Autocoordination of protection settings of series reclosers

The paper deals with the problem of coordination of reclosers installed in series in overhead line. Existing practice is based upon set of rules that require human interference. This may lead to errors and incorrect operation of protection. We have developed a set of algorithms that allow determining settings of protection elements providing protection against short circuit and sensitive earth faults. Network parameters and grading margins serve as input data for the mentioned algorithms. The algorithms have been tested with the aid of network computer models. The tests proved applicability of the algorithms for field application.