WOLFRAM SYSTEM MODELER
SpaceVector Pulse Width Modulation
This information is part of the Modelica Standard Library maintained by the Modelica Association.
For a threephase system, 8 space vectors are available according to the following switching patterns:
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:
To obtain the positive fire signal, the switching time spans are distributed symmetrically: t0/4 + ta/2 + tb/2 +t0/2 + tb/2 + ta/2 + t0/4
The switching pattern of the negative fire signal is just the inverse of the positive fire signal.
Value: 1 / f
Type: Time (s)
Description: Sample period of component
Type: Time (s)
Description: First sample time instant
Type: Frequency (Hz)
Description: Switching frequency
Description: Maximum length of space vector = half diagonal of hexagon
Description: True, if sample time instant
Description: Rising edge signals first sample instant
Description: Reference space phasor
Description: positive fire signal
Description: negative fire signal