Current sensors based on GMR effect for smart grid applications

Abstract In the smart grid, wide-area current measurement system is of great importance to assist with the estimation of the power grid loss and the smart dispatching. However, the limited current sensing techniques have always been an obstacle to realizing such system. Recently, the development of giant magnetoresistance (GMR) based sensors has offered an effective solution to address this issue. The outstanding merits of compact size, high sensitivity and cost-effective price of GMR sensors have made them a perfect choice for widely distributed current measurement and data collection in smart grid. In this paper, with a design of flux guided structure for line current sensing, typical performance characteristics of optimized GMR design are illustrated. The validity of the structure is demonstrated with simulation and experiment. Based on the characteristics of GMR sensors, their prospects for application in smart grid are further discussed.