中文摘要：

在电力系统负荷中,感应电动机负荷占有很高的比例,其动态响应直接影响着系统稳定特性。电压失稳会引起感应电动机堵转失稳,因此部分观点将感应电动机失稳等同于暂态电压失稳。通过理论分析发现,电压失稳并非诱发感应电动机失稳的唯一因素,暂态过程期间发电机群的功角摆动同样具有较大影响。当电力系统受到扰动冲击后,暂态不平衡能量在机群摇摆过程中被系统消纳,机群功角摆开造成系统等效戴维南电势降低,直接影响负荷感应电动机电磁转矩,可能造成自身速度失稳。通过实际电网算例验证了理论研究的准确性。因此,运行人员应当全面研究系统的电源分布、网架结构和负荷特性,预判系统真正面临的风险点,采取对应的安全稳定防范措施,保障电网的安全稳定运行。

英文摘要：

Induction motor load accounts for a high proportion of power system load, whose dynamic response directly affects system stability characteristics. Voltage instability will lead induction motor blocked to lose stability, so induction motor instability is equivalent to transient voltage instability in some views. Through theoretical analysis in this paper, it is fotmd out that voltage instability is not unique factor to cause induction motor instability; generator group＇s power-angle oscillation during transient process also has a great influence. After power system disturbance, unbalanced transient energy is absorbed by the system in process of generator group＇s power-angle oscillation. Generator group＇s power-angle swing-off reduces Thevenin＇s equivalent electric potential of the power system, directly affecting induction motor electromagnetic torque, and possibly causing its speed instability. At last, accuracy of the theoretical research in this paper is verified with an actual power grid example case. Therefore, operators are supposed to have comprehensive command of power source location, grid structure and load characteristics, so as to prejudge potential risks and prepare corresponding countermeasures to assure safety and stability in power system operation.