Research On Multi-objective Coordination Planning Method For DG Configuration And Distribution Grid

Traditional centralized generation is no longer adaptable to the development of power system due to tight energy supply,serious environmental pollution,and insufficient safety and stability of its own.Developing distributed generation can make full use of renewable energy,improve the energy supply structure,alleviate the energy and environmental crisis and compensate for the lack of centralized power generation.However,with a large number of DG accessing to the distribution network,it brings many challenges to distribution system's planning,operation and control.If DG configuration is unreasonable,it will have a negative impact on node voltage,system power flow,network loss,and power supply reliability.Obviously,the traditional distribution network planning cannot meet the requirements of modern power system since it mostly considers only economic costs.This article studies the collaborative planning method of DG configuration and distribution grids,establish a multi-objective bi-level planning model for distribution networks.Introducing Multi-scene technology and Chance Constrained Programming to deal with uncertainty problems,using Random Sampling Method and Timing Method to simulate DG's intermittent output and load timing power,which could fully consider the impact on distribution system's planning and operation;Focusing on demand respons under the power system reform,taking into account the effect of time-sharing price and incentive mechanism on load demand,establishing the load response model,which could drive users to actively participate in load regulation and smooth the power load curve;Study the impact of DG's access on distribution system's planning and operation,determine the network topology based on improved Krustal algorithm,find the reachability matrix to determine its connectivity,calculate the system power flow after DG's access,utilize Chance Constrained Programming processing the Multi-scene flow results and calculate the power supply reliability when it meets the probabilistic safety restraint;Focusing on the system's safe and reliable operation,directly integrating power supply reliability into planning goals,the upper layer establishes a multi-objective planning model with economy and reliability and satisfies reliability requirements during the planning stage;Focusing on clean and green energy,not only do the upper layers consider the environmental benefits of DG from the investment level,the lower level directly takes the DG's annual minimal removal output as the planning goal and ensures the distribution network's consumption of DG from the simulation operation level.The paper uses multi-objective Particle Swarm Optimization based Pareto dominance to solve the model and obtain the best solution by technique for order preference by similarity to ideal solution.Finally,applying this method to the improve IEEE-33 node system,an A+ class and D class actual distribution areas,comparing the results of other planning methods,It is found that the planning scheme obtained in this article has obvious superiority both in reliability index and economic cost.