Active Power Decoupling for Cascaded H-Bridge Single Phase Inverter to Mitigate Double-line Frequency in PV Applications

This paper presents a novel active power decoupling (APD) technique for the cascaded H-Bridge (CHB) three-phase inverter to mitigate the double line frequency ripples. The proposed technique combines a full-bridge converter with each cell of the CHB and uses coupled inductors to cancel the double line ripple in each phase employing a very low capacitor size. The proposed strategy has the following merits: low capacitor size for handling only the high switching frequency ripples, low coupled inductor size with a reduced current rating, and long lifetime thanks to mitigating bulky capacitors. A comparative study with the latest existing topologies has been introduced. Extensive simulation and experimental results are carried out for verifying the superiority of the proposed APD technique.