Abstract
A large part of the energy involved in the braking stage of conventional
DC railway traction units is dissipated in rheostat resistors, which is
controlled by means of a braking chopper. A setup was developed to
calibrate transducers used to measure the resulting high-current chopped
DC current signals under conditions mimicking the real application.
Preliminary results indicate that the reference transducer used in this
setup can accurately measure chopped signals with magnitudes up to at
least 250 A and pulse repetition rates up to 500 Hz with uncertainties
better than 0.01 %.