A Flexibility Planning Methodfor Hybrid AC / DC Distribution Network

With the increasing penetration of variable renewable generation in power systems., planning for the effects of variability will become more important. This paper analyzed the flexibility metric that reflects the flexibility variability in its time series and the flexibility of a system to manage periods of variability. The time series of system flexibility demand and supply scenarios are established based on the proposed flexibility metric. The timing characteristics of flexibility requirements and flexibility resources are integrated into the traditional coordinated DG and network planning through a bi-level planning model. The upper-level model is a multi-objective model aimed at maximizing the balance between the system flexibility demand and supply., and the social and economic benefits. The optimal scheduling strategies for various flexibility resources can be achieved by the multiobjective particle swarm optimization algorithm based on meshing. The lower model optimizes the location of DG and demand side loads., and the line expansion decision according to previously constructed flexibility requirement scenarios and flexibility resource deployment strategies. Through this new bilevel planning method., available flexibility providers from the resources., network., loads and storage are considering into the planning of distribution system.