Adaptation of the simplex algorithm to modeling of cold load pickup of a large secondary network distribution system

This paper describes a mathematical approach to the determination of the electrical load composition of a secondary network during cold-load reenergization. It is intended to answer two questions: What fraction of the normal steady-state demand must be restored at the time of reenergization in the most pessimistic case? What is the composition of this worse case restoration load? The answers were obtained by making use of the Simplex Algorithm, a mathematical, but physically based, optimization procedure. The input data consisted of a customer survey of connected-load; maximum demand for this customer sample; experience-based power requirement limits as a function of the time-of-day. For comparison with the mathematically-based results, on-site visits were made to representative commercial enterprises. The results were used to construct, independently, a second cold-load restoration model. The two models were surprisingly close.