An Overview of Cold Load Pickup Modeling for Distribution System Planning

The study of the load diversity in networks with high penetration of thermostat-controlled loads is an important process in the distribution system planning stage as it provides useful information for the proper selection and sizing of power equipment, and calibration of protective devices. However, as the load diversity in a power system could be negatively impacted during extended outages, the estimation of the cold load pickup current magnitudes during restoration must be taken into account, as these may cause significant overloading and interfere with the intended operation of overcurrent devices. In this paper, several cold load pickup (CLPU) models are recompiled from the literature and an analytical comparison between them is presented with the purpose of presenting the differences in the estimation of the CLPU levels during service restoration.