GEK-105593C
19
Recloser logic.
Figure 5, which shows the states diagram of the recloser, will help to understand this section. For those who
are not familiar with this type of representation the following paragraphs give a summary of how a states
diagram works.
The states diagram uses circles to represent each state of the recloser. In each circle there is a text with a
description of the actions the recloser has to carry out (wait, close, start timer, etc) or the name of the state
("lock-out", for example).
The double circle shows where the states diagram starts, which in this case is the "lock-out" state and
coincides with the end of the recloser function.
Each circle has at least one exit arrow and one input arrow. The exit arrow is called "transition" and has
some conditions associated with it. This means that for the recloser to pass from this state to the next one,
the conditions indicated in the transition must be fulfilled. The logical condition AND is shown by a dot (·),
and the logical condition OR is represented by the plus sign (+). The complement or negation is represented
by a bar situated above the condition. The transitions which refer to times occur at the end of the time period
indicated in the previous state.
We will now give an example of how the recloser works using a "normal" sequence for only one
programmed reclosing attempt.
Let us suppose that the starting point is the "lock-out" status and that the breaker is open. Then a manual
closing command is issued, the breaker closes and the automate passes to the next state in which it starts
the reset timer. When this time has passed successfully (without the occurrence of any reclose initiation), the
recloser checks the blocking signal. If there is no block, the recloser resets itself, getting ready for the first
reclosing attempt. This means that the unit has to get ready to count the time for the first reclosing attempt,
to initiate the recloser only for the programmed functions and to get ready to trip after the reclosure only for
the functions allowed to trip after the first reclosure.
It then passes to the reset state and leaves this state when the first reclose initiation occurs, whether it is
external (IRE) or internal. To simplify things, let us imagine that we are in the most common situation which
shows the reclose initiation as being internal.
The recloser initiates the first reclosing timer if the following three conditions are met : that the breaker opens
after the trip, the protection system does not issue a trip signal and the last programmed reclosing attempt
has not occurred. After this time the unit checks whether any reclosing condition has been programmed. If
none has been programmed, or if it has been programmed and the condition is met, a reclosing command is
issued immediately and the Closing Time is started. (Tclose).
If the breaker closes successfully, the unit will detect that the breaker has closed and will start the reset time.
After this time, assuming there is no failure, the recloser will return to the initial reset state and will be ready
to carry out a complete new reclosing cycle.
For the most general case of "n" reclosing attempts, from the last state (start reset time) the cycle would be
repeated until it reaches the n programmed reclosing attempt, assuming the fault persists. If the last
reclosing is attempted unsuccessfully, the unit will go into the lock-out status and will only change this status
by means of a manual breaker closing.
The SMOR reclosing unit has been designed to achieve the following objectives:
•
To increase safety. In any "anomalous" situation the recloser goes into lock-out.
•
To make it independent of the protection functions. The only protection function required by the
recloser is the breaker FAILURE TO OPEN and the detection of a TRIP condition and its corresponding
RECLOSE INITIATION.
•
To offer maximum flexibility. By means of settings made using the communication software, keyboard
or digital inputs it is possible to generate almost any imaginable reclosing scheme.
Figure 5 shows the recloser states diagram.
Summary of Contents for SMOR-B GEK 105593C
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Page 89: ...GEK 105593C 84 FIGURE 1 PANEL DRILLING DIMENSIONS FOR 19 RACK MODELS 226B6086H10 ...
Page 91: ...GEK 105593C 86 FIGURE 3 INVERSE CHARACTERISTIC OPERATING CURVE 226B7414H1 ...
Page 92: ...GEK 105593C 87 FIGURE 4 VERY INVERSE CHARACTERISTIC OPERATING CURVE 226B7414H2 ...
Page 93: ...GEK 105593C 88 FIGURE 5 EXTREMELY INVERSE CHARACTERISTIC OPERATING CURVE 226B7414H3 ...
Page 94: ...GEK 105593C 89 FIGURE 6 RECLOSER PROGRAM FLOWCHART 226B2200H1 ...
Page 95: ...GEK 105593C 90 FIGURE 7 FRONT VIEW FOR 19 RACK MODELS 226B7412H9 ...
Page 96: ...GEK 105593C 91 FIGURE 8 FRONT VIEW FOR 1 2 RACK MODELS ...
Page 97: ...GEK 105593C 92 FIGURE 9 EXTERNAL CONNECTIONS FOR 19 MODELS 189C4101H1 ...
Page 100: ...GEK 105593C 95 FIGURE 13 REAR VIEW FOR 19 MODELS 226B7412H10 ...
Page 102: ...GEK 105593C 97 FIGURE 15 DIMENSIONS DIAGRAM FOR 19 MODELS 226B6086H10 ...
