Power supply hold-up time is increased using regenerative braking. A power line disturbance (“PLD”) event is detected in a power supply unit. One or more fan motors associated with the power supply unit may be signaled to provide regenerative braking based on identifying the PLD event, where the one or more fan motors transition from a motor operating mode to a regenerative braking mode. The regenerative braking may be applied to the one or more fan motors associated with the power supply unit, where a hold-up time is extended to prevent shut down of the power supply unit.