不含调压室的长引水管道水电站小波动稳定分析

Stability Analysis of Water Conveyance System in the Hydropower Station without Surge Tanks

具有长引水管道的中小型水电站,设置调压阀、爆破膜等调压措施后对大波动过渡过程中的内水压力变化和转速上升均能有较好的控制,但对机组的运行稳定性并无改善。通过假定水流为刚性水体,推导长距离输水管道系统理想水轮机下小波动微分方程组系数矩阵及其特征方程系数,根据Routh-Hurwitz稳定性判据,分别讨论了Tw和Ta以及PID调速器参数对小波动稳定域的影响,从而合理整定调速器的参数,保证小波动稳定。

For medium and small hydropower stations with long diversion pipelines, when setting voltage regulating measures such as pressure reducing valve and blasting membrane, it may control well in the large fluctuating transient process, which makes internal water pressure of pipeline and rotation speed rise meet command, but it would not work on the stability of hydropower station opera- tion. With the assumption of rigid water and ideal turbine model, coefficient matrix of dif{erential equations and characteristic equa- tion in the long distance water conveyance pipeline system is derived. According to the Routh-Hurwitz stability criterion, the impact of Tw, To and PID governor parameters on the stability region are discussed. Thus governor parameters are worked out reasonably and make the small fluctuation stable.