Research On Improving Active Distribution Network's Ability Of Accepting Distributed Generation

In recent decades,coal,oil,natural gas and other fossil energy is largely mining and consuming,which has led to increasingly serious energy and environmental problems.In this context,Distributed Generation(DG),as an important part of clean energy,has attracted wide attention in various countries.So that the penetration of DG gradually increase in the distribution network,especially renewable DG such as wind energy,photovoltaics and so on.With a large number of DG access to the distribution network,active distribution network has been developing at a high speed.The greater proportion of DG,the more advantages of DG.Through actively control and manage DG can increase distribution network's ability of accepting DG.However,when too much DG merge into ADN,the control and management of the DG becomes difficult due to the intermittent nature of the DG.Therefore,ADN can accept DG's capacity is limited.After reading a large number of relevant literature at home and abroad,this paper aim at researching how to improve ADN's ability of accepting DG.The main works are as follows:(1)The distribution network reconfiguration method is proposed to improve distribution network's ability of accepting DG.The condition of DG access to the distribution network is optimized by static reconfiguration method.Therefore,the distribution network's ability of accepting DG is improved.The genetic algorithm is used as the optimization algorithm,and case studies on the IEEE33 node system.The result shows static reconfiguration can obviously improve the distribution network's ability of accepting DG.Two different types of DG(wind and photovoltaics)are considered in a one-day cycle.Based on the characteristics of two kinds of DG in different time periods,and the dynamic reconfiguration model is put forward.Case studies on IEEE33 node system show that the dynamic reconfiguration is more efficient than the static reconfiguration in improving the distribution network's ability of accepting DG.(2)Applying DG optimal configuration improve distribution network's ability of accepting DG.PSO algorithm may fall into the local optimal solution in the optimization process.In order to overcome the shortcoming of PSO,hybrid particle swarm optimization is used as an optimization algorithm.The genetic algorithms are introduced into PSO to improve the efficiency of optimization.Case studies on IEEE33 node system show that DG optimal configuration can significantly improve the distribution network's ability of accepting DG.(3)A inner and outer bi-level stratege is proposed for improving the ability of accepting DG.The condition of DG access to the distribution network is optimized by reconfiguration and site selection.For the inner layer,genetic algorithm is used to optimization algorithm for dynamic reconfiguration.For the outer layer,PSO algorithm is used to optimization algorithm to determine the location of DG.Case studies on IEEE33 node system show that the bi-level optimization strategy is more efficient than reconfiguration or site selection in improving the distribution network's ability of accepting DG.