scholarly journals Parallel PV Configuration with Magnetic-Free Switched Capacitor Module-Level Converters for Partial Shading Conditions

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 456
Author(s):  
Georgios Kampitsis ◽  
Efstratios Batzelis ◽  
Remco van Erp ◽  
Elison Matioli
Keyword(s):  
Fixed Ratio ◽  
Maximum Power ◽  
Switched Capacitor ◽  
Total System ◽  
Pv System ◽  
Partial Shading ◽  
Power Extraction ◽  
Point Tracking ◽  
Dc Bus ◽  
Conversion Stage

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.

Design & Real-time Implementation of MIDO Converter Based PV Water Pumping System with BES

2020 ◽  
Vol 14 (2) ◽  
pp. 194-204
Author(s):  
Anuradha Tomar
Keyword(s):  
Real Time ◽  
Rural Areas ◽  
Maximum Power ◽  
Pump System ◽  
Partial Shading ◽  
Power Extraction ◽  
Pumping System ◽  
Point Tracking ◽  
Water Pumping ◽  
Battery Energy

Background: Despite so many developments, most of the farmers in the rural areas are still dependent on rainwater, rivers or water wells, for irrigation, drinking water etc. The main reason behind such dependency is non-connectivity with the National grid and thus unavailability of electricity. To extract the maximum power from solar photovoltaic (SPV) based system, implementation of Maximum Power Point Tracking (MPPT) is mandatory. PV power is intermittent in nature. Variation in the irradiation level due to partial shading or mismatching phenomena leads to the development of modular DC-DC converters. Methods: A stand-alone Multi-Input Dual-Output (MIDO) DC-DC converter based SPV system, is installed at a farm; surrounded with plants for water pumping with stable flow (not pulsating) along with battery energy storage (BES) for lighting. The proposed work has two main objectives; first to maximize the available PV power under shadowing and mismatching condition in case of series/ parallel connected PV modules and second is to improve the utilization of available PV energy with dual loads connected to it. Implementation of proposed MIDO converter along with BES addresses these objectives. First, MIDO controller ensures the MPPT operation of the SPV system to extract maximum power even under partial shading condition and second, controls the power supplied to the motor-pump system and BES. The proposed system is simulated in MATLAB/ SIMULINK environment. Real-time experimental readings under natural sun irradiance through hardware set-up are also taken under dynamic field conditions to validate the performance. Results and Conclusion: The inherent advantage of individual MPPT of each PV source in MIDO configuration, under varying shadow patterns due to surrounding plants and trees is added to common DC bus and therefore provides a better impact on PV power extraction as compared to conventional PV based water pumping system. Multi-outputs at different supply voltages is another flag of MIDO system. Both these aspects are implemented and working successfully at 92.75% efficiency.

scholarly journals Maximum Power Point Tracking of PV Systems under Partial Shading Conditions Based on Opposition-Based Learning Firefly Algorithm

2021 ◽  
Vol 13 (5) ◽  
pp. 2656
Author(s):  
Ahmed G. Abo-Khalil ◽  
Walied Alharbi ◽  
Abdel-Rahman Al-Qawasmi ◽  
Mohammad Alobaid ◽  
Ibrahim M. Alarifi
Keyword(s):  
Firefly Algorithm ◽  
Maximum Power ◽  
Pv System ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Point Tracking ◽  
Opposition Based Learning ◽  
Power Point Tracking ◽  
Convergence Process ◽  
Power Point

This work presents an alternative to the conventional photovoltaic maximum power point tracking (MPPT) methods, by using an opposition-based learning firefly algorithm (OFA) that improves the performance of the Photovoltaic (PV) system both in the uniform irradiance changes and in partial shading conditions. The firefly algorithm is based on fireflies’ search for food, according to which individuals emit progressively more intense glows as they approach the objective, attracting the other fireflies. Therefore, the simulation of this behavior can be conducted by solving the objective function that is directly proportional to the distance from the desired result. To implement this algorithm in case of partial shading conditions, it was necessary to adjust the Firefly Algorithm (FA) parameters to fit the MPPT application. These parameters have been extensively tested, converging satisfactorily and guaranteeing to extract the global maximum power point (GMPP) in the cases of normal and partial shading conditions analyzed. The precise adjustment of the coefficients was made possible by visualizing the movement of the particles during the convergence process, while opposition-based learning (OBL) was used with FA to accelerate the convergence process by allowing the particle to move in the opposite direction. The proposed algorithm was simulated in the closest possible way to authentic operating conditions, and variable irradiance and partial shading conditions were implemented experimentally for a 60 [W] PV system. A two-stage PV grid-connected system was designed and deployed to validate the proposed algorithm. In addition, a comparison between the performance of the Perturbation and Observation (P&O) method and the proposed method was carried out to prove the effectiveness of this method over the conventional methods in tracking the GMPP.

scholarly journals A Modification of the Perturb and Observe Method to Improve the Energy Harvesting of PV Systems under Partial Shading Conditions

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2521
Author(s):  
Alfredo Gil-Velasco ◽  
Carlos Aguilar-Castillo
Keyword(s):  
Maximum Power ◽  
Global Maximum ◽  
Pv System ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Pv Systems ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Computational Resources

There are multiples conditions that lead to partial shading conditions (PSC) in photovoltaic systems (PV). Under these conditions, the harvested energy decreases in the PV system. The maximum power point tracking (MPPT) controller aims to harvest the greatest amount of energy even under partial shading conditions. The simplest available MPPT algorithms fail on PSC, whereas the complex ones are effective but require high computational resources and experience in this type of systems. This paper presents a new MPPT algorithm that is simple but effective in tracking the global maximum power point even in PSC. The simulation and experimental results show excellent performance of the proposed algorithm. Additionally, a comparison with a previously proposed algorithm is presented. The comparison shows that the proposal in this paper is faster in tracking the maximum power point than complex algorithms.

scholarly journals Hybrid Fuzzy Based MPPT Techniques for Maximum Power Extraction

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1140-1148
Keyword(s):  
Maximum Power ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Pv System ◽  
Power Extraction ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Incremental Conductance ◽  
Power Point

The extensive usage of solar has extended the opportunity of research to increase the efficiency of PV module. Maximum Power Point Tracking technique plays an important role. In P & O and Incremental conductance the power produced is less. In this paper a Fuzzy based P & O and Fuzzy based Incremental Conductance MPPT techniques are presented to extract the maximum power from the photovoltaic system by considering the dynamic variation in irradiations and temperature also. Here the 100 kW PV array is considered and it is connected to the utility grid via a DC-DC boost converter of 500volts with a 3 phase three level voltage source converter. The result is obtained by the MAT LAB Simulink and the same is appraised with the traditional P & O and Incremental conductance. The PV System produces the maximum power by the application of Fuzzy based incremental Technique compared to conventional methods.

A Comparative Study on Maximum Power Point Tracking Techniques of Photovoltaic Systems

2018 ◽  
Vol 7 (1) ◽  
pp. 66-85 ◽  
Author(s):  
Afef Badis ◽  
Mohamed Habib Boujmil ◽  
Mohamed Nejib Mansouri
Keyword(s):  
High Efficiency ◽  
Maximum Power Point Tracking ◽  
Maximum Power ◽  
Pv System ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Conventional Methods ◽  
Power Point

This article concerns maximizing the energy reproduced from the photovoltaic (PV) system, ensured by using an efficient Maximum Power Point Tracking (MPPT) process. The process should be fast, rigorous and simple for implementation because the PV characteristics are extremely affected by fast changing conditions and Partial Shading (PS). PV systems are popularly known to have many peaks (one Global Peak (GP) and several local peaks). Therefore, the MPPT algorithm should be able to accurately detect the unique GP as the maximum power point (MPP), and avoid any other peak to mitigate the effect of (PS). Usually, with no shading, nearly all the conventional methods can easily reach the MPP with high efficiency. Nonetheless, they fail to extract the GP when PS occurs. To overcome this problem, Evolutionary Algorithms (AEs), namely the Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) are simulated and compared to the conventional methods (Perturb & Observe) under the same software.

scholarly journals PV Solar-Optimal Maximum Power Search using a Modified P&O Technique

2017 ◽  
Vol 2 (5) ◽  
pp. 13
Author(s):  
Mohamed Salama Ebrahim ◽  
Adel M. Sharaf ◽  
Ahmed M. Atallah ◽  
Adel Sedky Emarah
Keyword(s):  
Smart Grid ◽  
Reactive Power ◽  
Search Algorithm ◽  
Digital Simulation ◽  
Maximum Power ◽  
Energy Utilization ◽  
Pv System ◽  
Partial Shading ◽  
Point Tracking ◽  
Power Point

Smart Grid- PV system interface requires power electronic converter interface and robust optimal controller to ensure maximum solar energy utilization. This paper presents a new Controller based on an optimized search algorithm for maximum power point tracking controller performance using a modified Perturb and Observe P&O Algorithm for a smart grid connected PV DC-AC interface system. The modified P & O method is based on dividing the change of the power into three distinct zones with assigned zone- duty cycle ratio of the Chopper converter (D) has an initial preset value. The feasibility of the proposed method is easily implemented using proportional plus integral and fuzzy logic controllers. The controllers are assumed to control the active output power through adjusting of the dc bus voltage as well as the reactive power given to the ac smart grid network. Digital simulation results of a comparison with conventional P&O approach reflects the fast conversion and dynamic superiority of the new algorithm even under both uniform and partial shading conditions. Furthermore, the active and reactive output powers are regulated at the inverter interface with smart grid.

scholarly journals Power optimization in partially shaded photovoltaic systems

2018 ◽  
Vol 12 (1) ◽  
pp. 34-38
Author(s):  
Halil Erol ◽  
Mahmut Uçman
Keyword(s):  
Climatic Conditions ◽  
Maximum Power ◽  
Hill Climbing ◽  
Solar Pv ◽  
Pv System ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Point Tracking ◽  
Linear Behaviour ◽  
Power Point

The Power-Voltage characteristic of a photovoltaic (PV) array exhibits non-linear behaviour when exposed to uniform solar irradiance. Maximum Power Point (MPP) tracking is challenging due to the varying climatic conditions in a solar PV system. Moreover, the tracking algorithm becomes more complicated due to the presence of multiple peaks in the power voltage characteristics under the condition of partial shading. This research is devoted to the Stochastic Beam Search (SBS) based algorithm and Stochastic Hill Climbing (SHC) for a maximum power point tracking (MPPT) at a partial shading condition in the PV system. To give a partial shading effect over the entire array of a PV system, a mast is placed in front of the modules. The modules in the array are connected in such a way that one does not need to rewire the electrical connection during the rearrangement of modules. It is validated that the power generation performance of an array under a moving shading condition is increased. Furthermore, it is observed that the SHC method outperforms the SBS method in the MMP tracking.

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