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Energy Loss in Solar Photovoltaic Systems Under Snowy Conditions
Anis Haque,
Namrata Sheth
Issue:
Volume 5, Issue 6, December 2017
Pages:
209-214
Received:
20 October 2017
Accepted:
1 November 2017
Published:
12 December 2017
Abstract: The objective of this study is to quantify the energy loss due to snow on solar photovoltaic systems. Solar photovoltaic systems in cold temperatures have an advantage over warmer regions due to improved efficiencies. However, colder regions generally receive a significant amount of snow, which may hinder the energy output of the photovoltaic systems. For this experimental research, a solar photovoltaic system was set up in Calgary, Canada to analyze and quantify the energy losses due to snow. This research demonstrates a 9% loss in energy yield per year due to snow accumulation in absence of bypass diodes.
Abstract: The objective of this study is to quantify the energy loss due to snow on solar photovoltaic systems. Solar photovoltaic systems in cold temperatures have an advantage over warmer regions due to improved efficiencies. However, colder regions generally receive a significant amount of snow, which may hinder the energy output of the photovoltaic syste...
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A Cascaded Switched-capacitor AC-AC Converter with a Ratio of 1/2n
Jiachuan You,
Qian Guo,
Hui Cai
Issue:
Volume 5, Issue 6, December 2017
Pages:
228-234
Received:
27 December 2017
Published:
28 December 2017
Abstract: Based on the existing AC-AC switched-capacitor (SC) converter, this paper demonstrates a new cascaded AC-AC converter circuit topology with a ratio of 1/2n, which only consists of power switches and capacitors. The converter consists of multi-stage converters and the pre-and post-stage circuits are independent with each other. The principle of the topology and the formula of related parameters, including equivalent resistance, equivalent capacitance and switching loss, are deduced with the port network theory, thus the equivalent circuit is gained in this paper. After the theoretical analysis, simulation models and experimental prototype were established to validate the correctness of the circuit topology. Both simulation and experimental results have verified the effectiveness of the circuit topology and the correctness of the theoretical derivation.
Abstract: Based on the existing AC-AC switched-capacitor (SC) converter, this paper demonstrates a new cascaded AC-AC converter circuit topology with a ratio of 1/2n, which only consists of power switches and capacitors. The converter consists of multi-stage converters and the pre-and post-stage circuits are independent with each other. The principle of the ...
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Research on Maximum Power Point Algorithm Based on Adaptive Duty Cycle
Suting Liang,
Lei Zhao,
Wenjing Wang
Issue:
Volume 5, Issue 6, December 2017
Pages:
235-241
Received:
27 December 2017
Published:
28 December 2017
Abstract: In solar photovoltaic (PV) system it has been a tendency to extract the maximum output power from the PV panel with the decrease of production price. There are many novel control algorithms to track the maximum power point. The commonly used control algorithm is based on perturbation and observation algorithm (P&O). However, the traditional P&O method has some problems between the tracking speed and the control accuracy. In this paper, the mathematic model of photovoltaic cells is studied and a modified perturbation observation method is proposed. The algorithm adjusts the duty cycle step by step according to the variation of the slope of the power voltage curve. Simulink simulation of the PV module with the buck circuit proves the superiority of the variable duty cycle perturbation method in terms of tracking speed and stability compared with the traditional perturbation observation method.
Abstract: In solar photovoltaic (PV) system it has been a tendency to extract the maximum output power from the PV panel with the decrease of production price. There are many novel control algorithms to track the maximum power point. The commonly used control algorithm is based on perturbation and observation algorithm (P&O). However, the traditional P&O met...
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CMOL Based Quaded Transistor NAND Gate Building Block of Robust Nano Architecture
Mohammed Hadifur Rahman,
Shahida Rafique,
Mohammad Shafiul Alam
Issue:
Volume 5, Issue 6, December 2017
Pages:
242-249
Received:
15 June 2017
Accepted:
30 June 2017
Published:
2 January 2018
Abstract: Nano architectures are more prone to defects. This work is aimed at finding the effectiveness of using quaded structure devices to improve the reliability of logic gates in Nano lavel. Transistor level redundancy (Quaded Structure) has been applied in a CMOS gate (NAND) design to improve the reliability. Being an universal gate, NAND gate can be the building block for nano architecture. CMOL is a hybrid architecture that combines conventional CMOS and Nano architecture together. Based on CMOL, a NAND gate design has been proposed. To study the performance of the proposed architecture, theoretical analysis has been proposed. Moreover, to evaluate the effectiveness of the quaded structured NAND (QNAND) gate, detailed simulation was carried out. Simulation results illustrates that quaded structured design achieves significantly higher defect tolerance by enhancing the reliability of the QNAND gate.
Abstract: Nano architectures are more prone to defects. This work is aimed at finding the effectiveness of using quaded structure devices to improve the reliability of logic gates in Nano lavel. Transistor level redundancy (Quaded Structure) has been applied in a CMOS gate (NAND) design to improve the reliability. Being an universal gate, NAND gate can be th...
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