High-voltage dc (HVdc) circuit breakers (CBs) are a key technology of multiterminal dc (MTdc) systems and grids. In this article, a state-of-the-art 500-kV hybrid CB (HCB) topology is proposed and compared with other existing HCB solutions. Implementing the topology includes three important components: a modular designed high-current bidirectional solid-state switch (SS), an ultrafast mechanical switch (MS) based on a Thomson (CCDC) equipment with no conduction loss, whose corresponding functional verification test results have been presented in detail. On this basis, the overall 500-kV HCB and a comprehensive experimental platform are developed. Detailed experiments, including 25-kA turn-off and reclosing experiments, are conducted. The HCB was found to be capable of breaking a 25-kA current in 2.7 ms with 800-kV overvoltage, which is on par with the level of leading CBs worldwide.

中文翻译：

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适用于直流电网的最先进的500 kV混合断路器：世界上最大容量的高压直流断路器

高压直流（HVdc）断路器（CB）是多端子直流（MTdc）系统和电网的一项关键技术。本文提出了一种最新的500 kV混合CB（HCB）拓扑，并将其与其他现有HCB解决方案进行了比较。实现拓扑包括三个重要组件：模块化设计的高电流双向固态开关（SS），基于Thomson（CCDC）设备且无传导损耗的超快机械开关（MS），其相应的功能验证测试结果包括：详细介绍。在此基础上，开发了整个500 kV六氯苯（HCB）和一个综合的实验平台。进行了详细的实验，包括25 kA的关断和重合闸实验。发现HCB能够在2.7 ms内断开800 kV电压下的25 kA电流，