Design Of Solid-State On Load Tap-Changer for Transformer Using Microcontroller

Abstract

The on-load tap changing (OLTC) regulators have been widely used in various industry & power Application. They ensure a good regulation of the output voltage in presence of large variations of the input voltage with typical response time from several ms to several seconds. Earlier mechanical type of on load tap changers were into practice. But they had considerable limitations and drawbacks like arcing, high maintenance, service costs and slow reaction times. In order to overcome these limitations and drawbacks electronic (or solid-state) tap-changers were developed. The continuous growth of power semiconductor devices, such as the insulated gate bipolar transistor (IGBT), triac, thyristor, has allowed the development of fast OLTC regulators which has helped to fix other problems in the ac mains, like flicker and sags. The major idea in the solid-state-assisted tap changer is that solid-state switches with more controllability operate during the tap-changing process instead of mechanical switches which helps in reducing the arc during the tap-changing process. In this project design a microcontroller based controller, this is able to properly control a “Solid State on Load Tap-changer of 1 KVA Transformer”. The existing mechanical on load tap-changer has few disadvantages, as below  Produces arcing,  Require regular maintenance,  Increase service costs,  Due to slow response times,  Create noise disturbance. On using high power semiconductor devices, the problem associated with the mechanical on load tap-changing have been eliminated. Hence In this project selected the project design and fabrication of electronic tap-Changer, Which will overcome all these drawbacks