岭澳核电站二期3号发电机进相试验风险分析

Risk analysis on the under-excitation test for the 3# turbogenerator of Ling'ao Ⅱ

进相试验是发电机商运前必须要做的试验,试验数据将作为发电机今后进相运行的重要依据。发电机进相试验时有一定的风险,主要是随着发电机吸收无功不断加大,发电机有可能越过发电机静稳边界圆进入异步运行引起系统振荡。因此,发电机进相运行时必须限制发电机吸收的无功功率同时适当降低发电机的有功,防止试验时发电机突然越过静稳边界圆。根据岭澳二期3号发电机参数和系统参数计算出发电机的静稳边界圆,确定发电机进相的极限无功功率;再根据3号发电机失磁保护阻抗圆确定发电机进相试验时的最佳有功功率;确保发电机进相试验时不发生发电机不稳定运行。

Under-excitation test shall be done before the commercial operation of turbogenerator.The test data is very important in the future operation of the turbogenerator under-excitation.There is certain risk in the test;for the turbogenerator will absorb a lot of reactive power during the test,the turbogenerator may cross the static stability border round,and the turbogenerator will operate unsteadily,which may also cause power swing.Therefore the turbogenerator absorption of reactive power shall be limited during the test,and the turbogenerator active power shall be reduced appropriately,so as to prevent the turbogenerator across the static stability border round suddenly.According to the 3# turbogenerator and system parameters of Ling Ao Ⅱ the static stability border round is derived through calculation,and the limit of reactive power absorption during test is determined.According to the excitation-loss protection impedance border round of the 3# turbogenerator,the best active power is determined to ensure the turbogenerator operate steadily during the test.