Power Failure Ride Through for an Inverter System Using Its Own Induction Motor Load as Energy Source

The functioning of a system when energy in rotation motors are used to provide continuous operation during a momentary failure of ac input power is investigated. The system includes an ac power input, a dc rectifier, and an inverter which normally provides ac power to high-inertia induction motors. During a failure of the ac input, the frequency of the inverter is reduced so that the motors can transfer their rotational energy back to the dc bus through the inverter. When ac power returns, the system returns to its original condition.