Current measurement of flat conductors with a circular array of magnetic sensors

摘要

To fully realize the advantages of DC microgrids, such as high energy efficiency, excellent reliability, and the ability to handle high-dynamic loads, special DC measurement equipment for control, safety and monitoring tasks are required. The equipment must be energy efficient, precise, and should combine a high bandwidth with fast digital communication. To fulfill all the special needs of DC microgrids, a fully electronic current sensor, using a circular array of six uniformly installed micro fluxgate magnetic field sensors, was developed and evaluated. The circular array combines low-power consumption with a certain amount of mechanical flexibility and thus is a big improvement over older, closed-loop DC sensors. In this study, the influence of the geometry of different flat conductors on the accuracy of current measurement was theoretically and experimentally evaluated. Under certain conditions, specifically at certain angles between the flat conductor and sensor arrangement, the measurement error associated with the geometry of the flat conductor becomes zero. In the end, it was possible to achieve current errors of less than 1.5%.