【摘要】 注入信号法发电机定子接地保护受定子绕组对地电容的影响 ,灵敏度较低 ,难以满足大型机组高灵敏度继电保护的要求。而采用外加小电抗器、选择合适的注入信号频率 ,以补偿定子绕组对地容抗、测量故障接地电阻或测量信号电压、信号电流相位差进行接地保护则可改善大型机组定子接地保护的灵敏度。计算、分析与仿真表明 :该方法具有较高的灵敏度。更多还原

【Abstract】 Tradition methods for detecting single phase to ground faults in generator stator windings based on injecting signal have poor performance in high resistor grounding fault, because of the capacitance of generator stator windings. In order to improve it, an inductance, which parallels connection on the neutral grounding resistor at the second side of distribution transformer, is used to compensate the capacitance of generator stator windings. By selecting a suitable frequency of injection signal, the grounding fault protection can be realized by measuring the grounding resistance of fault point or injecting signal power factor. By simulation, it can detect very high impedance ground fault.更多还原