Thytronic SME2-IS User Manual

38
38
SME2-IS - Manual - 06 - 2021
FUNCTIONAL CHARACTERISTICS
— Maximum directional active power - 32P
Measurement criterion
The protection calculates the active power P using the formula:
P=U
L1
I
L1
cosf
L1
+ U
L2
I
L2
cosf
L2
+U
L3
I
L3
cosf
L3
where U
L1
, U
L2
, U
L3
are the fundamental components of the three phase voltages, I
L1
, I
L2
, I
L3
are the
fundamental components of the three phase currents, cosf
L1
, cosf
L2
, cosf
L3
are the power factors
of the three phases and f
L1
, f
L2
, f
L3
, are the phase shifts of the phase currents I
L1
, I
L2
, I
L3
relative to
the phase voltages U
L1
, U
L2
, U
L3
respectively, considered conventionally positive with the currents
delayed relative to the voltages.
The active power is positive by convention when it is supplied from the substation to the user, and
negative when it is supplied to the substation by the generator.
Regulations
The protection is enabled to start and trip in the following three selectable modes:
• positive active power (default)
• negative active power
• positive or negative active power (modulus)
• For each of the three modes, the response when the threshold is exceeded can be selected:
• Only signal to the centre (Mode-a, default);
• This sends an alarms to the centre and an active power reduction signal to the effected generator
unit. If the threshold remains violated for a period of 30 s, a trip command is sent to the control
device (Mode-b);
• Trip command to the control device and signalling (Mode-c).
The protection is enabled at start and trip according to the tripping direction settings, which are
programmed independently for the two thresholds.
Tripping direction setting: Direct (Negative):
Tripping direction setting: Inverse (Negative):
Tripping direction setting: Direct / Inverse (Modulus)
The function has an adjustable tripping threshold (P>) which can be delayed (t
P
>) and has a time-in-
dependent characteristic.
P
Q
Tripping characteristic of the threshold P> of the Directional active overpower function
(32P)
Trip direction setting: P Direct (Positive)
TRIP
P>
P
Q
Tripping characteristic of the threshold P> of the Directional active overpower function
(32P)
Trip direction setting: P Inverse (Negative):
TRIP
P>
P
Q
Tripping characteristic of the threshold P> of the Directional active overpower function
(32P)
Trip direction setting: P Positive/Negative (modulus)
TRIP
P>
TRIP
P>

Thytronic SME2-IS Specifications

General

Brand	Thytronic
Model	SME2-IS
Category	Security Sensors
Language	English