Transformers for static power converters. Design, constructions, research

Przetwornice statyczne pojazdów trakcyjnych charakteryzuje szeroki zakres parametrów znamionowych oraz różnorodność układów elektrycznych, do których muszą być dostosowane transformatory obniżające napięcie. Wynika z tego rozmaitość rozwiązań konstrukcyjnych transformatorów oraz konieczność ich indywidualnego projektowania. W artykule przedstawiono teoretyczne i praktyczne aspekty konstruowania transformatorów.Electrotechnical Institute has been conducting research and design of transformers with nominal frequency greatly exceeding 50 Hz. Over 30 types of transformers were designed and built by the institute. This paper was elaborated basing on acquired experience in and the research results. Basing on the laws of electric machines growth, dependencies of size, mass, losses and efficiency on nominal frequency were derived. It was shown that raising the nominal frequency by multiple factor does not give much benefit. It was shown that, for the transformer mass decrease, the key factor is dissipation of magnetic materials, construction and technology of production of the core. Table 3 contains parameters of nine types of transformers designed and built in the institute. High efficiency was obtained, and in case of nanocrystalline cores, exceptionally small mass of the transformers. This paper contains practical advices and remarks regarding construction and method of production of the transformers. Brief description of the research conducted in the Electrotechnical Institute was presented. Sample results of the dissipation of several types of cores were presented