Optimal Voltage Control Of Active Distribution Network Considering Reactive Power Ability Of DER

With the rapid development of new energy technologies, the penetration of Distributed Energy Resources (DER) in the distribution network is improving. However, the basic characteristic of volatility and intermittent of DER, has brought difficalties to stable operation of distribution networks,especially fluctuation problems of voltage. For this reason, the technology of Active distribution network(ADN) getting rapid development with active management and control functions. DER at the beginning of the design has been equipped with corresponding reactive power devices, but at present, DER usually run with unit power factor and has no reactive power exchange with the power grid, partly causing waste of reactive power resources. Therefore, the reaserch of optimization of voltage control capacity is meaningful for lager scale of DER connecting into the grid.First, this paper studies the inflluence of DER to power quality,and scheduling for DER and distribution network voltage regulating device and control mode are also studied. Later, the reactive power control mode and control strategies of ADN are studied and the comprehensive comparison of different voltage control methods are carried on considering different factors.Secondly, the nonlinear reactive power optimization model of multi-objective function is established considering the optimal network loss, smallest average voltage offsetsa and other security factors of the power grid. the model is on the basis of voltage centralized control framework, and give full consideration to DER reactive power adjustment ability.Finally, IEEE33 nodes is selected to verify this model analysis,with the aid of simulation platform built in Matpower of Matlab. Aiming to solve the model,the original dual interior point is used in this paper, and the results show that the optimization effect of DER to voltage fluctuation is more obvious when running in variable power factor than in constant power factor,and in return,the ability of distribution network to accept more DER is also greatly promoted.