WOLFRAM SYSTEM MODELER

# SVPWM

SpaceVector Pulse Width Modulation

# Wolfram Language

In[1]:=
`SystemModel["Modelica.Electrical.PowerConverters.DCAC.Control.SVPWM"]`
Out[1]:=

# Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

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: 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.

# Parameters (4)

samplePeriod Value: 1 / f Type: Time (s) Description: Sample period of component Value: 0 Type: Time (s) Description: First sample time instant Value: Type: Frequency (Hz) Description: Switching frequency Value: Type: Real Description: Maximum length of space vector = half diagonal of hexagon

# Outputs (2)

sampleTrigger Type: Boolean Description: True, if sample time instant Type: Boolean Description: Rising edge signals first sample instant

# Connectors (3)

u Type: RealInput[2] Description: Reference space phasor Type: BooleanOutput[m] Description: Positive fire signal Type: BooleanOutput[m] Description: Negative fire signal

# Used in Components (1)

 PWM Modelica.Electrical.PowerConverters.DCAC.Control PulseWidthModulation