A systematic method for power system restoration planning

This paper describes a systematic method for power system restoration planning. System restoration at Hydro-Quebec is performed according to a set of detailed emergency instructions. The basis for these instructions is a restoration plan that is prepared off-line by operation planners. This plan includes a switching scenario with a set of values for the control variables-generator voltages, shunt reactors and load levels-that satisfy the operating constraints. Finding a suitable set of control variables usually requires many load-flow runs in a trial-and-error process. However, the problem can be formulated as a nonlinear optimization problem. The optimization algorithm which solves that problem provides values for the control variables automatically. This algorithm is linked to a user interface which constitutes a powerful tool for system restoration planning