Numerical simulation analysis of hydraulic transient process of hydropower station based on field test

Taking No.1 hydroelectric generating unit of Gongzui Hydropower Station after technical modification as the research object, and taking the load rejection test data of it as the reference, numerical simulation inversion is carried out by adopting the method of characteristics in order to modify the simulation model. On this basis, a numerical simulation analysis was carried out for No.1 unit at typical operating conditions of load dumping to determine a more appropriate equivalent closing time of the gate servomotor (<i>T_f</i>). The results show that the <i>T_f</i> (hydrostatic condition) should be adjusted to 8.7 s. When the water level of the upstream reservoir is at the normal storage level and the rated load is dumped at the maximum head, the inlet pressure of the spiral case (<i>P_s</i>) is not more than 0.838 MPa. Meanwhile, the frequency of the unit (<i>f</i>) is not more than 71 Hz, when dumping loads at rated operating conditions.