DESIGN AND PERFORMANCE IMPROVEMENTS IN POWER TRANSFORMERS USING RIBBON CABLE

An advanced core-form transformer with significantly lower losses and weight has been produced and brought to commercial status. First, a nu mber of designs and design studies were made on actual medium power tr ansformer specifications. Several windability models were built, as we ll as a complete 250-kVA core-form advanced transformer model to devel op the new manufacturing technology and to verify many performance cha racteristics of the new technology. Then extensive thermal, short-circ uit strength, and loss studies were made. Finally, a cooperating utili ty ordered two units, one conventional and one advanced, to the same s pecification to provide ideal conditions for the verification of the n ew technology. Construction and test of the prototype proceeded withou t incident. Full verification was achieved for all aspects of the tech nology: dielectric design, thermal design., short-circuit strength, lo ss performance, impedance, noise level, and manufacturability. The pro totype was installed and energized in 1991 and continues in operation today. Subsequently, other units were built and tested, with performan ce results confirming the technology.