| With the increasingly prominent energy crisis and environmental pollution problems,the increasing proportion of installed capacity and power generation of distributed generation also brings great challenges to how to ensure the power quality of distribution network and improve the reliability of power supply.In addition,under the impact of extreme weather events,the traditional fault recovery strategy of the distribution network has been unable to meet the requirements of rapid recovery of power supply,and the frequent occurrence of such events has led to long-term and large-scale blackouts in the distribution network,highlighting the vulnerability of the distribution network structure and the new distribution system with higher demand elasticity.Therefore,this paper studies the two-stage optimal configuration model of distributed generation location and capacity considering fault recovery,which provides a reference for distributed generation expansion planning.The fault recovery control strategy of distribution network considering wind and solar access and the robust recovery considering source-load uncertainty are discussed,which provides theoretical support for the construction of elastic distribution network.The main research contents are as follows:(1)A two-stage distributed generation location and capacity optimization model considering fault recovery is proposed.Firstly,the first stage combines loss sensitivity,voltage stability index and system operation related knowledge,and proposes two acceleration strategies with candidate grid-connected nodes as the goal.After obtaining the grid-connected position,the DGs capacity is adjusted with active loss,voltage deviation index and voltage stability index as the optimization goals.In the second stage,a fault recovery optimization model is established to maximize the complex power as the objective function and meet the constraints of safe and stable operation of the distribution network.Then the two-stage model is transformed into a mixed integer second-order cone programming model by second-order cone convex relaxation technique.Finally,the effectiveness and superiority of the proposed model are verified in the PG&E69 node system.(2)A multi-period power supply restoration strategy considering the coordination of different types of DGs,microgrid integration constraints and load control constraints is proposed.Firstly,an improved single commodity flow model is constructed to constrain the number of microgrids and solve the topology problem of microgrid integration.On this basis,the damage degree of extreme events is described.and a multi-period power supply restoration optimization model is established with the objective function of minimizing weighted load shedding and the constraint condition of safe operation of distribution network.Then,according to the cone relaxation and Big-M method,the power supply recovery model is further transformed into a mixed integer second-order cone programming problem,and the model is efficiently solved by the commercial solver Gurobi.Finally,the effectiveness and superiority of the proposed model are verified in the improved IEEE-33 node system.(3)A three-layer affine adjustable robust fault recovery optimization model considering source-load dependent uncertainty is proposed.Firstly,the relevant polyhedral uncertainty set is introduced to describe the uncertainty of wind turbine output and load demand,and a three-layer robust fault recovery optimization model is established to meet the constraints of safe and stable operation of distribution network with the objective of minimizing the load shedding.Then,the two-layer Max-Min problem is transformed into a single-layer Max problem by strong duality theory and KKT condition,and then the nested column constraint generation algorithm is used to solve the model to obtain a robust solution.Finally,the feasibility of the proposed model is verified in the improved IEEE-33 node system. |
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