Title :
New line-selection method for single phase grounding fault in distribution networks with two phase’s current transformers
Author :
Yanxia, Zhang ; Zhiqiang, Jin ; Fengxian, Dai ; Ting, Fang
Author_Institution :
Key Lab. of Power Syst. Simulation & Control of Minist. of Educ., Tianjin Univ., Tianjin
Abstract :
In China, current transformers (TAs) are just installed at A-phase and C-phase in most distribution networks with neutral indirectly grounding. It is a very difficult problem to select single-phase grounding line using the currents of A phase and B phase. After analyzing the currents of A-phase and C- phase when B-phase grounding fault occurs, the fault line detection algorithm applying the transient characters of the sum of A-phase mutational current and C-phase mutational current is proposed. For A-phase to ground fault or C-phase to ground fault, the algorithm of constructing B-phase transient current and furthermore constructing the exact zero-sequence current is founded out through the analysis in frequency domain and time domain, and the fault line-detection method can be actualized according to zero-sequence current´s transient characters. Based on them, a new method used to identify single phase to ground fault line using transient characteristics in two TAs distribution networks is formed. The proposed line-selection method is not affected by the mode whether the Petersen coil exists at neutral and the unbalanced current under normal operation condition.
Keywords :
current transformers; earthing; fault diagnosis; frequency-domain analysis; power distribution faults; time-domain analysis; China; Petersen coil; fault line detection algorithm; frequency domain analysis; line-selection method; phase current transformers; power distribution networks; single phase grounding fault; time domain analysis; zero-sequence current; Algorithm design and analysis; Control system synthesis; Current transformers; Educational institutions; Fault diagnosis; Grounding; Laboratories; Power system simulation; Power system transients; Transient analysis; A-phase or C-phase to ground fault line selection; B-phase to ground fault line selection; constructing zero sequence current; two TAs distribution network;
Conference_Titel :
Electric Utility Deregulation and Restructuring and Power Technologies, 2008. DRPT 2008. Third International Conference on
Conference_Location :
Nanjuing
Print_ISBN :
978-7-900714-13-8
Electronic_ISBN :
978-7-900714-13-8
DOI :
10.1109/DRPT.2008.4523791