单极调制单周控制有源电力滤波器

单周控制单相有源电力滤波器(APF)有双极调制和单极调制2种调制方式。采用双极调制方式单周控制APF补偿后的电源电流中存在直流分量。在阐述单极调制单周控制APF工作原理的基础上,根据开关器件的动作过程,设计了控制器中的逻辑电路;分析了系统的全局稳定条件,从而获得APF交流侧滤波电感的设计依据;最后,利用Matlab软件对系统带非线性负载时的补偿性能进行仿真。仿真结果表明,单极调制单周控制APF能有效补偿非线性负载所导致的谐波和无功电流,补偿后电源电流中不含直流分量;且与双极调制方式相比,单极调制方式在一定程度上降低了开关损耗,是单周控制APF中很有前景的一种调制方式。

Unipolar modulation active power filter with one-cycle control

Single-phase APF(Active Power Filter) with one-cycle control has two modulation me-thods-bipolar modulation and unipolar modulation.There are DC off-sets in the compensated source current of the APF with one-cycle control under bipolar modulation.Based on the principle of unipolar modulation APF with one-cycle control,the logic circuit of the controller is designed according to the operation process of the switches.Based on the analysis of global stability condition,the design gist for filtering inductor at AC side is obtained.The compensation performance of the system with nonlinear loads is simulated with Matlab.The simulative results show that the unipolar modulation APF with one-cycle control can compensate the harmonic and reactive currents caused by nonlinear load effectively and there is no DC off-set in the compensated source current.Compared with the bipolar modulation,the switching loss of the APF with one-cycle control under unipolar modulation is reduced to a certain extent.Unipolar modulation method is an effective way for the APF with one-cycle control.