scholarly journals Power Enhancement under Partial Shading Condition Using a Two-Step Optimal PV Array Reconfiguration

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Mohamad Hossien Nahidan ◽  
Mehdi Niroomand ◽  
Behzad Mirzaeian Dehkordi
Keyword(s):  
Large Scale ◽  
Short Circuit ◽  
Optimal Solution ◽  
Dynamic Reconfiguration ◽  
Short Circuit Current ◽  
Step Method ◽  
Partial Shading ◽  
Pv Array ◽  
Improved Performance ◽  
Mismatch Losses

Under partial shading conditions, photovoltaic (PV) arrays are subjected to different irradiance levels caused by nonuniform shading. As a result, a mismatch between the modules, a reduction in the power generated, and the hotspot phenomenon will be observed. One method to reduce mismatch losses is to reconfigure the total-cross-tied (TCT) array in dynamic and static forms, where improved performance can be achieved through more efficient shading distribution thanks to increased dimensions. However, the increase in dimensions leads to the complexity of wiring and installation in static reconfiguration and the large number of switches and sensors required in dynamic reconfiguration. To rectify these problems, a two-step method is proposed in this paper. In the first step, the modules inside the PV array are divided into subarrays with wiring in static reconfiguration, rather than being wired as large-scale PV arrays. In the second step, an algorithm is developed for dynamic reconfiguration. The introduced algorithm searches for all possible connections and finally identifies the most optimal solution. As an advantage, this algorithm employs only the short-circuit current values of the subarray rows, which reduces the number of switches and sensors required in comparison to dynamic reconfiguration. Under 8 different partial shading patterns, simulations are conducted and results confirm that the proposed method outperforms the TCT array and statically modified TCT array in terms of power and mismatch losses. Among these, the highest power improvement is obtained with regard to the TCT array and statically modified TCT array under the fourth and eighth shading patterns, respectively.

scholarly journals A Fault Detection Method for Photovoltaic Systems Based on Voltage and Current Observation and Evaluation

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1712 ◽  
Author(s):  
Tingting Pei ◽  
Xiaohong Hao
Keyword(s):  
Fault Detection ◽  
Detection Method ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Current Data ◽  
Partial Shading ◽  
Pv Array ◽  
Current Observation ◽  
Power Point

Photovoltaic (PV) power generation systems work chronically in various climatic outdoor conditions, therefore, faults may occur within the PV arrays in PV systems. Online fault detection for the PV arrays are important to improve the system’s reliability, safety and efficiency. In view of this, a fault-detection method based on voltage and current observation and evaluation is presented in this paper to detect common PV array faults, such as open-circuit, short-circuit, degradation and shading faults. In order to develop this detection method, fault characteristic quantities (e.g., the open-circuit voltage, short-circuit current, voltage and current at the maximum power point (MPP) of the PV array) are identified first to define the voltage and current indicators; then, the fault-detection thresholds are defined by utilizing voltage and current indicators according to the characteristic information of various faults; finally, voltage and current indicators evaluated at real-time voltage and current data are compared with the corresponding thresholds to detect potential faults and fault types. The performances of the proposed method are simulated verifying by setting eight different fault patterns in the PV array. Simulation experimental results show the effectiveness of the proposed method, especially the capacities of distinguishing the degradation faults, partial shading faults and variable shading faults.

Research of Large-Scale Offshore Wind Farm Collection System Short Circuit Equivalent Network

2013 ◽  
Vol 448-453 ◽  
pp. 1732-1737
Author(s):  
Liu Bin ◽  
Hong Wei Cui ◽  
Li Xu ◽  
Kun Wang ◽  
Zhu Zhan ◽  
...  
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Short Circuit ◽  
Short Circuit Current ◽  
System Optimization ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Collection System ◽  
Medium Voltage ◽  
The Impact

This paper analyses the characteristics of large-scale offshore wind farm collection network and the impact of the medium voltage collection system optimization,while from the electrical technology point,it proposes the short circuit current of the collection network computational model and algorithms,based on the principle of equivalent circuit.Taking a wind power coolection system planned for a certain offshore wind farm planning for example, the validity of the model and algorithm is verified.

Effects of Partial Shading on the PV Module Characteristic Curves

2010 ◽  
Vol 670 ◽  
pp. 391-398 ◽  
Author(s):  
Eva Paraskevadaki ◽  
S. Papathanassiou ◽  
Georgios Vokas
Keyword(s):  
System Performance ◽  
Significant Contribution ◽  
Photovoltaic System ◽  
Partial Shading ◽  
Array Configuration ◽  
Module Design ◽  
Pv Array ◽  
Pv Module ◽  
Pv Generator ◽  
Mismatch Losses

Photovoltaic system performance is influenced by a variety of factors such as irradiance, temperature, shading, degradation, mismatch losses, soiling, etc. Especially shading, complete or partial, can have a significant contribution to the reduction of power output, depending mainly on the PV array configuration, the shading pattern and the existence of bypass diodes incorporated in the PV module design. In order to obtain the maximum power from a PV generator, it is of great importance to evaluate the complex effects of shading on the P-V and I-V curves.

A Solar Cell Made by a Hybrid Film of P3HT and Cubic-Like PbS

2012 ◽  
Vol 479-481 ◽  
pp. 166-169
Author(s):  
Peng Wang ◽  
Li Bo Fan ◽  
Zhen Hua Zhang ◽  
Yan Lei ◽  
Yan Ge Zhang ◽  
...  
Keyword(s):  
Solar Cell ◽  
Large Scale ◽  
Near Infrared ◽  
Hybrid Film ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Special Treatment ◽  
X Ray Diffraction ◽  
Ft Ir

Cubic-like lead sulfide (PbS) films were in situ fabricated on lead (Pb) foil on a large scale by solvothermal method. Ethanol and ethylenediamine were used as the solvent. The films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), absorption and the Fourier transformation-infrared (FT-IR) spectra. A solar cell was made by the hybrid film of P3HT and cubic-like PbS. The solar cells are photosensitive in a large spectral range (visible and near infrared regions). The cell with the area of 0.20 cm2 without any special treatment has shown the values of open-circuit voltage (Voc) of 250 mV and short circuit current (Jsc) of 0.01 mA/cm2 with the efficiency of 0.01 % and the fill factor (FF) is 0.36 under illumination intensity of 100 mW/cm2.

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