Photovoltaic chain operation analysis in condition of partial shading for systems with and without bypass diodes

Optik ◽  
2021 ◽  
Vol 247 ◽  
pp. 167840
Author(s):  
Wojciech Kreft ◽  
Estera Przenzak ◽  
Mariusz Filipowicz
Author(s):  
Raysa Aleyzia ◽  
Hasan Yudie Sastra

Manajemen supply chain yang tidak maksimal akan mempengaruhi kinerja suatu perusahaan. Di Aceh Tengah terdapat suatu koperasi yaitu Koperasi Baitul Qiradh (KBQ) Baburrayyan yang sudah menerapkan manajemen supply chain. Koperasi ini bergerak di bisnis perdagangan biji kopi (green bean). Penelitian ini bertujuan untuk mengukur kinerja supply chain dari KBQ Baburrayyan. Metode yang digunakan adalah SCOR® dengan praktik perbaikan Convergence of SCOR® with Lean and Six Sigma. Target kinerja yang diperoleh untuk total cost to serve adalah sebesar 94,71% dari nilai target 65,00% dan untuk return on supply chain fixed asset adalah sebesar 1,60 dari nilai target 2,50. Hasil yang diperoleh dari penggunaan praktik tersebut adalah terdapat 8 akar penyebab waste di antaranya kurangnya tenaga pengawas, training/briefing belum maksimal, kurangnya kepedulian tentang pentingnya K3, layout yang kurang efisien, belum adanya unit penyuluhan, alat yang masih sederhana, pekerjaan yang monoton, dan tidak dilarang secara tegas.   Supply chain management that is not optimal will affect the performance of a company. In Central Aceh there is a cooperative namely Koperasi Baitul Qiradh (KBQ) Baburrayyan which has implemented supply chain management. This cooperative is engaged in the business of trading in green beans. This study aims to measure the supply chain performance of KBQ Baburrayyan. The method used is SCOR® with the practice of improving Convergence of SCOR® with Lean and Six Sigma. The performance target for total cost to serve is 94.71% of the target value of 65.00% and the return on supply chain fixed assets is 1.60 of the target value of 2.50. The results obtained from the use of the practice are that there are 8 root causes of waste including lack of supervisors, training / briefing is not maximal, lack of concern about the importance of K3, inefficient layouts, absence of extension units, simple tools, monotonous work, and not strictly prohibited.


2021 ◽  
Vol 40 (1) ◽  
pp. 49-62
Author(s):  
Abdelrahman M. Mohamed ◽  
Abou-Hashima M. El-Sayed ◽  
Yehia S. Mohamed ◽  
Husam A. Ramadan

2020 ◽  
Vol 14 (2) ◽  
pp. 194-204
Author(s):  
Anuradha Tomar

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.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1121
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

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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