A Magnetic Integrated LCL Filter With Enhanced Ripple Attenuation Capability and a Core Size Optimization Method

In virtue of their strong ripple attenuation capability, LCL filters are widely used in grid-connected inverter to effectively filter the switching frequency harmonics of grid-connected currents. However, the downside of conventional LCL filters is that they are large size and low core utilization. Although magnetic integration of the two discrete inductors of the LCL filter is an effective solution to reduce the size, the existing magnetic integration solutions mainly suffer from the problem of reduced ripple attenuating capability in high frequency zone. Aiming at this problem, a magnetic integrated LCL filter with enhanced ripple attenuation capability is proposed in this paper. In addition, the joint optimization method of core volume-efficiency-ripple attenuation capability is realized by reasonable core structure and parameter design, which further improves the practicability of the proposed magnetic integrated LCL filter. Finally, the effectiveness of the proposed magnetic integrated LCL filter and joint optimization method is experimentally verified.