WOLFRAM SYSTEM MODELER

ThreePhaseTwoLevel_PWM

Test of pulse width modulation methods

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Electrical.PowerConverters.Examples.DCAC.PolyphaseTwoLevel.ThreePhaseTwoLevel_PWM"]
Out[1]:=

Information

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

A reference space vector (formed by real part = cosine and imaginary part = sine) of length √2*RMS and frequency 2 Hz is applied. The resulting switching patterns are applied to a three-phase twolevel bridge with switching frequency 100 Hz, fed by DC voltage = √2*√3*1 where 1 is the theoretical maximum voltage from terminal to neutral. The resulting voltages with reference to midpoint of the DC voltage are measured.

The RMS of the first harmonic of the first of these voltages is calculated. Please note that the value of the first harmonic is valid after the first period (i.e. 0.5 s).

Furthermore, these three voltages are transformed to the corresponding space phasor. Note that the zero component is not zero, indicating the shift of the neutral with respect to the midpoint of the DC voltage.

The space phasor is rotated to the coordinate system rotating with 2*π*2 Hz. To suppress the influence of switching, real and imaginary part of the rotated phasor are filtered. The polar representation of this rotated and filtered phasor are calculated.

Please note that the filter has a settle time depending on the filter parameters.

Parameters (1)

RMS

Value: 1

Type: Real

Description: Reference RMS Y

Components (15)

cosine

Type: Cosine

Description: Generate cosine signal

sine

Type: Sine

Description: Generate sine signal

pwm

Type: PWM

Description: Pulse width modulation

multiPhase2Level

Type: Polyphase2Level

Description: Polyphase DC to AC converter

dcPos

Type: ConstantVoltage

Description: Source for constant voltage

dcNeg

Type: ConstantVoltage

Description: Source for constant voltage

ground

Type: Ground

Description: Ground node

potentialSensor

Type: PotentialSensor

Description: Polyphase potential sensor

harmonic

Type: Harmonic

Description: Calculate harmonic over period 1/f

toSpacePhasor

Type: ToSpacePhasor

Description: Conversion of polyphase instantaneous values to space phasors

rotator

Type: Rotator

Description: Rotates space phasor

const

Type: Constant

Description: Generate constant signal of type Real

integrator

Type: Integrator

Description: Output the integral of the input signal with optional reset

filter

Type: Filter[2]

Description: Continuous low pass, high pass, band pass or band stop IIR-filter of type CriticalDamping, Bessel, Butterworth or ChebyshevI

toPolar

Type: ToPolar

Description: Converts a space phasor to polar coordinates