基于虚拟磁链的PWM整流器内模控制研究

发布时间：2018-05-21 07:46

本文选题：PWM整流器 + 虚拟磁链观测器　；参考：《中南大学》2014年硕士论文

【摘要】：PWM整流器以其网侧电流信号的正弦化、功率因素单位运行、能量双向流动等特点,被广泛地运用于变流变频装置,如电力电子新能源、电力系统、工业控制等领域。目前,PWM整流器控制大多是建立在精确的数学模型之上的,很难适应电网频率波动和幅值不平衡条件。因此,研究一种在未知环境下仍能稳定运行的PWM整流器具有重大意义。从PWM整流器工作原理出发,以电压型PWM整流器(VSR)为对象,建立数学模型。分析了虚拟磁链观测器工作原理,将二阶广义积分器自适应滤波器(SOGI-AF)与频率跟踪环节(FLL)结合(称为SOGI-FLL)用于虚拟磁链观测器,消除传统积分环节带来的直流偏移和抑制高次谐波,跟踪电网频率波动,适应电网不平衡条件,进而估计电网矢量同步角度。结合内模控制(IMC)和PWM整流器控制特点,用一自由度内模控制取代PI控制实现PWM整流器电流内环解耦；采取三自由度内模电压环控制,消除PWM整流器对模型的依赖性,实现系统抗扰性和鲁棒性的独立控制。通过MATLAB仿真平台,将SOGI-FLL与IMC结合用于VSR控制,在100KVA的PWM整流器样机上进行仿真研究。结果表明：基于SOGI-FLL的PWM整流器内模控制系统在电网波动及参数突然改变的情况下具备良好的跟随性和鲁棒性,验证了提出算法的可行性和优越性。图35幅,参考文献78篇。
[Abstract]:PWM rectifier is widely used in converter such as power electronic new energy, power system, industrial control and so on because of its sinusoidal current signal, unit operation of power factor, two-way flow of energy and so on. At present, the control of PWM rectifier is mostly based on accurate mathematical model, it is difficult to adapt to the power network frequency fluctuation and amplitude imbalance conditions. Therefore, it is of great significance to study a PWM rectifier which can operate stably in unknown environment. Based on the working principle of PWM rectifier, the mathematical model of VSR is established. The principle of virtual flux observer is analyzed. The second order generalized integrator adaptive filter (SOGI-AFF) and frequency tracking link FLL (called SOGI-FLL) are applied to the virtual flux observer to eliminate the DC offset caused by the traditional integral link and to suppress the high order harmonics. Tracking the frequency fluctuation of the power network, adapting to the unbalanced condition of the power network, and estimating the synchronization angle of the grid vector. Combined with the control characteristics of IMC) and PWM rectifier, the current inner loop decoupling of PWM rectifier is realized by replacing Pi control with one degree of freedom internal mode control, and the dependence of PWM rectifier on model is eliminated by using three degrees of freedom internal mode voltage loop control. The independent control of system immunity and robustness is realized. Through the MATLAB simulation platform, the SOGI-FLL and IMC are used in VSR control, and the simulation research is carried out on the PWM rectifier prototype of 100KVA. The results show that the internal model control system of PWM rectifier based on SOGI-FLL has good following and robustness under the condition of power grid fluctuation and sudden change of parameters. The feasibility and superiority of the proposed algorithm are verified. There are 35 pictures and 78 references.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM461

【参考文献】