scholarly journals Parallel and Series Connection of Dark Electric Current in Liquid and Second Law of Thermodynamics

2021 ◽  
Vol 3 (2) ◽  
pp. 16-18
Author(s):  
Sergey A. Gerasimov
Keyword(s):  
Voltage Drop ◽  
Second Law Of Thermodynamics ◽  
Electrical Energy ◽  
Load Resistance ◽  
Internal Resistance ◽  
Multiple Sources ◽  
Weak Source ◽  
In Series ◽  
Spiral Shape ◽  
Aluminum Electrodes

Liquid in contact with two asymmetrical spiral-shape aluminum electrodes behaves like a still weak source of electrical energy. Almost the only way to increase the efficiency of such a source of electrical energy is to reduce internal resistance. Reducing internal resistance is equivalent to using multiple sources of electrical energy connected in series or in parallel. To check this for such unusual sources it is first necessary to study the properties of each source, which is the voltage drop across the load resistance and the internal resistance of each source. Detailed analysis of experimental data shows that the process of forming the dark current is different from a chemical one.

scholarly journals Switching Regulators Features in the Matching Mode Operation

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Larysa Mykolaivna Batrak ◽  
Volodymyr Yakovych Romashko
Keyword(s):  
Electrical Energy ◽  
Load Resistance ◽  
Power Source ◽  
Internal Resistance ◽  
Maximum Power ◽  
Output Resistance ◽  
Utilization Factor ◽  
Switching Regulator ◽  
Step Down ◽  
Range Of Variation

Currently, various types of non-traditional and renewable sources of electrical energy are widely used. If the energy carrier of such sources is free, in the process of operation it is advisable to select the maximum possible power from them, regardless of the fact that the utilization factor of the source's electrical energy in this case may be relatively low. To obtain the maximum amount of electrical energy from the source, two conditions must be met: 1) the source must be brought to the maximum power point (МPP); 2) energy from the source must be taken continuously. As you know, to bring the source into the MPP, it is necessary that the load resistance be equal to the output resistance of the source. Otherwise, the power will be taken from the source, which is less than the maximum possible. Therefore, in cases where the load resistance differs from the output resistance of the source, a matching switching regulator is turned on between the source and the load to match the output resistance of the source with the load resistance. In this case, the input impedance of the switching regulator will be the load of the source. This resistance depends on the load resistance of the regulator, as well as on the relative time of the closed (open) state of the controlled switch S of the regulator t*. Thus, by adjusting the parameter t*, it is possible to ensure the fulfillment of the condition for removing the source into the MPP at various values of the load resistance. In this case, the maximum possible power of the source will be transferred to the load, regardless of the value of its resistance. The dependence of the output parameters of the switching regulator on the parameter t* describe its regulation characteristics. Since, when operating in the maximum power transmission mode, the internal resistance of the source and the load resistance are of the same order of magnitude, when determining the regulating characteristics of the regulator, the internal resistance of the source must be taken into account. The aim of the work is to analyze the control characteristics of the regulator, which operates in the mode of transferring maximum power from the source of electrical energy to the load, as well as to determine the conditions under which it is possible and advisable to operate in this mode. These issues were analyzed using the example of the two most common switching regulator circuits - step-down and step-up regulators. It is shown in the work that, in contrast to the up-type switching regulator, in the down-type regulator, the energy from the power source is taken in discrete portions. Therefore, it can ensure the selection of maximum power from the source only in the t* = 1 mode at a certain value of the load resistance. To ensure continuous extraction of energy from the source, at the input of the switching regulator of the step-down type, it is necessary to install a capacitance of sufficient value. In this case, the circuit can provide maximum power transfer from the source at different load resistances. The paper presents the adjusting characteristics of the analyzed circuits for the case of their operation in the mode of transferring maximum power from the power source to the load, which makes it possible to determine the parameter t* at which the power source is output to the MPP. It is shown that each of the considered circuits can provide the output of the power supply to the MPP only in a certain range of variation of the load resistance of the regulator. For each regulator, an appropriate range of variation of the t* parameter is indicated, depending on whether the power source is a voltage source or a current source.

Taming the Load Current of Identical Cells in Matrix

2021 ◽  
Vol 03 (04) ◽  
Author(s):  
Seok-In Hong
Keyword(s):  
Short Circuit ◽  
Maximum Load ◽  
Load Resistance ◽  
Relative Magnitude ◽  
Internal Resistance ◽  
Rectangular Array ◽  
Load Current ◽  
The Matrix ◽  
In Series ◽  
Fractional Function

We explore the load current [Formula: see text] for a rectangular array (matrix) of [Formula: see text] identical cells where [Formula: see text] strings (columns) of [Formula: see text] serial cells (rows) are arrayed in parallel. [Formula: see text] is equal to [Formula: see text] with the internal resistance of the cell and the load resistance exchanged. By treating a linear fractional function as a translated inversely-proportional function, we can easily capture the properties of [Formula: see text] and the relative magnitude of [Formula: see text] and [Formula: see text] via their ratio. The limiting behaviors of the load current are discussed beyond the ideal-cell and short-circuit limits. For the given total number of cells, we graphically verify the recent findings on the matrix of cells that produces the maximum load current. Finally, we analyze the possibility of a car starting with lemon cells or AA dry cells in matrix. This work would be useful in creating a high school or university curriculum that unifies identical cells in series, parallel, or matrix.

scholarly journals Modeling of a hybrid energy system, Photovoltaic and Generator (PV/GE) at the Higher Institute of Technology of Mamou, Guinea

2021 ◽  
pp. 10-16
Author(s):  
Ansoumane Sakouvogui ◽  
Amadou Diarra ◽  
Faya Oulare ◽  
Elhadj Ousmane Camara ◽  
Saïdou Barry ◽  
...  
Keyword(s):  
Power Systems ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Energy System ◽  
Solar Irradiation ◽  
Energy Potential ◽  
Hybrid Energy ◽  
Energy Education ◽  
In Series ◽  
Institute Of Technology

This present work was carried out at the Energy Department of the Higher Institute of Technology of Mamou and at the Applied Energy Education and Research Laboratory of the Faculty of Sciences of the Gamal Abdel Nasser University of Conakry, Guinea. Given the solar energy potential available to the continent, Hybrid Photovoltaic Power Systems and Generating Sets could constitute a suitable technological solution for the supply of electrical energy in isolated sites. This study led to the following results: average unfavorable solar irradiation in June (4.16 kWh/m2.d); the building's electrical load balance is 254760 Wh/d; the sizing of the photovoltaic field (the type of panels chosen Cip-60-270, the peak power of the PV field 59435.420 Wp, the number of panels 220 including 2 in series and 110 in parallel); the C4000-48 type inverter-chargers, 62 in number to achieve a power of 40 nickel-cadmium 1.2 V type accumulators in series in 140 batteries connected in parallel, the voltage drop in the cables is between 0.01 and 0.02. The electrical diagram of the installation is done.

Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

Effect of series and parallel combination of photovoltaic thermal collectors on the performances of integrated active solar still

2021 ◽  
pp. 1-28
Author(s):  
G N Tiwari ◽  
Md Meraj ◽  
M.E. Khan ◽  
V K Dwevedi
Keyword(s):  
Water Depth ◽  
Electrical Energy ◽  
Solar Still ◽  
Packing Factor ◽  
Pv Module ◽  
Parallel Arrangement ◽  
Passive Solar Still ◽  
In Series ◽  
Parallel Case ◽  
Operating Temperature Range

Abstract In this paper, an analytical expression for hourly yield, electrical energy and overall exergy of self-sustained solar still integrated with series and parallel combination of photovoltaic thermal-compound parabolic concentrator (PVT-CPC) collectors have been derived. Based on numerical computations, it has been observed that the yield is maximum for all self-sustained PVT-CPC collectors are connected in series [case (i)]. Further, the daily yield and exergy increase with the increase of water depth unlike passive solar still for all collectors connected in series. However, overall exergy decreases with an increase of water depth for all collectors connected in parallel [case (iv)]. For numerical simulations, the total numbers of self-sustained PVT-CPC collectors has been considered as constant. Further, an effect of series and parallel combination of PVT-CPC collectors on daily yield, electrical energy and overall exergy have also been carried out. Following additional conclusions have also been drawn: (i) The daily yield of the proposed active solar still decreases with the increase of packing factor of semi-transparent PV module for a given water depth and electrical energy and overall exergy increase with water depth for case (i) as expected due to low operating temperature range at higher water depth in the basin. (i) The daily yield, electrical energy and overall exergy increase with the increase of water depth for all combination of series and parallel arrangement of PVT-CPC collectors for a packing factor of 0.22 as per our expectation.

scholarly journals OPTIMASI PENEMPATAN KAPASITOR BANK UNTUK PERBAIKAN RUGI DAYA PADA PENYULANG SABA MENGGUNAKAN ALGORITMA GENETIKA

2019 ◽  
Vol 6 (2) ◽  
pp. 7
Author(s):  
I. K. A. Wijaya ◽  
R. S. Hartati ◽  
I W. Sukerayasa
Keyword(s):  
Genetic Algorithms ◽  
Power Loss ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Total Power ◽  
Network Reconfiguration ◽  
Power Losses ◽  
Combined Method ◽  
Capacitor Banks ◽  
Distribution Transformers

Saba feeder is a feeder who supplies 78 distribution transformers with feeder length 38,959 kms, through this Saba feeder electrical energy is channeled radially to each distribution substation. In 2017 the voltage shrinkage at Saba feeder was 9.88% (18,024 kV) while the total power loss was 445.5 kW. In this study an attempt was made to overcome the voltage losses and power losses using the method of optimizing bank capacitors with genetic algorithms and network reconfiguration. The best solution obtained from this study will be selected for repair of voltage losses and power losses in Saba feeders. The results showed that by optimizing bank capacitors using genetic algorithms, the placement of capacitor banks was placed on bus 23 (the channel leading to the BB0024 transformer) and successfully reduced the power loss to 331.7 kW. The network reconfiguration succeeded in fixing the voltage on the Saba feeder with a voltage drop of 4.75% and a total power loss of 182.7 kW. With the combined method, reconfiguration and optimization of bank capacitors with genetic algorithms were obtained on bus 27 (channel to transformer BB0047) and managed to reduce power losses to 143 kW.

Vulcanization or Other Heat Treatment by Electrical Conduction

1944 ◽  
Vol 17 (1) ◽  
pp. 188-191
Author(s):  
Felix L. Yerzley
Keyword(s):  
Heat Treatment ◽  
Electric Current ◽  
High Frequency ◽  
Direct Consequence ◽  
Electrical Energy ◽  
Internal Resistance ◽  
Appreciable Amount ◽  
Rubber Belt ◽  
High Dielectric ◽  
Electrical Conductors

Abstract This communication relates to the heating of plastic materials of. a semiconducting nature by passing electricity through them. In particular, it relates to the vulcanization of rubber and rubberlike materials, including Neoprene, with heat generated by the conduction of an electric current and, similarly, it relates to the heat treatment of thermosetting plastics by conduction of an electric current. It is well known that all electrical conductors are heated to some extent by the passage of an electric current. This heating is a direct consequence of internal resistance. The effect so obtained is proportional to the electrical energy absorbed, and is expressed by the equation: power=I2R, in which I is the current in amperes between two points and R is the corresponding resistance in ohms. The unit of power is the watt. Others have used electrical means of heating unvulcanized rubber, but the disclosures differ fundamentally from this proposal. For example, Neerlye coils a steel ribbon and an uncured rubber belt in a spiral and heats the coil by passing electricity through the steel. Newton claims vulcanization by abeam of electrons from a cathode ray tube. The most significant disclosure is by Dufour. This claims the “process for the vulcanization of rubber characterized by the feature that the rubber to be heat-treated is arranged as a dielectric between the electrodes of an electric condenser to which there is applied a high frequency alternating current of a periodicity of several million cycles per second”. This patent is characterized by utilization of high-frequency fields of the order of several megacycles per second. Further, it is not required in induction curing with high-frequency current that the electrodes be in actual mechanical contact with the rubber. Induction curing is facilitated when the material to be heated has both a high power factor and a high dielectric constant, but high electrical conductivity of appreciable amount is not essential to the application of the method.

scholarly journals HousEEC: Day-Ahead Household Electrical Energy Consumption Forecasting Using Deep Learning

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2672 ◽  
Author(s):  
Ivana Kiprijanovska ◽  
Simon Stankoski ◽  
Igor Ilievski ◽  
Slobodan Jovanovski ◽  
Matjaž Gams ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Error Score ◽  
Load Forecasting ◽  
Electrical Energy ◽  
Electrical Energy Consumption ◽  
Sources Of Information ◽  
Multiple Sources ◽  
Short Term ◽  
Benchmark Model ◽  
Short Term Load Forecasting

Short-term load forecasting is integral to the energy planning sector. Various techniques have been employed to achieve effective operation of power systems and efficient market management. We present a scalable system for day-ahead household electrical energy consumption forecasting, named HousEEC. The proposed forecasting method is based on a deep residual neural network, and integrates multiple sources of information by extracting features from (i) contextual data (weather, calendar), and (ii) the historical load of the particular household and all households present in the dataset. Additionally, we compute novel domain-specific time-series features that allow the system to better model the pattern of energy consumption of the household. The experimental analysis and evaluation were performed on one of the most extensive datasets for household electrical energy consumption, Pecan Street, containing almost four years of data. Multiple test cases show that the proposed model provides accurate load forecasting results, achieving a root-mean-square error score of 0.44 kWh and mean absolute error score of 0.23 kWh, for short-term load forecasting for 300 households. The analysis showed that, for hourly forecasting, our model had 8% error (22 kWh), which is 4 percentage points better than the benchmark model. The daily analysis showed that our model had 2% error (131 kWh), which is significantly less compared to the benchmark model, with 6% error (360 kWh).

Development of a Pulsed Power Supply Utilizing 13 kV Class SiC-MOSFETs

2020 ◽  
Vol 1004 ◽  
pp. 1141-1147
Author(s):  
Katsuya Okamura ◽  
Fujio Naito ◽  
Ken Takayama ◽  
Hidenori Kitai ◽  
Hisato Michikoshi ◽  
...  
Keyword(s):  
Rise Time ◽  
Short Pulse ◽  
Load Resistance ◽  
Pulsed Power ◽  
Circuit Board ◽  
Resistive Load ◽  
Circuit Boards ◽  
Pulse Switching ◽  
2Nd Generation ◽  
In Series

To resolve the drawback of conventional thyratron switches, development of a semiconductor high voltage switch utilizing a 13 kV class SiC-MOSFET developed by Tsukuba Power Electronics Constellations (TPEC) is proceeding. At first, the device evaluation test was carried out with a resistive load circuit. With the conditions of drain voltage of 10 kV and load resistance of 1 kΩ, turn on loss Eon, turn off loss Eoff, rise time Tr and fall time Tf were 1.7 mJ, 1.1 mJ, 64 ns, and 75 ns, respectively. Thereafter, the 2s-12p switch array was designed and assembled, where 12 MOSFETs are equally aligned on a circle shaped circuit board and two circuit boards are stacked in series. An 18 kV-318 A-1 us pulse with a rise time of 289 ns in the short pulse switching test were successfully demonstrated. Moreover, switching tests of 2nd generation MOSFET that has a twice larger device area was conducted. As a result, 60 % reduction of on-resistance was confirmed.

scholarly journals Electrical characterization of CIGS thin-film solar cells by two- and four-wire probe technique

2020 ◽  
Vol 34 (11) ◽  
pp. 2050102
Author(s):  
Amirhosein Mosavi ◽  
Beszedes Bertalan ◽  
Felde Imre ◽  
Laszlo Nadai ◽  
Nima E. Gorji
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Current Density ◽  
Ideality Factor ◽  
Electrical Characterization ◽  
Load Resistance ◽  
Internal Resistance ◽  
Thin Film Solar Cells ◽  
Wire Probe

A precise characterization of thin-film solar cells is of huge importance for obtaining high open-circuit voltage and low recombination rates from the interfaces or within the bulk of the main materials. Among many electrical characterization techniques, the two- and four-wire probe using the Cascade instrument is of interest since the resistance of the wires and the electrical contacts can be excluded by the additional two wires in four-wire probe configuration. In this paper, both two- and four-point probes configuration are employed to characterize the CIGS chalcogenide thin-film solar cells. The two-wire probe has been used to measure the current–voltage characteristics of the cell which results in a huge internal resistance. Therefore, the four-wire connection is also used to eliminate the load resistance to enhance the characterization’s accuracy. The load resistance in the two-wire probe diminishes the photogenerated current density at smaller voltage ranges. In contrast, the proposed four-wire probe collects more current at higher voltages due to enhanced carrier collection efficiency from contact electrodes. The current conduction mechanism is also identified at every voltage region represented by the value of the ideality factor of that voltage region. It is observed that a longer time given to the charge collection results in increased current density at a higher voltage. According to the results and device characteristics, a novel double-diode model is suggested to extract the saturation current density, shunt and series resistances and ideality factor of the cells. These cells are shown to be efficient in terms of low recombination at the interfaces and with lower series resistance as the quality of the materials is in its most possible conductive form. The measured internal resistance and saturation current density and ideality factor of the two measurement configurations are measured and compared.

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