运行方式变化对密集型固有振模电力系统的影响分析

Effects of operation mode variation on power system with close modes

大规模电力系统具有振荡模式非常密集的特点,参数的变化会使系统产生模态不稳定现象。运用复模态摄动理论分析了密集型固有振模电力系统的模态不稳定特性,用夹角变化来度量振荡模态的变形程度,研究了系统运行方式发生不同变化时的模态不稳定现象及其特点。算例分析表明,模态不稳定现象的发生与系统运行方式的变化有关,同一个系统开始出现模态不稳定现象时,其对应负荷的增加量和减少量是不同的,密集振荡模式参与机组邻近的负荷波动容易使系统出现模态不稳定现象。

The frequencies of natural oscillation mode in large power system are very close and system parameter change may cause its mode instability. The perturbation technique for complex modes is used to analyze the mode instability of power system with close modes and the change of eigenvector turning angle is applied to measure it. The mode instability and its characteristics during system operating mode change are studied and results show that,the occurrence of mode instability is closely related with the system operating mode change,the increase or decrease of corresponding loads are different when the mode instability of a system occurs,and the load disturbance close to the generator participating in close mode may induce system mode instability easily.