Low-cost amorphous-metal rolled-up-core distribution transformer

The technology of an amorphous-metal rolled-up-core distribution transformer is under development at Hydro-Québec. This transformer, a core-type configuration, comprises a magnetic core made of a flexible annealed amorphous-metal ribbon rolled up around the coils. The coils and core are mounted on a molded skeleton fulfilling multiple functions, namely a winding frame, coil and core support, coil cooling, and anchoring to the tank. This topology provides efficient cooling of the coils, comprises non-bulky interlacing connections, and incorporates preformed secondary lead terminals ready to connect with the tank bushings. The technology allows automated manufacturing processes and mass production of generic designs of transformer kernels (core and coil only) at the DOE baseline efficiency level for transformer power ratings up to 100 kVA. Flexible annealed amorphous-metal ribbon could be supplied from the casting plant to a few component manufacturers which would mass-produce transformer kernels that would then be shipped to transformer assemblers for final tanking according to local utility specifications. These generic transformer kernels would be cost competitive with foreign production.