A study on outage planning for electric power facilities by using GAs

This paper presents a formulation of outage planning for electric power facilities treated as a combinatorial optimization problem considering power supply reliability. We utilize two indices to evaluate a security level of system configurations during outage works. The indices are defined as power supply shortage assuming N-2 contingencies and transmission loss assuming N-1 contingencies. A lot of constraints are also introduced to this problem with respect to the allocation of outage works and the determination of system configurations. Since it is expected that solving the problem is so hard due to combinatorial explosions, we apply a genetic algorithm to obtain feasible solutions. Simulation is executed to the real test system which is a part of the 110 kV transmission system belonging to Chugoku Electric Power Company (CEPCO). It seems that some results show good solutions from the viewpoint of reliability indices. However, it is not clear how far these solutions are close to the optimal ones. In order to confirm the quality of solutions, we develop a program for searching all outage work combinations on the PC cluster constructed with 5 computers. As a result, the solutions by GA show us midway between the optimum and the worst.