Protection Function Logic
281
7UM62 Manual
C53000-G1176-C149-3
2.44
Protection Function Logic
The function logic is the heart of the device. It coordinates the sequence of both the
protective and auxiliary functions, processes functional decisions, and processes data
received from the system. In particular, the function logic is responsible for the
following:
•
Processing Measurement and Detection Logic
•
Processing Tripping Logic
2.44.1 Functional Description
2.44.1.1 Processing Tripping Logic
General Device
Pickup
The pickup signals for all protective functions in the device are connected via an OR
function, and lead to the general device pickup. General device pickup is initiated by
the first function to pickup, and general device drop out occurs when the last function
drops out. A corresponding message ”
Dev. Pickup
” indicating that general device
pickup has occurred is reported.
General device pickup is a precondition for a series of internal and external functions
that occur subsequently. The following are among the internal functions controlled by
general device pickup:
•
Start of Trip Log: From general device pickup to general device drop out, all fault
messages are entered in the trip log.
•
Initialization of Oscillographic Records: The storage and maintenance of
oscillographic values can also be made dependent on the general device pickup.
•
Generation of Spontaneous Messages: Certain fault messages are displayed in the
device display as so-called spontaneous messages (see below ”Spontaneous
Messages”). These display messages can also be made dependent on the general
device trip.
Spontaneous
Messages
Spontaneous messages are fault messages that appear in the display automatically
when general device pickup has occurred. For the 7UM62, these messages include:
•
“
Relay PICKUP
”: protective function that last picked up
•
”
Relay TRIP
”:
protection function that last initiated a trip signal
•
“
PU Time
”:
running time from general device pickup to general device
dropout, with time indicated in ms;
•
“
TRIP Time
”:
running time from general device pickup to initiation of the first
trip signal by the device, with time indicated in ms;
Please note that the overload protection does not have a pickup comparable to the
other protective functions. The general relay pickup time
PU Time
is first started with
the trip signal, and an abnormal occurrence is opened. The dropout of the thermal
image of the overload protection ends the fault message and, thereby, the running
time from general relay pickup to general device dropout
PU Time
.
