A new algorithm for digital filtration, namely Forth Back digital Filter, is put forward for the need of actual data processing and reduction of the phaseshift.
A repetitive controller can be obtained by designing a zero phaseshift low pass filter. With the help of digital signal processing and software tools, it is easy to design a satisfactory controller.
By analyzing the current ripple of the filter inductor on the condition that the phaseshift is different, the reduced value of the current ripple with the interleaving modulation strategy can be got.