Research On Protection Of Distributed Network Containing Distributed Generation

The problem of distributed network protection and feeder automation brought byDistributed Generation(DG) integrating into distributed network, grid characteristics ofinverter-based distributed generation and output characteristics of inverter when thedistributed network has fault is analyzed, then an equivalent model for fault analysis ofdistributed network with DG is proposed. Taking a widely used inverter for example,according to the known parameters, by calculation and get the equivalent outputimpedance of the inverter. Then considering the protection value and time limit of theinverter, eventually these parameters will be included in the established model.The short-circuit fault characteristic quantity of distributed network with DG isanalyzed, sum up the different influences on protection of DG integrating differentlocations. And the location and capacity of protection of distributed network with DG,namely considering the protection as well as the active power loss of distributed network,using the improved particle swarm algorithm, planning distributed network with DG andthe location and capacity of DG is determined.On the basis of existing research results, the fault calculation of distributed networkwith DG is carried out. According to the proposed algorithm for locating and sizing ofDG, and get the distributed network with DG for fault calculations; equivalentimpedance of the inverter and its control strategy are the important condition for theestablishment of equivalent model, control strategies and fault output characteristics ofthe inverter will be the main constraint in the process of fault calculation. Byprogramming calculation, each node and branch in the distributed network with DG, theamount of electrical slip case under different faults.This article does not want to change the original protection and automatic reclosingconfiguration greatly, by adjusting the protection value and time limit, and the protectionof distributed network with DG to act reliably and sensitively. The results calculated bydistributed network fault with DG is analyzed, compared with the distributed networkwithout DG, sum up the protection scheme of distributed network with inverter-based DG.Finally, the protection configuration methods and procedures are proposed when theinverter-based DG is "T" connected to10kV distributed network.