High precision range extenders for an AC calibrator up to 600 V and 100 A

High precision range extenders for high voltage (600 V) and large current (100 A) have been developed as separate units to be used with a previously developed AC calibrator 111. To obtain high accuracy and stable operation an error feed-forward technique was implemented. A current-comparator-based capacitance bridge was used for the gain and phase calibration of the high voltage range extender. A precision two stage current transformer and a very stable time-division based wattconverter were u8ed for the verification of the current range extender.