Multi objective Hydrothermal Generation Scheduling based on Heuristic Algorithms

Abstract

Electric power today plays an exceedingly important role in the life of the community and in the development of various sectors of economy. In view of increase in the demand of electricity, considerable attention is given to interconnection between different systems. The hydro plants have high capital cost and low operating cost as compared to thermal plants. Hydro resources are considered to provide a clean and environment friendly energy option. Hydro plants are usually scheduled for peak load periods and thermal plants are normally scheduled for base-load period as hydro units are started-up and shut-down efficiently as compared to thermal units. Hence, the exploitation of hydro resources becomes important. The major concern of hydro resources is stochastic nature of availability. So, the integration between hydro and thermal systems is essential for the welfare, development and economic progress of our society. The fundamental requirement of hydro-thermal generation scheduling (HTGS) is to utilize the limited amount of water available to its fullest extent, such that the total system production cost and pollutants emission of thermal units are minimized while satisfying hydraulic and power system network constraints. The integrated operation of the hydro-thermal system is split into long-term and short-term generation scheduling problems. The planning period is one or more years for long-term HTGS problems. For short-term HTGS, planning period is an hour or a day or a week as the load demand on the power system exhibits cyclic variations. The amount of water to be utilized for short-range HTGS problem is known from the solution of the long-range HTGS problem. Conventional hydroelectric plants are classified into run-of-river plants and storage plants. Run-of-river plants have little storage capacity, and utilize water as it becomes available. Storage plants are associated with reservoirs, during periods of low power requirements water is stored in the reservoirs and then released when the demand is high.