A proposal for the study of voltage sag in isolated synchronous generators caused by induction motor start-up

This study presents a proposal based on controlled capacitor switching at the moment of three-phase induction motor start-up, when such motors are fed by isolated synchronous generators. This procedure allows for the mitigation of voltage sag that occurs during this transitory period, since a large portion of the reactive power requested during the motor start-up is provided by capacitor banks, thereby relieving a portion of current from the synchronous generator, and with it mitigating the voltage sag. Traditionally, oversizing of the generator was used, under the pretext of mitigating voltage sag. This proposal represents not only an economy, but also power optimization, developed through the motor-generator group, leading to a greater working life.