Research On Voltage Stability Constrained Optimal Power Flow Under Electricity Markets Context

Market rules dominate the electricity trading in electricity markets. Decision-making combines the economy, stability and security is an important research field for power system planning and operation. The accelerating pace of electricity market reform in China make it a challenge to develop the power system. Taking the electricity trading as study investigated, this thesis proposes a modified strategy to enhance the voltage stability and system security. Specific results are as follows:In order to reduce variances between trading decision and system actual operation, an optimal power flow model contains FACTS devices was proposed. Given the context of contingencies includes N-1security criterion, this paper used a static model to evaluate the voltage stability by calculating load margin. Also, a contingency filtering procedure to select the contingencies faced the shortage of voltage stability and security was proposed.On the basis of analyzing the economic costs in decision-making, the paper put forward a voltage stability constrained optimal power flow model with FACTS devices to ameliorate voltage stability and security. It consists both re-dispatching in reserve market and adjusting FACTS devices. This make it possible to achieve correction on economic operation point with minimal economic cost, and provided system operator corrective control actions. In order to improve the computational efficiency of the optimization model, and to solve the inapplicability in large scale system, the paper provided a voltage stability constrained post-contingency operating model. By breaking down the large calculations into many smaller ones, the solution procedure can be replaced by corrections and calibrations. Moreover, the simultaneous solution of multi state can be avoided with the help of contingency ranking. The interior point method was applied to solve the optimization models, can supply the more rapid convergence.