Predictive Control of Three Phase AC/DC Converters

6.1. STEADY STATE OPERATION 93
Control F sw F swAV F swMax F s T HD
Method per cycle [kHz] [kHz] [kHz] [%]
ST-DPC var. 3.6 40 40 3.6
VSF-P-DPC var. 3.7 20 20 2.7
HC-VSF-P-DPC var. 3.7 20 20 5.6
FL-VSF-P-DPC var. 3 20 20 4.4
DPC-SVM fixed 5 5 5 2.1
CSF-P-DPC fixed 5 7.5 7.5 0.7
VF-CSF-P-DPC fixed 5 7.5 7.5 0.8
Table 6.2: Sampling and switching frequencies of tested control methods and
achieved T HD factors
(a) (b) DPC-SVM (c)
CSF-P-DPC
VF-CSF-P-DPC
Figure 6.4: Line current T HD factors and spectrum in: DPC-SVM, CSF-P-DPC
and VF-CSF-P-DPC, (a) T HD factor measured up to 2.5 kHz, (b) harmonics
spectrum up to 2.5 kHz, (c) harmonics spectrum up to 12.5 kHz
For fixed switching frequency approaches (see Tab. 6.2) line current spectrum
is concentrated around switching frequency (Fig. 6.4 (c)). In other cases the
spectrum is spread over wide range of frequencies. The exception is HC-VSF-P-
DPC, which allows to concentrate current spectrum within desired frequency (in
presented case around 4 kHz, Fig. 6.3 (c)). However, it generates also low order