Design of a Wideband Amplifier to test Instrument Current Transformers in the Supraharmonic Range

Testing of current Instrument Transformers relies
on low-distortion wideband generation, in particular for the
modern exigency of extending testing in the supraharmonic range
(up to 150 kHz). Whereas single-tone amplitude accuracy and
controllability has been mostly considered so far, low-distortion
for non-linearity verification and transient behaviour in presence
of commutating semiconductor devices are also relevant. The
design of a stable, accurate and low-distortion amplifier is dis-
cussed, featuring 15 A output and sub-μs rise time in the present
realization, but scalable to higher current. Design solutions were
selected that can be easily replicated, including minor variants
to adapt to different exigencies. Preliminary experimental results
of the prototype are reported.