Setting parameters are static inputs for the function which are changed only by user input in the setup
phase of the function. Sequence voltage function utilizes total of eight separate setting groups which
can be selected from one common source.
The function can be operating on instant or time delayed mode. In time delayed mode the settable
operation modes are either de nite time or IDMT.
The operational logic consists of input magnitude processing, input magnitude selection, threshold
comparator, block signal check, time delay characteristics and output processing.
Inputs for the function are the operating mode selections, setting parameters and measured and pre-
processed voltage magnitudes and binary input signals. Function outputs are START, TRIP and
BLOCKED signals which can be used for direct IO controlling and also for user logic programming. The
function registers its operation into 12 last time-stamped registers and also generates general time
stamped ON/OFF events to the common event buffer from each of the three output signal. In instant
operating mode the function outputs START and TRIP events simultaneously with equivalent time
stamp. Time stamp resolution is 1ms. Function provides also cumulative counters for START, TRIP and
BLOCKED events.
Simpli ed function block diagram of the positive sequence protection is presented in the following
gure.
Figure. 5.4.14. - 83. Simpli ed function block diagram of the sequence voltage function.
Measured input values
The function block uses analog voltage measurement values. Function block always utilizes
fundamental frequency RMS values. -20 ms averaged value of the selected magnitude is used for the
pre-fault data registering.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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