A new method for dynamic calculation of load steps during power system restoration

One of important subject in load pickup that is not addressed, is selection of suitable load steps, especially in the initial phase of restoration. Operators are often concerned with the size of load, which can safely be picked-up, and the effectiveness of the generation reserve. Load pickup in small increments tends to prolong the restoration duration. With large increment, there is always the risk of falling into a frequency decline and recurrence of the system outage. In this paper a novel method for dynamic calculation of load steps is presented. This method consider dynamics of all components and their limitation and use an expert idea for behaviour of frequency. The presented method is capable of on-line guiding the operator for: (i) selecting suitable load steps, or (ii) calculation of the minimal frequency for a determined load step. Simulation tests were carried out on the 39-bus New England system, verifying the effectiveness of the proposed method.