Security-constrained Economic Dispatch (SCED) Considering Load Level Uncertainty

In power system operation, security-constrained economic dispatch (SCED) is used to provide a reference point for the next time period for each dispatchable generator, and load forecasting needs to be involved in the SCED procedure. In real-time operation, forecasting errors and the nonlinearity of the load change might cause undesirable dispatch patterns in terms of system security. This study presents an SCED that considers the uncertainty of the system load level. For this purpose, a fuzzy model was employed to express the uncertainty in the load level change, and a practical two-stage SCED solution method was adopted. In addition, to resolve the difficulty in determining the reference generation pattern from solutions using this model, a procedure is required to determine the secure upper and lower limits for the dispatchable generators as the final SCED outcome. The numerical results were obtained using a 43-bus test system to test the feasibility of the proposed method.