Ac Voltage And Current Waveforms - ABB ACS800-37-0060-3 Hardware Manual

AC voltage and current waveforms

The AC current is sinusoidal at a unity power factor. 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 voltage depends slightly on the Short Circuit
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
I , U
u
U
i
U
An example spectrum and THD value of the current at the input of the drive are
shown below. Each harmonic is presented in percent of nominal current. n denotes
the ordinal number of the harmonic.
I [%]
10
9
8
7
6
5
4
3
2
1
0
THD 3 5 7 9
) and phase voltage (u
U
11 13 15 17 19 21 23 25
) waveforms are shown below.
U
27 29 31 33 35 37 39 41
33
t [ms]
n
43 45 47 49
The ACS800-37