ABB REG650 User Manual

Name Values (Range) Unit Step Default Description
OperDCBiasing Off
On
- - Off Operation DC biasing On / Off
OpenCTEnable Off
On
- - Off Open CT detection feature Off/On
tOCTAlarmDelay 0.100 - 10.000 s 0.001 1.000 Open CT: time to alarm if an open CT is
detected, in sec
tOCTResetDelay 0.100 - 10.000 s 0.001 0.250 Reset delay in s. After delay, diff. function
is activated
tOCTUnrstDelay 0.100 - 100.000 s 0.001 10.000 Unrestrained diff. protection blocked after
this delay, in s
TempIdMin 1.0 - 5.0 IdMin 0.1 2.0 Temp. Id pickup when input
raisePickUp=1, multiple of IdMin
Table 48: GENPDIF Non group settings (basic)
Name Values (Range) Unit Step Default Description
GlobalBaseSel 1 - 6 - 1 1 Selection of one of the Global Base Value
groups
6.4.6 Operation principle
The task of Generator differential protection GENPDIF is to determine whether a fault
is within the protected zone, or outside the protected zone. The protected zone is
delimited by the position of current transformers, as shown in figure 50.
IEC06000430-2-en.vsd
IEC06000430 V2 EN
Figure 50: Position of current transformers; the recommended (default)
orientation
If the fault is internal, the faulty generator must be quickly tripped, that is,
disconnected from the network, the field breaker tripped and the agent to the prime
mover interrupted.
GENPDIF function always uses reference (default) directions of CTs towards the
protected generator as shown in figure
50. Thus, it always measures the currents on the
two sides of the generator with the same reference direction towards the generator
windings. With the orientation of CTs as in figure 50, the difference of currents
flowing in, and out, of a separate stator winding phase is simply obtained by
summation of the two currents fed to the differential protection function.
Numerical IEDs have brought a large number of advantages and new functionality to
the protective relaying. One of the benefits is the simplicity and accuracy of
calculating symmetrical components from individual phase quantities. Within the
1MRK 502 048-UEN A Section 6
Differential protection
125
Technical manual

ABB REG650 Specifications

General

Brand	ABB
Model	REG650
Category	Protection Device
Language	English