An Optimal Power Dispatch Technique Using Spot Price of Electricity for Multi-Area Interconnected Systems

Authors: Salih FADIL

Abstract: In this study, an optimal power dispatch technique using spot price of electricity for multi-area interconnected systems is proposed. It is assumed that all areas in multi-area system agreed upon the formulation of a base spot price for electricity in advance rather than agreeing upon a transfer schedule at a fixed price. This results in a flexible transfer schedule among them. The proposed base spot price of electricity is a linear function of frequency error and integral of frequency error of a system. As long as the tie-line losses are ignored in the system, using the base spot price in the algorithm is enough to find the optimum generation of each areas. Later, the dispatch algorithm is extended to lossy multi-area case and demonstrated on a five area interconnected system. Inclusion of the tie-line transmission losses is achived by modification of the base spot pirce of electricity. A transfer power algorithm is developed to handle optimal power transfers for the given area transferrable powers among the areas. The dispatch algorithm can handle different system configurations where some tie-lines in the system can be taken out, generation and tie-line transmission constraints. The proposed technique gives the most economical generation of each area together with the most economical energy exchange among them. It results in frequency regulation as well as economic dispatch.

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