将非线性模型预测控制方法应用于紧急电压控制器的设计,以准稳态近似为基础,建立包含连续-离散时间微分-代数方程组的滚动动态优化模型.为提高求解该动态优化模型的计算效率和控制精度,将移动区间技术和直接动态优化方法结合起来求解该滚动优化问题.首先,将研究时间段划分为有限个区间,借助排列法将所有状态变量、代数变量和控制变量在各个区间内用一系列多项式近似,从而将动态优化问题转化为非线性规划问题.然后,引入移动区间技术动态调整每个区间的长度,实现控制变量断点的精确定位,并同时提高整个算法的精度.采用AMPL优化建模软件提供的内点算法求解.在新英格兰10机39节点系统上的计算结果验证了所提方法的有效性.%The nonlinear model predictive control method is applied to emergency voltage controller design. Based on quasi-steady-state approximation, the receding dynamic optimization model containing differential-algebraic equations with continuous-discrete time variables is established. To enhance computational efficiency and control precision of solving this dynamic optimization model, direct dynamic optimization approach combined with moving finite elements is proposed to solve the problem of dynamic optimization. Firstly, the research interval is divided into finite elements. Radau collocation method is used to convert the optimization model into a nonlinear programming by approximating all of the state variables, algebraic variables and control variables by a family of polynomials on each element. Then moving finite elements is introduced to adjust the length of each interval dynamically, achieve the precise positioning of control variable and improve the accuracy of the algorithm. The interior-point algorithm given by AMPL as a mathematical optimization solver is used to solve the problem. Simulation results on New England 10-machine 39-bus system verify the effectiveness of the proposed method.This work is supported by National Natural Science Foundation of China (NSFC) (No. 50777021 and No. 50907023) andGuangdong Natural Science Foundation (No. 9451064101003157).
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