Woodward LS-5 v2 Series - Phase Shift

The alarm must be acknowledged and
reset by manually pressing the
appropriate buttons or by activating
the LogicsManager output "External
acknowledgement" (via a discrete
input or via an interface).
4.3.1.3 Phase Shift
General notes
A vector/phase shift is de󰈡ned as the sudden variation of the voltage curve which may be
caused by a major generator load change.
The unit measures the duration of a cycle, where a new measurement is started with
each voltage passing through zero. The measured cycle duration will be compared with
an internal quartz-calibrated reference time to determine the cycle duration di󰈠erence of
the voltage signal.
A vector/phase shift as shown in ╚═▷ Fig. 73 causes a premature or delayed zero passage.
The determined cycle duration di󰈠erence corresponds with the occurring phase shift
angle.
Fig. 73: Phase shift
The monitoring may be carried out three-phase or one/three-phase. The monitoring can
be con󰈡gured in di󰈠erent ways. The vector/phase shift monitor can also be used as an
additional method to decouple from the grid. Vector/phase shift monitoring is only
enabled after the monitored voltage exceeds 50% of the PT secondary rated voltage.
Function "Voltage cycle duration not within the permissible range"
The voltage cycle duration exceeds the con󰈡gured limit value for the phase/vector shift.
The result is, that the power circuit breaker that disconnects from the mains, is opened,
the message "SyA. phase shift" is displayed, and the logical command variable "07.14" is
enabled.
The "Phase shift"
con󰈡guration parameters are located below the "SyA. decoupling"
function menu on the display.
100 LS-5 v2 Series 37650
4 Con󰈡guration
4.3 Con󰈡gure Monitoring
Released