Check The Undervoltage Block Function; Check The Upper And Lower Busbar Voltage Limit; Check The Overcurrent Block Function - Hitachi RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /Time /t1
and t2
3. Lower the voltage 1% below U1 and wait for the issue of a Raise command from the voltage
control after the expiry of a constant or inverse time delay set by t1. Detection of this command
will involve locating the allocated binary output for a raise pulse command in the Signal Matrix
in PCM600 and monitoring a positive from this output.
4. After the issue of the raise command, return the applied voltage to USet (nominal value).
5. Raise the voltage 1% above the upper deadband limit U2 and wait for the issue of a lower
command from the voltage control after the expiry of a constant or inverse time delay set by t1.
Detection of this command will involve locating the allocated binary output for a low pulse
command in the Signal Matrix in PCM600 and monitoring a positive from this output.
6. Return the applied voltage to USet.
11.11.5.4

Check the undervoltage block function

1. Confirm the setting for Ublock, nominally at 80% of rated voltage.
2. Confirm the voltage control function response to an applied voltage below Ublock, by reviewing
the setting in the local HMI under Main menu /Settings /IED Settings /Control /
TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /UVBk that
may cause an alarm, total or automatic block of the voltage control function to be displayed on
the local HMI.
3. Apply a voltage slightly below Ublock and confirm the response of the voltage control function.
11.11.5.5

Check the upper and lower busbar voltage limit

1. Confirm the settings for Umin and Umax in the local HMI under Main menu /Settings /IED
Settings /Control /TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90,
U↕||):x /Voltage /Umax or Umin and Main menu/Settings /IED Settings/Control /TR8ATCC
(90)/TR8ATCC:n /Voltage/Umax
2. Confirm the voltage control function response to an applied voltage below Umin and above
Umax, by reviewing the settings in the local HMI under Main menu /Settings /IED Settings /
Control /TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /
UVPartBk and Main menu /IED Settings /Control /TransformerVoltageControl(90, U↕) /
TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /OVPartBk. These conditions may cause an alarm
or total block of the voltage control function to be displayed on the local HMI.
3. Decrease the injected voltage slightly below the Umin value and check for the corresponding
blocking or alarm condition on the local HMI. For an alarm condition, the voltage regulation
function is not blocked and a raise command should be issued from the IED.
4. Increase the applied voltage slightly above the Umax value and check for the corresponding
blocking or alarm condition on the local HMI. For an alarm condition, the voltage regulation
function is not blocked and a lower command should be issued from the IED.
11.11.5.6

Check the overcurrent block function

1. Confirm the setting for Iblock in the local HMI under Main menu /Settings /IED Settings /
Control /TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /
TCCtrl /Iblock
2. Confirm the voltage control function response to an applied current above Iblock, by reviewing
the settings in the local HMI under Main menu /Settings /IED Settings /Control /
TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /OVPartBk.
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1MRK 504 165-UEN Rev. K
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Transformer protection RET670
Commissioning manual