Multi-period Islanding Partition Method Of Active Distribution Networks Considering The Operation Characteristics Of DG,Energy Storage And Load

The continuous increasing of the distributed generation penetration in active distribution network(AND)has changed the operation mode and controls strategies of the system.Islanding operation of ADN with distributed generators(DG)and energy storage system(ESS)can efficiently improve the reliability of the system under extreme fault conditions.Considering the operation characteristics of DG,ESS and load in distribution network,a multi-period islanding method for ADN is proposed.By introducing soft of open points(SOP)into the island partition model,the level of load recovery can be effectively improved.It is of great significance for the safe and reliable operation of ADN.The main contributions are summarized as follows:1)In the presence of photovoltaic and other intermittent power sources,a time series islanding partition model of ADNs considering the characteristics of DG,ESS and load is established.It takes into account the effect of different types of DGs and ESS as well as the failure time and its duration.In addition to the coordination of ESS and DG,network reconfiguration is further used to adjust the system operation mode and improve the level of load recovery.2)A SOP based islanding partition model considering the characteristics of DG,ESS and load is proposed.The island formed by DG is highly determined by the capacity and location of DG,so the load in ADN can't be fully recovered usually.SOP is a novel power electronic device with powerful real-time power control ability,which can achieve flexible interconnection of different islanded area.Meanwhile,SOP can supply voltage and frequency support of the fault area.The application of SOP in island partition can effectively reduce the range of power loss area and improve power recovery level.3)The proposed islanding partition model belongs to a mixed integer nonlinear programming problem and it is transformed into a second-order cone programming model by convex relaxation technique,which can be solved more efficiently compared with the results of the interior point method.Finally,case studies on IEEE 33-node test feeder verify the correctness and effectiveness of the proposed model.