三峡水电站发电机变压器组内部短路主保护方案的理论分析和试验研究

The Main Protection Scheme of Internal Short Circuit for Generator-Transformer Bank of Three Gorges Hydroelectric Power Station

根据对龙羊峡电厂和岩滩电厂机组保护的理论分析、试验研究和运行经验总结，本文提出了三峡电站机组短路主保护方案，即：发电机第一主保护为高灵敏单元件横差保护，第二主保护为故障分量负序方向保护；变压器第一主保护为考虑励磁特性的变压器短路保护，第二主保护为故障分量标积制动式差动保护，后者采用三相电流和的谐波制动方式。

Based on the theoretical analysis and test research of the main protections for Long Yang Xia station and YanTan station,the main protection schemes of Three Gorges station are put forward in this paper.The first mainprotection for generator is the unit transverse differential with high sensitivity,The second main protection is thenegative sequence directional relay based on fault component,For transformer,the relay considering magnetizingcharacteristic is adopted as the first main protection and the differential relay with the restraint of scalar product offault component may be used as the second main protection,The differential relay of transformer is restrained byharmonic of sum of three phase current。