针对广泛应用的整流负荷,提出一种直流侧串联型有源电力滤波器(active power filter,APF)。这种DC侧APF串联在整流桥与负载之间,通过产生谐波电压达到补偿谐波源的目的,使电源电流成为与电源电压同频同相的正弦波。与传统的交流侧有源电力滤波器相比,有源开关的数量减少了一半,简化了电路结构,降低成本。串联型DC侧APF采用双环控制,电流控制跟踪电源电压变化,电压控制调整APF的能量流向,通过改变APF储能电容电压极性,实现对电感电流的连续可控,从而实现谐波治理。这种控制方法具有结构简单、控制效果好等优点。实验结果验证了文中所得结论。
For the wide application of rectified loads, a DC side series active power filter (APF) was proposed. This DC side APF is equipped between rectifier bridge and load to compensate the harmonic source by producing harmonic voltage, making the supply current has same phase and shape as the supply voltage. Compared with typical AC side APF, only half number of active switches are needed. The circuit structure was simplified and so the cost .was reduced. Dual-loop control was applied to DC side APF. The current control tracks the power voltage and the voltage control regulates the APF power flowing. By changing the voltage polarity of energy storage capacitor, it makes the inductor current continuous and controllable so as to suppress harmonics. This control method is effective and simple in structure. The conclusions were verified by experimental results.