Adaptive Operation Optimization Method For Distribution Network With Three-Terminal SOP

With the aggravation of environmental pollution and the depletion of fossil energy,the development of renewable energy has received extensive attention.Large scale deployment of renewable distributed generation(DG)is generally seen as the most promising option for displacing fossil fuel generators,but the uncertainty and fluctuation of its output cause many problems to the distribution network.The traditional regulating equipment mainly consists of contact switch,capacitor bank and transformer tap-changer is difficult to deal with these problems.Soft Open Point(SOP)is a power electronic device which can solve those problems by adjusting reactive power compensation and active power transmission.This paper focuses on the operation optimization of distribution network with three-terminal SOP.In order to balance the safety and economy in power flow optimization better,a self-adaptive operation optimization method for active distribution network with multi-terminal SOP considering difference of the risk of node voltage beyond limit is put forward.Firstly,six common two-terminal SOP topologies are introduced.Then,based on back-to-back voltage source converters(B2B VSCs),the transmission loss model of three-terminal SOP equipment is established.Then,the distribution network operation optimization model is constructed,which takes both weighted voltage deviation and the network loss into objective function to construct the optimal operation model and mainly has two improvements:one is taking initial voltage deviation and penetration of the DG into consideration to build the self-adaptive weight model of the sum of voltage deviation;the other is putting forward the weighting strategy for node voltage deviation which decided by the electrical distance,DG position and correlation between source output and load.After that,three improved IEEE33 node feeders are used to verify the validity of the strategy.The results confirm that the self-adaptive strategy can reduce the loss and improve the regulation of voltage better and is useful in distribution network under different penetration.