LCL filter for regen drives and active infeed converter

LCL filters are essential to connect AFE (active front end) drives and AIC (active infeed converters) to the power grid. With the increasing need for saving electrical energy AFE/AIC’s are now frequently installed for energy regeneration reasons.

Regaining energy when an AC motor is coming to rest or braking avoids wasting energy in the motor or from the braking resistance.

In addition, LCL filters are also required to enable DC-AC converters feeding the electrical energy back to the grid.



Schaffner introduces the FN 6840 standard LCL filter range. They are ready to be installed and connected as one unit, as all the necessary LCL components are mounted in one preassembled package.

The FN 6840 design allows various configurations from the same platform to also fulfil specific regeneration application needs.

With the correct match of an LCL filter to the AFE/AIC and the power grid, the FN 6840 LCL filter can limit the ripple current generated by the AFE/AIC to a level <5% and helps to reduce voltage distortions while improving the power quality.

The new compact 3 phase FN 6840 LCL filter series is available with 5 current ratings from 25 to 380A for 480 VAC.

Depending on AFE/AIC versions, the LCL filter can be selected with or without a passive damping function.

Typical examples of AFE regenerative motor applications are: elevators, hoists and cranes or similar transportation systems, machine tools and machines with frequent braking cycles, centrifuges and special machines with high inertias, flywheels, winder/unwinder, press feeders and test stands.

All models are CE and RoHS compliant.