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