9FA型燃气-蒸汽联合循环发电机组的国产保护设备配置方案

Configuration scheme with homemade protections for 9FA gas-steam combined-cycle generator-transformer unit

9FA型燃气-蒸汽联合循环发电机组一般采用配套进口保护设备,还没有采用国产保护设备的应用实例。结合电厂的工程实践,分析比较了9FA型燃气轮发电机组的运行方式与常规机组的差异,重点针对发电机启停机保护、发电机定子接地保护、发电机差动保护、主变压器差动保护,以及其他后备保护。深入研究了这些保护在负载换流型变频器(LCI)系统变频启动过程中的运行特点。通过采用与频率无关的保护原理以及特性化配置,提出了9FA型燃气-蒸汽联合循环发电机组采用国产保护设备的变频启动解决方案和主保护解决方案。

9FA gas- steam combined- cycle generator- transformer unit are normally equipped with imported protections without any applications of homemade equipment. Combined with the project practice of gas power plant,the differences of operational modes between 9FA and conventional units are analyzed, focusing on the generator startup/shutdown protection,generator stator grounding protection, generator differential protection, main transformer differential protection and other backup protections. The operational characteristics of these protections during the variable- frequency startup process of LCI system are deeply analyzed. By applying the frequency-, independent principle and customized protection configuration,the variable-frequency startup protection scheme and main protection scheme with homemade equipment are put forward for 9FA gas- steam combined-cycle generator-transformer unit.