一种改进的PWM方法在APF中的应用

A MODIFIED PWM TECHNIQUE FOR ACTIVE POWER FILTER

在有源电力滤波器中 ,直流电压的控制对其补偿效果有重要的影响。由于能量交换以及设备各部分的损耗 ,直流电压总是存在一定的能量脉动 ,恶化了谐波补偿效果 ,传统的增大电容器容量的解决办法增加了装置成本和安装空间。文中以并联有源电力滤波器为例提出一种改进的 PWM方法 ,采用前馈控制消除直流电压波动对变流器输出交流电压的影响 ,使有源电力滤波器获得了理想的补偿效果。仿真和试验结果证明了该方法的有效性。

With the development of custom power technology, the research of APF (active power filter) is improved. The effect of compensation is often determined by the control of the stability of the DC voltage. However, because of the loss of the switching, maintenance of the constant DC voltage at the input of the inverter is often impossible. The traditional method of increasing the capacity of the DC capacitor raises cost and size of APF. A modified inverter PWM technique is proposed for APF that the effect of the compensation becomes immune to fluctuations in the DC voltage by using reference feedback. The result of simulation and test proves the validity of the technique.