Optimal hydro-termo scheduling on a personal computer

Abstract

The purpose of optimal short-term scheduling is to maximize electrical energy production depending on the natural water inflows of a river, according to a daily load duration curve and the operation of thermal power plants with minimal oscillating load. Thermal power plants have a long start-up time and cannot follow changes in load demand so they are used to cover the constant part of the load, but peaks in load demand are covered by hydro units. A new mathematical model of a hydro plant chain was developed which used only two, instead of three, variables. The optimization algorithm used Newton's method which is applied on the exact $\text{L}$ penalty function which allows a nonfeasible starting point so no phase $\text{I}$ simplex or projection method is needed at the beginning. The mathematical model was implemented on a PC as a computer program using the FORTRAN 77 programming language and spreadsheet software. The program was applied to a hydro-chain on the river Drava. Preliminary results show that applying optimization techniques can greatly reduce costs of operating a hydro plant chain.