中文摘要：

针对当前的抽水蓄能电站上游调压室设置套用常规水电站准则、缺乏专门研究的问题,本文首先从水泵水轮机的过流特性出发提出了甩负荷机组流量变化过程的三种模拟方法,并给出三种方法下的流量有效减小时间Ts的解析表达式,然后据此从理论上推导出了抽水蓄能电站上游调压室设置条件的判别式。结合工程实例对比分析了不同流量模拟方法所得判别式的差异,揭示了影响抽水蓄能电站水击压力上升的是流量由初始值减为最小值的整个过程,而非流量减小局部阶段（快速减小阶段、由初始值首次减为零阶段）,以此结论为基础的流量模拟方法对应的判别式真实反映了实际流量变化对水击压力上升的作用,且计入了水泵水轮机全特性和压力脉动的影响,可以正确合理的进行抽水蓄能电站上游调压室设置与否的判别

英文摘要：

The setting condition of upper surge chamber for pumped storage hydropower station still applies the standards of conventional power station and lacks specialized study. This paper presents three simulation methods for the transient flow process of pump-turbine units in load rejection, formulates analytical expressions of the operation time Ts for effectively flow reduction by these methods, and derives a setting condition of upper surge chamber for pumped storage hydropower station. We have compared the discriminants obtained by different flow simulation methods in a case study and draw the conclusion： what determines water hammer pressure rising in a pump-turbine system is the entire process of flow reduction from initial to minimum value, rather than a local flow reduction （e.g. rapid decrease or process from initial value to zero）. A discriminant corresponding flow simulation method only based on this conclusion can truly reflect the role of flow change on this pressure rising and the influences of the unit＇s characteristic curves and fluctuating pressure, and thus such a discriminant could be used to judge the setting of upper surge chamber for pumped storage hydropower station.