The dynamic representation of protection systems

This paper presents a dynamic model of a protection system based on a diffe rential feeder protection along with the primary power system. A commercial ly available relay is modelled and its functions explained. A general prima ry power system model structure that includes a fully integrated protection system model is discussed. The protection system model contains dynamic mo dels of both the relays and the transducers. A technique will be described for developing an accurate dynamic model of a numerical protection relay us ing actual microprocessor codes from a commercially available relay. Finall y, the practical application of the analysis under abnormal system conditio ns is demonstrated. Different faults are applied to the internal and the ex ternal regions of the feeder, and the response of the relays examined. (C) 2000 Elsevier Science Ltd. All rights reserved.