Possible applications of chokes

Safety of transformers, chokes, power supply units and similar products for supply voltages up to 1 100 V part 2-20: Special requirements and tests for small reactors

Drive engineering:
Input sided line chokes for rectifiers or frequency converters, with or without energetic recovery system, increase the life-time of downstream components; commutator choke; direct link inverter; smoothing choke for DC-drives; balance choke; basic load choke; motor chokes at the inverter output to attenuate the steep voltage (du/dt) to e.g. < 500 V/µs protect the motor winding insulation and reduce disturbances; motor chokes related to capacitors as L-C filters or sinusoidal filters for an improved output signal additionally reduce frequency noise, spare screened motor feed lines, enable longer lines and improve the EMC; equal frequency chokes at the inverter output reduce common-mode-currents over the engine brackets against earth (ball bearing wear, see also IEC 60034-25), in the easiest case as a toroidal core via the power output.

Digital audio technology:
Rod core choke for audio crossovers; filter reactor; balance choke

Railway technology:
Air chokes are used in railway technology and in electric power transformation substations to smooth voltage peaks. Air chokes don’t switch to saturation when overloaded.

Reactance compensation units:
Three-phase filter circuit chokes, constructed for various required filter factors p resp. resonance frequencies (fres = fNetz * wurzel1durchp ), with low inductance tolerance, linearity far over In, as protection of capacitors against tensile loading as a result of harmonics in nets, especially with rectifier load. Altogether the net impedance is improved.

EMC interference suppression:
RFI choke / rod core choke for line input; current compensated choke / filter choke (mostly a toroidal core made of iron powder - or ferrite materials) to assemble interference suppression circuits; line choke with sheets to attenuate current harmonics; protective conductor choke conform to VDE 0565 / EN 60938-1.

Power electronics:
Series choke e.g. for current limitation, storage choke (magnetic energy (magn. Energie W = ½ * L * I²); PFC-choke for an increasement of the power factor of switch-mode power supplies (EN 61000-3-2); filter reactor; resonance and transduction choke for clocked batteries, resonance transformers etc.; ballast choke; two-phase direct link inductor to reduce harmonics, thyristor choke; symmetric choke; saturable choke

Communication engineering:
Intermediate frequency and HF-choke

Test equipment:
1- or 3-phase load and reactance choke

1- or 3-phase line choke in series circuit to achieve 4% Uk (short circuit voltage to net); limitation of start-up or current inrush; attenuation of current harmonics conform to EN 61000-3-2 (passive PFC), especially in units with rectifiers resp. DC link (inverter); balance choke; locking choke; reactance choke.

Welding equipment:
Inverter loading choke; direct link choke; line choke; suppressor choke; commutation choke

Photovoltaic systems:
Pot core chokes are used to smooth high frequency ripples (e.g. 25 kHz) for inverters of photovoltaic systems.

Further terms to this topic:
Start-up current, commutation, idle current, iron core choke, harmonics, electrical engine, idle current compensation, motor choke, air choke, rod core choke, energy content

© 2014 Tauscher Transformatoren GmbH                                                                                                                                                         Impressum