OPTIMAL AND SECURE OPERATION OF POWER TRANSMISSION SYSTEMS IN DEREGULATED ENVIRONMENT

Abstract

From the last two decades the vertically integrated power system is undergoing the deregulation due to which the consumer will ultimately get benefited. However, deregulated power system confronts few technical problems. Congestion in the transmission lines is a critical one of such problems. Congestion or overload in one or more transmission lines may occur due to lack of coordination between generation and transmission utilities or as a result of unexpected contingencies such as generation outages, sudden increase of load demand, or failure of equipments. In deregulation environment, transmission regime results in more -intensive use, of the transmission system, which, in turn, leads to more frequent congestion. Congestion in the transmission lines can be relieved and/or reduced by cost free and non-cost free methods. One of the non-cost free techniques and most practiced technique of congestion management is rescheduling the power outputs of generators in the system. This dissertation report consists of introduction to deregulation environment and congestion problem, and studied techniques for optimum selection of participating generators in congestion using generator sensitivities (GS) and real power transmission congestion distribution factor (PTCDF) to the power flow on congested lines and an algorithm based on particle swarm optimization (PSO) which minimizes the deviations of rescheduled values of generator power outputs from scheduled levels. The effectiveness of the proposed methodologies has been analyzed on IEEE 30-bus, 57-bus and 118-bus systems.