Evaluation of a 100 A Current Shunt for the Direct Measurement of AC Current

This paper describes development and evaluation of a new coaxial current shunt for the nominal current of 100 A. The current shunt has been developed for both ac-dc transfer difference measurement and direct measurement of ac current. The direct ac measurement method was proposed by the Slovenian Institute of Quality and Metrology in 2002 and has now been expanded up to 100 A with the shunt described here. The forced air cooling system was implemented and evaluated to improve the shunt characteristics while keeping the current shunt resistors well within the safe operating range.