Research On Operation Optimization Of AC/DC Hybrid Distribution System With Distributed Generation

In recent years,with the rapid development of economy,energy consumption of China continues to increase dramatically.Distributed energy resources play an indispensable role in the modern power system which bring economic benefits with a promoting effect on the improvement of the environmental problems.At the same time,the traditional distribution network structure and way of distribution have become increasingly unable to meet the rapid development of economy which put forward many new requirements for the power system.It is a hotspot to modify the current power system structure and construct the AC/DC hybrid distribution network which can meet the energy demand of the future society.This paper mainly studies the operation optimization of the AC/DC hybrid distribution network.The dynamic scene analysis is used to deal with the uncertainty of distributed energy output,traditional load and flexible load.The alternate iteration method is adopted to run the AC/DC didtribution network power flow.Use particle swarm optimization algorithm to do research on the operation optimization of the AC/DC hybrid distribution network with the coordination of active power and reactive power.Firstly,it is necessary to make the forecast of wind power and load.Use the Latin hypercube sampling technology to deal with the forcast error sampling and use the K-means method to handle with the dynamic scene cuts.It is also necessary to analyze the characteristics of electric vehicles' charging and discharging.After these steps,combine the forcast error with the forcast value of wind power and load to create dynamic scenes.Considering time series,create the continuous time series dynamic scenes.Secondly,research on the construction of the AC/DC hybrid distribution network with distributed energy resources and electric vehicle charging stations intergration.Create the power flow model of distributed energy resources,VSC,DC-DC converter and so on.Use alternate iteration method to study the power flow calculation of the AC/DC hybrid distribution network with VSC.The improved IEEE33 node distribution network model is adopted to analyze the power flow adding with the distributed energy resources,VSC and six DC nodes.Considering the uncertainty of wind power output,load with electric vehicles,calculate the power flow on dynamic scenes.The results verify the effectiveness of AC/DC hybrid distribution network power flow calculation method.Finally,research on the operation optimization of the AC/DC hybrid distribution network with distributed energy resources intergration.Create a reactive power optimization model with an objective of minimum operation cost.The constraints is considered separately in AC distribution network and DC distribution network.Use second-order cone relaxation technology to convert the original reactive power optimization model to a convex feasible region form of mathematical programming.Use particle swarm optimization(PSO)algorithm to optimize the DG output,flexible load,reactive power capacitor compensation.Then develop a single moment into the continuous time sequence reactive power optimization.Form a set of scheme which is adapted to the continuous time sequence distribution network operation and make decesions and suggestions on the dispatching operation of the AC/DC hybrid distribution network with distributed energy resources intergration.