天荒坪抽水蓄能电站甩负荷过渡过程实测成果仿真分析

Measurement and Simulation of Load Rejection Transients at Tianhuangping Pump-Storaged Power Plant

介绍了天荒坪抽水蓄能电站一管一机和一管二机现场甩负荷试验实测成果和仿真分析结果 ,通过对蜗壳进口水压力、机组转速等的现场试验实测曲线与数值仿真计算曲线的比较分析 ,论证了输水系统及机组各有关参数的可能误差对电站甩负荷过渡过程数值仿真计算结果的影响 ,同时校正了该电站甩负荷过渡过程计算软件中的有关系数和基本参数 。

There are two separate water conveyance systems and each system carries three parallelled pump-turbine units at Tianhuangping Power Plant. To alleviate the performace instability due to the 'S' region of pump-turbine characteristic curves, the MGV (Misaligned Guide Vanes) devices are installed for each unit. The transient simulation of pump-turbine with MGV is original in all of the world. In this paper, a numerical model to simulate the load rejection transients, including MGV application, is introduced by comparison of numerical calculations with field tests. The pressure change at runner inlet ( or, the inlet of the spiral case) and the unit speed variation during the transients of one unit or two units of load rejection tests within one hydraulic system are recorded and compared with each numerical modeling, which demonstrates the possible errors of parameters and coefficients of the hydraulic system and pump-turbine units have more or less effects on the transient simulation; thus the sensitivity analyses of these errors are performed and meanwhile their magnitudes used in the numerical model are verified by the initial steady state measurements. Finally, the numerical model with MGV is in turn employed to predict the more severe transient of the hydraulic system with three units rejecting their loads simultaneously.