Reactors harmonic elimination

Create date:
Modify date:
User visits:

What harmonic elimination reactors

The increase in automation systems, increased use of semiconductor elements in the control circuit, which in turn will create a variety of harmonics in the network. Harmonic frequencies with multiple frequency and the impedance of the capacitor is inversely proportional to frequency, the harmonics caused a dramatic increase in the capacitance and capacitor cause premature failure.In order to fix this problem harmonic elimination reactors in series with the capacitor installed the type of harmonic capacitor network and be applied in a variety of reactors to be supplied.

Harmonic risks for capacitors

With regard to the relationship between the current in the capacitor, (Ic = fcUc.2π) increase in frequency when the capacitor voltage is to increase the flow of leads. Since the impedance of the capacitor is inversely proportional to the frequency of the harmonic impedance of the capacitor fewer and more current passes through it, causing premature failure of the capacitor. This problem is exacerbated when the resonant frequency close to the frequency of the harmonic capacitor network. For example, if the voltage amplitude voltage fifth harmonic component is 5%, due to the harmonic currents in the capacitors 25% of the mainstream As a result, the flow into the serious damage to the capacitor.

Capacitor protection method

To prevent damage and protect the best way to install capacitors in harmonic reactor (inductor) is a capacitor in series. Reactors installed in series with the capacitor, the capacitor resonant frequency of each branch Dhd.mqdar arbitrarily reduce the frequency to be adjusted so that the best type of filtering is conducted. The combination of inductance and capacitance at frequencies higher than the resonant frequency of the inductive properties and lower frequencies, the property will be capacitive. The power factor correction at higher frequencies without disturbing frequency will be working capacitor.

Harmonic filter performance

Harmonic filters like this is how the first moment measured by a current transformer current value, then the control circuit is obtained by Fourier analysis of the scope and number of harmonics Vrd.sps the same flow rate, but with a difference 180 ° phase injected into orbit. The result is a perfectly sinusoidal current and no harmonic obtained.