New Sub-Module with Reverse Blocking IGBT for DC Fault Ride-Through in MMC-HVDC System

When integrating multi-grid renewable energy systems, modular multi-level converters (MMCs) are promising for high-voltage DC (HVDC) transmission. Because of the characteristics system, however, it is more difficult to prevent a fault at terminal than AC MMC. Accordingly, ride-through (FRT) strategy operation MMC in required stable system operation. In this paper, solution closed-circuit overcurrent caused by permanent line-to-line proposed. This method able reduce current through adjustment slope total voltage operating sub-module having lower switching losses and fewer passive devices compared with existing topologies. Additionally, equivalent circuit proposed scheme case fault, FRT mechanism explained. The feasibility technique was verified time-domain simulations implemented Powersim, Inc.