Results from the magnetization of an 80 kVA power transformer, using a directly coupled nonfiltered three-phase voltage-source\r\ninverter (VSI), are presented. The major benefits of this topology are reduction in switching filter size as well as filter losses.\r\nDrawbacks include higher stress on the transformer windings and higher transformer magnetization losses. In this paper, the\r\ntotal magnetization losses are presented for different voltage levels. The transformer has been magnetized with the rated frequency\r\nof 50Hz at various voltage levels. The saturation characteristics as well as the magnetizing resistance are derived as functions of the\r\nvoltage.These are used as inputs for the simulations.Themagnetization losses have been experimentallymeasured and simulated for\r\nthree different DC levels. Results fromthe simulations show good agreement with the experimental results. As expected, the pulsed\r\nvoltage waveforms generate larger magnetization losses than the corresponding 50Hz case. The losses are strongly dependent on\r\nthe DC level.
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