High Impedance Differential Protection, Single Phase Hzpdif (87); Identification; Functionality - ABB RELION 670 Series Technical Manual

Section 6
Differential protection
Function
*Trip time at 0 to 10 x Idunre,
unrestrained function
*Reset time at 10 x Idunre to 0,
unrestrained function
**Trip time, unrestrained negative
sequence function
**Reset time, unrestrained negative
sequence function
Critical impulse time
*Note: Data obtained with single three-phase input current group. The operate and reset times for T2WPDIF/
T3WPDIF are valid for an static output from SOM.
**Note: Data obtained with two three-phase input current groups. The rated symmetrical currents are applied on
both sides as pre- and after-fault currents. The fault is performed by increasing one phase current to double on
one side and decreasing same phase current to zero on the other side.
6.2 High impedance differential protection, single phase
HZPDIF (87)
6.2.1

Identification

Function description
High impedance differential
protection, single phase
6.2.2

Functionality

High impedance differential protection, single phase (HZPDIF) (87) functions can be used when
the involved CTs have the same turns ratio and similar magnetizing characteristics. It utilizes an
external CT secondary current summation by wiring. Actually all CT secondary circuits which are
involved in the differential scheme are connected in parallel. External series resistor, and a voltage
dependent resistor which are both mounted externally to the IED, are also required.
The external resistor unit shall be ordered under IED accessories in the Product Guide.
HZPDIF (87) can be used to protect generator stator windings, tee-feeders or busbars, reactors,
motors, auto-transformers, capacitor banks and so on. One such function block is used for a high-
impedance restricted earth fault protection. Three such function blocks are used to form three-
phase, phase-segregated differential protection.
144
Range or value
Min. = 5 ms
Max. = 15 ms
Min. = 15 ms
Max. = 35 ms
Min. = 10 ms
Max. = 20 ms
Min. = 10 ms
Max. = 30 ms
2 ms typically at 0 to 5 x IdMin
IEC 61850 IEC 60617
identification identification
HZPDIF Id
SYMBOL-CC V2 EN-US
1MRK 502 066-UUS B
Accuracy
-
-
-
-
-
ANSI/IEEE C37.2
device number
87
Technical manual
IP14239-1 v4
M14813-1 v4
M13071-3 v13