Behavior of current transformers under distorted waveforms

Abstract

The use of nonlinear loads connected to the power networks that produce distorted currents has been increased in the last years. At the same time, distributed generation has also been increased. It uses power electronic devices to inject the energy to the network, generating harmonic currents that flow though the networks. Being current transformers key elements for measuring electric power and energy, is it very important to know their precision performance under distorted waveforms. This paper analyzes the errors of typical current transformers used in power networks from a theoretical and experimental point of view. Errors with different distorted waveforms are measured, and several proposed testing methods are evaluated.