A multi‐port MMC topology with reduced capacitor size for use in grid‐connected PV systems. Issue 11 (23rd August 2021)

• Record Type: Journal Article
• Authors: Safaee, Sheila; Ketabi, Abbas; Farshadnia, Mohammad; Shahidehpour, Mohammad
• Is Part Of: Energy science & engineering. Volume 9:Issue 11(2021)
• Page Start: 2019
• Page End: 2035
• Publication Date: 2021-08-23
• Subjects: maximum power point tracking -- model‐predictive control -- modular multilevel converter -- photovoltaic array; Energy industries -- Periodicals; Energy development -- Periodicals; Power resources -- Periodicals; 621.042
• DOI: 10.1002/ese3.963
• Languages: English
• ISSNs: 2050-0505

Abstract

Abstract: In this article, a novel multi‐port modular multilevel inverter topology is presented for grid‐connected photovoltaic systems, which feature a smaller capacitor size compared with its counterparts. In the proposed MMC topology, each submodule is an individual input port being fed by an independent PV array through a boost converter. This allows modularity of the proposed topology, easing its maintenance and facilitating its expansion for PV integration. Individual maximum power point tracking controllers are used to operate the boost converters in each submodule to extract maximum energy from their PV arrays under different radiation conditions. A model‐predictive control scheme is designed for regulating the proposed multi‐port MMC topology to inject the harvested solar power to the grid. This controller enables minimized circulating currents in the MMC arms and balanced capacitor voltages in the MMC submodules, while total harmonic distortion (THD) of injected current to the grid is kept within the limits. The proposed multi‐port MMC topology with model‐predictive control is validated under different radiation conditions for a grid‐connected PV system to indicate that the proposed topology has a desirable performance under different radiation conditions. Abstract : In this study, we have presented a novel multi‐port MMC topology with FCS‐MPC scheme for use in grid‐connected PV systems. The proposed system features complete modularity and maximizes the harvested energy by the PV arrays. The size of total dc capacitance decreases significantly (42%) in comparison with its conventional type and it utilizes fewer diodes, which make this topology more reliable and economical.