Field Performance of Three-Phase Amorphous Metal Core Distribution Transformers at Pearl Harbor, Hawaii

Eight prototype three-phase amorphous metal core distribution transformers three 75-kVA and five 150-kVA units were installed at the Public Works Center PWC Pearl Harbor, Hawaii. The program objective was to evaluate the electrical performance and operational reliability of the amorphous metal core transformers compared to conventional silicon-steel transformers, and to determine the stability of the transformer core losses over and extended period of time. Three years of test and evaluation of these amorphous transformers has shown no degradation of the initial low core loss. No failures of any kind occurred. More importantly, test results obtained from these transformers indicate no long-term degradation of the low core loss is expected. No-load losses in the 75-kVA transformers tested were reduced by 62.6 percent and in the 150-kVA units by 70.1 percent. Distribution transformers are an area where more efficient materials, such as amorphous metal, significantly reduce core losses and help to lower the total losses on the distribution system. These eight relatively small three-phsase transformers have been in operation at Pearl Harbor for only a few years, but have already produced energy savings of approximately three thousand dollars.