基于Lyapunov函数的三电平SAPF控制策略.docxVIP

基于Lyapunov函数的三电平SAPF控制策略 Lyapunov-function-based Control Strategy for Three-level SAPF YU Jiaqi1， LI Yong1， CAO Yijia1， YU Jingrong2， XU Yong1 （1.College of Electrical and Information Engineering， Hunan University， Changsha *****， China； 2. School of Information Science and Engineering， Central South University， Changsha *****，China） Abstract：A Lyapunov-function-based control strategy for NPC-SAPF was proposed. The mathematical model of NPC-APF was built， and Lyapunov energy function including the tracking error of compensation currents and DC voltage was also constructed. Characteristic equation including control permanents was derived and plotted. Linear range of control permanents were also obtained after the overall consideration of system globally asymptotically stable conditions and pole location. Error feedback control technique was then utilized to keep neutral point potential balanced. In order to verify the compensation performance of the proposed current control scheme， nonlinear loads including diode bridge rectifier with an inductive load and a capacitive load was simulated and tested. Simulation and experimental results show that the proposed control strategy is effective in the nonlinear loads of both current-source type and voltage-source type. Key words： three-level technology； shunt active power filter； Lyapunov functions； power quality 并聯有源电力滤波器（Shunt Active Power Filter， SAPF）是用于抑制谐波、提高电能质量的有效手段之一[1-2].其中，三相中点箝位型并联有源电力滤波器（Neutral-Point Clamped， NPC-SAPF）与两电平APF相比具有系统容量大、补偿效果好、经济成本低等优点，受到了研究者的青睐. 然而由于NPC-SAPF系统是一个高阶强耦合的非线性系统，采用非线性控制器会取得更好的稳定性和指令跟踪控制效果.近年来，许多学者将非线性理论应用于APF控制系统的设计中[3-5].文献提出基于滑模控制的混合型APF，该控制策略虽能获得较好的补偿效果，但其存在高频抖动的现象.文献提出自适应无源性控制方法，补偿效果较好，但无源性控制易受参数及外界扰动影响.文献针对速度、负载力矩变动的直流电机驱动装置提出基于神经网络的APF控制方法，取得一定效果，但控制器设计相对复杂.基于Lyapunov稳定性理论的函数构造法作为非线性理论的基本方法，已应用于两电平APF控制，但在三电平NPC-SAPF上尚无应用[6-9].文献提出一种基于Lyapunov的单相APF电流控制方法，其控制增益选取是通过数学构造得到输出电流和直流电压的稳定范围，进而确定控制增益的极值.文献采用同样的方法应用于三相两电平APF中.文献提出将Lyapunov方法应用于混合型APF中，其控