基于柔性光学TA的发电电动机主保护优化设计

中国已投运大中型水电站发电机主保护技改工作日渐增多，受制于发电机现有分支引出方式和电磁型电流互感器（TA）的安装条件，虽经发电机主保护定量化设计，最终选择的主保护配置方案仍存在保护死区。以中国滩坑水电站发电机主保护技改为例，由于电磁型TA安装受限，不得不选择次优的主保护配置方案，导致技改后发电机的运行仍存在安全隐患。大型发电电动机因为转速高、风洞空间小，上述矛盾更加突出。中国深圳抽水蓄能电站发电电动机技改工程中，基于柔性光学TA绕制灵活的优点，在不改变发电机现有分支分组和铜环引出的前提下，通过光学TA的灵活装设虚拟分支引出方式，实现了接入发电机保护装置的分支电流（或分支组电流）的重新组合，在定量分析的基础上优化了深圳抽水蓄能电站发电电动机主保护配置方案，消除了主保护死区。

Optimal Design of Main Protection for Generator-motor Based on Flexible Optical Current Transformer

Renovation projects of generator main protection in large and medium hydropower stations in China are gradually increasing. Limited by the existing branch wiring mode and installation condition for electromagnetic current transformer (CT), there is still a protection dead zone in the final selection of the main protection configuration scheme, despite the quantitative design for the generator main protection. Taking the renovation project of main protection for Tankeng Hydropower Station in China as an example, a suboptimal main protection configuration scheme has to be selected due to the installation limitation of electromagnetic CT. As a result, safety risks still exist in generator operation after the renovation. Because of the high speed and small foundation space of large generator-motor, the problem above is more prominent. In the renovation project of main protection for Shenzhen pumped storage generator-motor, based on the advantages of the flexibility of flexible optical CT winding, the wiring mode of branches is virtually changed through the flexible installation of optical CT without changing the existing branch grouping or the copper ring wiring mode of the generator. And the branch currents and branch group currents connected to the generator protection devices are recombined. Then the configuration scheme of main protection for Shenzhen pumped storage generator-motor is optimized based on quantitative analysis, thereby eliminating the dead zone of main protection.