Research On Reactive Power Planning Optimization Of Distribution Network With Distributed Generation Based On Scenario Analysis

In order to alleviate the current situation of energy shortage and environmental degradation,a large proportion of renewable energy is connected to the distribution network,but this also changes the distribution structure of single generation and radial power flow in the original distribution network system,bringing new challenges to the planning,operation and control of the power grid.So that the original reactive power optimization measures are no longer effective,it is necessary to further study the reactive power optimization with distributed generation.The research idea of this paper is to establish static reactive power planning and dynamic reactive power optimization models taking into account distributed generation(DG)output fluctuation and random characteristics,and solve the model through modern intelligent algorithms.Firstly,the scenario analysis method is used as an effective method to solve the random output characteristics of distributed generation.Through a series of technical means such as Latin Hypercube Sampling to generate the output scene,scene reduction and elimination of redundant scenes,a probability model of grid-connected scene considering the random output of distributed generation is established.The improved forward/backward sweep power flow algorithm is selected as the basic calculation method of reactive power optimization in this paper.Then,a reactive power planning model is established on the basis of determining the random output of the generation,and the sensitivity analysis method is improved to find the best reactive power compensation point.The objective function is the reactive power compensation device,the annual payment of network loss,and the total deviation of node voltage.The results show that the candidate compensation points are arranged reasonably and the solution set of Pareto is uniformly distributed,so the net benefit of the selected reactive power planning scheme is the largest,and the feasibility of the model and algorithm is also verified.Finally,one day as scheduling period,considering the load fluctuation and DG output change,make full use of the energy storage device,flexible load and reactive power compensation equipment such as controllable resources coordinated optimization.At the same time,the daily switching times of reactive power compensation equipment are considered and the active power loss is minimized,to establish the generation-load-storage coordination of dynamic reactive power optimization model.Considering that the coordinated operation of energy storage as well as discrete and continuous control variables exist in the optimization process,a multi-stage optimization strategy is formulated.The elite reserved genetic algorithm with tabu strategy was adopted to solve the model,and the improved IEEE 33 node system was taken as an example to conduct simulation on DG reactive power output scheduling,reactive power control device constraint,and energy storage coordination optimization,to verify the effectiveness of the optimization strategy in this paper.