The ACS800-11/U11
26
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 current is given in chapter Technical data /
Input power connection. The 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
U
) and voltage (u
UV
) waveforms are shown below (Note: The
diagrams represent a larger unit than the ACS800-11).
An example spectrum of the voltage distortion at the output of the transformer is
shown below. Each harmonic is presented as compared to fundamental voltage
(reference value = 1). n denotes the ordinal number of the harmonic.
-1200
-800
-400
0
400
800
1200
02468101214161820222426283032343638
u
UV
t [ms]
i
U
I , U
0
0,5
1
1,5
2
THD 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 181 191
To Next Page
Loading...
Need help?
General