Verifying Settings - ABB REG670 2.0 IEC Commissioning Manual

1MRK502053-UEN B
12.6.6.2
Generator protection REG670 2.0 IEC
Commissioning manual
Testing functionality by secondary injection
DU
=
Beta
U
3 N
EQUATION2072 V2 EN
considering stated accuracy (beta is a setting parameter)
4. Increase the voltage U
U to zero and measure the time delay for the activation of the signals TRIP and
3N
TRIP3H.
The 100% stator earth fault protection also has a fundamental frequency neutral
point overvoltage function (95% stator earth fault protection). This part of the
protection can be tested separately by means of fundamental frequency voltage
injection from a test equipment.

Verifying settings

1. With the generator rotating at rated speed but not connected: check the value of
the following analogue signals: E3 (the magnitude of the 3
voltage in the stator), U
measured at the neutral side of the generator), U
harmonic voltage measured at the terminal side of the generator) and ANGLE
(the angle between the third-harmonic voltage phasors U
of E3 should be close to the following value:
(
= -
E3 U U
3 N 3T
EQUATION2076 V1 EN
Make sure that ANGLE has a value bigger than 125°
2. Read the value of DU (differential voltage). The value of DU should be close to
the following value:
(
= +
DU U U
3 N
EQUATION2078 V1 EN
3. Read the value of BU (bias voltage: Beta ·U
below 1 for a non-faulted generator.
4. After synchronization of the generator the ratio DU/BU is checked for different
load levels of the generator. These different monitoring of load levels should be
the base for the setting of beta.
If the function is used with the option of neutral point measurement only the test
is performed by check of this voltage. The operate value should be above the
measured residual third-harmonic voltage in the neutral point at normal
operation (non-faulted generator).
so that the sart signal falls. After that, switch the voltage
3N
(the magnitude of the third-harmonic voltage
3N
) (
2
× +
cos(ANGLE) U
3T
) (
2
× +
cos(ANGLE) U
3T
Section 12
rd
harmonic induced
(the magnitude of the third-
3T
and U
3N 3T
)
2
×
sin(ANGLE)
)
2
×
sin(ANGLE)
3T
). The ratio DU/BU should be well
3N
(Equation 102)
). The value
(Equation 103)
(Equation 104)
187