A dependent Active Power Decoupling Solution for the Single-Phase Switched Boost Inverter

In recent literature, the Switched Boost Inverter (SBI) has been explored, which can offer several advantages, such as improved ac output voltage range, shoot-through immunity, concurrent functioning with both dc and ac loads, etc. It can also achieve better power density as well as improved efficiency than impedance-source inverters owing to a reduced number of passive elements. However, the intrinsic dc-side low-frequency ripple issue often plagues the single-phase SBI, which makes it necessary to employ bulky dc-side passive elements. As an alternative solution, a dependent active power decoupling (APD) method is proposed, where two auxiliary capacitors are added to the SBI, and the ac output filter inductor is replaced with two separate inductors without increasing the overall size of filter inductors. As a result, low-frequency ripple is significantly reduced, and the dc-side passive elements no longer need to be bulky, which improves power density. With the help of a closed-loop control strategy, all of the inverter bridge switches are regulated to perform both dc-ac power conversion as well as APD operation. The effectiveness of the proposed APD is verified using PSCAD/EMTDC simulation.