An LCPSL filter with multi-tuned traps for grid-connected converters

This paper presents a new passive filter for grid-connected converters, named the LCPSL filter, which utilizes both the parallel and series LC trap branches to suppress the harmonics at switching frequency and its multiples. Particularly, the LCPSL filter can provide more attenuation and quality factor at the selected frequencies, and inherit the merits of the traditional LCL filter with -60dB/dec attenuation rate in high-frequency band. The basic parameter selection criteria and the parameter design procedure of the LCPSL filter are introduced. Besides, considering the simplicity of the single-current loop control, the stability regions of the resonance frequencies are derived for the filter design. Finally, the superiority and effectiveness of the proposed filter are proved by simulation results.