Design of an LCL-filter for space vector PWM in grid-connected 3-level inverters system

This paper proposes a design scheme of the LCL-filter for space vector PWM (SVM) at the three-level inverter system. Although there are several studies in progress, the conventional methods are erroneous because they do not focus on the other switching methods. This paper shows the design methodology for an LCL-filter optimized in SVM switching. The design sequence for the LCL-filter is presented gradually. The inverter-side inductor was decided by an analysis of the ripple components mathematically. Based on the reactive power absorption ratio, the filter capacitor was determined. The grid-side inductor was determined by the ripple factor. Simulation results are shown to verify the validity of the proposed filter design method