Development of a Small and Wide-Range Three-Phase Current Sensor Using a MI Element

A three-phase electric current sensor is described in this paper using the magneto-impedance sensor. Experimental results show a low energy consumption of 20 mW and a wide measuring range of 1:600 obtained by using both the positive/negative equality alternating bias and the unequality bias. Hence, the measurement range of the developed compact size current sensor is 15 times as wide as that of the conventional sensor.