"Reactive power control role" is a control method used to manage and control reactive power in electrical systems. In electrical systems, there are two types of power: active power (real power) and reactive power (imaginary power). Reactive power is the power caused by inductive and capacitive loads and can lower the power factor in the system. The reactive power control role aims to balance reactive power by switching capacitors or reactors in or out of the circuit to increase or decrease the power factor. This helps electrical systems operate more efficiently and stably.