If all three phase voltages and phase currents are fed to the protection
relay, the positive-sequence alternative is recommended.
The calculated powers S, P, Q and the power factor angle PF_ANGL are available in the
Monitored data view.
Level detector
The Level detector compares the magnitude of the measured apparent power to the set
Pickup value. If the measured value exceeds the set Pickup value, the Level detector sends
an enabling signal to the Timer module.
Directional calculation
The Directional calculation module monitors the direction of the apparent power. When
the apparent power flow is in the operating area, the module sends the enabling signal to
the Timer module. The directional operation can be selected with the combination of the
settings Directional mode and Power angle. The selectable options for the Directional
mode setting are "Forward" and "Reverse". The Power angle setting can be used to set the
power direction between the reactive and active power.
A typical error is, for example, that the VT or CT poles are wrongly
connected. This is seen as a power flow opposite to that of the intended
direction. The Pol Reversal setting can be used to correct the situation. By
setting the value to "True", the measured apparent power is turned 180
degrees.
Non trippting
area
Tripping
area
P
Q
Pickup value
GUID-88535C85-A1BA-414B-A73C-4E9FFAF6D630 V1 EN
Figure 362: Operating characteristics with the Pickup Value setting, the Power angle
setting being 0 and Directional mode "Forward"
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 727
Technical Manual
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