When using regenerative converters, chokes are used in order to obtain a clean sinusoidal current. Depending on the type of inverter, so-called common-mode disturbances can occur, which thermally load the choke and lead to leakage of the magnetic field, which can significantly affect nearby metal components. An additional unwound limb, ensures that the choke can always transfer and attenuate these interferences, until they can be discharged to earth.
Furthermore, the line choke limits the mains disturbances occurring as current peaks and voltage drops in the network. Such disturbances can affect electrical systems and are caused by switching operations or ground faults.
The choke has the effect of a typical series inductance and smoothes the symmetrical actual current and the asymmetrical parasitic current.
This solution attenuates the cable-conducted disturbance very well even in the lower frequency range.
The electromagnetic radiation of the lead is considerably attenuated. Losses and typical motor noise caused by harmonics are reduced.
The voltage maximum and the voltage rise are considerably lower when using a motor choke. Thus, the motor isolation will be treated with care.
In addition to damages to the engine, Inverters can cause the increase of harmonics load and harmonics distortion factor of the network.
Used between the line and the inverter, mains chokes allow a reduction of harmonics and a reduction of commutation losses leading to a significant increase of semiconductor lifetime.