Research On Optimal Planning Of Unified Power Flow Controller Applied To Active Distribution Network

As an effective supplement to centralized power generation,distributed generation has developed rapidly in the context of energy transformation with its advantages of low pollution and high energy efficiency.However,the fluctuation of distributed generation output increases the uncertainty of distribution network operation,which brings many challenges to the safety and regulation technology of active distribution network.With the improvement of users’ requirements for power supply quality and reliability,power electronic technology has been gradually applied to the regulation of active distribution network.Unified power flow controller is a new type of power electronic compensation device,which faces applicability challenges when applied in active distribution network.Therefore,this paper studies the planning optimization of unified power flow controller in active distribution network.The main research work is as follows:(1)Aiming at the application of unified power flow controller in active distribution network,an optimal configuration method of unified power flow controller is proposed considering the uncertainty of multi-type distributed generation and load operation.Firstly,the multi-scenario analysis method is used to deal with the uncertainty of distributed generation output and load.Secondly,the multi-objective programming model of unified power flow controller is constructed from the aspects of voltage deviation and network loss,and the NSGA-Ⅱ algorithm is used to solve the model.The comparative analysis shows that the proposed optimal allocation model of unified power flow controller can effectively overcome the randomness and volatility of distributed generation power and load,and the optimization scheme shows that the proposed planning model can effectively improve the power quality and economy of active distribution network.(2)Considering that there is a certain correlation between the distributed generation and load in active distribution network that are geographically close to each other,a multi-objective planning method of unified power flow controller considering the correlation between source and load is proposed.Based on the random distribution characteristics of uncertain variables(wind speed,light intensity and load),the correlation between variables is considered,Latin hypercube sampling and Cholesky decomposition are used to quantify the correlation of random variables.The optimization model is established and solved by NSGA-II algorithm.The proposed method is applied to different scale node systems,and the unified power flow controller planning schemes under different correlation intensities are quantitatively analyzed.The solution results can provide multiple sets of unified power flow controller planning schemes for decision-making,and the obtained configuration schemes can achieve better optimization results.