ABB REB650 - Ph High Impedance Differential Protection HZPDIF (87)

Section 6 Differential protection
6.1 1Ph High impedance differential protection HZPDIF
(87)
6.1.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
1Ph High impedance differential
protection
HZPDIF
Id
SYMBOL-CC V2 EN
87
6.1.2 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.
Three instances of 1Ph High impedance differential protection function (HZPDIF, 87)
can be used to provide a three phase differential protection function to be used for
example as busbar protection. One instance of HZPDIF (87) can also be used as high
impedance REF protection.
6.1.3 Function block
ANSI05000363-2-en.vsd
HZPDIF (87)
ISI*
BLOCK
BLKTR
TRIP
ALARM
MEASVOLT
ANSI05000363 V2 EN
Figure 29: HZPDIF (87) function block
1MRK 505 277-UUS C Section 6
Differential protection
69
Technical Manual