Distributed Optimal Power Flow Calculation Using Synchronous Alternating Direction Method Of Multipliers Under The Background Of Modern Energy System

Along with the power system making transition to the third generation of power grid and the gradually establishing of the modern energy system,the scale of AC/DC interconnected power grid is growing bigger,the connection between regional grid is getting closer and the proportion of clean energy power generation is rising steadily.For large-scale AC/DC interconnected power system with multiple dispatching centers,as well as power-gas interconnected integrated energy system with multiple decision centers,the distributed solution to optimal power flow calculation is more in line with the information privacy and security requirements.Therefore,the study of distributed optimal power flow calculation using synchronous alternating direction method of multipliers under the background of modern energy system is of engineering significance and application value.This paper carries on the thorough discussion and study on the improvement of synchronous alternating direction method of multipliers,the algorithm applying to solving large-scale AC/DC interconnected power grid distributed optimal power flow and power-gas interconnection integrated energy system distributed optimal energy flow.Specific as follows:Firstly,in order to solve the centralized optimization algorithm in information security and privacy issues during the process of calculation,based on the frame of Gauss Seidel alternating direction method of multipliers,we use the weighted average value of boundary variables of adjacent regions obtained from current iteration as the reference values of both regions for the next iteration which realizes the parallel computation among different regions,obtaining a completely parallel iterative algorithm named synchronous alternating direction method of multipliers with boundary variables only exchanging between adjacent regions and no form of central controllers.Boundary overlap method is adopted for regional power grid partition,ensuring the linear characteristic of coupling constraints.And we take a provincial power grid as test example to verify the algorithm of computing performance.Secondly,for the AC/DC interconnected power grid distributed optimal power flow model,we use boundary overlap method and introduce boundary consistency constraints.With regard to network partitioning for DC tie-lines,convertor stations are maintained in their own regions and only the DC transmission lines are duplicated.According to the characteristics of optimal problems,value for the parameters in the algorithm are rationally determined,and the convergence speed is accelerated.And we take an actual large-scale AC/DC interconnected power grid and two modified IEEE AC/DC power grids as test examples to verify the correctness of the proposed algorithm and the validity of parameter selection method.Thirdly,by adopting node tearing method for network partition,we establish power-gas interconnected integrated energy system distributed optimal energy flow model with gas generator as coupling carrier whose input/output characteristic equation as coupling constraint,fully considering the structure and operation state of gas system.And we take a power-gas interconnected system as test example to validate the correctness of the proposed algorithm on solving distributed optimal energy flow problem.