按支路计算制动的母线三折线比例差动保护

常规母线保护比例差动区内故障和区外故障制动特性相同，区外抗CT饱和的能力受到制动系数提高的限制。根据母线区内故障和区外故障时短路电流的分布特点，提出了按支路计算制动电流的母线保护比例差动原理。各支路的制动特性取为非线性的两段折线特性，制动电流按支路分别计算再求和。新方法区内故障时动作特性和常规差动相同，区外故障时提高了制动电流，在各支路CT变比不同时制动能力也更强。算例分析和仿真表明，区外故障时的抗饱和能力较常规差动提高了30％。

Bus Three Segments Polyline Ratio Differential Protection Restraint by Branch Current

Conventional bus ratio differential protection of interior and exterior fault has same restraint characteristic.The performance of anti-CT saturation is weaked by increased restraint coefficient.Considering the difference between interior and exterior bus fault current distribution,this paper presents a new bus protection ratio differential principle that calculates restraint current according to branch current respectively.The restraint characteristic of each branch is compared of two non-linear segments p...