For the calibration methods, e.g., calibration of instrument
voltage transformers and high-voltage dividers, it is necessary
to have a high-voltage source with an appropriate frequency
range. The main element of these high-voltage sources is
the high-voltage transformer, for our purposes operating at
nominal voltage of 10 kV and at a frequency from 200 Hz
up to 10 kHz. The magnetic core of these transformers is
usually C-shaped, for easier implementation of the highvoltage
windings. A nanocrystalline alloy seems to be a
suitable material for the magnetic core of the transformer, due
to its good magnetic properties in a wide range of frequencies.
Unfortunately, these properties are slightly deteriorated by the
cutting process. An interesting study of nanocrystalline alloy
cut cores has been presented in [6]. This investigation shows
that there is a big dispersion in terms of amplitude permeability
and magnetic losses among manufacturers. For the correct