Predictive Control of Three Phase AC/DC Converters

(Sa=1, Sc=0) UP2 (Sa=1, UP1 Sb=1, Sb=0, Sc=0) UP3 (Sa=0, Sb=1, Sc=0) 1 1 1
UP5 (Sa=0, Sb=0, Sc=1) UP6 (Sa=1, Sb=0, Sc=1) 0 0 0 A B C 1 1 1
0 0 0 A B C A B C 1 1 1
0 0 0
1 1 1 A B C 1 1 1 A B C 1 1 1 Sc=1) Sb=1, (Sa=0, UP4
0
(Sa=0, Sb=0, Sc=0) 0 0 0 UP0
(Sa=1, Sb=1, Sc=1) 0 0 0 0 0 A B C
UP7
2.2. MATHEMATICAL MODEL OF VSC 9
as L and R respectively. Six IGBT transistors with parallel placed freewheeling
L
Ra uPa iLa uLb uLa Lb La iLb iLc Rb Rc uPb uPc UDC A
C B + IDC ic iload
Lc uLc
O
A
D
Figure 2.2: Scheme of VSC
-
Voltage Source Converter DC-side
diodes create VSC module. There are two transistors connected in series per leg.
Transistor is “on” when gate signal is “1 ” and “off ” when gate signal is “0 ”. Such
AC-side
a topology gives 64 possible states of the converter, however only 8 are permitted
and generates voltage vectors U P . Figure 2.3 shows permitted states of the
converter. It gives 6 active voltage vectors and 2 zero vectors. The converter
1 1 1 A B C 1 1 1
0 0 0 A B C
Figure 2.3: Switching states of VSC
0 0 0