Arcteq AQ-F210, Инструкция по эксплуатации

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Instruction manual –AQ F210 Feeder Protection IED 229 (292
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changed only by user input in the setup phase of the function. THD function utilizes total of
eight separate setting groups which can be selected from one common source.
The operational logic consists of input magnitude processing, threshold comparator, block
signal check, time delay characteristics and output processing.
Inputs for the function are setting parameters and measured and pre-processed current
magnitudes and binary input signals. Function outputs THD Alarm act 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 two
output signal. Time stamp resolution is 1ms. Function provides also cumulative counters for
THD Start and Alarm act and BLOCKED events.
In the following figure is presented the simplified function block diagram of the THD function.
Figure 4.4.6-104 Simplified function block diagram of the THD function.
4.4.6.1 M
EASURED INPUT VALUES
Function block uses analog current measurement values. Function block always utilizes
FFT measurement of whole harmonic specter of 32 components from each measured
current channel which from the THD is calculated either as amplitude or power ratio THD. -
20ms averaged value of the selected magnitude is used for pre-fault data registering.