Functionality; Identification; Signals - ABB RELION 670 Series Technical Manual

Section 8
Current protection
8.7.1

Identification

Function description
Thermal overload protection, two
time constants
8.7.2

Functionality

If a power transformer reaches very high temperatures the equipment might be damaged. The
insulation within the transformer will experience forced ageing. As a consequence of this the risk
of internal phase-to-phase or phase-to-ground faults will increase.
The thermal overload protection estimates the internal heat content of the transformer
(temperature) continuously. This estimation is made by using a thermal model of the transformer
with two time constants, which is based on current measurement.
Two warning pickup levels are available. This enables actions in the power system to be done
before dangerous temperatures are reached. If the temperature continues to increase to the trip
value, the protection initiates a trip of the protected transformer.
The estimated time to trip before operation is presented.
8.7.3 Function block
I3P*
BLOCK
COOLING
MULTPU
RESET
ANSI06000272 V2 EN-US
Figure 272: TRPTTR (49) function block
8.7.4

Signals

Table 250: TRPTTR (49) Input signals
Name
I3P
BLOCK
COOLING
MULTPU
RESET
518
TRPTTR (49)
TRIP
PICKUP
ALARM1
ALARM2
LOCKOUT
WARNING
ANSI06000272-2-en.vsd
Type Default
GROUP
SIGNAL
BOOLEAN
BOOLEAN
BOOLEAN
BOOLEAN
IEC 61850 IEC 60617
identification identification
TRPTTR
SYMBOL-A V1 EN-US
Description
- Group signal for current input
0 Block of function
0 Cooling input Disabled/ Enabled. Changes Ib setting and time
constant
0 Enable Multiplier for currentReference setting
0 Reset of function
1MRK 502 066-UUS B
ANSI/IEEE C37.2
device number
49
PID-4148-INPUTSIGNALS v4
Technical manual
M14877-1 v2
M13243-3 v10
M13299-3 v5