Capacitor Bank Protection Cbpgapc - ABB REC670 Applications Manual

1MRK 511 401-UEN A
8.15
8.15.1
8.15.2
Bay control REC670 2.2 IEC
Application manual
Set the unsymmetrical current, which is relation between the difference of the
minimum and maximum phase currents to the maximum phase current to typical
Iub> = 50%.
Note that it must be set to avoid problem with asymmetry under
minimum operating conditions.
Set the time delay tOper = 5 - 60 seconds and reset time tReset = 0.010 - 60.000
seconds.

Capacitor bank protection CBPGAPC

Identification
Function description
Capacitor bank protection
Application
Shunt capacitor banks (SCBs) are somewhat specific and different from other
power system elements. These specific features of SCB are briefly summarized in
this section.
A capacitor unit is the building block used for SCB construction. The capacitor unit
is made up of individual capacitor elements, arranged in parallel or series
connections. Capacitor elements normally consist of aluminum foil, paper, or film-
insulated cells immersed in a biodegradable insulating fluid and are sealed in a
metallic container. The internal discharge resistor is also integrated within the
capacitor unit in order to reduce trapped residual voltage after disconnection of the
SCB from the power system. Units are available in a variety of voltage ratings
(240V to 25kV) and sizes (2.5kVAr to about 1000kVAr). Capacitor unit can be
designed with one or two bushings.
The high-voltage SCB is normally constructed using individual capacitor units
connected in series and/or parallel to obtain the required voltage and MVAr rating.
Typically the neighboring capacitor units are mounted in racks. Each rack must be
insulated from the other by insulators because the can casing within each rack are
at a certain potential. Refer figure
IEC 61850 IEC 60617
identification identification
CBPGAPC
92 for an example:
Section 8
Current protection
GUID-41731DCF-840C-4717-9F51-899FC648F881 v2
GUID-67FC8DBF-4391-4562-A630-3F244CBB4A33 v2
ANSI/IEEE C37.2
device number
- -
GUID-5EC8BAEC-9118-49EC-970C-43D6C416640A v1
GUID-BACAE67B-E64B-4963-B323-ECB0B69031B9 v2
215