Monitoring The Phase Angle Of The Positive Sequence Power - Siemens Siprotec 7VK61 Manual

Functions
2.7 Monitoring Function
Figure 2-49

2.7.1.4 Monitoring the Phase Angle of the Positive Sequence Power

This monitoring function allows to determine the direction of power flow. You can monitor the phase angle of
the complex power, and generate an indication when the power phasor is inside a settable segment.
One example of this application is the indication of capacitive reactive power. The monitoring indication can
then be used to control the overvoltage protection function. For this purpose, two angles must be set, as shown
in Figure 2-50. In this example, ϕA = 200° and ϕB = 340° has been set.
If the measured phase angle ϕ(S
by the angles ϕA and ϕB, the indication „ϕ(PQ Pos. Seq.)" (No. 130) is output. The angles ϕA and ϕB can
be freely set in the range between 0° and 359°. The area starts at ϕA and extends in a mathematically positive
sense as far as the angle ϕB. A hysteresis of 2° is provided to prevent erroneous indications which might
emerge at the threshold limits.
138
Logic diagram of the additional measured voltage failure monitoring
) of the positive sequence power is within the area of the P-Q plane delimited
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SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009