A High-Performance DC Controllable Arrester With Flexible Operation Based on Semicontrolled and Fully-Controlled Hybrid Bypass Switch

As the power system develops toward larger capacity and greater integration of new energy sources, the proportion of sensitive equipment such as power electronic converters is increasing, resulting in a heightened need for overvoltage suppression. The controllable arrester (CA), as a novel device capable of achieving deep overvoltage suppression, has gained significant attention. However, the use of semicontrolled switches in CAs often results in difficulties with exiting after activation in dc systems, leading to excessive energy absorption and limited suppression capability. This article proposes a novel controllable arrester with flexible operation (Flexible CA) for dc transmission systems. By integrating a fully-controlled switch with the existing semicontrolled switch, the Flexible CA enables both rapid operation and flexible exit capabilities, while also decoupling overvoltage suppression from energy absorption. Detailed parameter configuration and working strategies allow for improved performance in overvoltage suppression and energy management. Finally, 2 kV and 25 kV prototypes of Flexible CA and overvoltage suppression experimental platforms have been developed to validate the feasibility of the proposed design. In addition, a ±500 kV/3000 MW offshore VSC-HVdc simulation system with the Flexible CA has been also established. The results demonstrated effective decoupling of overvoltage suppression from energy consumption, limiting overvoltage to 1.6 p.u. while reducing excess energy demand by at least 54.1%, with better techno-economic performance.