Optimal power flow by considering system security cost and small signal stability constraints

Authors: MOHAMMAD SARVI, MOHAMMAD REZA SALIMIAN

Abstract: The main objective of optimal power flow is to find the proper operating point for the power system. In this paper, the optimal power flow by considering system security cost (OPFSC) and the small signal stability constraint is presented. For this purpose, the total profit of the system by considering the system constraints is optimized. The total profit of the system is equal to the combination of profit from the active power consumption, active power generation cost, and system security cost. System security cost includes the cost of load shedding, which is computed for all contingencies that may occur in the system. One of the system constraints is the small signal stability constraint. The small signal stability constraint causes increasing of the small signal stability margin of the system. In this paper, a hybrid genetic algorithm and PSO (HGAPSO)-based method for performing OPFSC is presented. The proposed method is then tested on the WSCC 9-bus system. The results of the proposed method are compared with the primal-dual interior point (PDIP) method. The total profit of the system obtained from HGAPSO is better than the results of PDIP and system constraints are not completely satisfied in the results obtained from PDIP.

Keywords: Optimal power flow, small signal stability, power system security, hybrid genetic algorithm, particle swarm optimization

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