节点文献

非线性汽门控制研究及有功中层控制初探

Research on Nonlinear Governor Control and Primary Exploration of Secondary Active Power Control

【作者】 赵大伟

【导师】 王勤; 戴先中;

【作者基本信息】 东南大学 , 控制理论与控制工程, 2006, 硕士

【摘要】 电力系统的有功功率控制对于电力系统的安全稳定运行具有重要的意义。在国家自然科学基金的资助下,针对目前已有的非线性汽门控制方法无法如实际使用的常规调速器那样考虑速度下降特性,同时需要在控制过程中预先知道扰动后系统的运行点的问题,本文研究了带速度下降特性的非线性汽门控制器。同时,针对目前广泛采用的有功中层控制系统――自动发电控制(Automatic Generation Control,简称AGC)系统中存在的一些问题,如在应付较小的负荷扰动时需要各受控机组一起动作,在进行经济负荷分配时所采用的等耗量微增率法无法计及实际机组的阀点效应等,本文对有功中层控制问题进行了初步探讨,尝试给出可处理发电机组阀点效应的有功中层控制方案。具体地,本文的主要工作内容有:1.设计了带速度下降特性的非线性汽门控制器。和已有方法选择单一控制目标(如功角或转速)不同,本文选取了由转速和机械功率的线性组合构成的复合控制目标,并针对此复合控制目标基于逆系统方法设计了非线性汽门控制器。所设计的控制器可保证稳态时的转速、机械功率与各自初始值的偏差量之间存在一确定的比例关系,进一步,将此比例设计为调差系数,就可使得所设计的非线性汽门控制器反映速度下降特性,同时也不需要预先知道扰动后系统的运行点。2.尝试给出了可处理发电机组耗量特性的阀点效应的有功中层控制方案。和目前AGC方案不同的是,在负荷扰动较小时,由系统中调节性能最好(调节容量大,调节速度快)的一台受控机组首先动作,完成有功中层控制系统的稳定控制任务,然后根据系统的稳定控制任务完成情况及先动作机组的剩余调节容量大小决定是否在其余受控机组间进行经济负荷分配。所提控制方案除了可以基于传统的等耗量微增率法进行经济负荷分配外,为考虑实际机组耗量特性的阀点效应,本文还研究了基于改进粒子群算法的经济负荷分配方法。对于以上各种控制器及算法,本文以EPRI-36纯交流系统为例,基于PSASP(Power System Analysis Software Package)软件进行了有关数值仿真,结果验证了其有效性。

【Abstract】 The active power control is of great importance for the safe and stable operation of power systems. As present various kinds of nonlinear governor controllers can not consider the speed-droop characteristic of practical governors, and should know system’s post-disturbance operating point in the process of control, the nonlinear governor controller with speed-droop characteristic is focused in this paper. Meanwhile, there are some problems existing in the Automatic Generation Control (AGC) system, which is a popular secondary active power control system, for example, all controlled units should act when suffered a relative small load disturbance; the equal incremental method used in AGC to solve the economic load dispatch problem can’t consider the valve point effect of practical units. So, this paper makes a primary exploration of secondary active power control problem, and attempts to give a scheme that can deal with the valve point effect of practical units. In detail, main contents of this paper are as follows:1. The governor controller with speed-droop characteristic is designed. Different from selecting single variable (such as rotor angle or rotor speed) as control output in normal nonlinear governor control methods, a combined output, or the linear combination of rotor speed and mechanical power, is chosen in the paper, and then the nonlinear governor controller is designed based on this combined output. Under the control of the proposed nonlinear governor controller, there will be a definite proportion relation between the differences of the rotor speed and the mechanical power with their initial values. Furthermore, this proportion is assigned as the speed-droop, and thus the proposed controller can reflect the speed-droop characteristic. Meanwhile, it does not need to know system’s post-disturbance operating point in the process of control for the proposed controller.2. The paper attempts to give a secondary active power control scheme, which can deal with the valve point effect of practical units. Different from present AGC scheme, when the load disturbance is relative small, the unit that has best regulation performance (largest capacity, fast speed) will be selected and will act firstly, and thus the stable control mission will be completed. Then based on the status of the stable control mission and the residual capacity of the first acting unit, the scheme decides whether conduct economic load dispatch among other controlled units or not. In order to consider the valve point effect of practical units, the proposed control scheme can conduct economic load dispatch based on not only the traditional equal incremental method but also the improved particle swarm optimization algorithm. Based on PSASP, and selecting the EPRI-36 AC system as a sample system, the simulations of above controllers and algorithms are performed in the paper, and the results demonstrate their validities.The work of this paper is supported by the National Natural Science Foundation of China.

  • 【网络出版投稿人】 东南大学
  • 【网络出版年期】2007年 04期
  • 【分类号】TP273.5
  • 【下载频次】124
节点文献中: 

本文链接的文献网络图示:

本文的引文网络