Research On Reactive Power Optimization Of Regional Distribution Network With Microgrid

Intermittent new energy such as wind power and solar energy are accessed to distribution network.The one-way power flow in the distribution network is uncertain,which is not applicable the original power flow calculation method,reduce the accuracy of reactive power planning,and affect the safe-stable operation of the whole distribution network.So the further study of reactive power planning and real-time reactive power optimization has a great significance for improving the distribution network's ability to accept new energy and ensuring the safe-stable operation of distribution network.In this paper,the main research contents and results are as follows:(1)Analyze the reactive power load of distribution network,and compare the existing source of reactive power compensation from the control,response,time delay,inrush phenomenon,overvoltage,power quality,loss,investment and so on.Select widely used capacitor group and on-load voltage regulating transformer as a typical representative of reactive power voltage regulator of distribution network.(2)According to micro grid structure and control strategy,analyze the effect of micro grid interconnected to distribution network.From the characteristics of micro grid "source-net-load-storage",PCC can be seen as PQ node which has been given active power and reactive power.Establish reactive power regulation mode participating in regional distribution network and determine orienting the branches forward-backward sweep method for power flow calculation.(3)In terms of reactive power planning,determine reactive power compensation capacity of transformer substation on the basis of short-term load forecasting.The reactive power compensation capacity of substation is configured by equal-capacity group.Eventually use an example of Yu He substation to prove the feasibility.(4)From the aspects of coding,genetic operation and so on to improve the standard genetic algorithm,in order to overcome the shortcoming of standard genetic algorithm and increase the speed of searching optimization,convergence and fitness.Finally,combine the micro grid accessed to distribution network,use MATLAB to simulate and comparative analysis.The results show that the improved genetic algorithm can increase the searching speed and fitness.(5)Use the auction principles and multiple Agent to build the reactive power comprehensive evaluation model which contains distribution network loss,equipment status,power quality.Finally take an example that the micro grid is accessed to region distribution network,and use JADE framework for simulation to verify the feasibility of auction strategy.The results show that it can meet the requirements of power quality,and increase the interaction between devices to reduce the frequent action of equipment.