DECOMPOSITION APPROACH TO THE NEWTON- RAPHSON BASED HYDRO-THERMAL OPTIMAL POWER FLOW SOLUTION

This paper presents a decomposition approach to the hydro-thermal optimal power flow problem to address the mathematical difficulty due to large number of variables and constraints associated with the problem. The decomposition of the problem is achieved by dividing the optimization period under consideration into hourly time intervals. The optimization problem for each time interval is first solved using the Newton-Raphson based solution technique. The results associated with each hydro plant for every hour are then used to adjust the water worth value for each plant. This procedure is repeated until the available water is optimally utilized. The proposed solution procedure is implemented using MATLAB version 7.14 software. The performance of the proposed algorithm is tested on IEEE 5-bus, 30-bus and 57-bus networks. The simulation results have shown the effectiveness of the proposed algorithm. The performance index of each hydro station has been measured using the average hydro plant energy.