水轮发电机定子接地的行波电流差动保护与故障选相

针对行波在水轮发电机定子绕组槽部和端部的传播特征，建立其分布参数的波动电路模型，提出将定子故障接地初瞬行波电流零模部分的高频分量作为故障判据进行行波差动保护，并通过接地时的电流模量特征实现故障选相。应用凯伦贝尔(Karebauer)变换对定子接地的行波信息进行模量分析，应用小波理论对零模高频部分进行提取。在Matlab 6.5中针对大型水轮发电机的参数建立定子绕组波动模型，叠加等效直流电源对其接地进行仿真，小波分解提取出的特征信号表明了将零模高频部分作为动作判据的可行性，仿真数据同时验证了故障选相原理的正确性与可行性。

Current Differential Protection and Faulty Phase Identification Based on Traveling Waves for Hydro-generator's Stator Single Phase to Ground

Models of hydro-generator stator windings' distributed parameter equivalent circuit aiming at traveling wave propagation outside and inside the slot is proposed. The ideas that current zero modulus portion' high frequencies as fault characters to active differential protection in initial fault phase are presented, and fault current wave's modulus characters implement faulty phase selection. Karebauer modulus transform analysis the travelling-wave data of stator to ground, Wavelet theory picks out the zero modulus' high frequencies signals. Circuit model is built based on a large salient generator's parameters in Matlab 6.5, a equivalent DV source is added to simulate grounded. Character signals from high frequency layer of wavelets' decomposes indicate that differential protection's available. Simulation results also indicate that faulty phase selection is valid and feasible.