Research On A Main Protection Testing System Based On Generator Internal Faults Simulation

Improving the performance of large generator relay protection depends on our knowledge of internal faults of large generators. But the analysis of internal faults of generators, especially that of transient behavior is a weak link in power system fault analysis. So researching transient behavior of internal faults of generators, finding laws of transient change of electric variables and testing protection devices based on fault simulation are significant to enhance generator relay protection.According to deep study in transient behavior of internal faults, this paper presents a main generator protection testing system for main generator protection based on transient simulation data of internal faults.Firstly, the paper builds up a simulation model of generator internal faults based on multi-loop theory. And then it develops a visual simulation program for transient behavior of generator internal faults, results of which are verified to guarantee an accurate simulation.After acquiring simulation data, the paper deeply researches IEEE standard common format for transient data exchange (COMTRADE), and develops a format conversion program for the simulation, making transient simulation results in common use. Meanwhile, test device is used to recur the transient waveform in terms of COMTRADE data, realizing D/A conversion and power amplifying.Finally, the paper constructs the whole main generator protection testing system, and gives detailed evaluation to main generator protection in various fault conditions. It is validated that this system, which is smaller in size, simpler in structure and lower in price than traditional testing methods, can meet the requirement of engineering application. This testing system is a replenish to dynamic simulation experiment.