柔性互联输配一体化电网有损潮流的精细化建模及应用OA北大核心CSTPCD

Lossy power flow model is an extension of the lossless linear power flow(LPF)model and has become one of the mainstream methods for approximation calculation and analysis in power systems.Mathematically,it is defined as a fixed-point iterative problem formulated jointly by the lossless LPF model and the network losses compensation model.Currently,existing network losses compensation models are only oriented to single-region,single-voltage level,and single-type of power grids,and mainly focuses on AC transmission grids.However,the operation modes of the integrated transmission and distribution grid with multi-terminal flexible interconnected are complex,and the network losses characteristics vary significantly.Obviously,existing models would weaken the applicability and effectiveness of the lossy power flow in the integrated transmission and distribution grids,also lead to further deterioration of the mismatch of the transmission and distribution boundary power flow.The reason is that conventional network losses compensation models cannot consider the significant differences of losses characteristics caused by the complexity of grids,which makes it difficult to accurately quantify the impact of the losses on power flow errors at different levels and types of grids.For this reason,a precise lossy power flow model based on two-layer fixed-point iteration is proposed in this paper. For the problem of inaccurate network losses compensation,this paper fully considers the characteristics of network structure,data attributes and physical features,and proposes precise lossy power flow models for transmission,distribution,AC and DC grids.First,the lossless LPF model is formulated for AC and DC grids.Second,differentiated network losses compensation models are proposed to modify the node power injection according to the characteristics of AC,DC,transmission,and distribution grids.Finally,the modified node power injections are re-substituted into the lossless LPF model and solved iteratively until convergence. For the mismatch problem of transmission-distribution boundary power flow,the integrated transmission and distribution lossy power flow is formulated as a two-layer fixed-point iterative problem.Among them,the outer fixed-point is the transmission-distribution boundary node,which is used to solve the mismatch problem of power flow between transmission and distribution grids,and the master-slave splitting method is used to solve the problem collaboratively.For the transmission grid power flow calculation,the distribution network is equated to the load,and the boundary node voltage information is solved.For the distribution network power flow calculation,the transmission grid is equated to the source,and the voltage information of the boundary node is utilized as the operating point for the slack node of the distribution network to solve the boundary node power injection.The inner fixed-point is node voltage information in the network to solve the AC/DC lossy power flow based on the proposed network losses compensation model. The errors and reasons for different lossy power flow models are analyzed in several test cases,and compared in terms of solution accuracy,convergence speed and computational efficiency.The results show that the proposed precise lossy power flow model achieves higher computational accuracy under both deterministic and uncertainty scenarios.In addition,the proposed model is overall better than the existing model in terms of convergence performance and has lower computational complexity.Finally,for different control strategies and optimization objectives,the optimization errors of the proposed model are smaller than those of the conventional models,implying that the proposed model can provide operators with more reasonable economic scheduling decisions.