Real-Time Detecting Method of Negative Sequence Current in Traction System

When electric locomotive moves in power system, it will produce negative sequence current, which will threat the electric equipments and the power system security operation. So it is very important to measure the value of negative sequence current rapidly and exactly. This paper introduces one new kind of method to measure the negative sequence current. The method adopts digital sampling, exact filtering technology and multifarious alarm setting function, has the function of data save and return, and considers the influence of thermal effect. The method can measure accurately the negative sequence current of each surveillance spur track, and the process of measure is simple. The method is also satisfied with the measure in multiplicative different run condition, and it has stronger universality and practicality.