15 Results for the search " Protection":
Author: n.sene
Type: Publication
Date: 2015-04-01
Assessment of the Lightning Performance of Compact Overhead Distribution Lines
Description:
The assessment of the lightning performance of a compact configuration of MV overhead lines that is expected to be adopted in the near future by an electricity distribution company in a Brazilian regi... see moreon characterized by high keraunic levels is presented. The compact configuration is characterized by the presence of an unenergized wire that has the main function to sustain the spacers of the phase conductors. As the wire could be periodically grounded, the paper analyses its effectiveness in reducing the overvoltages due to indirect lightning. The results are compared with those relevant to a conventional configuration of MV overhead lines now adopted by the same distribution company. The effects of the presence of surge arresters along the line are also analysed.
Authors: F. Napolitano, A. Borghetti, D. Messori, C.A. Nucci, M.L.B. Martinez, G.P. Lopes, J.I.L. Uchoa
CIGRE SC C4 2012 Hakodate Colloquium
Tag(s): Lightning protection, Overhead distribution lines, Induced overvoltages, Electromagnetic transients.
Author: gerinlajoie.luc
Type: Library
Downloaded: 523 times
Date: 2012-11-23
A collection of PowerRelay devices
Description:
A collection of PowerRelay devices
Distance relay 21,
Synchronizing or synchronism-check device 25,
Instantaneous overcurrent 50 + Ac time overcurrent relay 51,
Frequency relay (ov... see moreer) 81O,
Frequency relay (rate) 81R,
Frequency relay (under) 81U
Plus 6 controlled switch build to connect with theses protection devices.
Tag(s): Protection
Author: AdminEMTP-RV
Type:
Downloaded: 455 times
Date: 2012-06-18
Cross_Bonded_Cable
Description:
Insulation coordination - 225 kV cross bonded cable - protection of the sheath.
In the configuration a 225 kV cross-bonded cable is connected at both ends to an otherhead line. The sheath is prot... see moreected by star-connected arresters.
The modelling used is adapted for the study of Fast-Front-Overvoltages (see IEC 60071)
A current source, with a CIGRE concave shape (See CIGRE 63 document), representing a lightning stroke has been connected to a tower close to the cable.
The case includes the modelling of the different elements of the configuration (cable, spans, arresters...).
Author: AdminEMTP-RV
Type: Model
Downloaded: 396 times
Date: 2012-06-18
CB_arc_CM
Description:
This is an interesting case of the study of arc-circuit interaction in case of the interruption of a short-line fault.The arc is represented by a composite Cassie-Mayr model and the line is represente... see mored as frequency-dependant.
The case shows the application of black-box arc modeling in the study of kilometric-line fault capability of a 420 kV circuit-breaker. By zooming on the arc current and voltage near current-zero, post-arc current and initial TRV may be visualized in both cases of clearing and thermal failure.
Tag(s): Example, Protection
Author: AdminEMTP-RV
Type:
Downloaded: 231 times
Date: 2012-06-18
Motor_Protection
Description:
The following circuit presents a protection scheme for an induction motor due to voltage dips.
The voltage dip generator is presented in a masked subcircuit where it is possible to control ... see morethe shape and duration of the voltage dip.
Tag(s): Motor, Protection