【摘要】 柔性光学电流互感器(flexible optical current transformer,FOCT)在水电领域的推广应用，为奇数多分支发电机主保护定量化改造奠定了基础。经内部故障的全面分析计算，某每相7分支的大型发电机主保护定量化设计结果推荐采用“3-1-3”分支分组方式，相应的主保护配置方案保护死区虽小(0.5%)但对相间短路存在保护死区——发生在每相未装设分支电流互感器(TA)的第4分支之间，利用柔性光学TA绕制灵活的特点，通过增设每相第4分支的光学TA及对应的不完全纵差保护即可消除上述相间短路保护死区。上述主保护定量化改造思路将为后续奇数多分支大型发电机的技术改造提供借鉴。更多还原

【Abstract】 Flexible optical current transformers (FOCT) has found extensive applications in the hydropower field,laying the foundation for quantitative transformation of main protection for generators with odd branches. In the case of the large-sized generator comprising 7 branches per phase,a comprehensive internal fault analysis and quantitative design process for main protection are conducted. It is recommended to adopt the “3-1-3” branch grouping method. While the main protection dead zone is small (0. 5%),there exists a protection dead zone for phase-tophase short circuits—occurring between the 4 th branches where CTs are not installed in each phase. Leveraging the flexibility of flexible optical current transformers,this dead zone can be eliminated by adding optical CTs for the 4 th branches in each phase and corresponding incomplete longitudinal differential protection. This quantitative transformation approach for main protection will serve as a reference for the subsequent technical transformation of largesized generators with odd branches.更多还原