Transformers in conjunction with tap changers are utilized in the power industry to regulate the amount of power traveling through transmission lines. The number of windings in a transformer induces a proportionate voltage in the adjacent transmission line. Tap changers are implemented to alter the number of operational windings in a transformer, and thus the amount of power that passes through the line.
Fig. A1. Original concept design from our Senior Design predecessors (image courtesy of SEL).
Two years ago the phase-shifting transformer tap changer originated as a senior design project with an emphasis on the electrical workings of the design. This design was to be used for simulating real-life situations in the University of Idaho (UI) power lab for students, and for fault-testing at SEL. The original design team specked and purchased three transformers, and constructed an initial tap changer prototype. However, this prototype needs further refinement with regards a functional make-or-break contact pattern, position locking mechanism, and polarity switch.