Xue Yongduan1,Feng Zuren1,Xu Bingyin2
(1.School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an 710049,China;2.School of Electrical Engineering,Shandong University of Technology,Zibo 255031,China)
Abstract:The modal network of single phase earth fault in non-solidly earthed network based on feeders's distributed parameters is constructed to overcome the deficiency of traditional transient analysis methods. The characteristics of transient zero sequence voltage and current produced by earth fault in different frequency bands£¬which can be decomposed according to angleª²frequency characteristics of feeders' detected impedance£¬are analyzed. It is found that the impedance of zero sequence network is capacitive in the selected frequency band (SFB), and it's boundary frequencies are given£®The distribution of transient zero sequence current and reactive power within SFB is presented£® The zero sequence current and reactive power of the faulty feeder within SFB are larger than or equal to any healthy feeders in amplitude.The flow direction is from the feeder to the bus in faulty feeders and opposite in healthy feeders£® The fault transient characteristics are verified by simulation results using ATP(alternative transient program).
Keywords£ºnon-solidly earthed network;single phase earth faults;faulty transients; angle-frequency characteristics