Introduction  Low voltage flexible DC microgrid is a bridge between DC devices such as energy storage, electric car and mid-voltage DC power grid. As the DC technology develops and many more DC devices connecting to the grid, it′s feasible and necessary to develop low voltage flexible DC microgrid. DC current transformer is a chief component of low voltage flexible DC microgrid.

  Method  This article analyzed typical application scenario of low voltage flexible DC microgrid and compared several types of DC current transformer. It analyzed the reliability and economy of DC current transformer.

  Result  Under specified circumstance, for branches of higher requirements of precision, DC current transformer is equipped independently for protection and control, while for branches of low requirements DC current transformer is shared between protection and control. Under current technical level, it′s recommended to use resistor shunt or giant magnetoresistance sensors.

  Conclusion  It′s proved that under current technical level, the analysis this article mentioned is correct and effective. This article also gives advice for application under other scenarios.