High-penetration distributed generations(DGs)connected into the distribution network leads to fluctuation and uncertainty in distribution network. In order to improve the capability of uncertainty treatment of distribution network
the flexibility enhancement of distribution network with high-penetration DG is studied. Firstly
the flexibility demand of distribution network with high DG penetration is explored. Then
five distribution network flexibility evaluation indexes are proposed
which include line capacity margin
transformer capacity margin upward
transformer capacity margin downward
net load fluctuation rate and maximum allowable net load fluctuation rate. The indexes represent the flexibility adequacy of distribution network capacity and the flexibility adaption of the embedded distributed generations
respectively. A multi-objective optimal scheduling model is established to improve the flexibility considering interruptible loads and energy storage. Simulation results show that the flexibility of the distribution network with high-penetration DGs can be improved by optimizing the scheduling of the flexible resources
and the hosting capability of distribution network for DG accommodation can increase.