Selected problems of protective relaying for distribution network with distributed generation

This paper deals with protective relaying issues in relation to connecting the distributed generation sources into the distribution network. The considerations on fault conditions in the networks with incorporated distributed generation sources are analyzed. Protective relaying for such sources is considered. An impact of the sources on fault currents and operating conditions of protective relaying of the distribution network itself is presented. It is shown that in some cases the logics of the protective systems has to be modified, together with changing of the settings, as well as a need for introducing the extra protective systems arises.