- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Simulation and experimental validation of fast adaptive particle swarm optimization strategy for photovoltaic global peak tracker under dynamic partial shading
摘要： The P–V characteristics of PV array has one peak under uniformly distributed irradiances. Whereas, there are many peaks in the P–V curve when the irradiance is not uniformly distributed over the PV array which is called “partial shading conditions (PSCs)”. Due to its robustness in tracking the global peak (GP) of many applications, metaheuristic techniques are used as maximum power point tracker (MPPT) for the PV system under PSCs. Particle swarm optimization (PSO) has been used in this paper for this purpose. Three problems associated with the PSO have been solved in this paper using a novel fast adaptive PSO (APSO) strategy. The problem of long convergence time has been solved by updating starting values of the duty ratio of the DC-DC boost converter to be at the anticipated places of peaks. This modification reduces the convergence time and avoids the premature convergence. The problem of stored GP in the memory will prevent the PSO from capturing the current GP in case of it is lower than the stored one. This problem is solved in this paper by updating the memorized GP with the current maximum power when it is not changed for two successive iterations. The third problem of sudden change in PSCs is solved by using the updated values of duty ratio at anticipated peaks as initial values for particles. To the best of the authors’ knowledge, these problems have not been discussed or solved before in the literature. A comparison to the state-of-the-art random initialization PSO strategy shows the superiority of the proposed APSO technique in terms of tracking speed and dynamic GP tracking. The results obtained from the simulation of this strategy proved its superiority in always tracking the GP under dynamic PSCs change.
关键词： Partial shading conditions,Photovoltaic,Dynamic irradiance change,Maximum power point tracker,Global peak,Adaptive particle swarm optimization
更新于2025-09-23 15:19:57
-
Performance Evaluation and Optimization of a Building-Integrated Photovoltaic/Thermal Solar Water Heating System for Exterior Shading: A Case Study in South China
摘要： Building-integrated photovoltaic/thermal (BIPV/T) systems can produce both electrical and thermal energy through the use of photovoltaic/thermal modules integrated with building envelope. Exterior shading is a common way to improve summer indoor thermal environment of the buildings in low latitudes. This study presents a BIPV/T solar water heating system for exterior shading of residences. In order to evaluate and optimize the system performances, a model was developed to simulate the thermal and electrical production of such system. The simulations for an example system in Guangzhou, a city in South China, were performed to investigate the influences of tank installation height and panel tilt angle on system performances. According to simulation results, the suggested tank installation height is 0.6~0.8 m. The shading coefficient ranges from 0.797 to 0.828 when the tilt angle varies from 14° to 38°. The reduction of panel tilt angle causes a certain improvement of shading performance. The annual auxiliary heat reaches the minimum when the panel tilt angle equals 28°, and the annual electric energy output changes little when the panel tilt angle ranges from 20° to 28°. Comprehensively considering thermal, electrical, and shading performances, the suggested panel tilt angle is 20°~28°. The average thermal and electrical efficiencies are respectively 38.25% and 11.95% when the panel tilt angle ranges from 20° to 28°. The presented system is a promising way to provide hot water, electricity, and exterior shading for residences.
关键词： exterior shading,BIPV/T,thermosyphon photovoltaic/thermal water heater,performance evaluation and optimization
更新于2025-09-23 15:19:57
-
[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - A Novel Differential Power Processing Architecture for a Partially Shaded PV String Using Distributed Control
摘要： This paper proposes a differential power processing (DPP) architecture applied to a series PV string which enables each PV element to operate at its local maximum power point (MPP) while processing only a small portion of its total generated power through the module integrated converters (MICs). The current processed through each converter is the difference between the local PV element MPP current and the local PV string current. This feature allows for a reduced current stress on the MIC components relative to the most common DPP topology. Thus, a higher system efficiency is realized at a reduced cost. A state space model of the proposed system is derived, and a comparison analysis is carried out with respect to the conventional DPP architectures. Additionally, a modular and compact design is proposed for a large number of PV panels in a series PV string. A hardware prototype is designed and built for 3 PV panels connected in series to validate the proposed architectures effectiveness and experimentally demonstrate its robustness. The modularity of the system is also tested to ensure low current and voltage stress on the MICs.
关键词： Distributed Control,maximum power point tracking (MPPT),Differential Power Processing,DC-DC Converters,Photovoltaic (PV) String,Partial Shading
更新于2025-09-23 15:19:57
-
A High Performance Shade-Tolerant MPPT Based on Current-Mode Control
摘要： This paper proposes a high performance shade-tolerant maximum power point tracking (STMPPT) technique for DC-DC converter stage of photovoltaic (PV) applications. The average current-mode control (ACMC) is utilized to regulate the PV array current using two feedback control loops. The current-mode control is a superior scheme in control of DC-DC power electronic converters. The proposed STMPPT technique operates in two modes. The ACMC with the perturb and observe (P&O) MPPT algorithm functions in a local MPPT (LMPPT) mode under normal irradiance condition. When the PV array is likely to be partially shaded, a global MPPT (GMPPT) subroutine effectively scans the PV profile to optimize the PV system operation. This is achieved by implementing simple innovations to the ACMC-based P&O algorithm. The innovations benefit from useful observations of I-V characteristics. The idea behind using the I-V characteristics is to significantly reduce the search space, make the algorithm independent of shading conditions and PV array configuration, and inherently recognize the occurrence of partial shading conditions (PSCs). The proposed STMPPT technique enables very fast and reliable tracking of global maximum power point (GMPP). In addition, it can stably work under dynamic environmental change without losing correct sense of tracking direction. Its simplicity and independency would offer a viable solution for PV converter products. Simulation and experimental performance assessments are presented under different operating conditions that could happen in outdoor PV installations.
关键词： perturb and observe algorithm,partial shading condition,Photovoltaic system,current-mode control,shade-tolerant maximum power point tracking
更新于2025-09-19 17:15:36
-
The impact of shading on the exploitation of photovoltaic installations
摘要： The article presents an overview of aspects of shading’s influence in photovoltaic systems that are the most important in the opinion of the authors. Discussing this particular problem is essential for minimizing the losses in the energy gain which is heavily dependent on the amount of radiation reaching photovoltaic cells. The radiation itself may be considerably limited due to the pollution or shading of the working area of PV panels. Because of that, it is necessary to undertake actions to prevent the unfavorable effects of shading. Due to its importance in research on PV panels, the authors of the following publication decided to introduce most crucial factors responsible for shading; including its characteristics, influence on overall functionality of PV panels or possible prevention methods. The analyzed issues were supplemented with the results of the original researches and simulations conducted for the need of this very article. Thus, appropriate steps should be undertaken as early as the design process of PV begins. Such measures may contribute to not only the increase of energy gain, but potential improvement in terms of profitability of the entire investment.
关键词： Reasons for shading,Efficiency of photovoltaic installation,Skyline shading,Panel orientation
更新于2025-09-19 17:13:59
-
Number of maximum power points in photovoltaic arrays during partial shading events by clouds
摘要： This article presents a study of the number of maximum power points (MPPs) of photovoltaic (PV) module arrays during partial shading events by clouds. Around 9000 shadow edges were identified in measured irradiance data, and the electrical characteristics of 250 to 500 PV module arrays with different configurations were studied during the irradiance changes. It was found that most of the partial shading events caused by clouds do not cause multiple MPPs for PV arrays, even for a moment. The number of MPPs was found to decrease with the increasing number of parallel-connected PV strings, but to increase strongly with the increasing length of the strings. According to the results, the use of a total-cross-tied electrical PV array configuration leads to worse system performance compared to a simple series-parallel configuration during partial shading events. Dark shadows with sharp edges moving parallel to the PV strings caused the largest MPP numbers, up to 20. The results show that energy losses due to operation at a local MPP instead of the global one during partial shading events by clouds have only a minor effect on the total energy production of PV arrays.
关键词： Maximum power point,Photovoltaic Array,Partial shading,Irradiance change,Photovoltaic power generation
更新于2025-09-19 17:13:59
-
Butterfly optimization algorithm based maximum power point tracking of photovoltaic systems under partial shading condition
摘要： Because of dust, trees, high buildings in the surrounding area, partial shading conditions (PSC) occur in photovoltaic (PV) systems. This condition affects the power output of the PV system. Under PSC there is a global maximum power point (GMPP) besides there are a few local maximum power points (LMPP). This condition makes the maximum power point tracking (MPPT) procedure a challenging task. In order to solve this issue, soft computing techniques such as gray wolf optimization (GWO), particle swarm optimization (PSO) and Gravitational Search Algorithm (GSA) are implemented. However, the performance of MPP trackers still needs to be improved. The main contribution of this paper is improving the tracking speed by implementing BOA to the MPPT of the PV system under PSC. Thus, in real-time applications a promising alternative presented to the literature to improve the performance of the PV systems under variable PSC because of its fast tracking speed. PV system consists of PV array, boost converter and load are modeled and simulated in MATLAB/Simulink. BOA algorithm is implemented for three different insolation scenarios on the PV array. The results of the BOA algorithm verified by a comparative analysis with PSO-GSA and GWO algorithms. The results show that BOA can give high accuracy and better tracking speed than these algorithms in recent literature.
关键词： Partial shading,energy,MPPT,butterfly optimization algorithm,solar,photovoltaic
更新于2025-09-19 17:13:59
-
Performance of photovoltaic canarian greenhouse: A comparison study between summer and winter seasons
摘要： A large-scale use of the renewable energy in agriculture has become an optimal way to successfully deal with the issues of sustainability and climate change. Recently, the integration of solar panels on the roof of the greenhouse gave birth to a new crop production system called photovoltaic greenhouse. In this paper, we investigated the shading effect of the flexible photovoltaic panels, mounted on the greenhouse roof area in the checkerboard format, on the microclimate and the tomatoes yield during the summer and winter period. This study was undertaken in a two tomato canarian greenhouses, typical of the south Mediterranean region. The results of our study showed that the photovoltaic panels covering 40% roof area of the canary type greenhouse does not have a significant effect on the climatic parameters. Additionally, during the hot period, the photovoltaic panels reduced the temperature inside the greenhouse and sometimes falling in the optimum range for the tomatoes growth. Furthermore, this occupancy rate of the photovoltaic panels does not have a significant effect on the overall yield of tomatoes.
关键词： Shading,Flexible photovoltaic panels,South Mediterranean area,Tomatoes,Renewable energy,Microclimate
更新于2025-09-19 17:13:59
-
Coordinated Control Strategy of a Combined Converter in a Photovoltaic DC Boost Collection System under Partial Shading Conditions
摘要： Series–parallel module technology can meet a DC converter’s requirements of high-power, large-capacity, and high step-up ratio in photovoltaic a DC boost collection system. However, the cascaded structure has the problem of voltage and current sharing between modules, and due to the duty cycle limitation of converters, the combined converters in the PV-converter unit have an unbalanced voltage, which may also exceed the voltage range under partial shading conditions (PSCs). First, aiming at the problems of voltage sharing, current sharing, and low modularity in the combined converter, this paper proposes a distributed control strategy. Then, by adopting a coordinated control strategy based on the sub-module cutting in and out, the problem that the combined converter cannot normally boost under PSCs was solved. The paper not only takes the advantages of the cascade structure of the combined converter to increase the power and voltage, but also improves its modularity to solve the problem of abnormal operation under uneven irradiation. This dramatically improves the adaptability of combined converters in a photovoltaic DC collection system. Finally, a small power experiment was carried out, where the experimental results veri?ed the e?ectiveness of the control strategy.
关键词： voltage-sharing and current-sharing control,partial shading conditions (PSCs),combined converter,photovoltaic DC boost collection system,coordinated control
更新于2025-09-19 17:13:59
-
A Photovoltaic Greenhouse with Passive Variation in Shading by Fixed Horizontal PV Panels
摘要： The traditional shading systems that greenhouses use cause some of the solar radiation that is re?ected or absorbed to be lost and, therefore, not used by the plants under cultivation. An interesting solution to these problems is to position photovoltaic (PV) panels on the roofs of greenhouses. All of the photovoltaic greenhouses that have been realized in Mediterranean areas are characterized by a ?xed position of the PV panels and excessive shading, especially in autumn and winter. The purpose of this study is to describe a prototype of a photovoltaic greenhouse with both ?xed and horizontal PV panels that exploit the natural variation in the elevation angle of the sun’s rays during the year to allow for “passive” variation in shading. The considerable variation in the elevation angle of the sun’s rays (from 24.4° to 71.1°) results in a high variation in shading (from 39.4% to 72.6%), with the highest values in the summer months and the lowest values in the winter months. This trend is favorable for meeting the photosynthetically active radiation (PAR) needs of greenhouse plants. If the plants under cultivation require more solar energy, it is necessary to increase the distance between the panels. We implement a speci?c mathematical relationship to de?ne the precise distance to be assigned to the photovoltaic panels on the roof pitch.
关键词： ?xed horizontal PV panels,passive variation of shading,passive cooling system,PAR,renewable source
更新于2025-09-19 17:13:59