Optimization Of DC Distribution Network Operation Mode

As one of the technical forms in the future distribution network,DC distribution network has its theoretical knowledge and practical application in the preliminary research stage.DC distribution network is considered as the main carrier of distributed generation.Because of the strong fluctuation of distributed generation,it is of great significance to study its impact on the operation of distribution network When suffering from external interference of various types of power supply,it is necessary to strengthen some control over power supply and load,which reflects the performance advantages of DC distribution network.In order to solve the above problems,this thesis combines the characteristics of DC distribution network topology,component control strategy and power flow calculation,and constructs the operation optimization model of DC distribution network.This thesis is carried out through the following contents:(1)This thesis introduces the main mathematical model and control analysis principle of DC distribution network.The power flow calculation model,voltage source converter(VSC)model and droop control model of DC distribution network are described in detail.Then,based on these models,the analysis of DC distribution network is carried out.Finally,the general model of optimal operation of DC distribution network is established(2)By adjusting the parameters of the converter,cooperating with the network loss value and voltage difference of the distribution network to represent the operation excellence of the distribution network,the objective function of the minimum distribution network cost is finally constructed.All kinds of new energy and VSC are considered in the optimization model,with tie line power limit,node voltage limit and distributed power capacity as constraints(3)Establish the algorithm of solving the related model.Firstly,according to the characteristics of VSC droop control,the reference value of active power is solved iteratively in the power flow calculation part.In the optimization process,the optimization of the whole process is divided into two modules to solve alternately,in order to achieve the best.First,two different coding forms are used to adjust the droop coefficient and optimize the continuous variable of the initial voltage value Secondly,the adaptive penalty function is used to optimize the distribution cost,so that the search direction is toward the optimal solution direction of the whole search space.According to the characteristics of converter and distributed energy,different schemes are set up to analyze and verify the performance of the proposed model and method.(4)Matlab program is used to verify the practicability and reliability of the optimization model.After the optimization calculation of the algorithm proposed in this thesis,the distribution cost is improved,the voltage can be well maintained within its constraints,and the ability of the distribution network to cope with the fluctuation of the distributed power generation is improved.