An AMR-based three-phase current sensor for smart grid applications

In a smart grid (SG) scenario, accurate and realtime information about key grid parameters (such as voltage and current in each node of the net) are strategic requirements. In order to grant the best tradeoff between the measurement accuracy and the economic sustainability of SG distributed measurements, the design and the development of suitable lowcost current/voltage sensors are required. To this aim, this paper proposes a three-phase contactless current sensor based on anisotropic magnetoresistance effect. A suitable sensors placement strategy is used to compensate the uncertainty due to the interfering magnetic fields (i.e., magnetic fields generated from other electrical apparatus near to the sensors or from the other wires of the three-phase system). After a preliminary characterization of the proposed solution in a simulated environment, an experimental validation is carried out and reported in this paper.