Performance Optimization of a Novel DC Fault Current Limiter Combining Different Magnetic Materials and Topologies.

For future high voltage direct current (HVDC) grids, the dc protection system is often considered as one of th e main challenges due to the difficulty in interrupting a large dc current and the stringent time constraint imposed by the fast rising fault current[']. Therefore, a novel DC system fault current limiter based on saturable core reactor theory (DCSFCL) was proposed previously. In order to obtain better performance of DCSFCL that is unable to be accomplished by single magnetic material, mixed magnetic materials were applied to take advantages of different magnetic materials. Furthermore, magnetic valves were also added to original DCSFCL topology, which is a good way to optimize clipping performance and reduce the usage of both magnetic materials and permanent magnets (PM). ANSYS models were built and finite element analysis were carried out to verify the feasibility of these deductions.