Date Code 20001006 Overcurrent, Voltage, Synchronism Check, Frequency, and Power Elements 3-47
SEL-351 Instruction Manual
Resulting in:
Angle Difference = (∠V
P
- ∠V
S
) + [(f
P
- f
S
) x TCLOSD x (1 second/60 cycles) x
(360°/slip cycle)]
= (∠V
P
- ∠V
S
) + [-0.10 x 0.167 x 360°]
= (∠V
P
- ∠V
S
) - 6°
During the breaker close time (TCLOSD), the voltage angle difference between voltages V
P
and V
S
changes by 6°. This 6° angle compensation is applied to voltage V
S
, resulting in derived voltage
V
S
*
, as shown in Figure 3.28 (Note: The angle compensation in Figure 3.28 appears much greater
than 6°. Figure 3.28 is for general illustrative purposes only).
Courtesy of NationalSwitchgear.com
To Next Page
