Wind Power Consumption Considering Optimal Transmission Switching And Static Safety Constraints

With the increasingly serious problem of the shortage of fossil energy and environmental pollution,large-scale and high-proportion utilization of wind power has attracted more and more attention.Large capacity wind farms usually transmit wind energy to users through transmission network,so the grid structure of transmission network has an important impact on the large-scale and high proportion utilization of wind power.Optimal transmission switching is to optimize the network topology by adjusting the operation state of transmission lines.The wind speed of multiple wind farms is correlated when large-scale wind power is absorbed.Although the absorption capacity of wind power can be improved by optimal transmission switching,it may pose a potential threat to the security of power system.Therefore,it is of great practical significance to study the wind power consumption of the transmission network method considering the optimal transmission switching,wind speed correlation and static safety constraints.The main contents of this paper are as follows:(1)In view of the lack of considering both wind speed correlation and static voltage stability in the existing wind power consumption of the transmission network methods considering optimal transmission switching,the wind power consumption method considering optimal transmission switching,wind speed correlation and static voltage stability power margin are studied in this paper.Based on the nataf inverse transform and k-means clustering,the related scene considering the wind speed correlation is constructed.A wind power consumption optimization model considering optimal transmission switching,wind speed correlation and power margin is proposed,in which the power margin index constraint can take into account the influence of static voltage stability.The power margin estimator based on neural network is introduced to estimate the power margin index to improve the computational efficiency of the genetic algorithm for solving the model.The simulation results of the improved IEEE 39 bus system show that it is necessary to consider the influence of wind speed correlation and static voltage stability in the method onsidering the optimal transmission switching to enhance the wind power absorption capacity of the power system.(2)In order to solve the problem that the existing wind power consumption of the transmission network methods considering optimal transmission switching do not check the security constraints of n-1 line during the optimization process,a wind power consumption stochastic optimization model considering transmission switching and n-1line security constraints is builded.Latin hypercube sampling and k-means clustering are used to construct multi scenes to consider the random fluctuation of wind speed.Since the optimization problem considering tie line switching and n-1 line security constraints is complex,it is decomposed into two sub problems to construct the model respectively.Based on the relaxed branch AC power flow,a wind power consumption model considering the optimal transmission switching and a load shedding model considering the safety constraints of n-1 line are established.After these two models are transformed into the mixed integer convex second-order cone model respectively,based on the mature commercial software,the algorithms for solving the second-order cone model of wind power consumption considering line switching and the second-order cone model of load shedding considering n-1 line safety constraints are constructed.Thus,the purpose of solving the original optimization problem indirectly is achieved.The simulation results of the improved IEEE-RTS 24 node system show that it is necessary to consider the n-1 line security constraints in the method considering the optimal transmission switching to improve the wind power absorption capacity of the system.The connection of shunt capacitor reactive power compensation is beneficial to improve the wind power received by the system.Based on convex second-order cone model and alternating algorithm,the computational efficiency of the method solving the established model can be improved.