Calculo proteção conjunto baterias condensador

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Ninguem tem uma formula aplicada a realidade diaria!

THE OBJECTIVES OF THE HIGHER HARMONICS FILTERS IN POWER
NETWORKS
In the most common three-phase bridge converter systems (six-pulse systems), the current run on the
transformer primary side – assuming the supply voltages symmetry, commutation impendence and delay
angles of thyristors switching off – apart from the basic component, will include at least the following
harmonics: 5,7,11,13, whose numbers are defined by the general equation (1).
n = kp ±1, (1)
where: n – harmonic number, k – natural number, p – rectified voltage pulse number
The values of the harmonics component amplitudes may be determined by using the equation (2).
1
1 A
n
An = , (2)
where: A1 – voltage basic harmonic amplitude, An – nth harmonic amplitude.
Too high a number of the supply current higher harmonics may cause a considerable increase in power
losses in devices and machines operating with the converter as a result of the current flow with increased
frequency, or it may cause disturbances in the operation of the device by deforming the supply voltage.
This particularly refers to capacitors batteries, operating in parallel with the converting system.
Decreasing the capacitor’s impedances, combined with frequency growth, may cause defects in the
battery as a result of overload with the currents in the higher harmonics frequencies.
Additionally, the parallel resonance in the system is also a dangerous phenomenon. The harmonics
produced by non-degree power transmission systems may be enforced as many as 10-15 times in the
parallel resonance circuits, formed by capacitive reactance of the capacitors batteries and network
induction. This phenomenon may result in damaging both the capacitors batteries and converters.
In unfavourable conditions, the component harmonics may pose a threat to the mechanical structures


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