Air Core Smoothing Reactors

Smoothing Reactors are serially connected reactors inserted in DC systems. They reduce harmonic currents and transient over currents and/or current ripples in DC systems.

These reactors are necessary in order to smooth the direct current wave shape, reduce losses and improve system performance. Smoothing Reactors are used in HVDC links and industrial applications including traction systems, variable speed drives, UPS systems, etc.

Smoothing Reactors also reduce the occurance of alternation failure in inverters caused by the dips in AC voltage at the converter bus. When the direct voltage of another series connected bridge collapses, communication failures in inverters are prevented due to the reactor’s ability to reduce the rate of rise of direct current in the bridge.

Smoothing Reactors even out ripples in the direct current in order to prevent the current becoming discontinuous for light loads. They decrease harmonic voltages and currents in DC lines and limit the crest current in the rectifier due to a short circuit on the DC line.

Additionally, smoothing reactors limit the current in the valves during the converter bypass pair operation due to the discharge of shunt capacitances of the DC line.




  • Perfect mechanical strength to withstand high short-circuit forces
  • Limited temperature rise enables longer lifespan
  • Special surface protection against UV and pollution Class IV areas
  • Maintenance-free design




Technical Specifications
Voltage Up to 36 kV
Type Air core, dry type
Frequency 50 Hz / 60 Hz
Installation Indoor / Outdoor
Winding Aluminium or copper winding
Painting RAL 7035 or other colors on demand
Construction Epoxy impregnated, fiberglass encapsulated construction
Temperature -40°C to 55°C
Insulation class F class or custom
Cooling AN (air-natural)cooling method>

- Taps

- Enclosure available on demand

- Available designs as per IEEE, IEC and others

- DIN or NEMA terminal configuration

*Consult factory for higher values.