Exchange Platform

Author: n.sene
Type: Publication
Date: 2015-10-22

Fault Current Limiters in Industrial Power Systems

Description:
The concept of saturable core fault current limiter (FCL) is relatively known nowadays. It usually consists of two reversely magnetized cores per phase to effectively limit the fault current passively... see more and immediately upon its inception. In this paper prospects of application of fault current limiters in industrial power systems will be considered. Industrial power systems (distribution networks) are widespread and include a number of various electrical appliances. The power systems development (addition of new power plants, interconnections, etc.) may lead to more intense short circuit currents at the fault location. Furthermore, industrial systems may possess on-site generation which can increase fault current levels as well. All these factors might require appropriate upgrades of industrial system electrical equipment (especially switchgear) or special operating procedures (for instance avoiding parallel operation). Another alternative is the installation of fault current limiters. In this light, a series of simulations were carried out in order to observe the impact of fault current limiters on short circuit currents in an industrial power system using the EMTP-RV software program.

Keywords: saturable core fault current limiter (FCL), industrial power system, induction machine, EMTP; fault current analysis, medium voltage

Tag(s): saturable core fault current limiter (FCL), industrial power system, induction machine, EMTP; fault current analysis, medium voltage

Author: n.sene
Type: Publication
Date: 2015-04-01

Transient recovery voltages in vacuum circuit breakers generated by the early-interruption of the inrush current of large motors

Description:
The switching of medium voltage electrical motors is typically realized by means of vacuum circuit breakers (VCBs) essentially in view of their elevated number of switching cycles. As known, switching... see more of VCBs generates important transient recovery voltages (TRVs)
that need to be properly evaluated in both VCB sizing and in the power system insulation coordination. As large medium voltage electrical motors are installed into plants typically controlled by means of Supervisory Control And Data Acquisition (SCADA) systems,
maneuvers that involve the motor inrush followed by its sudden de-energization (due, in general, to the intervention of an automatic diagnostic function), resulting into important TRVs, are not unusual. The paper aims at investigating the TRVs due to this specific type of
VCB switching by means of a model implemented in the EMTP-RV simulation environment. By making reference to a real plant, the validation of the implemented models is obtained by comparing the simulation results with some experimental transients provided by the plant data fault recorder. The paper finally discusses the adequacy of different countermeasures by analyzing their effectiveness for the TRVs limitation.

Authors: A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Sultan, N. Tripaldi

CIGRE - International Symposium “Assessing and Improving Power System Security, Reliability and Performance in Light of Changing Energy Sources” Recife, Pernambuco, Brazil, April 3-6, 2011
Topic 3 – System technical performance
Subtopic 3.5 – Switching and lightning transient on power systems. Impact on performance and measurements

Tag(s): Transient recovery voltages, vacuum circuit breakers, motor inrush currents, EMTP simulations

Author: n.sene
Type: Publication
Date: 2015-04-01

Continuous-Wavelet Transform for Fault Location in Distribution Power Networks: Definition of Mother Wavelets Inferred From Fault Originated Transients

Description:
The paper presents a fault location procedure for distribution networks based on the wavelet analysis of the fault-generated traveling waves. In particular, the proposed procedure implements the conti... see morenuous wavelet analysis applied to the voltage waveforms recorded during the fault in correspondence of a network bus. In order to improve the wavelet analysis, an algorithm is proposed to build specific mother wavelets inferred from the fault-originated transient waveforms. The performance of the proposed algorithm are analyzed for the case of the IEEE 34-bus test distribution network and compared with those achieved by using the more traditional Morlet mother wavelet.

Authors: Alberto Borghetti, Senior Member, IEEE, Mauro Bosetti, Mauro Di Silvestro, Carlo Alberto Nucci, Fellow, IEEE, and Mario Paolone, Member, IEEE

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 23, NO. 2, MAY 2008

Tag(s): Continuous wavelet transform, distribution network, EMTP simulations, fault location, mother wavelet, power quality.

Author: e.rutovic
Type: Example
Downloaded: 1267 times
Date: 2013-02-20

JavaScript Examples

Description:
Some simple EMTP-RV scripts :
- Parameters sweep
- Change the simulation options
- Run simulation
- Change the fault location
- Change the transformer remanent flux
- Cha... see morenge the switching Times

Tag(s): Script, Javascript

Author: AdminEMTP-RV
Type: Model
Downloaded: 456 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