GE DTR GEK-106305A, Instruction Manual

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2. OPERATION PRINCIPLES
GEK-106305A DTR Digital Tap Changer Controller 11
The steady statuses of the automatism are the following:
1. Stopped:
DTR reaches this state by means of a Stop command and it can only leave this state by means of a Manual
command or an Automatic command.
2. Automatic:
DTR reaches this state by means of an Automatic command.
In this status, DTR system is always checking if the necessary conditions exist, to initiate a OLTC operation. When
these conditions exist, a timer is started and the DTR reaches the Timing Operation Status.
3. Manual:
The DTR system reaches this status by means of a Manual command or when it is in Automatic mode and there is
an anomalous situation such as
Irregular Tap Change, Regulator Alarm, Failed Tap-up/tap-down, etc . In this state
the DTR system is waiting for Tap-up, Tap-down, Automatic or Stop commands.
4. Timing Operation:
In this status, the DTR system is checking the operation conditions and counting the Operating Time. If the operation
conditions disappear, the DTR returns to
Automatic state, and if the Operation Time is exceeded, the DTR system
changes to Tap-up/ Tap-down status.
5. Tap-Up:
When the DTR system is in this state, it checks whether the OLTC is in the maximum tap; if so, then the DTR system
stops the operation. Otherwise, the DTR stays in this state during the time set for Operation Pulse before changing to
Waiting for Tap-up state.
6. Tap-Down:
When the DTR system is in this state, it checks whether the OLTC is in the minimum tap; if so, then the DTR system
stops the operation. Otherwise, the DTR stays in this state during the time set for
Operation Pulse before changing to
Waiting for Tap-Down state.
7. Waiting for Tap-up:
In this state, the DTR system waits for the change in the OLTC. If the Success Time finishes its count and the tap
change has been successful (OLTC has raised the tap) then the DTR changes to Successful Tap-up state, if not,
the DTR changes to Failed Tap-up .
8. Waiting for Tap-down:
In this state, the DTR system waits for the change in the OLTC. If the Success Time finishes its count and the tap
change has been successful (OLTC has lowered the tap) then the DTR changes its status to Successful Tap-down ;
if not, the DTR changes to Failed Tap-Down state.
9. Successful Tap-Up:
This state shows that the tap increase operation has been successful. The DTR system returns to the initial state,
previous to the tap increase, either Manual or Automatic.