Manual 37143A
MFR 15 - Protection Relay & Control
Page 68/119
© Woodward
Vector / Phase Shift Monitoring (
Option V
)
A vector/phase shift is defined as the sudden variation of the voltage curve which may be caused by a major gen-
erator load change. The control unit measuring circuit detects the change in the cycle duration. This change in the
cycle duration is compared with a mean value calculated from previous measurements. The monitoring may be
carried out three-phased or one/three-phased. The threshold in degrees indicates the time difference between the
mean value and the instantaneous value, referring to the duration of a full cycle. The monitoring can be config-
ured in different ways. The vector/phase shift monitor can also be used as an additional method to decouple from
the mains. Vector/phase shift monitoring is only enabled after the monitored voltage exceeds 70% of the PT sec-
ondary rated voltage.
Function:
"Cycle duration of the voltage not within permissible limits"
The voltage cycle duration is not within the configured vector/phase shift limits. The alarm message "
Ph.
shift
" appears. This message can be suppressed with the discrete input "Blocking of protective functions / re-
mote acknowledgement".
Phase jump
monitoring ON
Vector/phase shift monitoring
ON/OFF
ON
................Vector/phase shift monitoring is enabled. The voltage/frequency cy-
cle duration is being monitored to ensure it does not exceed the de-
fined limits. The subsequent screens of this function are displayed.
OFF
..............Vector/phase shift monitoring is disabled, and the subsequent screens
of this function are not displayed.
Phase jump monit
----------------
Vector/phase shift monitoring
one/three phase / 3 phase only
one/three phase:
An alarm will be issued if the phase angle in any one phase ex-
ceeds the configured phase shift phase angle limit. Monitoring of
single-phase voltage is exceptionally sensitive and may lead to nui-
sance tripping if the configured phase angle is to low.
3 phase only:
An alarm will be issued if the phase angle in all three phases exceeds
the configured phase shift phase angle limit within two waveforms.
NOTE
If the monitoring is configured as "
3 phase only
", only one of the two subsequent screens will be
displayed. If the monitoring is configured as "
one/three-phase
", both configuration screens will be
displayed.
Phase-jump value
(One phase) 00°
This screen is only visible
if monitoring is configured
"one/three phase".
Vector/phase shift monitoring phase angle, single-phase
2 to 90 °
An alarm will be issued if the phase angle in any one phase exceeds the configured
phase shift phase angle limit. If the monitored voltage/frequency reaches or ex-
ceeds the phase shift limit, the unit outputs the message "
Ph. shift
". If a relay
was assigned to this function in the relay manager, that relay will be energized.
Phase-jump value
(3-phase) 00°
Vector/phase shift monitoring phase angle, three-phased
2 to 90 °
An alarm will be issued if the phase angle in any all three phases exceeds the con-
figured phase shift phase angle limit. If the monitored voltage/frequency reaches
or exceeds the phase shift limit, the unit outputs the message "
Ph. shift
". If a
relay was assigned to this function in the relay manager, that relay will be ener-
gized.
