Predictive Control of Three Phase AC/DC Converters

5.4. LINE VOLTAGE DISTURBANCES 85
(a) (b) CSF-P-DPC
(c)
VF-CSF-P-DPC
Figure 5.13: Experimental steady state system operation under 12% of fifth
and 12% of seventh harmonics distorted line voltage: (a) line voltage u La , line
current i La , (b) line voltage u Lph−ph T HD u factor, (c) line current T HD i factor
(a) (b) CSF-P-DPC
(c)
VF-CSF-P-DPC
Figure 5.14: Experimental steady state system operation under 2% of seventh,
8.5% of eleventh and 1.3% of thirteenth harmonics distorted line voltage: (a) line
voltage u La , line current i La , (b) line voltage u Lph−ph T HD u factor, (c) line
current T HD i factor
In case of VF approach, control tries to keep constant values of instantaneous
powers, which are related to the fundamental frequency. Due to virtual flux
features (like natural filtering of higher harmonics) it is possible to achieve nearly
sinusoidal shape of the line currents, even under distorted line voltages.