Parallel PV Configuration with Magnetic‐Free Switched Capacitor Module‐Level Converters for Partial Shad‐ing Conditions
File(s)
Published version
OA Location
Author(s)
Kampitsis, Georgios
Batzelis, Efstratios
van Erp, Remco
Matioli, Elison
Type
Journal Article
Abstract
In this paper, a module-level photovoltaic (PV) architecture in parallel configuration is introduced for maximum power extraction, under partial shading (PS) conditions. For the first time, a non-regulated switched capacitor (SC) nX converter is a used at the PV-side conversion stage, whose purpose is just to multiply the PV voltage by a fixed ratio and accordingly reduce the input current. All the control functions, including the maximum power point tracking, are transferred to the grid-side inverter. The voltage-multiplied PV modules (VMPVs) are connected in parallel to a common DC-bus, which offers expandability to the system and eliminates the PS issues of a typical string architecture. The advantage of the proposed approach is that the PV-side converter is relieved of bulky capacitors, filters, controllers and voltage/current sensors, allowing for a more compact and efficient conversion stage, compared to conventional per-module systems, such as microinverters. The proposed configuration was initially simulated in a 5 kW residential PV system and compared against conventional PV arrangements. For the experimental validation, a 10X Gallium Nitride (GaN) converter prototype was developed with a flat conversion efficiency of 96.3% throughout the power range. This is particularly advantageous, given the power production variability of PV generators. Subsequently, the VMPV architecture was tested on a two-module 500 WP prototype, exhibiting an excellent power extraction efficiency of over 99.7% under PS conditions and minimal DC-bus voltage variation of 3%, leading to a higher total system efficiency compared to most state-of-the-art configurations.
Date Issued
2021-01-15
Date Acceptance
2021-01-11
Citation
Energies, 2021, 14 (2)
ISSN
1996-1073
Publisher
MDPI AG
Journal / Book Title
Energies
Volume
14
Issue
2
Copyright Statement
© 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
License URL
Sponsor
Royal Academy of Engineering
Royal Academy Of Engineering
Identifier
https://www.mdpi.com/1996-1073/14/2/456
Grant Number
RF\201819\18\86
RF\201819\18\86
Subjects
Science & Technology
Technology
Energy & Fuels
gallium nitride
magnetic-free converters
module-level converters
parallel architecture
partial shading
photovoltaic systems
switched capacitor converters
02 Physical Sciences
09 Engineering
Publication Status
Published
Article Number
4
Date Publish Online
2021-01-15