【作者】 孙晓华；

【导师】 韦化；

【作者基本信息】 广西大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 电力系统是典型的大系统,有很多可控点或可控元件,且按地域分布。因此,无论是常规控制器,还是电力系统稳定器(PSS),或是最优励磁控制器等新型控制器,均是分散控制的。当然,从分散的角度来看,这无疑是我们所希望看到的。然而,这些分别依据各局部模型设计的控制器是很难相互协调的。那么,是否可以从全局出发,对整个系统进行全盘考虑,并进行综合设计呢?若回答是肯定的,则在这种情况下,各局部控制器就能使整个系统在统一指标下达到最优,换句话说,各局部控制器就能很好协调,以实现系统的最优性。当然,从整个电力系统出发,是很难找具有解析表达式的控制规律,使系统在所选性能指标下达到最优。然而,若换个角度,从非线性规划方面出发,问题就变得相对简单多了,这是因为:非线性规划方法,如:现代内点理论,能从整个系统出发,并确保系统在所选性能指标下达到最优。鉴于此,本文旨在将非线性规划方法引入复杂电力系统的非线性控制研究中,从整个系统的角度出发,讨论电力系统的分散协调最优控制问题。首先,根据实际需要选取最优控制问题的二次性能指标,并将其转化为非线性规划问题的目标函数。其次,运用隐式积分方法,将控制系统的状态方程差分为等式约束,同时将控制量的上下限幅选取为不等式约束。最后运用现代内点法求解。可见,该设计是将最优控制问题转化为动态最优化问题进行求解。以复杂电力系统励磁控制为例,提出了基于现代内点理论的分散协调最优励磁控制方法,在6机22节点系统上进行仿真,以验证提出方法的有效性。仿真结果表明:所提方法使系统各发电机具有良好的响应特性。更多还原

【Abstract】 One of the most typical great systems is electrical power system. The great system has a general characteristic, all of them have so many control point or control component.From the feedback signal of controllers, whatever electrical system general controller, PSS or optimal excitation controller etc new controller, which is developing in near twenty years, and all of them belongs to decenritralized control. No doubt, when we design controller, that point we wish to get. By all appearances, for all controllers which is designed parting by local model, that is so difficulty to considering coordinated. If we design control law of control component, consider across-the-board, synthesize design, make parting controller not only for them control object or local system, which control effect is optimal, also they can coordinated work, it also can ensure the system achieve the optimization under the chosen objective function. On the nonlinear programming, there are some full mature methods such as modern interior point method. They are widely applied in the various programming and get massive achievements.This paper proposes a research for decenritralized coordinated optimal excitation control of an n-generator power system based on modern interior point nonlinear programming. The optimal control problem is transformed into nonlinear programming one. Modern interior point nonlinear programming method is applied to solve the nonlinear programming problem. The quadratic performance index of control system is chosen for actuality needs as the objective function. The state equations of control system are converted into numerical equivalent algebraic equations set by using the implicit trapezoidal method, and are involved in equality constrains set. The control quantity limits are used to be inequality constrains. The dynamic optimization problem is transformed as the static optimization one and the ideal to solve the nonlinear optimal control problem by using modern interior point nonlinear programming method is developed. For nonlinear control systems, the ideal is applicable universally. It also can ensure the system achieve the optimization under the chosen objective function.For the power system excitation control system, based on modern interior point nonlinear programming method, an optimal power system excitation control design scheme is deduced. The results of simulation show that the scheme can coordinate the dynamic and the static performances of the n-generator power system effectively, and make it have a good output performance.更多还原