Abstract:

[Objective] With the implementation of China’s dual-carbon strategy, pumped storage has become increasingly important in the new-type power system dominated by renewable energy resources. As the operating intensity of pumped storage units continues to increase, vibration problems of pumped storage powerhouses have become increasingly common. It is necessary to summarize solutions to vibration problems in operating pumped storage power stations and units to guide the design of future stations. [Methods] This study presented the identification of vibration sources and solutions to vibration issues of pumped storage power stations in Zhanghewan, Heimifeng, and Guangzhou. Two widely used structural design schemes for pumped storage powerhouses—thick-plate continuous wall structure and plate-girder frame structure—were presented, with a discussion of their advantages and disadvantages. Based on the actual cases, the layout of vibration measurement points for both the powerhouse and the unit was provided. Test methods and evaluation indicators were established for powerhouse vibration. [Results] Three typical methods for alleviating vibration in the powerhouse and pumped storage unit were proposed: controlling the energy generated by hydraulic excitation sources, staggering the frequencies between stationary parts and hydraulic excitation sources, improving the local or overall stiffness of structures. For structure stiffness and vibration resistance, the thick-plate continuous wall structure and plate-girder frame structure showed no significant difference. For the measurement and calculation of powerhouse vibration, more attentions should be paid to individual structural components to prevent local resonance with hydraulic excitation sources. [Conclusion] Both the thick-plate continuous wall structure and plate-girder frame structure can be widely used for pumped storage power stations, depending on specific engineering requirements. The natural frequencies of overall and local powerhouse structures should maintain a frequency deviation of 20% from hydraulic excitation source frequencies. If the vibration velocity is used as an evaluation indicator, the maximum vibration values should be less than 10 mm/s on the powerhouse floor and 5 mm/s in the pit. This study provides important guidance for improving the structural design of pumped storage power stations in China.

Key words: pumped storage, powerhouse vibration, thick-plate continuous wall structure, plate-girder frame structure, vibration testing, safety evaluation