基于全特性曲线抽水蓄能电站典型过渡过程特性分析

发布时间：2018-02-27 19:40

本文关键词： 水泵水轮机调节系统外特性方法传递系数非线性数学模型动力学分析　出处：《西北农林科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国电力系统的快速发展,能源调整不断向稳定高效发展。抽水蓄能电站在电网中承担调峰填谷的作用,具有很强的灵活性和储能性,其作用在改善电网质量上具有显著的影响,所以近年来发展迅速。在抽水蓄能电站的运行过程中,水泵水轮机调节系统是抽水蓄能电站的核心部分,其运行的安全稳定性对电站运行过程有重要影响。尤其是在大波动过渡过程中,机组变化剧烈,水流流态复杂,对机组运行的稳定性影响剧烈,所以本文从系统科学的角度揭示水力机组过渡过程的非线性动力行为,从而探究抽水蓄能电站大波动过渡过程的本质,进而对电站的安全稳定运行提供理论依据。本文的研究对象为混流式水泵水轮机调节系统,基于实测抽水蓄能电站运行数据,拟合全特性曲线,并利用外特性方法计算动态传递系数,由传递系数的变化来展现水泵水轮机组在运行过程中的各种特性,从而建立一套基于实际数据的水泵水轮机数学模型,来反映系统的非线性动力学特征。总结整个研究过程,主要内容包括以下几个方面:(1)利用外特性方法从实测数据中获得动态传递系数拟合曲线,并将传递系数引入到水泵水轮机调节系统建模过程中,针对水泵水轮机甩负荷工况试验,建立突甩负荷时的非线性数学模型,在PID调速器控制下,进行参数调节,将以往pk,ik和dk的单一化调节过程扩展到三者相互影响下的调节关系,由此得出水泵水轮机组运行的最佳参数组合域,并利用MATLAB软件具体分析每一参数的影响。(2)研究了水泵工况转换为水轮机工况中的开机并网段,对并网过程进行了深入分析。求解了整个并网过程的动态传递系数,将以往一点的工况扩展到整个过渡过程的工况分析,由此建立可以描述整个并网过渡过程的数学模型,仿真结果合理的显现了机组运行稳定性伴随着导叶开度变化的特性。此外,将哈密顿控制理论引入水泵水轮机调节系统中,并对开机并网过程中的参数进行控制分析,通过数值模拟计算,得到功角在开机过程中随导叶开度的变化规律,同时也验证了哈密顿理论对发电机系统参数镇定的作用。(3)针对水泵水轮机在开机并网时刻机组运行容易进入反水泵工况,从而导致开机并网失败的特点,将分数阶理论引入水泵水轮机调节系统,探究分数阶建模对导叶开度变化和对机组转速的影响,通过数值仿真计算,在理论上揭示了分数阶理论在实现快速开机的过程中具有指导意义。
[Abstract]:With the rapid development of power system in our country, energy adjustment has been developing steadily and efficiently. Pumped storage power station plays the role of peak and valley regulation in the power network, and has strong flexibility and energy storage. It has a remarkable effect on improving the quality of power network, so it has developed rapidly in recent years. In the process of operation of pumped storage power station, the governing system of pump turbine is the core part of pumped storage power station. The safety and stability of the operation have an important effect on the operation process of the power plant, especially in the large fluctuation transition process, the unit changes dramatically, the water flow state is complex, and the stability of the unit is affected greatly. Therefore, this paper reveals the nonlinear dynamic behavior of hydraulic unit transition process from the point of view of system science, so as to explore the nature of the large wave transition process of pumped storage power station. The research object of this paper is the governing system of Francis pump turbine. Based on the measured operation data of pumped storage power station, the full characteristic curve is fitted. The dynamic transfer coefficient is calculated by using the external characteristic method, and the variation of the transfer coefficient is used to show the various characteristics of the pump turbine unit in the course of operation, thus a set of mathematical model of the pump turbine based on the actual data is established. To reflect the nonlinear dynamic characteristics of the system. The whole research process is summarized. The main contents include the following aspects: 1) the dynamic transfer coefficient fitting curve is obtained from the measured data by using the external characteristic method. The transfer coefficient is introduced into the modeling process of the pump turbine regulation system. According to the load rejection condition test of the pump turbine, the nonlinear mathematical model of the sudden load rejection is established, and the parameters are adjusted under the control of the PID governor. In this paper, the single regulation process of pkkanik and dk is extended to the regulation relationship under the influence of the three factors, and the optimal parameter combination domain for the operation of pump turbine unit is obtained. MATLAB software is used to analyze the influence of each parameter in detail. (2) the conversion of pump working condition to turbine operating condition is studied, and the process of grid connection is deeply analyzed, and the dynamic transfer coefficient of the whole grid-connected process is solved. The working condition of the former point is extended to the condition analysis of the whole transition process, and a mathematical model can be established to describe the whole transition process of grid-connected network. The simulation results show that the operating stability of the unit is accompanied by the variation of the guide vane opening. In addition, the Hamiltonian control theory is introduced into the governing system of the pump turbine, and the parameters in the process of connection are analyzed. Through numerical simulation, the variation of power angle with the opening of guide vane is obtained. At the same time, the effect of Hamiltonian theory on the parameter stabilization of generator system is verified. The fractional order theory is introduced into the governing system of water pump turbine, and the influence of fractional order modeling on the change of guide vane opening and the speed of the unit is investigated, and the numerical simulation is carried out. It is revealed theoretically that fractional order theory has guiding significance in the process of fast boot.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV743;TV734

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