DocumentCode :
68563
Title :
Axial Magnetic Field Strength Needed for a 126-kV Single-Break Vacuum Circuit Breaker During Asymmetrical Current Switching
Author :
Yingyao Zhang ; Xiaofei Yao ; Zhiyuan Liu ; Yingsan Geng ; Ping Liu
Author_Institution :
State Key Lab. of Electr. Insulation & Power Equip., Xian Jiaotong Univ., Xi´an, China
Volume :
41
Issue :
6
fYear :
2013
fDate :
Jun-13
Firstpage :
1670
Lastpage :
1678
Abstract :
The objective of this paper is to investigate how strong an axial magnetic field (AMF) is needed in test duty T100a for a 126-kV single-break vacuum circuit breaker (VCB) when interrupting a rated short circuit current of 40-kA rms in light of arcing contact gap, arc duration and phase shift effect. The AMF is generated by a pair of 2/3 coil-type AMF contacts. First, the accuracy of a 3-D finite element simulation of AMF is validated by an AMF measurement at a contact gap 30 mm and the error is <; 10%. After that test duty T100a of the 126-kV single-break VCB are carried out 18 times with arc duration from 3.3 to 19 ms at 40-kA rms. With a given opening displacement curve, the contact gap as arc extinguishes within a range from 12 to 50 mm corresponding to the arc duration from 3.3 to 19 ms. Then the AMF distribution of the 126-kV single-break VCB at each contact gap at which arc extinguished is simulated to analyze the current interrupting results. The results show that there are successful interruptions at the short-circuit current 40-kA rms in test duties T100a, with the shortest arcing contact gap window from 18 to 23 mm and the longest arcing contact gap of 44 mm. The shortest arcing contact gap window corresponds to the maximum AMF at the intermediate plane of the contact gap per kilo-ampere of the breaking peak current from 9.3 to 8.5 mT/kA. In addition, the longest arcing contact gap corresponds to the value of 6.1 mT/kA. The phase shift time at the center of intermediate plane of the contact gap ranged from 1.36 to 0.75 ms corresponding to an increase of arcing contact gap from 12 to 50 mm in the tests.
Keywords :
arcs (electric); electrical contacts; finite element analysis; magnetic fields; vacuum circuit breakers; 2/3 coil-type AMF contacts; 3D finite element simulation; AMF measurement; T100a test duty; arc duration; arcing contact gap; asymmetrical current switching; axial magnetic field strength; current 40 kA; displacement curve; phase shift effect; short circuit current; single-break VCB; single-break vacuum circuit breaker; time 1.36 ms to 0.75 ms; time 3.3 ms to 19 ms; voltage 126 kV; Conductors; Copper; Current measurement; Magnetic field measurement; Plasma measurements; Short-circuit currents; Vacuum arcs; Magnetic fields; vacuum arcs; vacuum circuit breakers (VCBs); vacuum interrupters;
fLanguage :
English
Journal_Title :
Plasma Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-3813
Type :
jour
DOI :
10.1109/TPS.2013.2259598
Filename :
6517520
Link To Document :
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