Thytronic Pro-N NVA100X-D

96
NVA100X-D - Manual - 02 - 2016
FUNCTION CHARACTERISTICS
Directional active underpower - 37P
Preface
The active power is calculated as:
P=U
L1
I
L1L
cosφ
L1
+ U
L2
I
L2L
cosφ
L2
+U
L3
I
L3L
cosφ
L3
where:
U
L1
, U
L2
, U
L3
are the fundamental components of the phase-to-neutral voltages
II
L1L
, I
L2L
, I
L3L
are the fundamental components of the side L phase currents
cosφ
L1
, cosφ
L2
, cosφ
L3
are the phase power factors
φ
L1
, φ
L2
, φ
L3
, are the displacement angles of phase currents I
L1
, I
L2
, I
L3
respect to the phase voltages
U
L1
, U
L2
, U
L3
, (positive when lag currents compared the phase voltages).
For the conventions on the active power sign please refer to the wiring diagram.
Operation and settings
The element is enabled for start and trip on the base of the direction setting for the two indepen-
dently programmable thresholds.
User can disable the 37P protection threshold from the keyboard. During this command, the trip
output relay (U <and / or U << thresholds) are forced to reset state, the message “Disabled 27-27V1-
37P-37Q” is displayed and all LEDs blink until the end of the command.
P1< Tripping direction: P Forward:
P1< Tripping direction: P Reverse:
P1< Tripping direction: P Forward/Reverse:
—
•
•
•
P
Q
TRIP
P
1
<
P1< Tripping direction: P Forward:
General operation time characteristic for the directional active underpower element - 37P
P
Q
TRIP
P
1
<
P1< Tripping direction: P Forward:
General operation time characteristic for the directional active underpower element - 37P
P
Q
TRIP
P
1
<
P1< Tripping direction: P Reverse:
General operation time characteristic for the directional active underpower element - 37P
P
Q
TRIP
P
1
<
P1< Tripping direction: P Reverse:
General operation time characteristic for the directional active underpower element - 37P
P
Q
TRIP
P
1
<
P
1
<
P1< Tripping direction: P Forward/Reverse:
General operation time characteristic for the directional active underpower element - 37P
P
Q
TRIP
P
1
<
P
1
<
P1< Tripping direction: P Forward/Reverse:
General operation time characteristic for the directional active underpower element - 37P