二滩水电站低励限制与失磁保护配合关系研究

摘要

To meet the requirement of low excitation limit being switched before the switching of loss of excitation protection after the recent transformation of protection system of generator-transformer unit in Ertan Hydropower Station, the three switching criteria of loss of excitation protection, including low generator terminal voltage criterion, the stator impedance circle criterion and rotor voltage criterion, are firstly drawn in one P-Q coordinate system with the curve of low excitation limit to verify the switching relationship of loss of excitation protection and low excitation limit. The calculation results show that the setting value of loss of field protection is correct, the switching relationship meets the requirement of specification, and there is a certain stability margin between the loss of excitation protection and low excitation limit.%二滩水电站发变组保护系统改造后,为满足规范所要求的低励限制能优先于失磁保护动作,提出将失磁保护的机端低电压判据、定子侧静稳极限阻抗圆判据和转子侧电压判据与低励限制曲线绘制在同一P-Q坐标系中,以验证保护装置失磁保护与低励限制的配合关系.计算结果验证了失磁保护整定值的正确性,同时证明了失磁保护动作区与低励限制之间存在一定的稳定裕度,满足低励限制优先于失磁保护动作的关系.