Modeling and simulation of optical current transformer using operational amplifiers

Abstract

The importance of Conventional Current Transformer (CCT) for the monitoring and protection in power systems is not ignorable. Although there has been an extensive use of CCT for a long time but a lot of problems and issues such as inrush current, saturation, current transformer ratios, etc. faced by CCT make its use quite limited. Issues arising in CCTs have pulled the attraction of researchers and protection engineers towards a new instrument technology based on Opto-Electromagnetics. An Optical Current Transformer (OCT) model based on the simulation has been proposed here which follows the Faraday's law of Electromagnetics. The use of OCT will resolve almost all issues that were being faced by CCTs. So this new designed model of OCT can replace easily the CCTs for both the protection and metering purposes. This simulation model of OCT using operational amplifiers is being proposed here just to motivate the protection and design engineers especially in Pakistan to adopt the new technology of OCT for the measurement of current in place of CCT. In addition to resolving all issues related to CCT, OCT will also make the power quality better. Three types of outputs can be obtained from an OCT which are: low energy analog output (LEA), high energy analog output (HEA) and digital output. Due to sampling rate limitations involved, a digital output is hard to use to avail the wider bandwidth option. To use all the benefits of an OCT, a low energy output signal will be used here for the simulation requirement here. After the required OCT model development, simulation results will be included to prove that CCT can be replaced by the OCT.