High-Impedance Or Flux-Balance Based Differential Protection Mhzpdif (Ansi 87Him) - ABB RELION REX640 Technical Manual

Protection functions
4.3.8 High-impedance or flux-balance based differential
protection MHZPDIF (ANSI 87HIM)
4.3.8.1 Identification
Function description
High-impedance or flux-balance
based differential protection
4.3.8.2 Function block
Figure 458: Function block
4.3.8.3 Functionality
The high-impedance/flux-balance based differential protection for motors function
MHZPDIF provides winding short circuit protection for motors.
MHZPDIF starts and operates when any of the three-phase differential currents,
ID_A, ID_B or ID_C, exceeds the set limit. The operation timer characteristic is
according to the definite time (DT).
This function contains a blocking functionality. It is possible to block the function
outputs, timers or the function itself.
4.3.8.4 Analog channel configuration
MHZPDIF has one analog group input which must be properly configured.
Table 724: Analog inputs
Input
I3P
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings.
For troubleshooting, check the contents of this chapter and also the preprocessing
blocks in this document. The configuration can be written to the protection relay
once the mismatch is corrected.
806
See the preprocessing function blocks in this document for the possible
signal sources.
IEC 61850 IEC 60617
identification identification
MHZPDIF 3dIHi>M
Description
Three-phase currents
1MRS759142 F
ANSI/IEEE C37.2
device number
87HIM
REX640
Technical Manual