![ABB RELION RET670 Скачать руководство пользователя страница 634](http://html.mh-extra.com/html/abb/relion-ret670/relion-ret670_applications-manual_4714634.webp)
overexcitation occurs after a short time interval, the heating will start from a higher
level, therefore, OEXPVPH (24) must have thermal memory. A fixed cooling time
constant is settable within a wide range.
The general experience is that the overexcitation characteristics for a number of power
transformers are not in accordance with standard inverse time curves. In order to make
optimal settings possible, a transformer adapted characteristic is available in the IED.
The operate characteristic of the protection function can be set to correspond quite well
with any characteristic by setting the operate time for six different figures of
overexcitation in the range from 100% to 180% of rated V/Hz.
When configured to a single phase-to-phase voltage input, a corresponding phase-to-
phase current is calculated which has the same phase angle relative the phase-to-phase
voltage as the phase currents have relative the phase voltages in a symmetrical system.
The function should preferably be configured to use a three-phase voltage input if
available. It then uses the positive sequence quantities of voltages and currents.
Analog measurements shall not be taken from any winding where a
load tap changer is located.
Some different connection alternatives are shown in figure
G
24
en05000208_ansi.vsd
24
24
ANSI05000208 V1 EN-US
Figure 297:
Alternative connections of an Overexcitation protection OEXPVPH (24)
(Volt/Hertz)
Section 10
1MRK 504 163-UUS A
Voltage protection
628
Transformer protection RET670 2.2 ANSI
Application manual
Содержание RELION RET670
Страница 1: ...RELION 670 SERIES Transformer protection RET670 Version 2 2 ANSI Application manual ...
Страница 2: ......
Страница 48: ...42 ...
Страница 64: ...58 ...
Страница 74: ...68 ...
Страница 104: ...98 ...
Страница 194: ...188 ...
Страница 518: ...512 ...
Страница 618: ...612 ...
Страница 648: ...642 ...
Страница 666: ...660 ...
Страница 672: ...666 ...
Страница 682: ...676 ...
Страница 844: ...838 ...
Страница 868: ...862 ...
Страница 956: ...950 ...
Страница 964: ...958 ...
Страница 1004: ...998 ...
Страница 1014: ...1008 ...
Страница 1015: ...1009 ...