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2.3 ANALYSIS FUNCTIONS
DTR system keeps a historical record with the last 165 events with the following information: date and time (1 ms
resolution), event name (descriptive text), present measured voltages and internal status of the equipment.
This event register is recorded in a non-volatile memory (EEPROM) and it is maintained even if the power supply is
lost (independently from the duration of the external power supply interruption).
2.4 CONTROL FUNCTIONS
DTR systems include alarm generation and treatment functions. Alarms are relevant system operating conditions or
status, as defined by the user, which are desired to be specially indicated or signaled by the DTR system.
The user can define up to 48 alarms (32 protection alarms and 16 communications alarms). To define al Alarm, the
user may use all the information available in the internal status of the system, with the possibility to do logical
combinations of several statuses in order to generate an alarm.
Alarms will be shown on the graphical MMI display on the front panel of the relay, as soon as they are generated,
tagged with date and time information. Alarms will also be transferred through the communication link to the level 2
(substation level. Local Protection and control room) and Level 3 (dispatch center) if they are available and this
transfer is programmed.
There are four different status for a given alarm:
•
Active alarm and not acknowledged by the operator.
•
Active alarm and acknowledged by the operator.
•
Non active alarm and not acknowledged by the operator.
•
Non active alarm and already acknowledged by the operator.
DTR units will display alarms in different formats depending on their status. The text message associated to an
alarm, also defined by the user, will appear in the graphical MMI on the front panel using the following criteria:
-
Dark background means NOT ACKNOWLEDGED
Asterisk character means ACTIVE ALARM
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Therefore, according to this criterion the different formats will be displayed in the following way:
Active alarm and not acknowledged: Dark background, blinking text and marked with an asterisk.
Active alarm and acknowledged: Normal steady text marked with an asterisk.
Non active alarm and not acknowledged: Dark background, steady text marked with an asterisk
character
Non active alarm and acknowledged: Text disappears from LCD display.
By using the keys around the graphical display, user may acknowledge a particular alarm or all of them.
GEK-106305A
2. OPERATION PRINCIPLES
DTR Digital Tap Changer Controller
2.3.1 EVENT REGISTER
2.4.1 ALARMS TREATMENT
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