Influence of load behavior on service restoration

An extended fault in a distribution system may pose problems during feeder restoration. Immediately after energizing the feeder, high currents may arise due to a phenomenon called cold load pick-up (CLPU), causing activation of the overcurrent protection and preventing immediate reconnection of all load. The feeder should be sectioned and the restoration performed in steps. In the paper, an algorithm for determination of a sequence of restoration actions is presented. The algorithm determines the maximum number of customers that can be reconnected immediately and recommends time delays to restore the remaining sections with regards to the setting of overcurrent protection. The results of a restoration simulation on a part of the Slovenian distribution system are presented in the paper.