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Idiomas disponibles
Idiomas disponibles
AFQm IP54
4.- OPERATION
4.1.- HARMONICS
Non-linear loads such as: rectifiers, inverters, variable speed drives, ovens, etc., absorb periodic non
sine-wave currents from the mains.
These currents are composed of a fundamental frequency component, rated at 50 or 60 Hz, plus a
series of overlapping currents, with frequencies that are multiples of the fundamental frequency; they
are defined as HARMONICS.
Fundamental
Ware
50Hz
The result is a deformation of the current and, as a consequence, of the voltage, causing a series
of associated side effects. These can be machinery overload, electric cable heating, circuit breaker
disconnection, damage to sensitive devices, etc.
Order (n)
4.1.1.- BASIC CONCEPTS
It is best to define some terms related to harmonics, fundamental for interpreting any measurement
and study:
Fundamental frequency (f
Order of a harmonic (n): A whole number given by the ratio between the frequency of a harmonic
and the fundamental frequency. The order determines the frequency of the harmonic (E.g.: 5th
harmonic → 5•50 Hz: 250 Hz)
Fundamental component (U
development equal to the original periodic wave.
Harmonic component (U
serial development a whole multiple of the original frequency.
Instruction Manual
+
Harmonic ware
5th order 250 Hz
Figure 20: Distorted wave shape decomposition.
Table 10: Frequency of each harmonic.
Fundamental: 50 Hz
3
150 Hz
5
250 Hz
7
350 Hz
...
...
): Original wave frequency (50/60 Hz).
1
or I
): A sine wave component of order 1 of the Fourier frequency serial
1
1
or I
): A sine wave component of order over 1 of the Fourier frequency
n
n
+
=
Harmonic ware
Distorted ware
7th order 350 Hz
Mains frequency
Fundamental: 60 Hz
180 Hz
300 Hz
420 Hz
...
113
Capítulos
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