Title :
Traction system unbalance problem-analysis methodologies
Author :
Chen, Shi-Lin ; Li, Ray-Jong ; Hsi, Pao-Hsiang
Author_Institution :
Dept. of Electr. Eng., Nat. Tsing Hua Univ., Hsin-Chu City, Taiwan
Abstract :
This paper presents a novel methodology using a utility\´s existing software for the accurate prediction of total unbalance (UB) impact due to ac traction loads with emphasis on the estimation of negative sequence (N-Seq) current injection into utility generators. Traditionally, due to the requirement of complex 3Φ power-flow simulation, UB analysis has been limited to the evaluation of UB voltage at the point of common coupling (PCC) without addressing whether supply of this N-Seq current would exceed the remaining margin of each utility generator. By using the salient feature that a utility\´s N-Seq network is basically "sourceless" as such for any N-Seq current injection at a specific node, the "contribution ratio" of each utility generator for that N-Seq current injection is fixed irrespective of the magnitude of that injection, this paper provides a solution to this important problem by using a utility\´s existing fault analysis software.
Keywords :
failure analysis; load flow; machine protection; power engineering computing; railway electrification; traction power supplies; 3Φ power flow simulation; ac traction loads; fault analysis software; generator protection; high-speed rail; negative sequence estimation; point of common coupling; traction power system unbalance; utility generator current injection; AC generators; Analytical models; Load flow; Power generation; Power system analysis computing; Power system faults; Power system protection; Rails; Substation protection; Voltage; Generator protection; high-speed rail; negative sequence current; three-phase power flow; traction power system; unbalance;
Journal_Title :
Power Delivery, IEEE Transactions on
DOI :
10.1109/TPWRD.2004.829920