发电机低励限制与失磁保护的配合整定计算

Coordinative Setting Calculation of Minimum-excitation Limit and Loss-of-excitation Protection for Generator

提出一种适合工程应用的配合整定计算方案,来解决目前发电机励磁系统低励限制与发电机失磁保护之间配合整定计算不合理这一问题。首先推导失磁保护阻抗圆映射至P-Q坐标系的标准方程,并基于这些方程,经过分析得出结论:无论发电机失磁保护阻抗圆采用的是静稳圆或异步圆,低励限制的整定均没有必要考虑与异步圆配合,只须考虑与静稳圆配合即可。其次依据上述结论,依次从配合要求和计算步骤上对低励限制与静稳圆之间的配合整定计算进行讨论分析,并考虑了进相运行对计算的影响,提出一套完整的方案。最后,通过具体的实例分析,验证上述配合整定计算方案的正确性。

This paper proposes a suitable for the engineering application scheme of the coordinative setting calculation to solve the problem that the current coordinative setting calculation between the minimum-excitation limitation and the loss-of-excitation protection is inaccurate. Firstly, the standard mapping equations of loss-of-excitation protection impedance circles are established in the P-Q coordinate system, and based on those equations, through the analysis, the conclusion can be drawn that regardless of the equations of loss-of-excitation protection impedance circle isstatic stability circle or asynchronous circle, it is not necessary to consider the coordinative setting calculation between the minimum- excitation limit and the asynchronous circle, but to consider that the minimum-excitation limit is whether or not in coordination with the static stability circle. Then according to that conclusion, successively analyzes the requirements and the steps of the coordinative setting calculation, and considers the impact of the leading-phase operation of the generator on that calculation, that is, a comprehensive scheme is presented. Finally, the validity of the proposed scheme of the coordinative setting calculation is verified by the specific test case.