发电机定子接地故障会导致运行中的发电机组严重损坏,传统双频式100％定子接地保护在现代化的发电机保护中已经不能满足要求,外加电源式100％定子接地保护具有不受发电机运行工况和状态的影响、无保护死区、高灵敏的特点将逐步取代传统双频式100％定子接地保护.在Matlab中建立模型,通过仿真分析检验其科学性和合理性.结果证明,外加电源式100％定子接地保护有很高的灵敏度,且没有保护死区,是非常理想的发电机定子接地保护.%The ground fault in generator stator windings causes severe damages to the operation of generators; however, hardly can the traditional method based on zero -sequence fundamental voltage and third -harmonic voltage meet the requirements for generator stator grounding protection. The stator ground -fault protection with extra power supply as proposed in this paper, free of any impacts of the operating conditions and status of the generator and with high sensitivity but no protection dead zone, will gradually replace the traditional ground fault protection. In this paper, the simulation model is established with Matlab to verify the effectiveness of the stator ground-fault protection with injecting source (extra power supply). The result proves that the 100% stator ground-fault protection with injecting source is highly sensitive with no protection dead zone, which is an ideal pattern of generator stator grounding protection.
展开▼
