They are used to filter harmonics and to prevent them from entering a circuit. Single-phase and three-phase chokes limit inrush current rising speed in a power transmission system and reduce commutation influence between converters powered by the same transformer. A commutation process in systems with line chokes is smooth and commutation overvoltages are dampened.
Additionally, line chokes safeguard a power supply network against a detrimental effect of converters by limiting harmonics propagation within the network. They are inserted at a power supply, between the network and converters. Chokes are particularly recommended when connecting multiple power inverters to one power supply point and when a power supply network powers a number of other electronic devices.