D-PRO Protection relay Technical Manual 43
In the slope segment A-B, where Is is lower than the value set in the parameter P.0373 (Is2)
and Id is higher than P.0371 (Id1), the protection triggers if:
1
)
(
K
Id
Is
misurata
if Is < Is2 and Id > Id1 (K1 = P.0374)
In the slope segment B-C, where Id is lower than the value set in the parameter P.0372 (Id3)
and Is is higher than P.0373 (Is2), the protection triggers if:
2
)
(
K
OF
Id
Is
misurata
−
if Id < Id3 and Is > Is2 (K2 = P.0375)
OF is the extension of BC referred to the axis y and it is calculated as follows:
)
2
1
(
*
2
K
K
Is
OF
−
=
Anyhow, the protection is fixed according to the time configured in the parameter P.0376 (0 to
200msec maximum). Once the trigger threshold is exceeded, the controller waits for the time
configured before activating the alarm. If it is set to zero, the protection is disabled.
Notes
Is1 results from Id1:
Is1 = Id1 / K1
Id2 results from Is2:
Id2 = Is2 * K1
Is3 results from Id3:
Is3 = (Id3
– OF) / K2
Type:
Alarm
Related parameters:
P.0384
Power reverse threshold (% compared with P.0106)
P.0385
Power reverse delay
To disable:
P.0385 =0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status).
The controller measures the total active power on the three currents on side B.
The protection activates if the total active power of the system has a negative sign and is
higher (in absolute value) than P.0384 threshold (percentage of P.0106), uninterruptedly for
the P.0385 time span.
Type:
Alarm
Related parameters:
P.0386
Loss of excitement threshold (kvar)
P.0387
Loss of excitement delay
To disable:
P.0387 =0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status).
The controller measures the total reactive power on the three currents on side B.
The protection activates if the total reactive power of the system has a negative sign and is
higher, as to the module, than P.0386 threshold, uninterruptedly for P.0387 time span.
Summary of Contents for D-PRO
Page 11: ...D PRO Protection relay Technical Manual 5 2...
Page 52: ......
