Multi-objective generation dispatch considering the trade-off between economy and security

This study presents a multi-objective generation dispatch model based on security-constrained optimal power flow, in order to handle the contradictory economic and security objectives. In addition to the deterministic N-1 security criterion, a risk index is proposed to quantify the system security degree on a probabilistic basis. The risk index is defined as the summation of the products of the contingency probability and the associated severity function. Moreover, the cost of interruptible load is added into the generation cost, formulating the economic objective. In the meantime, wind power outputs and load variations are considered as uncertainties in the dispatch process. Furthermore, a multi-objective evolutionary algorithm is employed and developed to provide a set of trade-off solutions. The proposed approach is verified by the 4-bus and IEEE 24-bus systems. Numerical results show that the proposed approach can effectively investigate the impacts of demand response on system economy and security. The obtained Pareto optimal solutions are less likely to incur insecurity risk and are robust to the studied stochastic variations.