Sensitivity Measure for Electric Power Load Dispatch Problem

Abstract

This study performed sensitivity analysis of a multi-objective thermal power dispatch problem and explored a solution methodology exploiting the quality measure approach, which verifies that the non-inferior solutions are uniformly scattered in the objective space. The multi-objective thermal power dispatch problem having non-commensurable objectives, such as operating cost and minimal emissions, is undertaken to meet the systems' real and reactive power demands within generators' capacity constraints. Real and reactive power transmission line flows are obtained from generalized Z-bus distribution factors and are restricted within prescribed limits for the secure operation of a power system. A sensitivity measure is incorporated as a dispersion index to be minimized in order to investigate the effects of random variations in the model parameters of the optimal solution. A non-linear programming problem provides the framework for examining the objectives along with constraints in a weighted sum form of the multi-objective problem. The best objective weights are evaluated by conventional statistical measures, which characterize the correlation coefficients matrix evolution. A quality measure approach is exploited to compare the relative quality of a different set of non-inferior solutions before presenting it to the decision-maker for a final decision. The validity of the proposed method is demonstrated on a 30-bus IEEE power system.

Keywords:

• multi-objective thermal power dispatch
• non-inferior solutions
• fuzzy membership functions
• generalized Z-bus distribution factors
• sensitivity analysis
• quality measure approach

Notes

^a Overloaded lines in the system.