水电机组灰色模糊PID调速器设计与仿真

发布时间：2018-03-07 21:09

本文选题：发电机调速　切入点：水轮机　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：在当前的环保压力和能源压力下,降低火电比重已成为大势所趋。然而随着各种清洁能源的发电出力不断提升,能源不稳定、更多电力电子设备的引入等诸多因素都会对系统稳定造成一些负面影响。水能是一种相对比较稳定和容易控制的清洁能源,在我国多个地区都有可利用的水力资源。但是“水锤效应”却使得水电机组的调速过程更加复杂,限制了水电机组在维持系统稳定中发挥更多的作用。因此本文考虑采用一种新型的控制策略来控制水电机组的调速器,以期能达到提升调速性能、进而提高电力系统稳定性的目的。本文对调速器在有功功率平衡和系统频率稳定中的作用进行了简要介绍,对多种控制策略与方法的特点以及应用也进行了综述。针对水轮机的特殊特性,最后选择了采用由一种智能控制方法——模糊控制、一种预测方法——灰色预测以及最常用、最简单的PID控制器结合而得的综合控制策略,设计了一种灰色模糊PID控制器,为了对其控制效果做出初步验证,将其应用于一个简单的三阶系统中,并使用MATLAB进行动态仿真研究。为了验证该控制器对于水电机组调速系统的控制作用,本文对水电机组单机无穷大系统进行了建模和仿真。为了更好地反映系统的振荡特性,对于引水管道和水轮机,采用了考虑弹性水锤效应的线性化模型。分别考虑满载和半载两种情况对系统进行扰动仿真,在与常规PID调速器、灰色PID调速器的比较中,证明了所设计的灰色模糊PID调速器对水电机组的调速特性具有明显的改善和优化作用,实现了提高系统稳定性这一目标,并且对于系统的运行工况具有一定的鲁棒性。在进行了水电机组单机无穷大系统的仿真后,为了对该调速器的控制性能做出进一步的验证,建立了一个三机九节点系统的模型,分别对持续的电磁力矩扰动、一回线路三相短路随后故障切除这两种情况进行模拟,对各个机组的转速和功角变化情况进行仿真研究。与传统PID调速器的比较证明,本文所设计的灰色模糊PID调速器可以使发电机的转速更快地稳定下来,机组之间的功角也得以更快地进入一个新的稳态,整个系统的稳定性都得到了提升。
[Abstract]:Under the current environmental and energy pressures, reducing the proportion of thermal power has become a general trend. However, with the increasing power generation of various clean energy sources, energy is unstable. The introduction of more power electronics and other factors will have some negative impact on the stability of the system. Water energy is a relatively stable and easy to control clean energy. There are available hydraulic resources in many areas of our country, but the "water hammer effect" makes the speed regulation process of hydropower units more complicated. Therefore, a new control strategy is proposed to control the governor of hydropower unit in order to improve the speed regulation performance. In this paper, the function of governor in active power balance and system frequency stability is briefly introduced. The characteristics and applications of various control strategies and methods are also summarized. In view of the special characteristics of hydraulic turbines, an intelligent control method-fuzzy control, a predictive method-grey prediction and the most commonly used method are selected. A grey fuzzy PID controller is designed based on the synthesis control strategy of the simplest PID controller. In order to make a preliminary verification of its control effect, it is applied to a simple third-order system. In order to verify the control effect of the controller on the speed regulation system of hydropower unit, this paper models and simulates the single machine infinite bus system of hydropower unit, in order to better reflect the oscillation characteristics of the system. For the diversion pipe and turbine, the linearization model considering elastic water hammer effect is adopted. The disturbance simulation of the system is carried out under the condition of full load and half load, respectively. In the comparison with conventional PID governor and grey PID governor, It is proved that the designed grey fuzzy PID governor can obviously improve and optimize the speed regulation characteristics of hydropower units and achieve the goal of improving the stability of the system. In order to verify the control performance of the governor, a model of a three-machine nine-node system is established after the simulation of the single-machine infinite bus system of the hydro-generator unit is carried out in order to further verify the control performance of the governor, and has a certain robustness to the operating conditions of the system. In this paper, the continuous electromagnetic torque disturbance, the three-phase short circuit of the primary circuit and the fault removal are simulated, and the changes of the rotational speed and the power angle of each unit are simulated. The comparison with the traditional PID governor proves that, The grey fuzzy PID governor designed in this paper can stabilize the speed of the generator faster and the power angle between the units can enter a new steady state more quickly. The stability of the whole system has been improved.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV734.4

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