ABB Relion 620 Series - High-Impedance;Flux-Balance Based Differential Protection for Motors MHZPDIF

4.3.6 High-impedance/flux-balance based differential
protection for motors MHZPDIF
4.3.6.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
High-impedance/flux-balance based
differential protection for motors
MHZPDIF 3dIHi>M 87MH
4.3.6.2 Function block
Figure 312: Function block
4.3.6.3 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.
4.3.6.4 Operation principle
The function can be enabled and disabled with the Operation setting . The
corresponding parameter values are "On" and "Off".
The operation of MHZPDIF can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
Figure 313: Functional module diagram
1MRS757644 H
Protection functions
620 series
Technical Manual
597