In a reactor starter, what purpose does the inductor serve?

In a reactor starter, the inductor is primarily used to limit the starting current of the motor when it is powered on. When an electric motor starts, especially if it is large, it can draw a significantly higher current than its normal running current in an effort to overcome inertia and reach its operating speed. This high inrush current can lead to several issues, including voltage drops in the supply network and potential damage to the motor windings and associated electrical components.

The inductor serves to impede the flow of this initial surge of current due to its property of opposing changes in current. This results in a smoother start-up of the motor, allowing it to gradually build up speed while keeping the starting current within acceptable limits. By addressing the inrush current in this way, the inductor helps protect both the motor and the power system, ensuring a reliable operation during the critical starting phase.