Predictive Control of Three Phase AC/DC Converters

86 CHAPTER 5. INVESTIGATIONS OF CONTROL METHODS PERFORMANCE
Line voltage CSF-P-DPC VF-CSF-P-DPC
distortion T HD u F sw 5 kHz F sw 5 kHz
5% (Fig. 5.11) 4.4 1.7
4.5% (Fig. 5.12) 5.7 1.6
17.4% (Fig. 5.13) 17.6 5.5
10.6% (Fig. 5.14) 7.1 3.6
Table 5.1: Summarized line current T HD i factors
5.4.2 Influence of Line Voltage Sags
Connections and disconnections of large loads, and short circuits in the system
can cause line voltage sags (sudden drop of line voltage value). In this subsection,
operation of CSF-P-DPC and VF approach under single and two phase voltage
sags will be investigated.
u La
u Lb
u Lc
CSF-P-DPC
(a)
VF-CSF-P-DPC
i La
(b)
u La
U DC
i La
P ref
Figure 5.15: Operation under single phase voltage sag: (a) line voltages u La , u Lb ,
u Lc (100 V/div), line current i La (10 A/div), (b) line voltage u La (200 V/div),
U DC voltage (100 V/div), line current i La (10 A/div), referenced active power
P ref (1 kW/div)
Figure 5.15 shows operation under single phase sag. As it can be seen, line