Protection schemes using resistive-type superconducting fault current limiters with mechanical DC circuit breakers in MMC-MTDC grids
Protection schemes using resistive-type superconducting fault current limiters with mechanical DC circuit breakers in MMC-MTDC grids
复制标题
在 MMC-MTDC 电网中使用带有机械直流断路器的电阻型超导故障限流器的保护方案
DOI：
10.1049/iet-gtd.2019.1546
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发表时间：
2020
影响因子：
2.5
通讯作者：
Ding Tao
中科院分区：
文献类型：
--
作者：
Xiang Bin;Luo Jinhui;Gao Lei;Wang Jianhua;Geng Yingsan;Liu Zhiyuan;Ding Tao
针对基于模块化多电平换流器（MMC）的多端直流（MTDC）电网，研究了电阻性超导故障限流器（R-SFCL）和直流断路器（DCCB）在故障切除中的协同工作特性。然而，在考虑后备保护和R-SFCL对MMC故障特性影响的同时，缺乏将联合收割机R-SFCL与机械式DCCB相结合的完整保护方案。本研究探讨一种包含主、后备保护的故障电流开断方案。分析了带R-SFCL的金属基复合材料的故障特征，将故障暂态过程分为三个阶段。然后提出了两种故障限流方案，分别在换流器输出端和线路端设置R-SFCL。将这两种保护方案应用于直流试验系统中，并进行了验证和比较。结果表明，在这两种方案中，设计的R-SFCL的尺寸一般应为几十Ω。这些R-SFCL保持转换器不被阻断，直到主断路器或备用断路器中断故障电流，并且M-DCCB仅需要断开几kA电流。故障发生后，主保护系统将在200 ms内恢复，后备保护系统将在250 ms内恢复。
The cooperative characteristics of resistive superconducting fault current limiters (R-SFCLs) and DC circuit breakers (DCCBs) have been investigated with regard to the fault clearing in modular multilevel converter (MMC)-based multiterminal direct current (MTDC) grids. However, research is lacking in complete protection solutions that combine R-SFCLs and mechanical DCCBs while considering the backup protection and the effect of R-SFCLs on the fault characteristics of MMCs. This study investigates a fault current breaking scheme that includes primary and backup protection. Moreover, the fault characteristics of MMCs with R-SFCLs are analysed, and the fault transient process is divided into three stages. Then two fault current limiting schemes with R-SFCLs located at the converter output or the line are proposed. These two protection schemes are applied to the DC test system, verified and compared. The results show that in both schemes, the size of the designed R-SFCL should be generally a few tens of Omega. These R-SFCLs maintain the converters unblocked until the primary breakers or backup breakers interrupt the fault currents, and the M-DCCBs are only required to break several kA currents. After a fault occurs, the system will restore within 200ms for primary protection or 250ms for backup protection.