Comprehensive Design and Experimental Validation of 30 kV Ultra‐Fast Flexible Controllable Arresters for HVDC Systems

ABSTRACT To effectively suppress transient overvoltages in HVDC systems, the design and experimental validation of a multi‐module series controllable arrester are presented. The voltage‐limiting performance, series voltage equalisation capability, and robustness under fault conditions in high‐voltage scenarios require further research. First, the necessity of the modular structure is analysed. Then, a multi‐module coordination control strategy is proposed to ensure the consistent operation of individual modules by triggering each module and coordinating the response. Furthermore, a monitoring and isolation control circuit suitable for high‐voltage environments is developed to enable fast signal sampling and transmission. Finally, the electrical parameters of the modules are optimised to ensure strong voltage‐limiting performance. The simulation results of a ± 500 kV/3000 MW VSC‐HVDC system verify the reliability and engineering applicability. Lightning surge tests on a three‐module prototype demonstrate that the equipment achieves excellent dynamic and static voltage equalisation performance and meets the expected voltage‐limiting effect, maintaining good robustness even under a failure rate set at one‐third. These results validate the feasibility, reliability and excellent technical and economic performance of the proposed solution in high‐voltage scenarios.