Pumped-storage power technology is currently the only available energy storage technology in the grid net, and its reliability is receiving attention increasingly. However, when a pump-turbine unit undergoes runaway transitions, hydraulic fluctuations intensively affect the reliable operation of a pumped-storage power station. To reduce hydraulic fluctuations, this study investigated the formation mechanism of hydraulic fluctuations and explored its influence factors. In this study, a developed one-dimensional and three-dimensional (1 D-3D) coupling simulation method was adopted. Transient runaway transitions of a pump-turbine with three different inertias (0.5 J, 1 J, and 2.0 J) at three different guide vane openings (21°, 15°, and 12°, respectively) were simulated and compared. The results suggest that, at smaller guide vane openings (15° and 12°), water hammer owing to the increase in rotational speed is the primary unstable issue compared to the pulsation of radial hydraulic exciting forces on the runner. However, at a larger guide vane opening (21°), the latter owing to the back-flow near the runner inlet is the primary unstable issue. Moreover, it is found that a sufficiently large inertia improves the hydraulic fluctuations of the pump-storage power station, particularly in reducing the pulsation of radial hydraulic exciting loads on the runner. The findings of this study provide a valuable reference for determining suitable rotor inertia.

抽水蓄能技术是目前电网中唯一可用的储能技术，其可靠性越来越受到重视。然而，当泵-轮机组经历失控转换时，水力波动会强烈影响抽水蓄能电站的可靠运行。为减少水力波动，本研究研究了水力波动的形成机理，并探讨了其影响因素。在这项研究中，采用了一种开发的一维和三维 (1 D-3D) 耦合模拟方法。模拟和比较了在三个不同导叶开口（分别为 21°、15° 和 12°）处具有三种不同惯性（0.5 J、1 J 和 2.0 J）的泵-涡轮机的瞬态失控过渡。结果表明，在较小的导叶开口（15° 和 12°）处，与转轮上的径向液压激振力的脉动相比，由于转速增加引起的水锤是主要的不稳定问题。然而，在较大的导叶开口 (21°) 处，后者由于流道入口附近的回流是主要的不稳定问题。此外，还发现足够大的惯量改善了抽水蓄能电站的水力波动，特别是在减少转轮上径向水力激振载荷的脉动方面。本研究结果为确定合适的转子惯量提供了有价值的参考。在较大的导叶开口 (21°) 处，后者由于流道入口附近的回流是主要的不稳定问题。此外，还发现足够大的惯量改善了抽水蓄能电站的水力波动，特别是在减少转轮上径向水力激振载荷的脉动方面。本研究结果为确定合适的转子惯量提供了有价值的参考。在较大的导叶开口 (21°) 处，后者由于流道入口附近的回流是主要的不稳定问题。此外，还发现足够大的惯性改善了泵储电站的水力波动，特别是在减少转轮上的径向水力激振载荷的脉动方面。本研究结果为确定合适的转子惯量提供了有价值的参考。