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1
Content available On the capacity of solar cells under partial shading conditions
Bartczak Mateusz
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
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2021
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T. 11, nr 4
47--50
PL
O pojemności ogniw fotowoltaicznych w warunkach częściowego zaciemnienia
2
Content available Development of rapid and reliable cuckoo search algorithm for global maximum power point tracking of solar PV systems in partial shading condition
Bentata Khadidja, Mohammedi Ahmed, Benslimane Tarak
Archives of Control Sciences
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2021
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Vol. 31, No. 3
495--526
EN
The solar photovoltaic output power fluctuates according to solar irradiation, temperature, and load impedance variations. Due to the operating point fluctuations, extracting maximum power from the PV generator, already having a low power conversion ratio, becomes very complicated. To reach a maximum power operating point, a maximum power point tracking technique (MPPT) should be used. Under partial shading condition, the nonlinear PV output power curve contains multiple maximum power points with only one global maximum power point (GMPP). Consequently, identifying this global maximum power point is a difficult task and one of the biggest challenges of partially shaded PV systems. The conventional MPPT techniques can easily be trapped in a local maximum instead of detecting the global one. The artificial neural network techniques used to track the GMPP have a major drawback of using huge amount of data covering all operating points of PV system, including different uniform and non-uniform irradiance cases, different temperatures and load impedances. The biological intelligence techniques used to track GMPP, such as grey wolf algorithm and cuckoo search algorithm (CSA), have two main drawbacks; to be trapped in a local MPP if they have not been well tuned and the precision-transient tracking time complex paradox. To deal with these drawbacks, a Distributive Cuckoo Search Algorithm (DCSA) is developed, in this paper, as GMPP tracking technique. Simulation results of the system for different partial shading patterns demonstrated the high precision and rapidity, besides the good reliability of the proposed DCSA-GMPPT technique, compared to the conventional CSA-GMPPT.
3
Content available Maximizing power output of a partially shaded total-cross-tied photovoltaic array
Shah N. S., Patel H. H.
Transactions on Environment and Electrical Engineering
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2017
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Vol. 2, No. 1
10--18
EN
Non-uniform conditions on the modules of the PV array, especially, partial shading reduces the output of the PV array to a large extent. The shaded module in a string limits the current of the entire string and hence, the output power of the string. The output power under such conditions is reported to be higher for total-cross-tied (TCT) configuration. This paper describes two different approaches, one based on current compensation (current equalization) and another based on voltage equalization, to extract higher power from the partially shaded total-cross-tied photovoltaic array. The TCT configuration is considered to minimize the number of converters, sensors, cost and complexity involved. The additional converters in the two distinct approaches evaluated here operate only when the partial shading occurs and are controlled to minimize the current and voltage miss-matches. The analysis and the control algorithm are presented. Simulation results obtained in MATLAB/Simulink are included to demonstrate the effectiveness of both methods and the relative merits and demerits of these approaches are highlighted.
4
Content available Hybrid MPPT algorithm for PV systems under partially shaded conditions using a stochastic evolutionary search and a deterministic hill climbing
Basiński K., Ufnalski B., Grzesiak L. M.
Power Electronics and Drives
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2017
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Vol. 2 (37), No. 2
49--59
EN
A hybrid maximum power point tracking method has been proposed for the photovoltaic system using a stochastic evolutionary search and a deterministic hill climbing algorithm. The proposed approach employs the particle swarm optimizer (PSO) to solve a dynamic optimization problem related to the control task in a PV system. The position of the best particle is updated by the hill climbing algorithm, and the position of the rest of the particles by the classic PSO rule. The presented method uses the re-randomization mechanism, which places five consecutive particles randomly, but in specified intervals. This mechanism helps track the maximum power point under partially shaded conditions.
5
Content available Partial Shading Detection in Solar System Using Single Short Pulse of Load
Bartczak M.
Metrology and Measurement Systems
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2017
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Vol. 24, nr 1
193--199
EN
A single photovoltaic panel under uniform illumination has only one global maximum power point, but the same panel in irregularly illuminated conditions can have more maxima on its power-voltage curve. The irregularly illuminated conditions in most cases are results of partial shading. In the work a single short pulse of load is used to extract information about partial shading. This information can be useful and can help to make some improvements in existing MPPT algorithms. In the paper the intrinsic capacitance of a photovoltaic system is used to retrieve occurrence of partial shading.
6
Content available A hybrid maximum power point search method using temperature measurements in partial shading conditions
Mroczka J., Ostrowski M.
Metrology and Measurement Systems
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2014
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Vol. 21, nr 4
733--740
EN
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.
7
Content available remote A grid-connected PV power system total considers the MPPT and SSRF-SPLL control technologies
Liu L. Q., Liu C. X.
Przegląd Elektrotechniczny
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2013
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R. 89, nr 3a
171--173
EN
At present, an optimal maximum power tracking (MPPT) and grid-connected control methods for a PV power system are very important to improve the output efficiency. However, most of literatures only introduce the MPPT or PLL method, respectively. A novel MPPT method is proposed by improving the convention perturbation and observation (P&O) method in this paper, which can track the real peak of PV array at different irradiation and partial shading. To analyze the locked performance, the Single Synchronous Reference Frame Software Phase Locked Loop (SSRFSPLL) is discussed at different grid faults such as single-phase voltage drop, two phase voltage drop, and frequency discontinuity.
PL
W artykule przedstawiono algorytm MPPT oparty na zmodyfikowanej metodzie perturbacji i obserwacji, umożliwiający śledzenie punktu mocy maksymalnej zespołu paneli PV w warunkach niejednorodnego nasłonecznienia i częściowego zacienienia. W celu analizy działania systemu podłączonego do sieci elektroenergetycznej, zastosowano algorytm synchronizacji fazowej PLL o pojedynczej ramce.
8
Content available remote MATLAB-based DC voltage superposition principle to study the output characteristics of PV array at partial shading
Liu L. Q., Sun Z. Y., Liu C.X.
Przegląd Elektrotechniczny
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2012
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R. 88, nr 12a
284-286
EN
Power-voltage characteristics of large scale photovoltaic (PV) arrays at partial shading are characterized by multiple steps and peaks. Most of the existing schemes are unable to accurately predict the output performance of PV array under these conditions. A Matlab-based DC voltage superposition principle is used in studying the output characteristic of a PV array under a non-uniform irradiation due to partial shading. It is observed that, for a given PV array configuration, the actual maximum power point can be gained by using the DC voltage superposition principle. The method has been experimentally validated by using several illustrative examples.
PL
W artykule opisano metodę wyznaczania charakterystyki moc-napięcie dla matryc fotowoltaicznych w warunkach nierównomiernego naświetlenia, na podstawie zasady superpozycji napięć DC w programie Matlab. Korzystając z tej metody można określić punkt mocy maksymalnej, co wykazano badaniami eksperymentalnymi.
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