![background image](http://html1.mh-extra.com/html/abb/relion-670-series/relion-670-series_applications-manual_3052129489.webp)
9.5.2
Application
SEMOD153893-5 v3
The Voltage differential protection VDCPTOV functions can be used in some different
applications.
•
Voltage unbalance protection for capacitor banks. The voltage on the bus is supervised
with the voltage in the capacitor bank, phase- by phase. Difference indicates a fault, either
short-circuited or open element in the capacitor bank. It is mainly used on elements with
external fuses but can also be used on elements with internal fuses instead of a current
unbalance protection measuring the current between the neutrals of two half’s of the
capacitor bank. The function requires voltage transformers in all phases of the capacitor
bank. Figure
shows some different alternative connections of this function.
Ud>L1
Ph L2
Ph L3
U1
U2
Ud>L1
Ph L2
Ph L3
U1
U2
Ph L3
Ph L2
Single earthed wye
Double wye
IEC06000390_1_en.vsd
IEC06000390 V3 EN-US
Figure 303: Connection of voltage differential protection VDCPTOV function to detect
unbalance in capacitor banks (one phase only is shown)
VDCPTOV function has a block input (BLOCK) where a fuse failure supervision (or MCB tripped)
can be connected to prevent problems if one fuse in the capacitor bank voltage transformer
set has opened and not the other (capacitor voltage is connected to input U2). It will also
ensure that a fuse failure alarm is given instead of a Undervoltage or Differential voltage alarm
and/or tripping.
Fuse failure supervision (SDDRFUF) function for voltage transformers. In many application the
voltages of two fuse groups of the same voltage transformer or fuse groups of two separate
voltage transformers measuring the same voltage can be supervised with this function. It will
be an alternative for example, generator units where often two voltage transformers are
supplied for measurement and excitation equipment.
1MRK 505 343-UEN B
Section 9
Voltage protection
483
Application manual
Содержание Relion 670 series
Страница 1: ...RELION 670 SERIES Line differential protection RED670 Version 2 1 IEC Application manual...
Страница 2: ......
Страница 40: ...34...
Страница 64: ...58...
Страница 150: ...144...
Страница 406: ...400...
Страница 472: ...466...
Страница 494: ...488...
Страница 512: ...506...
Страница 524: ...518...
Страница 604: ...598...
Страница 686: ...680...
Страница 718: ...712...
Страница 722: ...716...
Страница 758: ...752...
Страница 759: ...753...