A Fast Fault Detection Method for Protection of HVDC Transmission using Voltage of The PMFCL

High-voltage direct current (HVDC) systems efficiently carry significant amounts of renewable energy. An smoothing reactor (SR) has a poor ability to decrease the short-circuit current in the HVDC transmission line. The SR can be replaced by a permanent magnet-type saturated-core fault current limiter (PMFCL). The PMFCL behaves like the SR when operating normally for power quality reasons. Its inductance immediately rises in a short-circuit state and reduces the fault current. Detecting a high-resistance fault using the PMFCL is easier than that of the SR, which is caused by an increase in the inductance value. This paper proposes a fast fault detection method for the protection of the HVDC transmission lines using the voltage across the PMFCL. The proposed method can detect high-resistance faults in approximately 1 millisecond. The method does not cause the DC circuit breaker (DCCB) to malfunction during load changes and AC faults and is safe from noise. The PMFCL reduces the strict requirements on the protection scheme and DCCB, improving the grid’s operational safety.