Harmonic spectrum: Difference between revisions

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== Principle  ==


Each type of device causing harmonics draws a particular form of harmonic current (amplitude and phase displacement).<br>These values, notably the amplitude for each harmonic order, are essential for analysis.  
The harmonic spectrum is the representation of the amplitude of each harmonic order with respect to its frequency.


== Individual harmonic distortion (or harmonic distortion of order&nbsp;h)  ==
'''Figure M9''' shows an example of harmonic spectrum for a rectangular signal.


The individual harmonic distortion is defined as the percentage of harmonics for order h with respect to the fundamental.<br><math>U_h(%)=100 \frac{U_h}{U_1}</math>&nbsp;
Each type of device causing harmonics draws a particular form of current, with a particular harmonic content. This characteristic can be displayed by using the harmonic spectrum.


or
[[Image:Fig_M09.jpg|none]]
'''''Fig. M9 :''''' ''Harmonic spectrum for a rectangular signal U(t)''


<math>i_h(%)=100 \frac {I_h}{I_1}</math>&nbsp;


== Harmonic spectrum  ==
[[ru:Основные показатели гармонических искажений и принципы их измерения]]
 
[[zh:谐波畸变的基本指标和测量原理]]
By representing the amplitude of each harmonic order with respect to its frequency, it is possible to obtain a graph called the harmonic spectrum.'''Figure M12 '''shows an example of the harmonic spectrum for a rectangular signal.
 
== Rms value  ==
 
The rms value of the voltage and current can be calculated as a function of the rms value of the various harmonic orders.<br><math>Irms=\sqrt {\sum_{h=1}^\infty I_h^2}</math>
 
and
 
<math>Urms=\sqrt {\sum_{h=1}^\infty U_h^2}</math>&nbsp;
 
----
<br>[[Image:FigM12a.jpg|left]] <br><br><br><br><br><br><br><br><br><br><br><br><br>[[Image:FigM12b.jpg|left]] <br><br><br><br><br><br><br><br><br><br><br><br><br>
'''''Fig. M12:'''''<i>&nbsp;Harmonic spectrum of a rectangular signal, for a voltage U (t)</i>
 
----
 
[[ru:Гармонический спектр и гармоническое искажение]]
[[zh:谐波频谱和谐波畸变]]

Revision as of 16:09, 18 October 2013


The harmonic spectrum is the representation of the amplitude of each harmonic order with respect to its frequency.

Figure M9 shows an example of harmonic spectrum for a rectangular signal.

Each type of device causing harmonics draws a particular form of current, with a particular harmonic content. This characteristic can be displayed by using the harmonic spectrum.

Fig M09.jpg

Fig. M9 : Harmonic spectrum for a rectangular signal U(t)


ru:Основные показатели гармонических искажений и принципы их измерения zh:谐波畸变的基本指标和测量原理

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