Setting Guidelines - ABB REC670 Applications Manual

Section 8
Current protection
8.5.3
176
Curve name
ANSI Long Time Very Inverse
ANSI Long Time Inverse
IEC Normal Inverse
IEC Very Inverse
IEC Inverse
IEC Extremely Inverse
IEC Short Time Inverse
IEC Long Time Inverse
IEC Definite Time
User Programmable
ASEA RI
RXIDG (logarithmic)
There is also a user programmable inverse time characteristic.
Normally it is required that the negative sequence overcurrent function shall reset
as fast as possible when the current level gets lower than the operation level. In
some cases some sort of delayed reset is required. Therefore different kinds of reset
characteristics can be used.
For some protection applications there can be a need to change the current
operating level for some time. Therefore there is a possibility to give a setting of a
multiplication factor IxMult to the negative sequence current pick-up level. This
multiplication factor is activated from a binary input signal ENMULTx to the
function.

Setting guidelines

The parameters for Four step negative sequence overcurrent protection NS4PTOC
are set via the local HMI or Protection and Control Manager (PCM600).
The following settings can be done for the four step negative sequence overcurrent
protection:
Operation: Sets the protection to On or Off.
Common base IED values for primary current (IBase), primary voltage (UBase)
and primary power (SBase) are set in Global base values for settings function
GBASVAL. GlobalBaseSel: It is used to select a GBASVAL function for reference
of base values.
When inverse time overcurrent characteristic is selected, the
operate time of the stage will be the sum of the inverse time delay
and the set definite time delay. Thus, if only the inverse time delay
1MRK 511 401-UEN A
GUID-460D6C58-598C-421E-AA9E-FD240210A6CC v2
GUID-F7AA2194-4D1C-4475-8853-C7D064912614 v4
Bay control REC670 2.2 IEC
Application manual