Microcontroller Based Solid State on-Load Tap Changer for Pole Mounted Transformers

With the use of fast switching solid-state devices like the insulated gate bipolar transistor (IGBT), Triac, and Thyristor, issues such as arcing, slow reaction times, maintenance, and transient voltage that usually impact power utilities with mechanical on-load tap changer whenever the voltage ratio on power transformers is changing can be eliminated. In this paper, a microcontroller based solid state on-load tap changer is proposed. The results are based on a prototype developed incorporating power electronics devices at the heart of the switching. It demonstrated the effectiveness of this solution in resolving issues as a result of the switching between tap positions in response to changes in the load demand.