Research On Power Supply Restoration Strategy Of Integrated Energy System Considering Uncertaint

Integrated energy systems integrate a variety of heterogeneous energy flows organically and realize the complementary advantages of various energy through the mutual conversion between energy flows,so that when a fault occurs in integrated energy systems,the interactive response between different energy networks can be realized to support and make up for the faulty subsystems.However,the distribution networks in the traditional integrated energy systems is mainly a AC distribution networks,which has a slow response speed and weak tie connections with other distribution networks.In addition,different energy flows have certain time scale differences in energy supply,which is easy to lead to short-time power outage phenomenon when the system is in the face of extreme situations to restore power supply to important users,which seriously affects the operation reliability of the system.Therefore,in order to solve the above problems,the main research contents of this paper are as follows:(1)Soft open point(SOP)is firstly introduced into the integrated energy system constitute a new integrated energy system with a SOP,which combine SOP-based flexible interconnected distribution network(FIDN)with the traditional integrated energy system.Firstly,the main structure and components of the new integrated energy system are introduced,and then the model of the key equipment in the system is established.This system uses the characteristics of SOP’s non-stop power transfer and intelligent power regulation to solve the problems of weak tie connections among distribution networks and short-term power outage under the limitation of AC distribution network,and further guarantees the safe and reliable operation of distribution network.(2)Based on mixed integer second-order cone programming,a fault recovery model of FIDN is established,and the fault recovery capacity of SOP is explored.Firstly,the randomness of wind power,photovoltaic power output and load in FIDN is considered,and the chance constraint is used to limit the node voltage.Then,considering the integrity of flexible closed loop operation in multiple power supply areas,and taking the weighted sum of maximum load recovery and minimum network loss as the objective function,a stochastic optimization model for fault recovery of flexible interconnected distribution network is established.And the fault recovery model is converted into a mixed integer second-order cone programming model to solve the problem efficiently.Finally,a hand-in-hand IEEE33-node system is built for case analysis,which verifies that the access of SOP can effectively solve the fault recovery problem of multiple power supply areas,indicating that SOP can effectively improve the self-healing ability of power distribution systems.(3)Considering the time scale difference of energy flows in energy supply,based on various control modes of SOP,a two-stage power supply recovery strategy for the integrated energy system with a SOP is proposed.Firstly,the two-stage power supply recovery strategy proposed in this paper,which aims to better coordinate and integrate all energy sources under the time scale difference in the integrated energy system,is introduced.Then,based on the flexible interconnected distribution network model,the models of gas network and heat network are established,and a fault recovery model of the integrated energy system with a SOP is constructed,which is converted into mixed integer second-order cone model.Finally,an integrated energy system with a SOP is constructed for case analysis.The results show that the system can coordinate and integrate various energy forms under the two-stage fault recovery strategy,and effectively solve the problem of energy supply shortage during fault recovery.