Optimization of fixed tap transformer setting in bulk electric systems

A novel technique was developed to determine fixed tap transformer settings that are optimal for several load patterns representing, for example, winter peak, summer peak, and off-peak loading patterns. The solution algorithm is based on the Newton approach and employs a recently developed technique to identify binding inequality constraints. A special base case is constructed to represent several load patterns, and additional equality constraints on fixed tap transformer settings are enforced during optimization. Extensive tests have been performed to verify the validity of the approach in the power system operations planning environment