A Cutting-Edge Device for DC Fault Isolation and Enhanced AC/DC Fault Ride-Through for MTDC Systems —PART II: Verification and Comparisons

This two-part paper proposes a device that integrates dc fault isolation with ac/dc fault ride-through capacities. A four-terminal MTDC simulation system and a simplified low-voltage hardware experimental platform are established for demonstrating the functions of clearing the dc fault current and dissipating surplus power. The experimental results are compared with those of a simulation to analyze the feasibility of the proposed device and verify the reliability of the simulation. Using the simulation system, the proposed device competes against representative dc circuit breaker (DCCB) schemes with dc chopper schemes. The proposed device can effectively clear dc fault current and dissipate the surplus power. The proposed device lowers the cost of components by at least 33.7% from those of independently configured DCCBs with dc choppers.