Development of a Pillar-type CVT Leakage Current Sensor with High-Efficiency Magnetization

As an important physical quantity in the power system, current is of great significance to its accurate measurement.In this paper, through the introduction of three mainstream measurement technologies, combined with the actual work needs, the non-contact measurement theory is studied, and the TMR (Tunneling Magnetoresistance) measurement element is selected.Combined with the structural characteristics of capacitive voltage transformer (CVT), a pillar-type CVT leakage current sensor with efficient magnetic concentration was developed, and it was successfully applied in the 220kV Fanjiawan substation.The measurement results show that the CVT leakage current sensor developed in this paper can monitor the CVT leakage current without power failure, and has the characteristics of convenient installation, high safety and high measurement accuracy of measurement results.