A three-phase rotary UPS (Uninterruptible Power Supply) is a sophisticated power protection system used to ensure continuous and high-quality power supply to critical equipment, such as data centers, industrial processes, and sensitive electronics. It combines the benefits of a traditional UPS with a rotating machinery component to provide seamless and reliable power backup during outages and voltage fluctuations.
Here's how a three-phase rotary UPS generally operates:
AC Input Stage: The three-phase rotary UPS is connected to the utility power supply as its primary input source. The incoming AC power is typically rectified to DC power through a set of diodes or thyristors. This DC power is used to supply the rotary component and charge the batteries that are part of the system.
Rotary Component (Flywheel or Motor-Generator Set): The distinctive feature of a three-phase rotary UPS is its rotary component, which can be either a flywheel system or a motor-generator set.
a. Flywheel System: In this setup, a high-speed spinning flywheel is used to store kinetic energy. During normal operation, the AC input power drives an electric motor that accelerates the flywheel to a high rotational speed. The kinetic energy stored in the flywheel provides a short-term power buffer during brief power interruptions. The flywheel is connected to a generator that produces AC power to supply the load.
b. Motor-Generator Set: This configuration employs an electric motor coupled with a generator. The motor is driven by the AC input power and serves as a mechanical link between the input power and the output power. The motor drives the generator, which produces stable AC power for the connected equipment. When utility power is lost, the motor-generator set continues to provide power through its mechanical inertia.
Battery Backup: In addition to the rotary component, a three-phase rotary UPS usually includes a battery bank as a secondary backup source. The batteries are used to provide power during extended outages or when the rotary component reaches its maximum energy discharge. The batteries are continuously charged by the AC input power and are ready to take over in case of a more prolonged power interruption.
Inverter Stage: The AC power generated by the rotary component or the batteries might need to be conditioned and synchronized with the utility power before being delivered to the critical load. An inverter stage is used for this purpose. It converts the generated AC power from the rotary component or batteries into a stable and synchronized AC waveform that matches the utility power.
Output Distribution: The synchronized and conditioned AC power is then distributed to the critical load through the output distribution panel. This ensures that the connected equipment receives a continuous and high-quality power supply, regardless of the status of the utility power.
Control and Monitoring: A sophisticated control and monitoring system oversees the entire operation of the three-phase rotary UPS. It constantly monitors the utility power quality, the status of the rotary component, battery charge levels, and the output power. In case of any abnormalities, such as a power outage or voltage instability, the control system triggers the switch to battery power or the rotary component as needed.
Overall, a three-phase rotary UPS offers a reliable and seamless power backup solution by combining the mechanical inertia of rotating components with battery backup, ensuring that critical equipment remains powered and operational even in the face of power disruptions.