Optimizing the properties of the optical current transformer with special reference to faster transient response

Abstract

A current transformer, in general, is a means of measuring a very large electrical current, converting it to a much smaller current, requiring low power equipment as simple as a multimeter to display it. The traditional method is based on the electromagnetic principle of an iron ring around the current conductor, supplied with a secondary transformer winding. The latter will deliver a small current directly proportional to the large current, to be displayed by a small current measuring device. An optical current transformer (OCT) is constructed by winding an optical fibre cable around the current conductor. The phenomenon where the angle of a polarized light beam propagating through the optical cable, is deflected when the magnetic flux lines generated by the large current, are appearing longitudinal in the said cable, are utilized to determine the main current. OCT's are already well developed, but lack to respond to very fast changing transient impulses. This paper describes a research and developing process to address this problem.

Study of Current Measurement Method Based on Circular Magnetic Field Sensing Array

“…However, it cannot be used for DC measurement because of its sensing principle [ 7 , 8 , 9 , 10 ]. While an optical transformer can measure both alternating current (AC) and DC signals, the temperature stability and mechanical properties of optical crystals result in the low measurement accuracy of this instrument [ 11 , 12 , 13 , 14 , 15 , 16 ]. Commonly used methods for measuring DC current include shunt methods, magneto-resistance, and magneto-optical effects.…”

Design and theoretical analysis of current transformer based on B-dot planar printed circuit board coil

“…Therefore, developing the current measurement technology based on new principles has been becoming a trend. Recently, the non-contact measurement methods have been widely concerned and the new measurement technology represented by the optical current transformer has got great development (Oosthuysen and Walker, 2014). However, restricted by the outdoor operating conditions and technology, the optical current transformer is not widely used in practical engineering.…”