可变速机组具有运行调节的速动性、高效性、灵活性、可靠性等优势，如今已成为全球抽水蓄能行业新的发展方向，而我国暂无投运的可变速机组；可变速技术改变了传统抽水蓄能电站中水-机-电-磁多个物理量的耦合模式与响应特性，我国相关理论研究也较为薄弱，针对可变速抽水蓄能电站动态特性研究亟待开展。本项目综合应用数学、力学、电学、控制论等多学科知识，通过理论分析和数值模拟，紧扣可变速抽水蓄能电站系统物理本质开展研究：阐明由可变速技术带来的水-机-电-磁多物理量耦合新模式；从时、频域两方面探索新的模型，即推导描述频域响应特性的理论分析模型，建立非线性时域数值仿真平台；针对由机组功率控制与转速控制过程引起的系统小扰动，阐明反映系统水-机子系统特性的机组机械功率、反映系统电-磁子系统特性的机组电磁功率的响应特性及影响规律，揭示电站系统小扰动稳定性机理与影响机制，为我国可变速抽水蓄能机组的研发与投运提供理论支撑。

Variable speed pumped storage units has the advantages of operation, e.g. rapidity, high efficiency, flexibility and reliability, etc. In recent years, variable speed pumped storage unit has become a new development direction and challenge for the global industry of pumped storage; however, there are no variable speed units in operation in China. The coupling mode and response characteristics of the hydraulic-mechanical-electrical-magnetic physical quantities in the traditional pumped storage plants have been changed by the variable speed technique, and the related theoretical researches are relatively rare in China. Hence the dynamic characteristics of the variable speed pumped storage plants need to be studied. This project applies multi-disciplinary knowledge such as mathematics, mechanics, electricity and control theory, studies the physical essence of variable speed pumped storage plants through theoretical analysis and numerical simulation: this project expounds a new pattern of coupling of hydraulic-mechanical-electrical-magnetic physical quantities for pumped storage plants caused by variable speed technology; this project explores new models from both time domain and frequency domain, that is, the theoretical analysis model which describes the frequency response characteristic of the frequency domain, and the nonlinear time domain numerical simulation platform; Aiming at the small disturbances caused by the power control and the speed control of a variable speed unit, this project expounds the response characteristics and influence rules of the mechanical power reflecting the characteristics of the hydraulic-mechanical subsystem and the electromagnetic power reflecting the characteristics of the electrical-magnetic subsystem, and reveals the mechanism of small disturbance stability and the influence mechanism of the system, to provide theoretical support for the research and development of the variable speed pumped storage units in China.