【作者】 于洁；

【导师】 于飞；

【作者基本信息】 青岛科技大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 研究非线性系统的控制问题具有重要的理论意义和实用价值。高压直流输电系统(简称HvDC系统)是典型非线性系统,HVDC系统是高度可控的,其中控制系统是直流输电技术的核心。HVDC系统能否正常运行与其基本控制器的性能息息相关。本论文对鲁棒近似反馈线性化控制方法进行了研究,研究结果解决了一类非线性系统的控制问题,并应用到HVDC系统中,并设计了相应的控制器。本论文的主要内容和研究结果包括:1)研究了单变量非线性系统的鲁棒近似反馈线性化控制方法,通过对单变量非线性系统的拓展研究,进行了多变量非线性系统的鲁棒近似反馈线性化方法的理论研究,核心思想是对包含非线性动态、外部扰动等系统不确定总体的扩张状态进行自动的估计和补偿,在避免复杂数学运算、抵消系统的非线性动态的同时,增强了对未知强非线性和不确定强扰动作用的鲁棒性和适应性。同时完善了相应的鲁棒近似反馈线性化控制器的设计方法。2)研究了HvDC系统及其控制特性,首先建立了HVDC系统的状念方程,并将鲁棒近似反馈线性化方法应用到HVDC直流输电系统中,在整流侧采用定直流电流,逆变侧定无功功率的控制方式,设计了高压直流输电系统鲁棒近似反馈线性化控制器。最后通过PSCAD和MATLAB分别对此控制器进行仿真,仿真结果证明了所设计控制器的有效性与优越性。更多还原

【Abstract】 It is valuable in both theoretical and practical area to study the control of nonlinear systems. High Voltage Direct Current Transmission (HVDC) is a typical nonlinear system. HVDC is high controllable. The control system is the core of DC transmission system. The performance of its basic controller decides the operation condition of HVDC system. This dissertation researches and improves a novel nonlinear robust approximate feedback linearization method based on model observers to solve the control problems for a class of nonlinear systems. Also the application problems of HVDC control system are discussed in detail. And a nonlinear controller for HVDC system is designed.The main results and contributions of this dissertation are as follows:Firstly, robust approximate feedback linearization method is analyzed for single-variable nonlinear system. The multivariable nonlinear system is researched based on the analysis of the single-variable nonlinear system. The core ideas of the presented method are to estimate and compensate the extended state which includes the nonlinear dynamics, parameter uncertainties and disturbances. This method can avoid complex mathematic operations, counteract the nonlinear dynamics and enhance the robustness and adaptability of the control system against uncertainties. The corresponding design scheme of robust approximate feedback linearization is discussed and perfected.Secondly, HVDC system and its control characteristics are researched. First the state equations are established. Then the robust approximate feedback linearization method is applied to the HVDC system. This dissertation adopts the constant current control at the rectifier and the constant reactive power control at the inverter, and designs the robust approximate feedback linearization controller for HVDC system. At last, the simulation is done by PASCAD and MATLAB in this paper. The effectiveness and superiorities of new controller have been testified through simulation.更多还原