SVPWM
Space Vector Pulse Width Modulation
Description
Connections
Parameters
Modelica Standard Library
The SVPWM component
For a three-phase system, 8 space vectors are available according to the following switching patterns:
0 [0,0,0] length 0
1 [1,0,0] 000°
2 [1,1,0] 060°
3 [0,1,0] 120°
4 [0,1,1] 180°
5 [0,0,1] 240°
6 [1,0,1] 300°
7 [1,1,1] length 0
Vector 1..6 form a hexagon, vector 0 and 7 are of length 0.
First, the space vector is limited, and the sector of the hexagon is determined where the input space vector u is located; then the angle of the space vector within this sector 0≤φ<60° is calculated.
The input space vector is averaged by u=ta⁢ua+tb⁢ub+t0⁢0, where ua is the space vector at the left border of the sector and ub is the space vector at the right border of the sector. If necessary, a zero length vector is applied additionally.
The relative time spans for averaging over one switching period are determined by the following equations:
Real part: u⁢cos⁡φ=ub⁢tb⁢cos⁡60°+ua⁢ta⁢1
Imag. part: u⁢sin⁡φ=ub⁢tb⁢sin⁡60°
ta+tb+t0=1
To obtain the positive fire signal, the switching time spans are distributed symmetrically: t04+ta2+tb2+t02+tb2+ta2+t04
The switching pattern of the negative fire signal is just the inverse of the positive fire signal.
Name
Modelica ID
u
Reference space phasor
firep
positive fire signal
fire_p
firen
negative fire signal
fire_n
General Parameters
Default
Units
f
Hz
Switching frequency
T0
0
s
First sample time instant
startTime
umax
Maximum length of space vector = half diagonal of hexagon
uMax
Constant Parameters
samplePeriod
1f
Sample period of component
The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.
See Also
DC AC
DC AC Control
Electrical Library
Power Converters
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