A Hybrid Ep-Sa-Ts Method to Solve the Hydro - Thermal Unit Commitment Problem

Abstract

This paper presents ·a new approach to solve the Hydro - Thermal short-term unit commitment problem using hybrid algorithm based on Evolutionary Programming, Simulated Annealing and Tobu Search Method. The objective of this paper is to find the generation scheduling such that the total operating cost can be minimized, when subjected to a variety of constraints. This also means that it is desirable to find the optimal generating unit commitment in the power system for the next H hours. Evolutionary programming is a Global Optimization Technique for solving Unit Commitment Problem that operates on a system, which is designed to encode each unit's operating schedule about its minimum up/down time. Simulated Annealing and Tobu Search methods improve the status by avoiding entrapment in local minima. A seven-unit utility power system with twelve generating units In India demonstrates the effectiveness of the proposed approach; Extensive studies have also been performed for different IEEE test systems consisting of 10, 26 and 34 Units. Numerical results are shown comparing the cost solutions and computation time obtained by the proposed hybrid method and other conventional methods like Dynamic Programming, Lagrange Relaxation in reaching proper unit commitment.