An integrated unit of LCL filter for grid-connected inverter

In order to further increase the power density of the grid-connected inverter, a passive integrated unit is proposed by combining two inductors and one capacitor of the LCL filter in this paper. For saving the volume and the height of the three passive components, the planar PCB (Printed Circuit Board) integration technique is used. To avoid the coupling of two filter inductors, two integrated windings realize two LC filter respectively. And the total effect of two LC filter is the same as that of the LCL filter. The design process of the proposed integrated unit is introduced. And its structure parameters are given for a 600 W grid-connected inverter. Finally, the simulation is built to verify the of the LCL filter.