On Methods of Checking Digital Out-Of-Step Protection Devices

Abstract

The article addressed the issue of commissioning task that must take place before putting out-ofstep protection into operation. Most of the developers of digital out-of-step protection devices utilize control of impedance vector locus parameter during transient in a power system to detect its out-of-step operation, however checking the setting of such protection in the field conditions using existing means is often a challenging work. To facilitate the commissioning of such devices and provide means to automatize the process so as to rid of human factor the authors suggest means of simulating impedance vector locus with the desired parameters on the complex plane to check distance out-of-step protection. The means for checking current-oscillation based out-of-step protection is also considered. The results of a transient simulation representing instantaneous values of currents and voltages are saved in the international oscillography recording format COMTRADE, which makes it possible to carry out comprehensive verification of emergency control equipment using any kind of testing equipment that is able to generate the corresponding electrical signals stored in such format.