Single-Switch Differential Power Processing PWM Converter to Enhance Energy Yield of Photovoltaic Panels under Partial Shading

PWM Converter Integrating Voltage Equalizer for Photovoltaic Panels under Partial Shading

IEEJ Transactions on Industry Applications ◽

10.1541/ieejias.137.274 ◽

2017 ◽

Vol 137 (3) ◽

pp. 274-281

Author(s):

Masatoshi Uno ◽

Akio Kukita

Keyword(s):

Partial Shading ◽

Pwm Converter ◽

Photovoltaic Panels

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LLC Resonant Voltage Multiplier-Based Differential Power Processing Converter Using Voltage Divider with Reduced Voltage Stress for Series-Connected Photovoltaic Panels under Partial Shading

Electronics ◽

10.3390/electronics8101193 ◽

2019 ◽

Vol 8 (10) ◽

pp. 1193

Author(s):

Masatoshi Uno ◽

Toru Nakane ◽

Toshiki Shinohara

Keyword(s):

Voltage Divider ◽

Energy Yield ◽

Partial Shading ◽

Photovoltaic Panels ◽

Voltage Multiplier ◽

Voltage Stress ◽

In Series ◽

Multiple Power ◽

Negative Impacts ◽

Power Point

Partial shading on photovoltaic (PV) strings consisting of multiple panels connected in series is known to trigger severe issues, such as reduced energy yield and the occurrence of multiple power point maxima. Various kinds of differential power processing (DPP) converters have been proposed and developed to prevent partial shading issues. Voltage stresses of switches and capacitors in conventional DPP converters, however, are prone to soar with the number of panels connected in series, likely resulting in impaired converter performance and increased circuit volume. This paper proposes a DPP converter using an LLC resonant voltage multiplier (VM) with a voltage divider (VD) to reduce voltage stresses of switches and capacitors. The VD can be arbitrarily extended by adding switches and capacitors, and the voltage stresses can be further reduced by extending the VD. Experimental verification tests for four PV panels connected in series were performed emulating partial shading conditions in a laboratory and outdoor. The results demonstrated the proposed DPP converter successfully precluded the negative impacts of partial shading with mitigating the voltage stress issues.

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Reconfigurable Distributed Power Electronics Technique for Solar PV Systems

Electronics ◽

10.3390/electronics10091121 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1121

Author(s):

Kamran Ali Khan Niazi ◽

Yongheng Yang ◽

Tamas Kerekes ◽

Dezso Sera

Keyword(s):

Energy Yield ◽

Solar Pv ◽

Charge Redistribution ◽

Pv System ◽

Partial Shading ◽

Pv Systems ◽

Simulation Based ◽

In Series ◽

A Cell ◽

Power Balancing

A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a voltage boosting capability to the PV system under no mismatch by connected the available PV cells/panels in series. The technique performs a reconfiguration by measuring the PV cell/panel voltages and their irradiances. The power balancing is achieved by charge redistribution through SC under mismatch conditions, e.g., partial shading. Moreover, PV cells/panels remain in series under no mismatch. Overall, this paper analyzes, simulates, and evaluates the effectiveness of the proposed DPP architecture through a simulation-based model prepared in PSIM. Additionally, the effectiveness is also demonstrated by comparing it with existing conventional DPP and traditional bypass diode architecture.

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A Simple Mismatch Mitigating Partial Power Processing Converter for Solar PV Modules

Energies ◽

10.3390/en14082308 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2308

Author(s):

Kamran Ali Khan Niazi ◽

Yongheng Yang ◽

Tamas Kerekes ◽

Dezso Sera

Keyword(s):

Experimental Tests ◽

Energy Yield ◽

Power Electronic ◽

Solar Pv ◽

Partial Shading ◽

Loss Analysis ◽

Pv Systems ◽

Pv Module ◽

Pv Modules ◽

In Series

Partial shading affects the energy harvested from photovoltaic (PV) modules, leading to a mismatch in PV systems and causing energy losses. For this purpose, differential power processing (DPP) converters are the emerging power electronic-based topologies used to address the mismatch issues. Normally, PV modules are connected in series and DPP converters are used to extract the power from these PV modules by only processing the fraction of power called mismatched power. In this work, a switched-capacitor-inductor (SCL)-based DPP converter is presented, which mitigates the non-ideal conditions in solar PV systems. A proposed SCL-based DPP technique utilizes a simple control strategy to extract the maximum power from the partially shaded PV modules by only processing a fraction of the power. Furthermore, an operational principle and loss analysis for the proposed converter is presented. The proposed topology is examined and compared with the traditional bypass diode technique through simulations and experimental tests. The efficiency of the proposed DPP is validated by the experiment and simulation. The results demonstrate the performance in terms of higher energy yield without bypassing the low-producing PV module by using a simple control. The results indicate that achieved efficiency is higher than 98% under severe mismatch (higher than 50%).

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Growth and Physiological Characteristics of Lettuce (Lactuca sativa L.) and Rocket (Eruca sativa Mill.) Plants Cultivated under Photovoltaic Panels

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha46110846 ◽

2018 ◽

Vol 46 (1) ◽

pp. 206-212 ◽

Cited By ~ 9

Author(s):

Angeliki KAVGA ◽

Georgios TRYPANAGNOSTOPOULOS ◽

George ZERVOUDAKIS ◽

Yiannis TRIPANAGNOSTOPOULOS

Keyword(s):

Solar Radiation ◽

Photosynthetic Rate ◽

Lactuca Sativa ◽

The Other ◽

Physiological Characteristics ◽

Eruca Sativa ◽

Partial Shading ◽

Photovoltaic Panels ◽

Lactuca Sativa L ◽

Other Hand

Energy demand of greenhouses is an important factor for their economics and photovoltaics can be considered an alternative solution to cover their electrical and heating needs. On the other hand, plants cultivated under different solar radiation intensities usually appear different physiological adaptations. The objective of this research was to investigate the effect of photovoltaic panels’ induced partial shading on growth and physiological characteristics of lettuce (Lactuca sativa L.) and rocket (Eruca sativa Mill.) plants. Our results indicate that lettuce productivity and the corresponding photosynthetic rate were not affected under the photovoltaic cultivation in comparison with the reference one. On the other hand, the rocket cultivation was less productive and showed lower photosynthetic rate under photovoltaic panels than in the reference greenhouse. The different physiological response between lettuce and rocket seems to be associated with the effect of environmental factors such as solar radiation intensity, temperature and humidity apart from the possible inherent characteristics of each plant species.

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PWM Step-Up Converter Integrating Differential Power Processing Converter to Enhance Energy Yield of Partially-Shaded Photovoltaic Panels

IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society ◽

10.1109/iecon43393.2020.9255306 ◽

2020 ◽

Author(s):

Yusuke Sasaki ◽

Hayato Sato ◽

Masatoshi Uno

Keyword(s):

Energy Yield ◽

Photovoltaic Panels

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A Hybrid Maximum Power Point Search Method Using Temperature Measurements in Partial Shading Conditions

Metrology and Measurement Systems ◽

10.2478/mms-2014-0056 ◽

2014 ◽

Vol 21 (4) ◽

pp. 733-740 ◽

Cited By ~ 18

Author(s):

Janusz Mroczka ◽

Mariusz Ostrowski

Keyword(s):

Solar Panel ◽

Maximum Power ◽

Global Maximum ◽

Maximum Power Point ◽

Partial Shading ◽

Decision Algorithm ◽

Photovoltaic Panel ◽

Photovoltaic Panels ◽

Local Maxima ◽

Power Point

Abstract Photovoltaic panels have a non-linear current-voltage characteristics to produce the maximum power at only one point called the maximum power point. In the case of the uniform illumination a single solar panel shows only one maximum power, which is also the global maximum power point. In the case an irregularly illuminated photovoltaic panel many local maxima on the power-voltage curve can be observed and only one of them is the global maximum. The proposed algorithm detects whether a solar panel is in the uniform insolation conditions. Then an appropriate strategy of tracking the maximum power point is taken using a decision algorithm. The proposed method is simulated in the environment created by the authors, which allows to stimulate photovoltaic panels in real conditions of lighting, temperature and shading.

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