Inversion calculation and prediction of extreme conditions by in-situ test of real machine in a hydropower station

Abstract The in-situ test of the real engine in hydropower station is a necessary test before the unit is put into operation. During the test, the problems in the test process can be found through the auxiliary inversion calculation, and the calculation and analysis of extreme conditions can provide important support for the unit’s permanent operation. First of all, this paper analyzes the problem that the maximum pressure of the spiral shell and the increase rate of the unit speed in the load rejection test of the hydropower station exceed the control standard. Through inversion calculation, it is found that the closing law of the guide vane of the unit is different from the set closing law, and the robustness of the closing law is poor; then, combined with the test situation, the closing law of the guide vane of the unit was optimized. While the adjusted load rejection test was simulated under the same boundary conditions, and the measured data and numerical calculation results were compared and analyzed to obtain the modified values of the characteristic parameters. Finally, the extreme conditions in the transition process of large fluctuations are predicted and calculated by numerical simulation. This research idea provides reference and guidance experience for similar projects.