This paper considers the impact that the design of a directly connected generator will have upon the behaviour of an entire power system under the influence of a balanced three-phase bolted (LLLG) fault. Initially a method for illustrating the effect of the connection of a single generator upon the entire network is demonstrated. This is utilized to derive algebraic comparisons between the fault currents, voltage disturbances and the generator fault in-feeds that are produced in a power system in which an existing generator and GSU (generator step-up) transformer is replaced by a directly connected generator. The qualitative relationships are verified with data obtained from simulation of a 17-bus test system and a 600-bus realistic power transmission network. The results highlight that the variation in design of a single generator may produce perceptible change to network fault behaviour in an appreciable portion of a power system.
展开▼
