【摘要】 扎拉水电站的开工建设，使得大容量冲击式水电机组的设计与制造备受关注。为确保某大型冲击式水电机组的安全稳定运行，有必要在全面内部故障分析计算的基础上，针对每相7分支发电机的内部故障特点，对其主保护设计规律进行归纳总结——对于叠绕组发电机小匝数匝间短路保护灵敏度不足的问题，优先推荐“3-1-3”分支分组方式，立足于不完全裂相横差和不完全纵差保护的相互配合，不完全裂相横差保护舍弃的分支即不完全纵差保护中性点侧接入分支，以减少对小匝数匝间短路的保护死区；而“一横一纵”主保护的配置还为保留完全纵差保护创造了条件，既实现了无相间短路保护死区，又有助于偏心振动引起事故的排查。上述研究工作将为今后采用更大容量冲击式机组的水电站的建设提供借鉴。更多还原

【Abstract】 The start of construction of the Zara Hydropower Station has drawn significant attention to the design and manufacture of large-capacity impact hydro units.To ensure the safe and stable operation of a large impact hydro unit，it is essential to conduct a comprehensive internal fault analysis and calculations based on the internal fault characteristics of the 7-branch generator per phase，and summarize the design principles of its main protections.For the issue of insufficient protection sensitivity for inter-turn short circuits with few-turns in lap-wound generators，the "3-1-3" branch grouping method is preferred，which relies on the mutual coordination between incomplete split-phase transverse differential protection and incomplete longitudinal differential protection，and reduces the protection dead zone for inter-turn short circuits with few-turns through connecting the branch abandoned by the incomplete split-phase transverse differential protection to the neutral point side of the incomplete longitudinal differential protection.The configuration of the "transverse + longitudinal" main protection also creates conditions for retaining the complete longitudinal differential protection，achieving no dead zone for interphase short-circuit protection and facilitating the investigation of accidents caused by eccentric vibration.The above research work will provide a reference for the construction of subsequent larger-capacity hydropower stations with impact units.更多还原