Introduction; Function Block; Signals - ABB RET650 Technical Manual

Section 6
Differential protection
6.3.2
6.3.3
6.3.4
120

Introduction

The 1Ph High impedance differential protection HZPDIF functions can be used when
the involved CT cores have the same turns ratio and similar magnetizing
characteristics. Each utilizes an external summation of the currents in the
interconnected CTs, a series resistor, and a voltage dependent resistor which are
mounted externally connected to the IED.
The external resistor unit shall be ordered under accessories.
HZPDIF can be used as high impedance REF protection.

Function block

HZPDIF
ISI* TRIP
BLOCK ALARM
BLKTR MEASVOLT
IEC05000363-2-en.vsd
IEC05000363 V2 EN
Figure 48: HZPDIF function block

Signals

Table 44: HZPDIF Input signals
Name Type
ISI GROUP
SIGNAL
BLOCK BOOLEAN
BLKTR BOOLEAN
Table 45: HZPDIF Output signals
Name Type
TRIP BOOLEAN
ALARM BOOLEAN
MEASVOLT REAL
Default Description
- Group signal for current input
0 Block of function
0 Block of trip
Description
Trip signal
Alarm signal
Measured RMS voltage on CT secondary side
1MRK 504 135-UEN A
Technical manual