AC solar cells: An embedded "all in one" PV power system

Journal ArticlePower converters constructed from discrete components are difficult to mass produce, and the installation involves a significant labor cost to have the proper interconnection among the panel, inverter and the grid. These facts indicate that the present PV technology may not be able to address the challenges involved in reaching the DOE target of $1/W. Therefore, a paradigm shift in the design of the entire PV power system is needed to reach this goal. In order to increase the converter reliability and watts/$, the active and passive elements of a power converter (especially capacitors and active switches such as MOSFETs, JFETs or IGBTs) could be embedded on the same substrate material used for fabricating the p-n junctions in the photovoltaic panel. To the knowledge of the author, there is no prior work in cell level power conversion, and therefore, this project idea could be considered as an "Out of the box" kind. A novel fabrication process is proposed in this paper demonstrating the integration of PV cells and two major components needed to build a power converter. Because of the cell level power conversion, PV panels constructed from these cells are likely to be immune to partial shading and hot-spot effects. The end goal of this research is to produce 120V/240V ac output directly from the panel. An extremely accurate device simulator (*Silvaco Athena/Atlas) was used to generate reasonably accurate characteristics of the proposed PV system

Hardware Approach To Mitigate The Effects Of Module Mismatch In A Grid-Connected Photovoltaic System: A Review

This study reviews the hardware approach to mitigate the effects of module mismatch in a grid-connected photovoltaic (PV) system. Unlike software solutions, i.e. the maximum power tracking algorithm, hardware techniques are well suited to enhance energy yield because of their inherent ability to extract energy from the mismatched module. Despite the extra cost of the additional circuitry, hardware techniques have recently gained popularity because of their long-term financial benefits. Notwithstanding the growing interest in this topic, review papers that provide updates on the technological developments of the three main hardware solutions, namely micro inverter,DC power optimizer, and energy recovery circuits, are lacking. This is in contrast to software solutions, which have had a considerable number of reputable reviews. Thus, a comprehensive review paper is appropriate at this juncture to provide up-to-date information on the latest topologies, highlight their merits/drawbacks, and evaluate their comparative performance

Distributed Maximum Power Point Tracking: Challenges and Commercial Solutions

n/

Doctor of Philosophy

dissertationMicroelectromechanical systems (MEMS) resonators on Si have the potential to replace the discrete passive components in a power converter. The main intention of this dissertation is to present a ring-shaped aluminum nitride (AlN) piezoelectric microreson

Three-port Micro-inverter With Power Decoupling Capability For Photovoltaic (pv) Systems Applications

The Photovoltaic (PV) systems have been realized using different architectures, starting with the string and centralized PV system to the modular PV system. Presently, decentralized inverters are being developed at the PV panel power level (known as AC – PV Modules). Such new PV systems are becoming more attractive and many expect this will be the trend of the future. The AC-Module PV system consists of an inverter attached to one PV panel. This integration requires that both devices have the same life-span. Although, the available commercial inverters have a relatively short life-span (10 years) compared to the 25 –year PV. It has been stated in literature that the energy storage capacitor (electrolytic type) in the singlephase inverter is the most vulnerable electronic component. Hence, many techniques such as (power decoupling techniques) have been proposed to solve this problem by replacing the large electrolytic capacitor with a small film capacitor. This thesis will present a quick review of these power decoupling techniques, and proposes a new three-port micro-inverter with power decoupling capability for AC-Module PV system applications

Design of module level converters in photovoltaic power systems

The application of distributed maximum power point tracking (DMPPT) technology in solar photovoltaic (PV) systems is a hot topic in industry and academia. In the PV industry, grid integrated power systems are mainstream. The main objective for PV system design is to increase energy conversion efficiency and decrease the levelized cost of electricity of PV generators. This thesis firstly presents an extensive review of state-of-the-art PV technologies. With focus on grid integrated PV systems research, various aspects covered include PV materials, conventional full power processing DMPPT architectures, main MPPT techniques, and traditional partial power processing DMPPT architectures. The main restrictions to applying traditional DMPPT architectures in large power systems are discussed. A parallel connected partial power processing DMPPT architecture is proposed aiming to overcome existing restrictions. With flexible ‘plug-and-play’ functionality, the proposed architecture can be readily expanded to supply a downstream inverter stage or dc network. By adopting smaller module integrated converters, the proposed approach provides a possible efficiency improvement and cost reduction. The requirements for possible converter candidates and control strategies are analysed. One representative circuit scheme is presented as an example to verify the feasibility of the design. An electromagnetic transient model is built for different power scale PV systems to verify the DMPPT feasibility of the evaluated architecture in a large-scale PV power system. Voltage boosting ability is widely needed for converters in DMPPT applications. Impedance source converters (ISCs) are the main converter types with step-up ability. However, these converters have a general problem of low order distortion when applied in dc-ac applications. To solve this problem, a generic plug-in repetitive control strategy for a four-switch three-phase ISC type inverter configuration is developed. Simulation and experimental results confirm that this control strategy is suitable for many ISC converters.The application of distributed maximum power point tracking (DMPPT) technology in solar photovoltaic (PV) systems is a hot topic in industry and academia. In the PV industry, grid integrated power systems are mainstream. The main objective for PV system design is to increase energy conversion efficiency and decrease the levelized cost of electricity of PV generators. This thesis firstly presents an extensive review of state-of-the-art PV technologies. With focus on grid integrated PV systems research, various aspects covered include PV materials, conventional full power processing DMPPT architectures, main MPPT techniques, and traditional partial power processing DMPPT architectures. The main restrictions to applying traditional DMPPT architectures in large power systems are discussed. A parallel connected partial power processing DMPPT architecture is proposed aiming to overcome existing restrictions. With flexible ‘plug-and-play’ functionality, the proposed architecture can be readily expanded to supply a downstream inverter stage or dc network. By adopting smaller module integrated converters, the proposed approach provides a possible efficiency improvement and cost reduction. The requirements for possible converter candidates and control strategies are analysed. One representative circuit scheme is presented as an example to verify the feasibility of the design. An electromagnetic transient model is built for different power scale PV systems to verify the DMPPT feasibility of the evaluated architecture in a large-scale PV power system. Voltage boosting ability is widely needed for converters in DMPPT applications. Impedance source converters (ISCs) are the main converter types with step-up ability. However, these converters have a general problem of low order distortion when applied in dc-ac applications. To solve this problem, a generic plug-in repetitive control strategy for a four-switch three-phase ISC type inverter configuration is developed. Simulation and experimental results confirm that this control strategy is suitable for many ISC converters