Introduction - ABB REG650 Technical Manual

1MRK 502 043-UUS B
6.2.2
6.2.3
6.2.4
Technical Manual

Introduction

The 1Ph High impedance differential protection (HZPDIF, 87) function can be used
when the involved CTs have the same turns ratio and similar magnetizing
characteristics. It 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.
HZPDIF (87) can be used as high impedance REF protection.
Function block
HZPDIF (87)
ISI* TRIP
BLOCK ALARM
BLKTR MEASVOLT
ANSI05000363-2-en.vsd
ANSI05000363 V2 EN
Figure 43: HZPDIF (87) function block
Signals
Table 29: HZPDIF (87) Input signals
Name Type
ISI GROUP
SIGNAL
BLOCK BOOLEAN
BLKTR BOOLEAN
Table 30: HZPDIF (87) 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
Section 6
Differential protection
111