Calculation And Optimization Of Power Loss Of The Area-interconnected Power Grid

To achieve the optimization and rational allocation of electric power resources in different regions,China has already developed a large-scale regional interconnected transmission power grid structure of “transmitting electric power from the East to West and South to North”.In recent years,with the reform of the electric market,the transmission line loss is the inevitable cost of power transmission for power grid enterprises,which greatly affects the profit of the enterprise.The loss of the power grid has become an important task that the power company pays attention to and contributes to.Therefore,the regional connected power grid with AC-DC hybrid structure is taken as the research object in this thesis,and this research focuses on the calculation and optimization of power loss.The main work of this thesis is as follows:First of all,a loss optimization model for regional connected power grid is proposed.With reference to the domestic and international power industry standards,the components in the regional connected power grid are analyzed and the accurate loss calculation model of each component is established in this thesis.Then,the line loss calculation model of regional connected power grid based on power flow calculation is proposed on the basis of considering the converter station model.Moreover,with the adjustable parameters of reactive power output,the control angle of the converter station and the commutation change ratio,loss optimization model for regional connected power grid is established.Secondly,a line loss optimization model based on transaction power is established.Considering the power transaction between regions in large-scale regional connected transmission network,the power exchange plan of the inter-provincial connected sections is introduced to the optimization calculation of power,thus,a line loss optimization model based on transaction power is established.Furthermore,two practically treatments of line loss optimization model based on transaction power are proposed: 1)static equivalence of the transmission network to simplify the solution model;The stepped processing of the DC power in the optimization calculation results is applied to the actual scheduling requirements.Thirdly,an improved hybrid Artificial Bee Colony algorithm is proposed in order to calculate the line loss optimization model of cross-reginal power grid.The Shuffled Frog Leading Algorithm and Genetic Algorithm are introduced to improve the calculation efficiency of traditional artificial bee colony algorithm.This improved hybrid artificial bee colony algorithm combines the advantages of worst individual replacement strategy ofshuffled frog leading algorithm and the crossover process between individuals of genetic algorithm,so that the worst honey source in ABC algorithm realizes the process of learning and evolution and bee colony can be guided to search in dominant direction,which greatly promote the efficiency of ABC algorithm and solve the problem of slow convergence in the iterative calculation of the cross-region large ride loss optimization model.The effectiveness of the improved ABC algorithm is verified by numerical simulation.MATLAB simulation programs was written to simulate and analyze the proposed method of loss optimization calculation to several power systems.The optimization results show that the proposed loss optimization model of regional connected power grid enjoy higher economical efficiency than operation mode of the grid before optimization.And the improved ABC algorithm proposed in this thesis has faster convergence speed than the traditional ABC algorithm.This thesis provides an practical and effective tool for calculating and optimizing the loss of large-scale regional interconnected transmission power grid.