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Author: gerinlajoie.luc
Type: Model
Downloaded: 235 times
Date: 2012-11-23

Extra control functions

Description:
Extra control functions, 17 components: Dead band, Friction, QuantizerLess than (for T1 duration and reset at 110% of the level)
- useful for analogical inputLess than (for T1 duration and reset... see more after T2 duration when higher the level)
- useful for numeric inputGreater than (for T1 duration and reset at 90% of the level)
- useful for analogical inputGreater than (for T1 duration and reset after T2 duration when lower the level)
- useful for numeric inputInverse
- time (5points), external resetFrequency meter, with 4 outputs: rate(Hz/s), period(s), deltaF (pu) and F (hz); based on phase C measurementPI with variables low and hi limitsPI with variables Kp and Ki, low and hi limitsLim(du/dt) , rising and falling fixed, Lim(du/dt) , rising and falling variableFour second order filters,

Tag(s): Components

Author: AdminEMTP-RV
Type: Document
Downloaded: 912 times
Date: 2012-06-18

Look what happens without EMTP-RV

Description:
This is a nice video about the switching of a shunt reactor (most probably 500 kV) with a Circuit-Switcher.
>A circuit-switcher is a SF6 load-break swith with no fault current breaking cap... see moreability. The load current, in this case around 150 A, is normally interrupted first by the 2 interrupters and then the disconnect will open to isolate the reactor.
What happened in this video:
1 - During the opening, an external flashover occurs on one of the chamber most probably because of the contamination;
2 - The other chamber can not withstand the whole voltage and reignites internally;
3 - The external flashover vanishes because an arc is established inside;
4 - The disconnect opens on the full load current;
5 - The arc burns freely in the air for some 10 seconds until it is self-extinguished or eliminated by a circuit-breaker operation.

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Author: AdminEMTP-RV
Type: Document
Downloaded: 464 times
Date: 2012-06-18

Presentation of an approach based on EMTP for the calculation of lightning induced overvoltages

Description:
Authors:
A. Xémard, P. Baraton, B. Bressac, N. Qako, J. Mahseredjian, G. Simard, J. Ribeiro, R. Tarafi, A. Zeddam.

Abstract:
LIPS (Lightning Impact on Power Systems) is a toolbo... see morex based on EMTP (DCG version) and devoted to the calculation of the failure rate of apparatus due to lightning. This software covers direct and induced lightning. It has been developed in a partnership project between France Telecom, Hydro-Québec and électricité de France. The induced lightning nearby the electrical system. It is based on the following computational steps:
1) For each overhead line and underground cable of the electrical system, two equivalent current sources are calculated in the frequency domain, representing the illumination of the conductors by external electrical field due to lightning. These sources are evaluated in the frequency domain, taking into account the variation of the parameters of lines and cables with frequency. The conductivity of the ground is taken as finite. The modal theory is applied in the case of multi-conductor cable or line.
2) The equivalent sources are converted into time-domain and then included in an EMTP representation of the system allowing a time-domain transient computation. this approach and follow by comparisons between induced overvoltages calculated by LIPS and results from the literature.

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