Total Harmonic Distortion - MapleSim Help

Online Help

All Products    Maple    MapleSim


Home : Support : Online Help : MapleSim : MapleSim Component Library : Signal Blocks : Mathematical : Functions : componentLibrary/signalBlocks/math/functions/TotalHarmonicDistortion

Total Harmonic Distortion

Output the total harmonic distortion (THD)

 

Description

Connections

Parameters

Modelica Standard Library

Description

The Total Harmonic Distortion component determines the total harmonic distortion (THD) over the given period 1f.

Consider that the input u consists of harmonic RMS components U1, U2>, U3, etc. The total RMS component is then determined by:

The calculation of the total harmonic distortion is based on the parameter useFirstHarmonic. The default value useFirstHarmonic=true represents the standard THD calculation used in electrical engineering http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=551-20-13 . The non-default value useFirstHarmonic=false calculates the THD typically used for the assessment of audio signals. If useFirstHarmonic=true, the total higher harmonic content (harmonic order numbers > 1) refers to the RMS value of the fundamental wave:

If useFirstHarmonic=false, the total higher harmonic content (harmonic order numbers > 1) refers to the total RMS:

In case of a zero input signal or within the first period of calculation, the boolean output signal valid becomes false to indicate that the calculation result is not valid. Valid calculations are indicated by valid=true.

Connections

Name

Description

Modelica ID

u

Real input signal

u

y

Real output signal

y

valid

Boolean output signal; true, if output y is valid

valid

Parameters

Name

Default

Units

Description

Modelica ID

f

 

Hz

Base frequency

f

use first harmonic

true

 

THD with respect to first harmonic, if true; otherwise with respect to total RMS

useFirstHarmonic

Modelica Standard Library

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

Math Functions

Math Operators

Signal Blocks