云南水电机组功频控制中有功功率振荡的预防研究

发布时间：2019-06-15 05:48

【摘要】：随着经济的不断发展和社会的不断进步，电力系统的稳定性变得越来越重要，低频振荡作为威胁电网安全运行的主要因素之一时时刻刻都有可能发生。机组的功频控制中有功功率振荡是引起电力系统低频振荡的主要原因之一，针对机组侧的功率振荡，云南电网已经实施了机组低频振荡的实时监测与解列保护装置，但是针对机组侧的功率振荡预防的研究还属于空白。本课题依托于云南电网公司科技项目《云南水火电机组功率振荡的预防与解除研究》，选择云南水电机组为研究对象，针对云南水电站的水头季节性变动大、导叶开度非线性等问题展开了研究。首先，，基于水轮机的相似理论与运动相似率分析推导出了工作水头与水轮机组有功功率之间的关系，在理想的水轮机组模型的基础上引入水头变动干扰，仿真验证了水头变动对水轮机组有功功率调节品质的影响；其次，通过动态试验拟合出存在导叶开度非线性水轮机组的导叶开度与机组有功功率之间的函数关系，在理想模型基础上引入了此函数关系，仿真验证了开度非线性存在导致不同开度范围的水轮机组有功功率调节品质变差的结论；最后，针对存在振荡隐患的水轮机组分别在工程应用上和理论研究上提出了改进的控制方案。工程上基于自适应控制策略分别提出了水头自适应控制方案与导叶开度自适应控制策略，并建模仿真验证了改进控制方案的合理性；在理论研究层面提出基于二次性能指标的单神经自适应PID控制算法，通过与经典PID控制效果进行对比，验证了单神经元自适应PID在水轮机组有功功率调节振荡预防中应用的可行性。通过本课题的研究，减小了云南水电站由于季节性水头变动大和导叶开度非线性对水轮机组有功功率调节品质的影响，从而保证云南水电机组运行的稳定性以及云南电网的运行稳定与安全。
[Abstract]:With the continuous development of economy and the continuous progress of society, the stability of power system becomes more and more important. Low frequency oscillation, as one of the main factors threatening the safe operation of power grid, may occur all the time. The active power oscillation in the power and frequency control of the unit is one of the main causes of the low frequency oscillation in the power system. Aiming at the power oscillation on the unit side, Yunnan Power Grid has implemented the real-time monitoring and de-listing protection device of the low frequency oscillation of the unit, but the research on the prevention of the power oscillation on the unit side is still blank. Based on the scientific and technological project of Yunnan Power Grid Company, "Research on the Prevention and removal of Power oscillations of Water and Thermal Power Units in Yunnan", this paper selects Yunnan hydropower units as the research object, and studies the problems of seasonal variation of water head and nonlinear opening of guide vane of Yunnan Hydropower Station. Firstly, based on the similarity theory of hydraulic turbine and the analysis of motion similarity rate, the relationship between the working head and the active power of hydraulic turbine is deduced. On the basis of the ideal hydraulic turbine model, the disturbance of head variation is introduced, and the influence of head change on the active power regulation quality of hydroturbine is verified by simulation. Secondly, the functional relationship between the guide vane opening and the active power of the hydraulic turbine unit with nonlinear opening of the guide vane is fitted by dynamic test, and the function relation is introduced on the basis of the ideal model, and the conclusion that the nonlinear opening leads to the deterioration of the active power regulation quality of the hydroturbine unit with different opening ranges is verified by simulation. Finally, an improved control scheme is proposed in engineering application and theoretical research for hydroturbine units with potential oscillations. Based on the adaptive control strategy, the water head adaptive control scheme and the guide vane opening adaptive control strategy are proposed respectively, and the rationality of the improved control scheme is verified by simulation. At the level of theoretical research, a single neural adaptive PID control algorithm based on quadratic performance index is proposed. Compared with the classical PID control effect, the feasibility of single neuron adaptive PID in the prevention of active power regulation oscillations of hydroturbine units is verified. Through the research of this subject, the influence of seasonal water head variation and nonlinear guide vane opening on the active power regulation quality of water turbine units is reduced, so as to ensure the operation stability of Yunnan hydropower units and the operation stability and safety of Yunnan power grid.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV734

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