水电站水-机-电-磁多物理量耦合作用及振荡机理研究

Nowadays under the situation of electric power development in China, such as the increasing scale and complexity of hydropower plants (HPPs), the long distance between HPPs in Southwest China and the load centers, and the increasing proportion of intermittent renewable energy, the study on mechanism for coupling and oscillation of hydraulic-mechanical-electrical-magnetic physical quantities in HPPs needs to be carried out, to ensure stable operation of HPPs and to restrain the occurrence of low frequency oscillation and ultra-low frequency oscillation of power systems. This project applies multi-disciplinary knowledge such as mathematics, mechanics, electricity and control theory, studies the physical essence of HPPs through theoretical analysis, numerical simulation and physical model test: this project expounds the coupling mode of hydraulic-mechanical-electrical-magnetic physical quantities in dynamic process of HPPs, by considering the superposition of hydraulic interference and electrical interference between multiple hydropower units; this project explores the efficient mathematical analysis method of multivariable, multi time scale and nonlinear system from both time domain and frequency domain. This project deduces the theoretical analysis model describing the response characteristics in frequency domain, establishes the refined nonlinear time domain numerical simulation platform, and integrates the complete model experimental device of the hydraulic-mechanical-electrical-magnetic coupling system; this project studies the frequency oscillation and power angle oscillation of hydropower units, and illustrates the matching rule of multiple time constants and controller parameters for optimal stability of the system, to provide theoretical support for the stable operation of hydropower stations and power systems.

在水电站规模和复杂程度日益增加、我国西南水电站群远离负荷中心、间歇性可再生能源并网比重持续增长等我国电力发展形势下，为保证水电站稳定运行、抑制电力系统低频振荡与超低频振荡的发生，水电站中水-机-电-磁多物理量耦合作用及振荡机理研究亟待开展。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、数值模拟及模型实验研究手段，紧扣水电站整体系统物理本质开展研究：考虑多机组间水力干扰与电气干扰叠加作用，阐明水电站动态过程中水-机-电-磁多物理量耦合模式；从时域与频域两方面探寻多变量、多时间尺度、非线性系统的高效数学分析方法，推导描述频域响应特性的理论分析模型，建立精细化非线性时域数值仿真平台，集成完善水-机-电-磁耦合系统整体模型实验装置；研究水电机组频率振荡、功角振荡及失稳问题，阐明针对系统最优稳定性的多时间常数及控制器参数的匹配规律，为水电站及电力系统稳定运行提供理论支撑。

面向我国“双碳”战略目标，在目前水电站系统规模和复杂程度日益增加、间歇性可再生能源并网比重持续增长等电力发展需求下，为抑制含水电机组的电力系统低频振荡、超低频振荡的发生，水电站系统的水-机-电-磁多物理量耦合作用及振荡机理研究亟待开展。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、数值模拟及模型实验等研究手段，紧扣水电站整体系统物理本质开展研究。. 本项目取得了三个层面的研究进展：（1）在理论分析层面，揭示了多机组间水力干扰与电气干扰叠加作用特性，阐明水电站动态过程中水-机-电-磁多物理量耦合模式。（2）在模型方法层面，从时域与频域两方面提出了多变量、多时间尺度、非线性系统的高效数学分析方法，推导了描述频域响应特性的理论分析模型，建立了精细化非线性时域数值仿真平台，集成完善了水-机-电-磁耦合系统整体模型实验装置。（3）在技术应用层面，针对水电机组频率振荡、功角振荡及失稳问题，阐明了系统多时间常数及控制器参数的稳定性最优匹配规律，提出了利于水电站稳定性、灵活性的运行调控策略。. 项目取得的主要学术成果：发表论文36篇，其中SCI论文20篇、EI论文9篇，申请发明专利10项，获批软件著作权5项。成果应用于“一带一路”合作项目安哥拉凯凯水电站、我国白鹤滩水电站等大型水电站，以及我国文登、蟠龙、天池等系列抽水蓄能电站，为水电站及电力系统稳定运行提供了理论支撑。