基于无源控制策略的MMC-DVR控制系统

MMC-DVR CONTROL SYSTEM BASED ON PASSIVITY CONTROL STRATEGY

为了提高高压电网电压质量补偿效果,提出基于模块化多电平换流器(MMC)的动态电压调节器(DVR)系统的无源非线性控制方法。首先,介绍MMC-DVR的框图以及工作原理,根据基尔霍夫电压电流定律,分别构建abc静止与两相dq旋转坐标系下的数学模型;接着提出无源控制方法来解决问题;最终,在Matlab/Simulink软件实验平台上构建MMC-DVR系统,构建仿真验证无源非线性控制的可行性和优越性。与传统PID相比,无源策略能使系统迅速稳定,提高抗扰能力,采取阻尼注入,能快速、有效地对电压降落/升高和谐波进行补偿,并且无源非线性控制器控制规律简单,所需控制器数量少,可避免PI控制参数选择困难及繁复的缺点。

MMC-DVR combined with dynamic voltage regulator(DVR) and modular multilevel converter(MMC) can be used to solve the problem of sag/swell compensation for medium and high voltages. Since MMC-DVR is a non-linear system,the compensation effect of linear control methods such as PID commonly used in DVR systems is not satisfactory. To this end,this paper proposes a passive nonlinear control method for the MMC-DVR system,which can be deeply integrated in the wind farm grid-connected system,and can solve the negative problems such as power quality degradation. First,the circuit topology and working principle of MMC-DVR are introduced,and the mathematical model under the static and rotating coordinate system is established. Then,the passive control method is proposed to solve the problem. Finally,the MMC-DVR control system is built on Matlab/Simulink software experimental platform,and the experimental results verify the feasibility and superiority of the passive nonlinear control strategy proposed in this paper.