中文摘要：

为保证水电站机组的稳定运行和供电质量，对设置并联调压室的长引水式水电站建立了准确的数学模型，以全面模拟水力-机械系统的动态特性，开展系统的小波动稳定性分析；基于压力管道内水体刚性模型和弹性模型，分别建立了描述水力-机械系统动态特性的分析模型，综合频域和时域分析，研究了不同的输水系统布置形式和压力管道内水体采用不同阶数弹性模型对系统稳定性分析的影响。算例分析表明，考虑到传统刚性模型的应用局限性，长引水式水电站压力管道内水体应采用三阶或三阶以上的弹性模型，以全面揭示系统的振动特性和稳定性能。

英文摘要：

To guarantee stable operation and power quality in the turbine units of a hydropower station, an exact mathematical model was built for a long-distance water diversion-type hydropower station with parallel surge chambers. The dynamic characteristics of the hydro-mechanical system were comprehensively simulated, and stability analysis of small fluctuations in the system was conducted. Based on the rigid model and elastic model for the pipe flow, analysis models were established to describe the dynamic characteristics of the hydro-mechanical system. Combined with numerical analysis of both frequency and the time domain, the effects of different layouts of the water diversion system and elastic models with different orders for the pipe flow on the system＆#39;s stability analysis were investigated. An example shows that, instead of the commonly used rigid model, which has application limitations, a three-order or higher-order elastic model should be used for the pipe flow at the long-distance water diversion-type hydropower station to fully demonstrate the system＆#39;s vibration characteristics and stability performance.