Down, but Not Out: A Brief Overview of Restoration Issues

Modern power systems are highly reliable. They are operated to withstand the variability in system conditions that occurs in the course of normal operations, including the daily changes in load levels, generation dispatch, and equipment availability. Modern power systems must also provide reliable service to load during unusual events, such as faults and the tripping of transmission lines or generating units. Extreme events can occur, however, that may lead to partial or total system blackouts. To recover from such catastrophic events, utilities thus have a responsibility to develop detailed plans and procedures for restoring the power system safely, efficiently, and as expeditiously as possible. This article gives a brief overview of many issues involved in power system restoration.