田湾核电1#、2#机组发电机定子接地保护改进方案

Improvement Scheme of Generator Stator Grounding Protection for Tianwan Nuclear Power Units 1 and 2

本文介绍了田湾1#、2#机组现有发电机定子接地保护的配置情况及其缺点,并提出改进方案。目前田湾1#、2#机组使用的发电机定子接地保护原理为基波零序加三次谐波电压。根据保护特有缺点,并不能保护全部定子范围,并且存在拒动、误报警等风险。为更好地保护发电机定子安全,提出增加注入式定子接地保护的方案,可弥补现有定子接地保护的缺陷,更好的保障发电机安全稳定运行。

This paper introduces the configuration of the existing generator stator grounding protection for Tianwan Units 1 and 2 and its shortcomings,and proposes an improvement scheme.The current generator stator grounding protection principle used in Tianwan units 1 and 2 is fundamental zero sequence plus third harmonic voltage.According to the unique shortcomings of the protection,it does not protect the entire stator range and there is a risk of rejection and false alarm.In order to better protect the generator stator,a solution to increase the injected stator earth protection is proposed.The inclusion of the injected stator grounding protection can make up for the defects of the existing stator grounding protection and better ensure the safe and stable operation of the generator.