A generator excitation system plays a key role in both generators protection and power system stability. Therefore, the protective loss of excitation relay has an important effect on the performance of the protection system and can save the generator and the power system against damage and instability, respectively. Often protective loss of excitation relays operate based on generator terminal impedance. In this paper, different structures of a simple power system network are studied, the behaviour of the generators in the loss of excitation situation is simulated, and the results are discussed. Moreover, in the simulations the effect of different external faults, parallel generators and load on the seen terminal impedance of generators is investigated. In addition, the effect of changing generator excitation of one generator on the other generators is discussed.
W artykule omówiono różne struktury sieci zasilającej, zasymulowano właściwości generatora przy stanach wzbudzenia i przedyskutowano rezultaty. Zasymulowano też różne zewnętrzne uszkodzenia i różne obciążenia.