The voltage and current ratings of the voltage source converter (VSC) based high voltage direct current (HVDC) transmission line projects have increased over the years. It testifies the increasing popularity of VSC-HVDC technology. Since the long-distance, VSC-HVDC transmission lines are more exposed to commonly appearing short circuit faults; thus, protection equipment with increased fault-current handling capability is required. The DC circuit breakers (DCCBs), with or without fault current limiters (FCLs), can effectively handle the fault-current. The variations in VSC-HVDC projects’ ratings and their impact for DCCB with FCL and without FCL are thoroughly analysed in this paper. The paper further includes an in-depth discussion on DCCBs with FCL and without FCL. An equivalent circuit modelling approach is used for simulation analysis of three case studies under the influence of these breakers to analyse current behaviour; the case studies include the Zhoushan HVDC Project, Xiamen HVDC Project, and Zhangbei-I HVDC Project. All these projects have different capacities in terms of their power, voltage, and current ratings. For DCCBs, this paper includes a detailed analytical model to understand the fluctuations in the size of fault-current limiting components (in DCCBs) for increased fault-current handling requirements. The simulation results using PSCAD/EMTDC and MATLAB are presented to verify different aspects of this study. A small scale laboratory prototype is also developed to validate the performance of DCCB with and without FCL. Based on theoretical, simulation, and experimental validations, it is substantiated that for increased VSC-HVDC projects’ ratings, DCCB with FCL can perform better compared to conventional DCCB without FCL.

中文翻译：

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高压直流断路器中故障限流器和参数优化对于增加 VSC-HVDC 输电网络应用容量的意义

多年来，基于电压源换流器（VSC）的高压直流（HVDC）输电线路项目的电压和电流额定值不断增加。这证明了VSC-HVDC技术的日益普及。由于VSC-HVDC输电线路距离长，更容易出现短路故障；因此，需要具有增强的故障电流处理能力的保护设备。带或不带故障限流器 (FCL) 的直流断路器 (DCCB) 均可有效处理故障电流。本文全面分析了 VSC-HVDC 项目评级的变化及其对带 FCL 和不带 FCL 的 DCCB 的影响。本文还对带 FCL 和不带 FCL 的 DCCB 进行了深入讨论。在这些断路器的影响下，使用等效电路建模方法对三个案例研究进行仿真分析，以分析电流行为；案例研究包括舟山直流输电工程、厦门直流输电工程、张北一级直流输电工程。所有这些项目在功率、电压和电流额定值方面都有不同的容量。对于 DCCB，本文包含一个详细的分析模型，用于了解故障电流限制组件（DCCB 中）尺寸的波动，以提高故障电流处理要求。使用 PSCAD/EMTDC 和 MATLAB 的仿真结果验证了本研究的不同方面。还开发了一个小型实验室原型来验证带和不带 FCL 的 DCCB 的性能。基于理论、仿真和实验验证，证实对于提高 VSC-HVDC 项目的额定值，带有 FCL 的 DCCB 比不带 FCL 的传统 DCCB 具有更好的性能。