In the UHV DC transmission system, used to measure DC current and transmit the measurement results to the DC control and protection equipment, fiber optic current sensor can measure the high current in the line with high precision, provide accurate current data for the stable operation of the system, and guarantee the normal performance of the control and protection functions of the UHV DC transmission system in the process of high-power, long-distance transmission.

Mainly used in ± 200kV Zhoushan flexible DC transmission, ± 500kV Zhangjiakou - Beijing flexible DC transmission and other projects. As the DC side of the flexible DC transmission system is prone to generate large fault current when the fault, the transient performance of the current measurement device requires high, fiber optic current sensor can quickly and accurately measure the current, provide key data support for the rapid protection and control of the flexible DC transmission system, to meet the needs of the project on the rapid detection and suppression of fault current, to enhance the safety and stability of the power system.

Jiangsu Ru dong ± 400kV offshore wind power flexible DC transmission project, is China's first far offshore wind power via DC transmission project, as the world's highest voltage level, the largest transmission capacity of the offshore wind power flexible direct project, creating eight world firsts, large-scale development and construction of China's large-scale far offshore wind power is of great significance as a demonstration. Our fiber optic current sensor, installed in ± 400kV transmission line, real-time monitoring of current changes in the line, for grid operation status assessment, trend control and fault diagnosis to provide data support. When the line overload, short circuit and other faults, it can quickly and accurately detect the current abnormality, trigger the protection device in time, cut off the circuit, and protect the line and equipment safety.

In DC distribution network, fiber optic current sensor can be used to measure the current in the DC distribution lines of ±35kV, ±10kV, etc., to realize real-time monitoring and protection of DC distribution system. It can also be used for current measurement when distributed energy sources are connected to DC distribution network to realize accurate monitoring and control of distributed power output current.