26
AC voltage and current waveforms
The AC line current of the drive is sinusoidal with power factor equal to 1. The IGBT
supply unit does not generate characteristic current or voltage overtones like a
traditional 6- or 12-pulse bridge does.
The Total Harmonic Distortion (THD) in current is given in chapter Technical data /
Input power
Ratio in the Point of Common Coupling (PCC). The high frequency switching and
high du/dt slightly distort the voltage waveform at the input of the converter.
Typical line current (i) and voltage (u) waveforms are shown below.
Example spectra of the current and voltage distortion at the output of the transformer
are shown below. Each harmonic is presented as compared to fundamental voltage
(reference value = 1). n denotes the ordinal number of the harmonic.
Phase current (A)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
The ACS800-31/U31
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connection. The THD in voltage depends slightly on the Short Circuit
u (V)
i (A)
Test 13
n
t (ms)
t (ms)
Line-to-line voltage (%)
1.6
1.4
1.2
1.0
0.8
IL1 [A]
0.6
0.4
0.2
0.0
Test 13
UL12 [%]
n