Fault Transient Study of a Meshed DC Grid With High-Temperature Superconducting DC Cables

This paper presents the DC fault transient study of a meshed DC grid with high-temperature superconducting (HTS) HVDC cables to integrate offshore wind power. A four-terminal meshed DC grid model with a +/- 100 kV DC voltage rating is developed. DCcircuit breakers (DCCBs) are implemented in the DC grid to deal with DC cable faults. To conduct the fault transient study, the fault scenarios with different fault locations and protection delays are studied. The sensitivity study versus different DC fault locations reveals that the faults on the faulted cable will not cause the quenching of healthy cables. The sensitivity study considering different DC fault protection delays demonstrates that the HTS cables have a current-limiting effect and the long delay of DC fault protection does not result in large fault current and the quenching of healthy cables. Extensive simulations in PSCAD/EMTDC validate the founding.

Automated summary

This paper presents a study on the DC fault transient of a meshed DC grid integrated with high-temperature superconducting (HTS) HVDC cables for offshore wind power integration. A four-terminal meshed DC grid model with a +/-100 kV DC voltage rating is developed, and DC circuit breakers (DCCBs) are employed to manage DC cable faults. Through fault scenario studies with different fault locations and protection delays, it is found that the faults on the faulted cable do not affect the functioning of other healthy cables and that the long delay of DC fault protection does not result in excessive fault current and the quenching of healthy cables. Extensive simulations in PSCAD/EMTDC software validate the research findings.