OPTIMAL LOAD SHEDDING FOR ELECTRIC POWER SYSTEMS

Abstract

A utility seeks to operate while satisfying system constraints and operational limits. Violation takes place due to events such as a sudden increase in system demand or an unexpected outage of a generator or a transmission line. Load shedding is a possible corrective action that forces the perturbed system to a new viable operational state.

In this thesis, the solution of optimal load shedding problem for any power system is considered. A new formulation for the problem is proposed. The objective of the proposed formulation is to consider the optimization of voltage profile of any network after a fault, as well as, minimizing the load to be shed. The optimization problem is solved using constrained non-linear programming technique. The computer programs are developed under MATLAB environment and using its optimization and power system toolboxes.

The evaluation of the proposed technique is carried out using a 26-Bus system. A computational comparison between the results of the new formulated approach and a well known previous approach is accomplished. The results obtained using the proposed approach appear to give better voltage profile of the power system.

The Egyptian Unified Power System (UPS) is simulated in order to compare the performance of the proposed approach and that of a previous approach. Testing is done using the Egyptian Unified Power System (UPS) under two different operating conditions. The optimal results obtained are compared with results obtained using a previous approach. These results verify that the proposed approach leads to better results than that of the previous approach.