Automatic Voltage Regulator for Uninterruptible Power Supplies

Power distortions such as power interruptions, voltage sags and swells, voltage spikes, and voltage harmonics can cause severe impacts on sensitive loads in the electrical systems. Uninterruptible Power Supply (UPS) systems are used to provide uninterrupted, reliable, and high quality power for these sensitive loads. The UPS systems are especially required in places where power outages and fluctuations occur frequently. This paper presents the concept of Automatic Voltage Regulator (AVR) section for offline UPS system. When the supply voltage is available to the oflline UPS, an AVR section regulates any ups and downs in the AC mains supply input and sends a regulated clean and constant AC output to its output socket with the help of switching of the relays as per the value of the input supply voltage. When supply voltage goes below or above the set range or the supply voltage gets cut off, the change over of supply to the load from AC supply to battery takes place.