To adapt to raising the penetration of renewables

meeting the demands of heavy load feeder balancing and system operation loss reduction

a multi-port-coordinated optimization control method for flexible multi-state switch is proposed in this paper. The algorithm consists of two layers: reference optimization and slope optimization. In the reference optimization layer

based on the long-term forecast data of sources and loads

the operation reference points are optimized after taking the load balancing constraints of AC feeders

power exchange direction and loss contraints

power flow constraints and other safety constraints into consideration and aiming at minimizing the total operation cost. In the slope optimization layer

according to the power exchange direction and operation reference points from the reference optimization layer

based on the short-term sources and loads forecast data in the dispatch interval

droop control slopes are optimized with the aim of minimizing the total operation cost

In this optimization model

the droop control schemes of active and reactive power

active and reactive power coupling constraints are considered. The simulation results show that the method proposed in this paper can be adopted to effectively reduce the system operation loss

and optimally share power resources among different feeders. In addition

the Monte Carlo simulation shows that the proposed method holds the capability to adapt to power fluctuation of intermittent renewables and loads

which can effectively reduce the risk of system insecurity.