Power System Restoration with an Automatic Voltage Regulated Distributed Generator

The restoration of power to unaffected sections of a network should be achieved under minimal time and within operational constraints in order to minimize power losses. Hence, versatile restoration plans are often required to handle different outage scenarios as well as total black-out scenarios. Distributed generators (DG) have been found to be valuable in providing ancillary services for voltage control and frequency regulation during power system restoration. The choice of a DG’s energy source, location, generator and black-start capability will determine its performance in the restoration of power to a network. This paper investigates the impact of DGs on power system restoration, giving a detailed attention to the choice of technology, black-start and automatic voltage regulation capability. Three distinct power restoration plans were investigated using DigSILENT. Each case had a distinct generator dispatch and switching plan to restore a network from a compromising state. The first restoration plan involved a central generator, the second involved DGs and the third involved DGs assisted by automatic voltage regulators and governor speed controllers. The third scenario was also structured to examine a network’s performance under unlikely strains.