Research On Distributed Photovoltaic Capacity Absorptive Of Distribution Network Considering Soft Open Point

Promoted by the policy background of carbon neutrality emission peak,the energy structure is gradually transform ed,the technology and scale of distributed photovoltaic(DPV)have developed rapidly,high proportion of DPV will be one of the important features of new power systems.Due to the uncertainty and volatility of DPV,the hosting capacity and absorption of DPV in distributed network are affected by some way.With the increase of the penetration,the inadequacy of absorption capacity of distribution network has attracted extensive attention of scholars.Power electronic devices represented by soft open point(SOP)can replace traditional interconnect switches,flexible interconnection of distribution network is realized,which has a positive impact on improving the local absorption of DPV in distribution network.Aiming at the absorption problem of high-proportion DPV,this paper mainly studies the DPV hosting capacity and consumption strategy of distribution network based on SOP and the DPV,and uses the flexible interconnection characteristics of SOP to improve the DPV hosting capacity of distribution network and the proportion of DPV generation.Meanwhile,the voltage control ability of SOP is fully utilized and cooperated self-reactive support ability of SOP and other equipment of the distribution network,the absorption of DPV is improved in distribution network.The research work is as follows::(1)The mathematical model of SOP applied to distribution network planning and operation is given,the operation characteristics of soft open point with energy storage system(ESOP)is analyzed,and the related model is given.Next,a simple example model is built in Powerfactory simulation software,the influence of SOP on voltage,power flow distribution and reliability of distribution network is analyzed in Powerfactory.(2)For the access problem of high penetration DPV,a DPV access capacity evaluation method of distribution network considering security boundary and SOP coordination is proposed.A DPV and SOP active power-reactive power collaborative planning model is established,aiming at maximizing the DPV access capacity of the distribution network,considering improved safety boundary and active management strategies.The nonlinear part of the model is linearized and the original model is transformed into a mixed integer linear programming model.The case studies are carried out in the 51-nodes rural network to verify the effectiveness and correctness of the proposed method.(3)For the absorption problem of high-penetration DPV,a two-stage optimal scheduling strategy for distribution network based on ESOP is proposed.In the first stage,aiming at minimizing the total operating cost and voltage deviation of distribution network,the adjustment price of reactive power equipment is used to control the execution sequence of each reactive power device,a day-ahead joint optimization model of active and reactive powe r is established.The schedule of discrete reactive power equipment and the charge and discharge range of energy storage are formulated,and sufficient dynamic reactive power is reserved.In second stage,aiming to minimize DPV reduction and voltage deviation,the ability of energy storage and dynamic reactive power to deal with DPV fluctuations is fully utilized,and the DPV reduction in the system is reduced.The case studies are carried out in the improved rural network to verify the effectiveness of the two-stage optimal scheduling strategy.The results show that SOP access to distribution network plays an important role in improving DPV access capacity and DPV absorption.