Woodward HighPROtec MCDLV4, Manual, Page: 879 / 1275

Protective Elements
Sync - Synchrocheck [25]
Available Elements:
Sync
The synchrocheck function can be bypassed by external sources. In this case,
synchronization has to be secured by other synchronizing systems before
breaker closing!
The first three measuring inputs of the voltage measuring card (VL1/VL1-L2,
VL2/VL2-L3, VL3/VL3-L1) are named /labeld as bus voltages within the snyc-
check element (this applies also to generator protection devices). The fourth
measuring input of the voltage measuring card (VX) is named/labeld as line-
voltage (this applies also to generator protection devices). In the menu [Field
Para/Voltage transf/V Sync] the User has to define to which phase the fourth
measuring input is compared.
Synchrocheck
The synchrocheck function is provided for the applications where a line has two-ended power sources. The
synchrocheck function has the abilities to check voltage magnitude, angle differences, and frequency difference
(slip frequency) between the bus and the line. If enabled, the synchrocheck may supervise the closing operation
manually, automatically, or both. This function can be overridden by certain bus-line operation conditions and can
be bypassed with an external source.
Voltage Difference
ΔV
The first condition for paralleling two electrical systems is that their voltage phasors have the same magnitude. This
can be controlled by the generator's AVR.
879 MCDLV4 DOK-HB-MCDLV4-2E
Line VL1
Bus VL2
Line VL3
Line VL2
Bus VL1
Bus VL3