Line-to-neutral voltages available
Power is calculated from line-to-neutral voltages and phase currents. If line-to-line voltages are
connected, the relay can calculate line-to-neutral voltages based on the measured zero sequence
voltage. The following equations apply for power calculations with the line-to-neutral mode and the line-
to-line voltage mode (with U0 connected and measured):
Figure. 5.2.3. - 47. Three-phase power (S) calculation.
Figure. 5.2.3. - 48. Three-phase active power (P) calculation.
In these equations, phi (φ) is the angle difference between voltage and current.
Figure. 5.2.3. - 49. Three-phase reactive power (Q) calculation.
Active power can be to the forward or the reverse direction. The direction of active power can be
indicated with the power factor (Cos (φ), or Cosine phi), which is calculated according the following
formula:
AQ-E215
Instruction manual
Version: 2.01
© Arcteq Relays Ltd
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