Abstract
To reduce boiler fuel cost, a new ELD method (economic load dispatching method) based on a dynamic fuel cost model, which is more accurate than the conventional quadratic model, is proposed First, ARMA model (Auto Regressive Moving Average model), which is a constant coefficient linear digital filter, is applied in order to supplement the quadratic model. We call the supplemented model ARMA-model-supplemented quadratic model. By using this model, the model deviations from actual data have been reduced Second, based on the ARMA-model-supplemented quaic model, we formulated the ELD problem into a quadratic programming problem, where the objective function is the summation of all units' fuel costs over multiple time points and the constraints are the supply-demand balances, the upper and lower generation limits, and the ramp rate limits. This problem can be solved by the standard quadratic programming technique. We call this new ELD method BEST method short for Boiler-dynamics-based Economic load diSpaTching method. Then, in order to make the problem size smaller, we propose a scheme to ignore all the time points except for the points corresponding to the peak, the bottom, and the steepest point on the forecasted load curve. We call this scheme sample scheme. Finally, the BEST method with the sample scheme are evaluated by numerical simulations on Kansai Electric Power Systems and it is shown that the proposed method can reduce the calculation time without compromising the fuel cost.
