发电机失磁保护与低励限制的整定配合

针对发电机失磁保护和自动电压调节器（AVR）中低励限制环节的整定存在不能统一在同一坐标系、两者整定配合不尽合理的现象，提出了一种适合于工程实际应用的配合整定方法。首先分析了3种低励限制曲线随机端电压变化的偏移情况，根据电工理论推导低励限制线与失磁保护阻抗圆之间的映射关系，得出了标准的映射方程;在此基础上，提出了基于标幺值和机端最低允许电压两者配合整定及校核的方法、原则和工程应用注意事项，最后给出了具体的计算示例。

Matching Setting of Loss-of-excitation Protection and Low Exciting Limit for Generator

Given that the settings of low exciting limiter of automatic voltage regulator and of loss-of-excitation protection cannot be established in a same coordinate and therefore cannot cooperate very well, a practical protection setting method is proposed. First, three low exciting limit curves corresponding to the changes of generator terminal voltage are analyzed. Then, according to the electric theory, the mapping relationship and equation between the low exciting limit curve and loss-of-excitation protection impedance circle are established. On this basis, the methods of how to match the protection settings, how to verify and how to apply in the real projects are proposed. Finally, a detailed example of calculation procedure is presented.