Design and implementation of triac based on load tap changer with primary tappings for constant output voltage

As the increase of distributed generation is expected to generate several inherent instabilities such as power imbalance or voltage deviation in power system. At the distribution level maintaining the bus voltage within the permissible limit is one of the major challenges for the distribution networks. The solution for voltage regulation close to output side usually requires manual and automatic tap changers (automatic assisted with motor) of transformer for constant output voltage and better voltage regulation which may result in high maintenance cost and uncontrolled output voltage level as mechanical switches are used. The traditional mechanical tap changing systems accompanies with undesirable characteristics like high maintenance cost and arcing, wear and tear of contacts resulting in inappropriate stability of system. In this paper implementation of TRIAC based on load tap changer topology is introduced. It is a prospective solution for the present and future power grid providing automatic voltage regulation. To overcome the drawback of the conventional tap changing system the implementation of power electronic assisted device (triac) is introduced. The proposed approach has primary tappings instead of secondary tappings to reduce switching losses and to get constant output voltages with faster switching response under several variations in voltage on the primary side. Triac based OLTC is having key advantages like arc quenching, faster response, no friction losses, improved life of contacts and significantly constant output voltage. The results shows that the voltage levels at the output side is kept within stipulated boundaries when applied the proposed system of Triac based on load tap changer.