The Research On Fault Location Technology And Transient Stability Of Distribution Network With Distributed Generation

With the energy crisis being serious gradually and electricity demands increasingdaily, and due to shortages of the existed distribution network, the distributedgeneration(DG) which is a renewable and no pollution energy source has drawn muchattention. Under the request of the smart grid evolution, there will be large amountDG penetrating into the smart distribution network in the future and can be dispatchedand controlled. However, DG is vulnerable to the effects from the environment andweather which leads to highly fluctuation and randomness of DG. Therefore, withlarge amount of DG penetrating into the distribution network, it will bring tremendousnegative impacts on the distribution network and even cause blackouts under severecircumstances. Therefore，it’s necessary to research the fault location technology andtransient stability of the distribution network with distributed generation which isbenefit for formulating the fault isolation scheme of the distribution network and faultcontrol strategy of DG.Three typical types of DG and it’s principle and modes of connecting to the gridwas introduced first, then the impacts to the fault location technology and transientstability of the distribution network were analyzed. And on this basis, the faultlocation technology and transient stability of the distribution network with DG werefurther studied.As for the research on fault location technology of the distribution network,based on the research of the fault location of distribution network without DG usingtraditional genetic algorithm and it’s defect in fault location, the genetic algorithm(GA) and it’s fitness function and switching function were improved, then themultiple faults location of distribution network with DGs were researched. And thefault information mutation and the time-varying problem in electrical load were takeninto consideration, the effectiveness of the improved fault location method wasverified and the fault location results with the unimproved GA were analyzed andcompared during the practical example analysis.As for the research of the transient characteristic and control strategy of DG,first, the transient model and transient behaviors of the doubly-fed induction windturbine(DFIG WT) were analyzed, and the coordination control strategy was proposed,then the simulating models of the IEEE14&IEEE34distribution network with DFIGWT were built with the simulation software PSCAD, and the transient stability ofDFIG WT was first studied by considering of the factors of fault location, interaction between DFIG WTs, fault clearing time, topological structure of distribution networkand unbalance level of three-phase loads. And the effectiveness of the proposedcoordination control strategy was verified during the simulation of the interactionbetween DFIG WTs. The transient stability of the distribution network was alsostudied with the combination of different types of DG. Finally, the correspondingcontrol strategies of DG were given according to the specific conditions of fault andoperating conditions of distribution network.This paper mainly focus on the fault location technology and transient stability ofthe distribution network with DG, the faults location of distribution network with DGsand the transient stability and control strategy of DG were studied with the purpose ofproviding references for follow-up study and improving the efficiency of DG and thereliability of distribution network.