A 150,000-A transient current measurement of AC comparator for national test station

A 150,000-A transient current measurement device based on self-balancing AC current comparator type, which can be used in National Test Station and industrial heavy current system for calibration and measurement is presented. Testing of the comparator indicates that its transient current tolerance is less than 1% under the conditions of 150,000-A primary transient current, 100% full offset DC component, and 150 ms time constant of primary current. The transient performance and the test results are discussed.