Basler Electric BE1-40Q - Manual (Page 44)

Step 3. The results from the above calculations can now be plotted on a graph of the complex power
plane.
Graph Example
Given:
Relay style number is F3E-E1P-B1S1F. (Reference the Style Chart, Figure 1-4.)
Pickup is set to 125. (Reference Table 1-1.)
Test results are obtained as given in Step 1. For this example, we are using the data shown in
columns [1] and [2] of Table 5-4.
Step 1. Calculate P and Q for a current phase angle of 20
° (Ө = –20°).
( ) ( )
° − =
20 cos 806 . 3
3
120
P
= 247.8 W
( ) ( )
° − =
20 sin 806 . 3
3
120
Q
= –90.18 vars
Note that the above results for a phase angle of –20
° have been entered in Table 5-4, columns
[3] and [4], first row. Similarly, the values of P and Q can be solved for the other phase angles of
column [1].
Step 2. Finally, the data from Table 5-4 is shown plotted on the complex power plane shown in Figure
5-3. A blank graph is provided as Figure 5-4.
Table 5-4. Data for the Hypothetical Graph of Figure 5-3
[1] [2] [3] [4]
Current Source
Phase Angle Degrees
System Phase
Angle
Ө
Current Magnitude for
Pickup (Amps)
Real Power
(Watts)
Reactive
Power (Vars)
+20 –20 3.806 247.76
–90.18
+30 –30 2.902 174.12 –100.53
+40 –40 2.404 127.60
–107.07
+50 –50 2.107 93.82 –111.81
+60 –60 1.927 66.75 –115.62
+70 –70 1.827 43.28 –118.92
+80 –80 1.788 21.51 –121.98
+90 –90 1.804 0.00 –125.00
+100 –100 1.879 –22.60 –128.18
+110 –110 2.024 –47.95 –131.74
+120 –120 2.267 –78.54 –136.04
NOTE
If:
β,
I I and V V
∠ = ∝ ∠ =
Then:
Real power (P) =
( )
,
β
- cos I V
∝ ×
Reactive power (Q) =
( )
and ,
β
- sin I V
∝ ×
System power factor angle (Ө) = β − ∝
5-6 BE1-40Q Setting and Testing 9171500990 Rev N