论文部分内容阅读
并联型有源电力滤波器能有效地抑制电网中的谐波电流,而其补偿精度取决于电流环控制器的设计。由于电流环参考和反馈电流由许多次谐波叠加而成且传统的比例积分控制器(PI控制器)带宽有限,因此控制器不能实现无静差输出。为此首先分析了传统单PI控制器在大容量有源电力滤波器应用中的局限性。然后提出了一种以T型滤波器(LCL滤波器)为控制对象的PI内环,重复控制器外环构成的双环复合控制策略用来改善输出电流波形,并给出了详细的设计方法和稳定性分析。该控制器对奇次、偶次谐波电流以及不平衡负载条件下的负序谐波电流均具有很高的补偿精度,且易于实现。仿真和实验结果证明了复合电流控制器在大容量有源电力滤波器应用中的有效性。
The shunt active power filter can effectively suppress the harmonic current in the power grid, and its compensation accuracy depends on the design of the current loop controller. Because the current loop reference and feedback current are superimposed by many sub-harmonics and the bandwidth of the traditional proportional-integral controller (PI controller) is limited, the controller can not achieve no dead-time output. To this end, the limitations of the traditional single-PI controller in the application of large-capacity active power filter are analyzed first. Then, a double-loop compound control strategy composed of PI inner loop and repetitive controller outer loop with T-filter (LCL filter) as the control object is proposed to improve the output current waveform, and a detailed design method is given Stability analysis. The controller has high compensation accuracy for odd-order, even-order harmonic currents and negative-sequence harmonic currents under unbalanced load conditions, and is easy to implement. Simulation and experimental results show the effectiveness of the composite current controller in the application of large-capacity active power filter.