基于复合控制的三电平APF的研究

有源电力滤波器(APF)的被控量为高频谐波及无功电流，传统的PI闭环控制已不能实现无静差的跟踪被控信号。为了提高APF的补偿精度及动态响应速度，引入复合控制器对APF输出电流进行控制。针对数字控制引入的延时问题，分析了延时对电流补偿效果的影响，并提出了谐波电流预测控制的解决方法。最后在对三电平APF模型分析的基础上，搭建了基于三电平空间矢量调制(SVPWM)的Matlab仿真模型，并在一台50 kVA的样机上对上述算法进行了验证。仿真分析和实验结果显示基于复合控制的电流跟踪控制相比于传统的PI控制能够有效地提高APF电流内环的稳态精度。

Research on three-level active power filter based on composite control

Traditional PI control algorithm has been unable to track control signal without static error, as the controlled variable of the active power filter is high frequency harmonic and reactive current. This paper introduces the composite controller which is used to control the output current of APF, in order to improve the accuracy of steady state and dynamic response speed. As for the delay problem introduced by digital control, the effect of delay on current compensation is analyzed, and the solution of harmonic current prediction control is put forward. Based on the analysis of three-level APF model, a Matlab simulation model based on three level space vector modulation (SVPWM) is built, and the algorithm is verified on a 50 kVA prototype. Simulation analysis and experimental results show that composite control based current tracking control can improve the steady state accuracy of APF current inner-loop compared to traditional PI control.