Effective economic dispatch model and algorithm

Under the electric power market environment, economic dispatch (ED) as part of the on-line Automatic Generation Control (AGC) problem considers unit, network and system constraints. For the ED problem, it is important to establish an effective model and algorithm. This paper examines the decoupled conditions that affect the solution optimality to this problem. It proposes an effective model and solution method. Based on the look-ahead technique, it finds the number of time intervals to guarantee the solution optimality. Next, an efficient technique for finding the optimal solution via the Interior-Point Method (IPM) based linear programming is described. Test cases, which include dispatching fourteen units over 10 time intervals on the test system with line flows, spinning reserve and ramp constraints are presented. Results indicate that as problem size increases the computational effort as measured by execution time increases dramatically if the optimal look-ahead time interval is not used.