Research On Active Distribution Network Fault Recovery Method In Extreme Weather

With the development of science and technology,users' dependence on electrical energy is constantly increasing.As an efficient and fast power transmission channel,the distribution network fault recovery method is an important guarantee to ensure its rapid recovery after failure.With the increasing penetration rate of distributed power supply,the participation of demand side load and the operation mode of distribution network More flexible and changeable,the traditional method of fault recovery is no longer applicable,especially in bad weather,the distribution network may suffer severe damage,resulting in large-area,long-term blackouts.How to use the existing flexible resources to achieve rapid recovery of the distribution network and improve the toughness response of the distribution network has become a new direction of research.The main work done in this paper is as follows:First,the basics of graphs and trees are introduced and the structure of the distribution network is simplified.On this basis,the power flow calculation of the distribution network is analyzed,and the method of linearizing the nonlinear power flow is proposed.The basic model and solution method of Mixed Integer Linear Program(MILP)for distribution network fault recovery are introduced,which lays a foundation for subsequent research.Then,for the large-scale power outage accidents caused by bad weather,the recovery time is longer,and the light intensity,wind speed and load demand will change with time.In order to ensure the sustained recovery of the load during the fault,the photovoltaic will be continuously supplied.The combination of fan and energy storage systems(ESS)uses ESS charging and discharging to ensure that the distributed power output matches the load demand,and establishes a mixed-inline linear programming model for the distribution network with the goal of restoring the maximum economic value of the load..The occurrence time of the distribution network fault is random.Considering the impact of the initial fault time,fault duration,presence or absence of ESS and battery state initial value on the fault recovery of the distribution network,seven kinds of fault scenarios are assumed,and mixed integer linear programming is adopted.The method solves the mathematical model of the distribution network.Finally,Mobile Emergency Generators(MEGs)were introduced in the problem of distribution network fault recovery.Local distributed power sources such as optical storage systems and diesel generators and mobile emergency power sources were used as power generation resources after distribution network failure.Considering the MEGs capacity,distribution network topology,diesel generator fuel reserve and volatility of PV output,factors will have an important impact on distribution network fault recovery,and the scheduling time of MEGs will greatly affect the power loss area.Optimize the MEGs dispatch route and distribution network operation mode to ensure the maximization of economic benefits under various resource constraints.A two-stage collaborative optimization method for MEGs scheduling and distribution network regulation is proposed to formulate mixed integer linearity.The planning model uses IEEE69 node examples to verify the effectiveness of the proposed method.