Progress on BEV foil shunts for AC-DC current transfer

Ten years ago the international community started the expansion of the measurement range for ac-dc current transfer from 20 A to a present level of 100 A at frequencies up to 100 kHz with uncertainties of around 100 μA/A. At BEV coaxial current shunts based on resistive foils as well as low inductance tee connectors suitable to compare the shunts were fabricated [1]. This paper describes progress in the theory and practice of these shunts and tees within the last decade.