Harmonic filter reactor

FDUEG supplies dedicate filter reactors to companies working in the energy transmission field. The products come as single piece, or complete with all other components of the harmonic filter.

Due to the increasingly larger presence of non-linear power electronics components in electrical systems, it is necessary to mitigate the current harmonics they can generate. A classic filter circuit involves a series coupling of a reactance and a capacitor bank, so that the resulting low impedance branch deviates the currents that are not desired on the power supply.

Harmonic Filter reactors: Reactor for parallel filter, Notch filter. Features and typologies of our products

A performing filter is able to retain the relevant currents without causing excessive losses or harmonic distortion. This is why the experts within the Engineering Department evaluate in details both overall filter setup and the contribution of the single harmonic frequency on the iron core. This analysis’ outcome, together with the choice of the right magnetic foil, directly translated in losses limitation and in the perfect linearity of the reactor even for the waveforms whose harmonic content is heavier.

The company mostly exploits, for its reactors the VPI dry type technology, which is able to handle medium voltages. The main filter inductances produced by FDUEG are the following:

• Reactors for parallel filters: deputed to the absorption of current harmonics, this filter needs inductors able to receive the whole harmonic spectrum. The company also produces modular inductor for power systems whose non-linear load varies in time, while also compensating the reactive power needed.
• Notch filter reactors: they show large impedance to the design resonance frequency through a parallel coupling. The main focus here is the quality factor of the inductance, so that the filter’s selectivity is enhanced.
• Low pass DC and AC filters: they are placed in series with the circuit to attains a nice rejection on the current disturbances. Their contribution is mandatory to have power electronic converters working as expected, and to stabilize the power flow.

In case of relevant current at high frequency, these reactors are also available as air core coils. FDUEG is available to assist a customer in designing filters for special purpose or unusual working conditions.