Reactor is a passive element that is connected to an inverter to keep the current constant for the purpose of improving the power factor and suppressing harmonics. There is an effect when the connection is made to the input side of the inverter (AC reactor) and when it is made to the output side (DC reactor), and when it is connected to the input side, the power factor is improved, harmonics are suppressed, and the power supply is used. When connected to the output side, such as in coordination, effects such as surge voltage suppression and noise suppression can be obtained. The reactor is roughly divided into an air-core type reactor and an iron-core type reactor according to the structural classification, and further, a starting reactor that suppresses inrush current, a shunt reactor that suppresses abnormal voltage, and a current limiting reactor that suppresses short-circuit current according to the purpose. Various types of reactors are used, and there are cases where several types of reactors are used together.

From Kitagawa Electric’s website