Integration into Undergraduate Courses of Transformer Tests Using MATLAB/Simulink

2007 ◽  
Vol 44 (4) ◽  
pp. 319-332 ◽  
Author(s):  
A. F. Zobaa ◽  
T. A. Boghdady
Keyword(s):  
Short Circuit ◽  
Equivalent Circuit Model ◽  
Simulation Models ◽  
Voltage Regulation ◽  
Open Circuit ◽  
Load Test ◽  
Undergraduate Level ◽  
Test Efficiency ◽  
Electric Machinery ◽  
Load Circuit

This paper is concerned with determining the element parameters of the equivalent circuit model of the transformer. Short circuit, open circuit and load circuit tests will be applied to determine these parameters. The viability of the model can then be checked against the results of a load test. Efficiency and voltage regulation can then be determined from the data. These simulation models are developed to support and enhance electric machinery education at the undergraduate level.

scholarly journals A NEW AND SUSTAINABLE PKL ELECTRICITY

2021 ◽  
Author(s):  
K. A. Khan ◽  
Shahinul Islam ◽  
M. A. Saime ◽  
S. R. Rasel ◽  
Sazzad Hossain
Keyword(s):  
Rural Areas ◽  
Electricity Generation ◽  
Short Circuit ◽  
Storage System ◽  
Research Work ◽  
Titratable Acidity ◽  
Voltage Regulation ◽  
Open Circuit ◽  
Electricity Production ◽  
Maximum Efficiency

A new method of electricity generation based on Pathor Kuchi Leaf (Genus: Kalanchoe, Section: Bryophyllum) has been developed at the Department of Physics, Jagannath University, Dhaka- 1100, Bangladesh. This electricity generation method has several advantages for smart grid over the conventional electricity production. This sustainable method is likely to generate the employment at particularly in the rural areas of where grid electricity is absent. This research work reports an invention made on Pathor Kuchi Leaf (PKL) electric power plant to enhance the PKL electricity production. The efficiency of the PKl electricity production device, Short Circuit Current ( Isc ), Open circuit Voltage ( Voc ), Temperature effect of the PKL malt, pH of the PKL malt, Titratable acidity of the PKL malt, Generation of PKL electricity, Storage system of the PKL electricity, Particular utilization of PKL electricity, I-V characteristics of the PKL, Classification of PKL, Longevity of PKL malt for PKL electricity generation, Preparation of PKL electric unit cell, module, panel, arrays and the constituent elements of the PKL, Voltage regulation, Internal resistance of the cell and efficiency of the cell have been studied. The chemical reactions of the PKL electrochemical cell have also been studied. In experimental study, it is shown that the maximum efficiency of the PKL electricity production device is ≈ 34%, the pH of the PKL malt is ≈ 4.6(without water), pH of the PKL malt is ≈ 4.8 (with 10% solution), the titratable acidity of the PKL malt is ≈ 0.88%. Most of the results have been tabulated and graphically discussed.

scholarly journals Grid-like Vibration Measurements on Power Transformer Tank during Open-Circuit and Short-Circuit Tests

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 492
Author(s):  
Karlo Petrović ◽  
Antonio Petošić ◽  
Tomislav Župan
Keyword(s):  
Power Transformer ◽  
Short Circuit ◽  
Frequency Component ◽  
Open Circuit ◽  
Load Test ◽  
Mode Shapes ◽  
Vibration Velocity ◽  
Tank Wall ◽  
Vibration Measurements ◽  
Short Circuit Test

In this work, the vibrations on the surfaces of the tank wall, stiffeners, and the cover of a 5 MVA transformer experimental model were measured during open-circuit and short-circuit transformer tests. Vibration measurements of a transformer tank side were conducted at discrete points using two different voltage sources in no-load test. Using interpolation functions, the RMS values of acceleration and vibration velocity are visualized and compared for each considered measurement configuration (no-load and load tests and two different excitation sources). Significant differences in mode shapes and amplitudes of vibrations at different frequencies are observed. The maximum RMS values of acceleration, velocity and displacement in the open-circuit test are 0.36 m/s2, 0.31 mm/s, and 0.42 µm, respectively. The maximum values in short-circuit test are 0.74 m/s2, 1.14 mm/s, and 1.8 µm, respectively. In the short-circuit test, the frequency component of 100 Hz is dominant. In the open-circuit test, the first few 100 Hz harmonics are significant (100 Hz, 200 Hz, and 300 Hz). In addition to the visualization of RMS values during the open-circuit and short-circuit tests, animations of the vibrations are created. Fourier analysis and phase comparison between frequency components are also used to show vibration animations at dominant frequencies in the spectrum (100 Hz harmonics). The visualization of the vibrations at the tank wall surfaces is transferred into 3D space in such a way that all 15 surfaces are mapped to the spatial coordinates of the surfaces so that a 3D model of the acceleration, vibration velocity, and displacement of the transformer tank is shown.

A Novel Method for Measuring the Open-Circuit Loss and Short–Circuit Loss of Distribution Transformers Online

2011 ◽  
Vol 128-129 ◽  
pp. 473-477
Author(s):  
Xia Li ◽  
Min You Chen ◽  
Shan Cheng
Keyword(s):  
Short Circuit ◽  
Equivalent Circuit Model ◽  
Cost Effective ◽  
Measuring Method ◽  
Open Circuit ◽  
The Novel ◽  
Distribution Transformers ◽  
Novel Method ◽  
Circuit Loss ◽  
Circuit Impedance

The paper proposes a novel method for online measuring the open-circuit loss (OCL) and the short-circuit loss (SCL) of distribution transformer DT, based on the consideration of the drawbacks of the offline measuring method, which is regarded as the mainly and traditionally used methods for measuring the OCL and the SCL of DT. The novel method avoids the drawbacks of the offline method which is not cost-effective and is not good for the reliability of the power supply. Firstly, the relation expression of the short-circuit impedance with respect to the voltage and current of the primary and secondary side is developed from the analysis of the equivalent circuit model of DT, and the relations between the SCL and OCL and the short-circuit impedance are also deduced according to power balance. Then, the online short-circuit impedance is computed by using linear regression technique and the value of online voltage and current of DT. Furthermore, according to the developed relations, the online OCL and the SCL of DT can be acquired by using the obtained short-circuit impedance. Numerical simulations have been carried out on Matlab/smulink and results verified feasibility and effectiveness of the novel method for online measuring the OCL and the SCL of DT.

Study on the Output Characteristics of Organic Photovoltaic Cells

2011 ◽  
Vol 347-353 ◽  
pp. 1314-1317
Author(s):  
Zhi You Zhong ◽  
C.Y. Yang ◽  
J.H. Gu
Keyword(s):  
Quality Factor ◽  
Open Circuit Voltage ◽  
Series Resistance ◽  
Short Circuit ◽  
Equivalent Circuit Model ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Organic Photovoltaic ◽  
Shunt Resistance ◽  
Output Characteristics

Based on the analysis of the equivalent circuit model of organic photovoltaic (OPV) cells, the explicit expression of current, short-circuit current and open-circuit voltage was obtained by means of W-function, and the effects of internal resistances and diode quality factor on the output characteristics of OPV cells were studied. The results demonstrate that the series resistance can effect short-circuit current but not open-circuit voltage, and the shunt resistance and diode quality factor can influence open-circuit voltage but short-circuit current unchanged. The decrease in series resistance and the increase in shunt resistance and diode quality factor can enhance the fill factor and energy conversion efficiency of OPV cells. This conclusion is essential in preparing OPV cells and improving device performance.

scholarly journals The Reliability Analysis of PV Panels Installed in KP Region

2020 ◽  
Vol 7 (10) ◽  
pp. 384-389
Author(s):  
Jawad Ahmad ◽  
Keyword(s):  
Short Circuit ◽  
Equivalent Circuit Model ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic System ◽  
Photovoltaic Module ◽  
Pv System ◽  
Peak Voltage ◽  
Pv Module ◽  
Term Performance

Reliability and long term performance of photovoltaic (PV) system is of vital importance in switching from conventional sources to sustainable one. Design, study and analysis of key components in a photovoltaic power system starting from generation of power to withstands number of climatic stresses and uninterrupted power supply plays a key role. One of the key elements in photovoltaic system is photovoltaic module. Also power generated in photovoltaic system is dependent on a source of energy that changes in every instant and with the passage of time during its operation .Hence it is paramount to build a long lasting photovoltaic module and analyze characteristics of the PV module under various conditions. This paper presents an efficient PV module based on PV equivalent circuit model using MATLAB/Simulink, and compared the simulated model results with manufacturer’s specifications like peak current, peak voltage, open circuit voltage and short circuit current .Also the performance of the module under variation of series resistance, irradiation, and temperature are analyzed. Data from five different areas across KP are noted and the results were Simulated and compared with the rated data.

Kinetics of Light-Induced Effects in Mixed-Phase Hydrogenated Silicon Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Guozhen Yuea ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Equivalent Circuit Model ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Initial Increase ◽  
Soaking Time ◽  
Hydrogenated Silicon ◽  
Kinetics Of

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.

Lock-in Thermography-Based Local Efficiency Analysis of Solar Cells

2012 ◽  
Author(s):  
Otwin Breitenstein
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Efficiency Analysis ◽  
Open Circuit ◽  
Local Defect ◽  
Whole Cell ◽  
Local Efficiency ◽  
Cell Efficiency ◽  
Lock In ◽  
Efficiency Data

Abstract The electronic properties of solar cells, particularly multicrystalline silicon-based ones, are distributed spatially inhomogeneous, where regions of poor quality may degrade the performance of the whole cell. These inhomogeneities mostly affect the dark current-voltage (I-V) characteristic, which decisively affects the efficiency. Since the grid distributes the local voltage homogeneously across the cell and leads to lateral balancing currents, local light beam-induced current methods alone cannot be used to image local cell efficiency parameters. Lock-in thermography (LIT) is the method of choice for imaging inhomogeneities of the dark I-V characteristic. This contribution introduces a novel method for evaluating a number of LIT images taken at different applied biases. By pixel-wise fitting the data to a two diode model and taking into account local series resistance and short circuit current density data, realistically simulated images of the other cell efficiency parameters (open circuit voltage, fill factor, and efficiency) are obtained. Moreover, simulated local and global dark and illuminated I-V characteristics are obtained, also for various illumination intensities. These local efficiency data are expectation values, which would hold if a homogeneous solar cell had the properties of the selected region of the inhomogeneous cell. Alternatively, also local efficiency data holding for the cell working at its own maximum power point may be generated. The amount of degradation of different cell efficiency parameters in some local defect positions is an indication how dangerous these defects are for degrading this parameter of the whole cell. The method allows to virtually 'cut out' certain defects for checking their influence on the global characteristics. Thus, by applying this method, a detailed local efficiency analysis of locally inhomogeneous solar cells is possible. It can be reliably predicted how a cell would improve if certain defects could be avoided. This method is implemented in a software code, which is available.

Calcium transport in turtle bladder

1987 ◽  
Vol 253 (6) ◽  
pp. R917-R921
Author(s):  
S. Sabatini ◽  
N. A. Kurtzman
Keyword(s):  
Calcium Transport ◽  
Calcium Absorption ◽  
Short Circuit ◽  
Open Circuit ◽  
Calcium Flux ◽  
Bladder Epithelium ◽  
Control Value ◽  
Sodium Calcium ◽  
Turtle Bladder ◽  
Absorptive Flux

Unidirectional 45Ca fluxes were measured in the turtle bladder under open-circuit and short-circuit conditions. In the open-circuited state net calcium flux (JnetCa) was secretory (serosa to mucosa) and was 388.3 +/- 84.5 pmol.mg-1.h-1 (n = 20, P less than 0.001). Ouabain (5 X 10(-4) M) reversed JnetCa to an absorptive flux (serosal minus mucosal flux = -195.8 +/- 41.3 pmol.mg-1.h-1; n = 20, P less than 0.001). Amiloride (1 X 10(-5) M) reduced both fluxes such that JnetCa was not significantly different from zero. Removal of mucosal sodium caused net calcium absorption; removal of serosal sodium caused calcium secretion. When bladders were short circuited, JnetCa decreased to approximately one-third of control value but remained secretory (138.4 +/- 54.3 pmol.mg-1.h-1; n = 9, P less than 0.025). When ouabain was added under short-circuit conditions, JnetCa was similar in magnitude and direction to ouabain under open-circuited conditions (i.e., absorptive). Tissue 45Ca content was approximately equal to 30-fold lower when the isotope was placed in the mucosal bath, suggesting that the apical membrane is the resistance barrier to calcium transport. The results obtained in this study are best explained by postulating a Ca2+-ATPase on the serosa of the turtle bladder epithelium and a sodium-calcium antiporter on the mucosa. In this model, the energy for calcium movement would be supplied, in large part, by the Na+-K+-ATPase. By increasing cell sodium, ouabain would decrease the activity of the mucosal sodium-calcium exchanger (or reverse it), uncovering active calcium transport across the serosa.

scholarly journals Wavelet Transform Based Fault Identification and Reconfiguration for a Reduced Switch Multilevel Inverter Fed Induction Motor Drive

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1023
Author(s):  
Arigela Satya Veerendra ◽  
Akeel A. Shah ◽  
Mohd Rusllim Mohamed ◽  
Chavali Punya Sekhar ◽  
Puiki Leung
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Short Circuit ◽  
Open Circuit ◽  
Multilevel Inverter ◽  
Fault Identification ◽  
Discrete Wavelet ◽  
The Novel ◽  
Inverter Topology

The multilevel inverter-based drive system is greatly affected by several faults occurring on switching elements. A faulty switch in the inverter can potentially lead to more losses, extensive downtime and reduced reliability. In this paper, a novel fault identification and reconfiguration process is proposed by using discrete wavelet transform and auxiliary switching cells. Here, the discrete wavelet transform exploits a multiresolution analysis with a feature extraction methodology for fault identification and subsequently for reconfiguration. For increasing the reliability, auxiliary switching cells are integrated to replace faulty cells in a proposed reduced-switch 5-level multilevel inverter topology. The novel reconfiguration scheme compensates open circuit and short circuit faults. The complexity of the proposed system is lower relative to existing methods. This proposed technique effectively identifies and classifies faults using the multiresolution analysis. Furthermore, the measured current and voltage values during fault reconfiguration are close to those under healthy conditions. The performance is verified using the MATLAB/Simulink platform and a hardware model.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

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