Technical
Specifications
Copyright © Itech Electronics Co., Ltd.
47
8.7 Frequency Measurement
Item
Specification
Measurement item
voltage or current frequencies applied to one selected
input element can be measured
Frequency
measurement
range
vaties depending on the data update interval (see
description given later)as follows
Data update interval
measurement range
0.1s
25Hz
≤ f ≤100kHz
0.25s
10Hz
≤ f ≤ 100kHz
0.5s
5Hz
≤ f ≤ 100kHz
1s
2.5Hz
≤ f ≤ 100kHz
2s
1.5Hz
≤ f
≤ 50kHz
5s
0.5Hz
≤ f ≤ 20kHz
Frequency filter
select OFF or ON (cutoff frequency of 500Hz)
Accuracy
requirements : When the input signal level is 30% or
moreof the measurement range if the crest factor is set
to 3 (60% or more if the crest factor is set to 6) , frequency
filter is ON when measuring voltage or current of 200Hz or
less. Accuracy:±(0.06%of reading)
8.8 Harmonic Measurement
Measured item
all installed elements
Method
PLL synchronization method
Frequency range
fundamental frequency of the PLL source is in the
range of 10Hz to 1.2kHz
PLL source
select voltage of current of each input element
When PF=3, the input level is equal to or greater than 50% of
the rated range
When PF=6, the input level is equal to or greater than 100%
of the rated range
When fundamental frequency is less than or equal to 200Hz,
the frequency filter must be opened.
FFT data length
1024
Measurement parameter
Name
Symbols and meanings
Voltage(V)
U(k): voltage effective
value of Kth harmonic
U(Total): voltage
effective value
Current(A)
I(k): curent effective value
of Kth harmonic
I(Total): curent effective
value
Active
power(W)
P(k): active power of Kth
harmonic
P(Total): Active power
Apparent
power(VA)
S(k): apparent power of
Kth harmonic
S(Total): total apparent
power
Reactive
power(var)
Q(k): reactive power of Kth
harmonic
Q(Total): total reactive
power
Power
factor
PF(k) : power factor of Kth
harmonic
PF(Total): Total power
factor
phase
φ(k): phase difference φ:
total
phase
