SineFormer EMC filters

Epcos has introduced an output filter for frequency converters.

In contrast to conventional filter topologies, the SineFormer simultaneously converts the phase-to-phase voltages into a sinusoidal signal, damps the common mode currents and also forms the conductor-to-ground voltage to sine-shaped voltage.

Voltage peaks that are harmful for the motor windings are suppressed and bearing currents are reduced to negligible levels, increasing the operating life of the motors.

Because the filter practically eliminates EMC problems, motors protected by the filter do not require expensive shielded motor cables or special cable ducts. Even with unshielded cable lengths of 1000 m it is possible to comply with Class A, Group 1 EMC limits.

Since unshielded cables are more flexible, installation expenses are reduced. Through the use of unshielded motor cables alone, users can save beginning with cable lengths of about 100 m, depending on current.

Moreover, the filter does not require forced ventilation and is stable without a feedback loop to the converter DC link.

It is available in 520 VAC rated voltage versions with rated currents of up to 180 A and in 600 VAC versions with rated currents of 320 A.