Design and Built of on - Load Fully Electronic Tap-Changer with Triac Switch: Simulation and Practical Results

This paper, introduces a new solid-state on – load Tap-changer that has four steps. One of the main requirements of any electrical system is that it should provide a voltage to the consumer which remains within closely defined limits regardless of the loading on the system. Industrial equipment such as speed drives, electronic and control systems are sensitive to voltage variation and affected by bad power quality and poor power factor. Voltage dips can cause shutdown of plants or result in damage of devices. By using of electronic tap-changer, most of the voltage dips can be avoided and lead to good power quality and thus, result in good operation of equipment. The prototype was built with triac switches as the switching devices and AVR microcontroller as the control circuit. In this work a fully electronic tap changer with four taps for 2 KVA, 220/1200V single phase transformer is designed and built. Also some of problems that caused to limitation of electronic tap changer application at high power and voltage system and technical solution ways for theses problems are described. The discrete cycle modulation (DCM) has been used in this tapchanger.