Study on the operational reliability of AC relay based on the impact from electric energy quality

In the power system there are variety of electric energy quality problems such as magnitude deviation, frequency deviation of the supply voltages and harmonic of them. As the exciting source, the voltage supplied by the power system has an important impact upon the operational performance of AC relay. In this paper, one sort of clap-type AC relays is chosen to study the impact from electric energy quality problems. First, Ansoft Maxwell 3D, based on the finite element method, is employed to create the 3D model of AC relay. Second, considering the magnitude deviation of the supply voltages, static suction characteristics of the chosen relay are calculated. Then, considering the magnitude deviation, frequency deviation and the distortion degree, series of simulations are done to obtain the dynamic characteristics of the clap-type AC relay. At last, based on the changes of electric energy quality parameters, the influence law about the operational reliability of the AC relay is given.