Seg HighTECH MRU3-2, Руководство пользователя

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TB MRU3-2 12.00 E 15
5.2 Setting procedure
In this paragraph the settings for all relay parameters
are described in detail. For parameter setting a pass-
word has to be entered first (please refer to 4.4 of de-
scription "
MR -Digital Multifunctional Relays").
5.3 System parameter
5.3.1 Display of residual voltage U
E
as primary quantity (U
prim
/U
sec
)
The residual voltage can be shown as primary measur-
ing value. For this parameter the transformation ratio of
the VT has to be set accordingly. If the parameter is set
to "sec", the measuring value is shown as rated secon-
dary voltage.
Example:
The voltage transformer used is of 10 kV/100 V. The
transformation ratio is 100 and this value has to be set
accordingly. If still the rated secondary voltage should
be shown, the parameter is to be set to 1.
5.3.2 D/Y – Switch - over
Depending on the mains voltage conditions, the input
voltage transformers can be operated in delta or Y
connection. Change-overs are effected via the <+>
and the <-> keys and stored with <ENTER>.
5.3.3 Setting of nominal voltage
For proper functioning it is necessary to first adjust the
rated frequency (50 oder 60 Hz).
It can be selected between „f = 50 Hz“, „f = 60 Hz“
or „v = 50 Hz“, “v = 60 Hz”.
The difference lies in the method of voltage measuring.
With the setting "v = 50 Hz“ or “v = 60 Hz” voltage
measuring is independent of the existing frequency.
This means, the voltage value can be correctly meas-
ured between 40 Hz and 70 Hz without adverse ef-
fects from the frequency.
With the setting "f“ = 50/60 Hz the measured voltage
value is influenced by the frequency. (see Table 5.2)
Declination of measuring value at 50Hz
97,5
98,0
98,5
99,0
99,5
100,0
100,5
44 46 48 50 52 54 56
[%]
[Hz]
Declination of measuring value at 60Hz
97,5
98,0
98,5
99,0
99,5
100,0
100,5
54 56 58 60 62 64 66
[%]
[Hz]
Table 5.2:
Impairment of voltage measuring
This difference in settings is required for the fault re-
corder. If the fault recorder is to be used, the setting
must be f = 50 Hz or f = 60 Hz.
At 50 Hz or 60 Hz the fault recorder determines 16
measured values per period. With the setting "v = 50
Hz" or “v = 60 Hz” 16 measured values of the pres-
ently measured frequency would always be deter-
mined. The disturbance recorder would not indicate
any frequency changes and thus render incorrect
measuring results.
Setting v = 50 f = 50 v = 60 f = 60
Rated frequency
50 Hz 50 Hz 60 Hz 60 Hz
Influence on voltage
measurement
none 0,5..1%/Hz
(refer to table 5.1) none 0,5..1%/Hz
(refer to table 5.1)
Fault recorder
Recording
distorted** Recording
correct** Recording
distorted** Recording
correct**
Influence on all other
functions
none none none none
Table 5.3: Deviation of measured value at 50 Hz or 60 Hz
* Setting is important for correct recording of fault recorder
** Sample rate is variably adjusted to the momentarily measured frequency. 16 samples are always measured in one period.
*** Sample rate setting is fixed to 50 Hz or 60 Hz. 16 samples per 20 ms or 16.67 ms are always measured.