Linear and Nonlinear System Modeling

8Modeling and Simulation of Current Transformer to Study Its Behaviors in Different Conditions

Aveek Chattopadhyaya¹* and Surajit Chattopadhyay²

¹Department of Electrical Engineering, GNIT, Panihati, Kolkata, India

²Department of Electrical Engineering, GaniKhan C. Institute of Engineering and Technology, Malda, W.B., India

Abstract

Current transformer (CT) is a pertinent device in electrical systems. This chapter aims to discuss modeling and simulation of current transformer to study its behaviors. For this purpose, CT secondary signal is considered. Applying wavelet transform (WT) and fast Fourier transform (FFT), different behaviors of CT are analyzed. Wavelet-transform-based multi-resolution analysis (MRA) and root mean square (RMS) are also used to ascertain the saturation of CT and to calculate the exact primary current during saturation.

Keywords: FFT, WT, DWT, RMS, interpolation, extrapolation

8.1 Introduction

For protection and measuring purposes, Current transformer (CT) is used. Current transformer is widely used in electrical systems for smooth and reliable operation of the electrical system. For this purpose, proper modeling, simulation, and behaviors of CT in different conditions are utmost required things. Otherwise, maloperation of CT can affect the performance of the system. In Reference [1], computer simulation is discussed to show the saturation and as a repercussion the deformation of the CT secondary due to direct current (DC) component in the CT primary ...