Characterization of DC current sensors under distorted conditions for railway applications

To assess the reliability of the DC current measurement function on board trains and other electrical metering systems for transportation applications, a measurement setup has been realized to characterize the error of DC current sensors under realistic, distorted operating conditions. The device under test in this paper is a high-current shunt, but the setup is suitable for other types of current sensors as well. The high-current shunt under test was exposed to a variety of test signals, including current patterns as measured in a traction unit from Metro de Madrid during normal operation, to investigate the effect of dissipation on the error, the intrinsic current dependence, and the effect of AC distortion. From the results we conclude that the setup is a helpful and reliable facility to characterize DC current sensors for practical railway applications under realistic and harsh operating conditions.