Development of a current sensor based on active materials for high-voltage transmissionsystems

Abstract

This paper presents the development of a new class of current sensor based on activematerials for high-voltage transmission systems. This current sensor is an innovative designwith respect to conventional current measurement transformers. The alternating currentsignal to be measured induces a magnetic field in an emitter which consists of amagnetostrictive material. The emitter transforms the current magnetic energy intomechanical energy in the form of mechanical waves due to the alternating nature of theinduced magnetic field. These waves are transmitted through a dielectric structure until apiezoelectric stack, the receiver, is reached which converts the mechanical energy backinto electrical energy. An electronic signal module processes this low electricalcurrent and estimates the primary current to be measured. A numerical modelhas been developed to evaluate the preliminary design. A small scale prototypehas been built and tested to demonstrate the feasibility of the current sensor.Experimental data have been used to fit the damping parameters of the model.