A Review Paper on Current Transformer

Abstract

A current transformer, also known as series transformer is a type of instrument transformer. Current transformer is an electric device which “steps down” the current, by means of primary and secondary winding. Current transformer produces an alternating current in its secondary which is proportional to the alternating current in its primary. Current transformer plays a vital role in protective systems such as relays and meters, so it is essential to obtain maximum accuracy. Current transformer is used with many electric instruments such as Wattmeter, power factor meters, as trip coils in magnetic circuit breakers, or MCB's and hence it can be said that Current transformer can be used in those applications where current is very high to be measured directly. An extensive review process of around 10 research papers results three major key issues “Burden, Saturation condition during fault, Variable phase error and variable ratio error, ” which have important role in the enhancement of accuracy. Study of these issues result various solutions and techniques which make the use of current transformer more dominant and effective.