Value of module efficiency in real operating conditions for low energy cost PV systems

Author(s):  
Xiaoting Wang ◽  
Allen Barnett
Author(s):  
Mostafa Ahmed ◽  
Ibrahim Harbi ◽  
Ralph Kennel ◽  
Mohamed Abdelrahem

AbstractPhotovoltaic (PV) power systems are integrated with high penetration levels into the grid. This in turn encourages several modifications for grid codes to sustain grid stability and resilience. Recently, constant power management and regulation is a very common approach, which is used to limit the PV power production. Thus, this article proposes dual-mode power generation algorithm for grid-connected PV systems. The developed system considers the two-stage PV configuration for implementation, where the dual-mode power generation technique is executed within the DC–DC conversion (boost) stage. Most of the techniques adopted for dual-mode power operation employ the conventional perturb and observe method, which is known with unsatisfactory performance at fast-changing atmospheric conditions. Considering this issue, this study suggests a modified maximum power point tracker for power extraction. Furthermore, a new adaptive DC-link controller is developed to improve the DC-link voltage profile at different operating conditions. The adaptive DC-link controller is compared with the traditional PI controller for voltage regulation. The inverter control is accomplished using finite-set model predictive control with two control objectives, namely reference current tracking and switching frequency minimization. The overall control methodology is evaluated at different atmospheric and operating conditions using MATLAB/Simulink software.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.


RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94895-94902 ◽  
Author(s):  
Cheng Ma ◽  
Yuehong Shu ◽  
Hongyu Chen

A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting method, is proposed for treating components of spent lead acid batteries with oxalate and sodium oxalate.


Author(s):  
Mariusz Jasiński ◽  
Jerzy Mizeraczyk ◽  
Zenon Zakrzewski

AbstractResults of the study of decomposition of volatile organic compounds (VOCs including Freons) in their mixtures with either synthetic air or nitrogen, and nitrogen oxides NOx in their mixtures with N2 or Ar in low (~ 100 W) and moderate-power (200-400 W) microwave torch plasmas at atmospheric pressure are presented. Three types of microwave torch discharge (MTD) generators, i.e. the low-power coaxial-line-based MID, the moderate-power waveguide-based coaxial-line MTD and the moderate-power waveguide-based MTD generators were used. The gas flow rate and microwave power (2.45 GHz) delivered to the discharge were in the range of 1÷3 l/min and 100÷ 400 W, respectively. Concentrations of the processed gaseous pollutants usually were from several up to several tens percent. The energy efficiency of decomposition of several gaseous pollutants reached 1000 g/kWh. It was found that the microwave torch plasmas fully decomposed the pollutants at relatively low energy cost. This suggests that the MTD plasma can be a useful tool for decomposition of highly-concentrated gaseous pollutants.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Peijie Lin ◽  
Yaohai Lin ◽  
Zhicong Chen ◽  
Lijun Wu ◽  
Lingchen Chen ◽  
...  

Fault diagnosis of photovoltaic (PV) arrays plays a significant role in safe and reliable operation of PV systems. In this paper, the distribution of the PV systems’ daily operating data under different operating conditions is analyzed. The results show that the data distribution features significant nonspherical clustering, the cluster center has a relatively large distance from any points with a higher local density, and the cluster number cannot be predetermined. Based on these features, a density peak-based clustering approach is then proposed to automatically cluster the PV data. And then, a set of labeled data with various conditions are employed to compute the minimum distance vector between each cluster and the reference data. According to the distance vector, the clusters can be identified and categorized into various conditions and/or faults. Simulation results demonstrate the feasibility of the proposed method in the diagnosis of certain faults occurring in a PV array. Moreover, a 1.8 kW grid-connected PV system with6×3 PVarray is established and experimentally tested to investigate the performance of the developed method.


2018 ◽  
Vol 6 (42) ◽  
pp. 21104-21109 ◽  
Author(s):  
Cheng Chen ◽  
Dan Liu ◽  
Jiemin Wang ◽  
Lifeng Wang ◽  
Jianhua Sun ◽  
...  

Multipurpose and super-stable molecular sieving membranes exhibit great potential for mixture separation at low energy cost within extreme chemical and thermal environments.


1985 ◽  
Vol 38 (11) ◽  
pp. 1585 ◽  
Author(s):  
NV Riggs

By optimization with the 3-21G basis set, pyrrolidin-2-one is found clearly to prefer an envelope conformation with the flap bent 27.4° out of the NC(=O)C reference plane. The ring may be bent or twisted through a few degrees at low energy-cost, and undergoes rapid inversion through a planar-ring structure lying only 3.3 kJ mol-1 above the preferred equilibrium structure.


2016 ◽  
Vol 87 (17) ◽  
pp. 2066-2075 ◽  
Author(s):  
ZH Zhang ◽  
ZQ Xu ◽  
XX Huang ◽  
XM Tao

This paper reports an investigation of dyeing processes of textiles made from a novel 100% bio-based and fully degradable polylactide/poly (hydroxybutyrate-co-hydroxyvalerate) (PLA/PHBV) fiber. The dye exhaustion, depth of shade and fastness, as well as bursting strength of dyed PLA/PHBV fabrics have been evaluated in terms of types and concentration of dyestuff, dyeing bath temperature, duration, liquor ratio and pH value. Finally, the energy cost of the whole dyeing process of the proposed material is calculated and compared with that of polyethylene terephthalate. The experimental results show that an excellent dyeing effect and bursting strength can be achieved by properly applied dyes (e.g. C.I. Disperse Orange 30, Red 74, and Blue 79) under optimal low-dyeing-temperature conditions (100℃, 10 min, pH 5, LR 30:1). In addition, considering the low energy cost during the whole process, PLA/PHBV fibers can be regarded as a promising and environment-friendly material for the textile industry.


2011 ◽  
Vol 233-235 ◽  
pp. 1708-1713
Author(s):  
Xiang Xue Zhu ◽  
Fu Cun Chen ◽  
Jie An ◽  
Peng Zeng ◽  
Long Ya Xu

This article demonstrates the design and industrial operation results of the ethylbenzene(EB) production technology from FCC dry gas by a combination of gas-phase alkylation and liquid-phase transalkylation, developed and commercialized by Dalian Institute of Chemical Physics (DICP), CAS. Based on the high active modified ZSM-5/ZSM-11 co-crystalline zeolite alkylation catalyst and modified β zeolite transalkylation catalyst, both the alkylation and transalkylation reactions are performed under much milder conditions, resulting in low energy cost and low content of xylenes impurities in the EB product. Also, the novel process for EB production, developed by DICP recently, through alkylation of dilute ethylene with gas-liquid mixed phase benzene and transalkylation feed is optimized. The results show that the transalkylation feed addition into the middle-lower part of the reactor improves the EB selectivity from about 90% to more than 99%, and the alkylation and transalkylation reactions are unified into a single reactor. Moreover, the alkylation reaction temperature decreases from more than 320 °C to about 170 °C, and the content of the xylenes impurities in the EB product is further decreased to less than 100 ppm.


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