods, which can't meet the requirements of large grid's operation. In this paper, a new protective relaying simulation method, which is direction-distance method, is brought up by considering the principles of direction and distance protection. Based on the topological analysis of logic, the direction-distance method combines the advantages of logic judgment and quantitative comparison methods, and introduces the short circuit power, which makes up the problem that the simple logic method cannot judge the direction protection action. Comparing with quantitative comparison method, the value of the impedance is replaced by the malfunctions equivalent distance, which simplifies the calculation of the protection value. It can realize almost all the malfunctions of complex power grid and do not have to maintain a large number of fixed value parameters. Direction-distance methods combines the strengths of logic judgment method and quantitative comparison method, which is especially suitable for protective relaying simulation.