Optimal Estimation of Piece-Wise Linear Incremental Cost Curves for EDC

Real-time economic dispatch is performed most efficiently using a Sorted Table Method. This method requires that the incremental cost curve be represented by monotonically increasing piece-wise linear segments. The primary focus of this paper is the development and demonstration of a very practical method by which the number of linear segments and their corresponding "break points". are determined in an optimal manner. The problem of determining break points by manually plotting the IC curve and then applying a series of "educated guesses" is totally eliminated. A weighted least-squares multiple linear regression method is used to calculate the coeff icients of a cubic fuel cost (I/O) curve. A special constraint equation is included to insure that the incremental cost curve exhibits a monotonically increasing characteristic. Numerical examples are included to demonstrate practical results.