考虑接力器特性的导叶关闭规律研究

为探究导叶关闭过程中接力器特性对蜗壳压力、尾水管压力及机组转速的极值与时程的影响,以国内某引水式水电站为研究对象,基于特征线法建立了水力过渡过程计算仿真模型,并在导叶关闭过程中考虑了迟滞与缓冲过程,结合真机甩负荷试验数据对模型进行验证,开展了考虑接力器特性的导叶关闭规律与未考虑接力器特性的导叶关闭规律对调保参数影响的对比分析,并对迟滞时间的敏感性进行分析.结果表明,迟滞过程主要影响机组的转速上升率,迟滞时间越长,转速上升率越大,但对蜗壳压力和尾水管压力的时程及极值影响较小;由于缓冲过程发生时间较晚,故对调保参数极值没有影响,但对导叶关闭末期后蜗壳压力与尾水管压力的时程影响较大.研究成果可为水力过渡过程导叶关闭规律的模拟仿真提供参考.

Investigation on wicket gate closure law considering servomotor characteristics

In order to explore the influence of servomotors characteristics on the extreme value and time history of volute, draft tube pressure and unit speed in the process of wicket gate closure, a diversion hydropower station in China was taken as the research object to establish the calculation simulation model of hydraulic transition process based on the characteristic line method, and the hysteresis and buffer process in the process of wicket gate closure was considered, then the model was verified combined with the real machine load rejection experimental data.The comparative analysis between the wicket gate closure law considering servomotor charateristics and the generalized broken line closing law and the hysteresis time sensitivity analysis was carried out. The results show that the hysteresis process mainly affects the speed rising rate of the unit. The longer the hysteresis time, the greater the speed rising rate, but has little effect on the time history and extreme value of volute pressure and draft tube pressure. The buffering process has no effect on the extreme value of regulation and maintenance parameters due to its late occurrence time, but has a great impact on the time history of volute pressure and draft tube pressure after the last closing of guide vane. The research results can provide reference for the simulation of guide vane closing law of unit in the hydraulic transition process.