【摘要】 可变速抽水蓄能机组是构建新型电力系统、满足大容量灵活储能需求的关键技术。国产中洞400MW机组作为单机容量最大的交流励磁变速机组，其转子绕组主保护设计是机组安全稳定运行的核心难题。本文旨在研究不同定子分支分组方式对新型转子主保护方案(基于定子零序横差电流谐波总有效值)性能的影响。首先，建立了中洞变速机组的多回路数学模型；继而，分析了转子绕组的故障特性与定子绕组分支电动势在空间谐波磁场作用下的变化规律，阐明了中洞变速机组定子绕组分支分组方式对中性点连线谐波电流频率的影响；最后，基于全面仿真结果，验证了上述理论分析，并表明优化定子分支分组方式能有效减小转子绕组新型主保护的保护死区。更多还原

【Abstract】 Variable-speed pumped storage units are a key technology for building new power systems and meeting the demand for large-capacity,flexible energy storage.The domestically produced Zhongdong 400MW unit,as the largest AC-excited variable-speed pumped storage unit in China,presents a critical challenge in its rotor winding main protection design,which is essential for the unit’s safe and stable operation.This paper aims to study the impact of different stator branch grouping methods on the performance of a new rotor main protection scheme (based on the total effective value of the stator zero sequence transverse differential current harmonics).First,a multi-loop mathematical model of the Zhongdong unit was established.Subsequently,the fault characteristics of the rotor winding and the stator branch potential patterns under spatial harmonic magnetic fields were analyzed,clarifying the influence of the branch grouping method on the harmonic current frequency in the neutral point connection.Finally,comprehensive simulation results verified the theoretical analysis and demonstrated that an optimized stator branch grouping method can effectively reduce the protection dead zone of this new main protection scheme.更多还原