scholarly journals Analysis of relaxation of varistor-posistor voltage limiting device in photovoltaic modules during renewal of lighting

2019 ◽  
Vol 27 (2) ◽  
pp. 99-104
Author(s):  
A. S. Tonkoshkur ◽  
A. V. Ivanchenko
Keyword(s):  
Relaxation Time ◽  
Thermal Resistance ◽  
Thermal Contact ◽  
Photovoltaic Cells ◽  
Photovoltaic Module ◽  
Initial State ◽  
Partial Shading ◽  
Photovoltaic Modules ◽  
Cold State ◽  
Solar Arrays

The features of the operation of the circuit method based on a structure of a varistor-PPTC fuse type being in thermal contact to protect the photovoltaic cells from overvoltages arising from the partial shading of the photovoltaic modules of solar arrays are considered. The conditions for the relaxation of the functional characteristics of such voltage limiting devices to the initial state which does not affect the operation of the photovoltaic module during renewal of lighting of the photovoltaic cells are analyzed. It is established that the temperature and resistance dependences of the PPTC element, which determine its state, have a relaxation character at small values of such parameters of the voltage limiting device as the passport values of the resistance of the PPTC element in the conducting (“cold”) state and thermal resistance of the voltage limiting device. The relaxation time is of the order of a few seconds. For large values of the indicated parameters, a situation may occur when such relaxation is absent and the voltage limiting device maintains an active low-conductive (“hot”) state.

scholarly journals APPLICATION OF POLYMER POSISTOR NANOCOMPOSITES IN SYSTEMS FOR PROTECTING PHOTOVOLTAIC COMPONENTS OF SOLAR ARRAYS FROM ELECTRICAL OVERLOADS

2021 ◽  
Author(s):  
Alexander Tonkoshkur ◽  
Alexander Ivanchenko ◽  
Liliya Nakashydze ◽  
Alexander Lyashkov ◽  
Igor Gomilko
Keyword(s):  
Polymer Composites ◽  
Thermal Contact ◽  
Photovoltaic Cells ◽  
Operating Time ◽  
Polymer Nanocomposite ◽  
Photovoltaic Cell ◽  
Solar Array ◽  
Photovoltaic Module ◽  
Positive Temperature ◽  
Solar Arrays

The experience of operating solar arrays indicates the need to solve the problem of creating effective and reliable switching elements to block defective and damaged photovoltaic cells. Available methods of solving this problem (for example, the use of transistor switches, electronic systems, etc.) either do not completely solve it, or are expensive. The tasks of increasing the reliability and efficiency of switching elements, preventing the destruction of photovoltaic cells which occurs during heating by dark current ("hot spots" and fire hazardous situations) are relevant. Recently, one of the promising solutions of this problem is the use of additional devices for isolating inactive (shaded or defective) areas of both separate photovoltaic cells and their modules. These devices are PPTC (polymeric positive temperature coefficient) resettable fuses of PolySwitch type, which are polymer composites with nanoscale carbon fillers. The basic functional property of PPTC fuse is an abrupt increase in electrical resistance by several orders of magnitude when a temperature is reached and a return to the initial high conductive state when the temperature drops. The advantages of such structures based on polymer composites with nanocarbon fillers include: – close to the metal resistance to the switching temperature and to the resistance of the insulator above the specified temperature; – possibility of realization in the form of discrete elements and continuous film-tapes (that is important at the decision of problems of realization of isolation of defective local area of the separate photovoltaic cell); – reaction in the form of temporary isolation of separate components of the solar array to increase their temperature. The research results are presented and the concept of overload protection by using resettable fuses based on polymer nanocomposite materials with nanocarbon fillers is substantiated in this paper. In particular, the expediency of series connection of PolySwitch fuses to photovoltaic modules with parallel connection of their strings is shown to prevent an abnormal situation, namely, a complete loss of electrical energy generated by such a string, which can occur when one of its modules is short-circuited. The circuit solutions in the form of combined structure based on layers of a varistor ceramics and a posistor polymer nanocomposite with carbon filler being in thermal contact are investigated. The prospect of its use to protect photovoltaic cells with a high reverse resistance from overvoltage is established. The problem of protection against local overheating in photovoltaic cells (or their parallel connections) by physical and technological methods, in particular, by creating photovoltaic cells with a built-in layer based on a posistor composite being in thermal contact with it, is analyzed. In general, the described results represent a new direction in the field of improving photovoltaic systems, in particular, in terms of increasing their efficiency, operating time and reliability by using solid-state devices based on polymer posistor nanocomposites and varistor ceramics as means of their protection from electrical and thermal overloads. Keywords: SOLAR ARRAY, PHOTOVOLTAIC MODULE, PHOTOVOLTAIC CELL, ELECTRIC OVERLOAD, POLYMER POSISTOR NANOCOMPOSITE, HOT SPOT, VARISTOR CERAMICS

scholarly journals ALGORITHM FOR SOFTWARE IMPLEMENTATION OF DESIGNING OVERVOLTAGE PROTECTION IN PHOTOVOLTAIC MODULES OF SOLAR ARRAYS USING A VARISTOR-POSISTOR STRUCTURE

2020 ◽  
Vol 1 (126) ◽  
pp. 124-143
Author(s):  
Alexander Tonkoshkur ◽  
Alexander Ivanchenko
Keyword(s):  
Thermal Contact ◽  
Software Implementation ◽  
Photovoltaic Module ◽  
Dynamic Correction ◽  
Technical Parameters ◽  
Photovoltaic Modules ◽  
Solar Arrays ◽  
Protection Circuits ◽  
Metal Oxide Varistor ◽  
Minimum Resistance

The use of modern hardware and software design allows to effectively solve a number of problems associated with the development of various technical devices. The specificity of this approach is the development of algorithms with the capabilities of dynamic correction of the design process with the participation of the user. The algorithm of the software implementation of designing protection circuits against electrical overloads in photovoltaic modules of solar arrays using a voltage limiting device based on metal oxide varistor and posistor of the PolySwitch type being in thermal contact is described in this paper. The algorithm provides for determining the optimal technical parameters of the voltage limiting device (minimum resistance and tripping current of the posistor element, classification voltage and non-linearity coefficient of the varistor element) for the operation of photovoltaic module, which is in the state of lighting in the absence and presence of faulty, degraded, or shaded photovoltaic cells.

RESULTS OF THE PERFORMANCE NUMERICAL SIMULATION OF A SOLAR CONCENTRATOR MODULE WITH A THERMAL-PHOTOVOLTAIC RECEIVER

2020 ◽  
Vol 4 (41) ◽  
pp. 51-56
Author(s):  
DMITRIY STREBKOV ◽  
◽  
NATAL’YA FILIPPCHENKOVA ◽  
Keyword(s):  
Renewable Energy Sources ◽  
Photovoltaic Cells ◽  
Calculated Data ◽  
Electrical Performance ◽  
Research Purpose ◽  
Photovoltaic Module ◽  
Solar Concentrator ◽  
Ansys Fluent ◽  
Photovoltaic Modules ◽  
Agroindustrial Complex

In the field of energy supply to agro-industrial facilities, there is an increasing interest in the development of structures and engineering systems using renewable energy sources, including solar concentrator thermal and photovoltaic modules that combine photovoltaic modules and solar collectors in one structure. The use of the technology of concentrator heat and photovoltaic modules makes it possible to increase the electrical performance of solar cells by cooling them during operation, and significantly reduces the need for centralized electricity and heat supply to enterprises of the agroindustrial complex. (Research purpose) The research purpose is in numerical modeling of thermal processes occurring in a solar concentrator heat-photovoltaic module. (Materials and methods) Authors used analytical methods for mathematical modeling of a solar concentrator heat and photovoltaic module. Authors implemented a mathematical model of a solar concentrator heat and photovoltaic module in the ANSYS Fluent computer program. The distribution contours of temperature and pressure of the coolant in the module channel were obtained for different values of the coolant flow rate at the inlet. The verification of the developed model of the module on the basis of data obtained in an analytical way has been performed. (Results and discussion) The results of comparing the calculated data with the results of computer modeling show a high convergence of the information obtained with the use of a computer model, the relative error is within acceptable limits. (Conclusions) The developed design of the solar concentrator heat and photovoltaic module provides effective cooling of photovoltaic cells (the temperature of photovoltaic cells is in the operating range) with a module service life of at least twenty-five years. The use of a louvered heliostat in the developed design of a solar concentrator heat and photovoltaic module can double the performance of the concentrator.

Investigation of Shading Characteristics of Mono-Crystalline and Poly-Crystalline Photovoltaic Modules Connected in Series

2015 ◽  
Vol 785 ◽  
pp. 220-224 ◽  
Author(s):  
Jin Chuan Teo ◽  
Rodney H.G. Tan ◽  
V.H. Mok
Keyword(s):  
Ideality Factor ◽  
Photovoltaic Module ◽  
Partial Shading ◽  
Photovoltaic Modules ◽  
In Series

This paper presents the investigation of partial shading characteristics of mono-crystalline and poly-crystalline photovoltaic module connected in series. Simulink models are developed to assist the investigation to determine the ideality factor for mono-crystalline and poly-crystalline photovoltaic module. Commercially available mono-crystalline and poly-crystalline photovoltaic module are used to extract measurable parameters for the model to study the behaviour of I-V curve. Measurements have been conducted for the investigation includingmono-crystalline only, poly-crystalline only, both unshaded, mono-crystalline shaded and poly-crystalline shaded. This paper contributes to the understanding of partial shading characteristics of different materials presence in photovoltaic string.

scholarly journals Application of “PolySwitch” fuses for the limitation of current overloads in photovoltaic systems of solar arrays

2018 ◽  
Vol 26 (1) ◽  
pp. 77-82 ◽  
Author(s):  
A. V. Ivanchenko ◽  
A. S. Tonkoshkur ◽  
S. V. Mazurik
Keyword(s):  
Short Circuit ◽  
Electrical Energy ◽  
Complete Loss ◽  
Total Power ◽  
Photovoltaic Module ◽  
Photovoltaic Modules ◽  
Solar Arrays ◽  
Current Voltage ◽  
In Series ◽  
Parallel Connections

The results of experimental study of the transformation of the light current-voltage and volt-watt characteristics for the parallel connections of photovoltaic modules when using “PolySwitch” polymer resettable fuses are given. The conditions for selecting such fuses which allow their correctly triggering and minimize the current overload are formulated and experimentally verified. It is established that if resettable fuses are connected in series to the circuits of all photovoltaic modules, which are connected in parallel thus forming a unit, this prevents such a situation as the complete loss of electrical energy generated by this unit due to the short circuit of one of its modules. At the fuse triggering the total power loss of the unit of  parallelly connected photovoltaic modules is mainly determined by the decrease of its current by the amount that is equal to the current of the disconnected photovoltaic module.

scholarly journals Application of varistor-posistor structure for protection from overvoltages of photovoltaic cells of solar arrays

2019 ◽  
Vol 27 (1) ◽  
pp. 79-88 ◽  
Author(s):  
A. V. Ivanchenko ◽  
A. S. Tonkoshkur ◽  
S. V. Mazurik
Keyword(s):  
Solid State ◽  
Fire Hazard ◽  
Low Cost ◽  
Thermal Contact ◽  
Photovoltaic Cells ◽  
Experimental Studies ◽  
Electric Energy ◽  
Solar Arrays ◽  
In Series ◽  
The Cost

The problems of reducing the cost of ensuring the safe operation of solar cells by using low-cost elements of solid-state electronics to protect against overvoltage photovoltaic cells of solar arrays are considered. The results of experimental studies of the use of a varistor-posistor structure based on a metal oxide varistor and PPTC fuses of the PolySwitch type being in thermal contact to prevent overvoltages in series connections of photovoltaic cells are presented. General schemes for using the considered solid-state structure to limit the indicated constant overvoltages are given and justified. The requirements to the parameters of this structure are determined and experimentally verified. It is shown that such a device makes it possible to limit the long-term constant overvoltages that occur in photovoltaic arrays at the level of photovoltaic cells in the case of their malfunction or shadowing, which can lead to fire hazard and other “abnormal” situations during the operation of solar electric energy sources.

scholarly journals Using a layer based on materials with a metal to semiconductor phase transition for electrothermal protection of solar cells

2021 ◽  
pp. 57-64
Author(s):  
A. S. Tonkoshkur ◽  
A. V. Ivanchenko
Keyword(s):  
Phase Transition ◽  
Solar Cells ◽  
Voltage Drop ◽  
Thermal Contact ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
Photovoltaic Cell ◽  
Power Sources ◽  
Solar Arrays ◽  
Local Overheating

One of the main problems in ensuring the reliability of solar electrical power sources is local overheating, when hot spots form in photovoltaic cells of solar arrays. It is currently considered that these negative phenomena are caused, among other things, by overvoltage in the electrical circuits of solar arrays. This leads to the appearance of defective elements and a significant decrease in the functionality of the entire power generation system up to its complete failure. This study considers the possible ways to increase the reliability of solar arrays by using thermistor thermocontacting layers for preventing overvoltage events and overheating. The authors use simulation to study electrical characteristics of a photovoltaic cell in thermal contact with an additional layer based on thermistor materials with a metal to semiconductor phase transition. Vanadium dioxide with a phase transition temperature of ~340 K is considered to be a promising material for this purpose. During the phase transition, electrical resistance sharply decreases from the values characteristic of dielectrics to the values associated with metal conductors. It is shown that such thermistor layers can be used for protecting solar cells from electrical overheating under the following basic conditions: — the layer’s resistance in the «cold» state significantly exceeds that of the lightened forward-biased solar cell; — the layer’s resistance in the «heated» state is sufficiently low compared to those of the reverse-biased photovoltaic cell and of the power source. The current and temperature of the reverse-biased photovoltaic cell are limited and stabilized, and the voltage drop sharply decreases from the moment when the temperature of the thermistor layer reaches the values close to the temperature of its transition to the low-conductivity state. The obtained results substantiate the potntial of the described approach to protect photovoltaic cells of solar modules against electric thermal overloads.

scholarly journals Validation of Shadow Effects on Solar Photovoltaic Modules Based on Module Positioning

2020 ◽  
Vol 9 (3) ◽  
pp. 1017-1022
Keyword(s):  
Power Loss ◽  
Photoelectric Effect ◽  
Photovoltaic Module ◽  
Solar Photovoltaic ◽  
Partial Shading ◽  
Photovoltaic Modules ◽  
Pv Module ◽  
Simulation Results ◽  
Shading Effects ◽  
Load Conditions

Solar Energy is one of the cleanest forms of energy harnessed from the sunlight using semiconductors through photoelectric effect. This paper reviews the existing models to study the effect of partial shading conditions or varying irradiance on the solar modules. In this paper a PV module is simulated in Matlab/ Simulink using solar cell block from Simelectronics Library to study the effect of shadows on the output power under different panel positioning under different load conditions. The simulation results have been validated against the real time study and measurements. Both the simulation and experimental results confirm that the power loss due to shading effects in a solar photovoltaic module is influenced by the topology and the interconnection of the PV cells.

scholarly journals Modeling the Functioning of the Half-Cells Photovoltaic Module under Partial Shading in the Matlab Package

2020 ◽  
Vol 10 (7) ◽  
pp. 2575
Author(s):  
Mariusz T. Sarniak
Keyword(s):  
Simulation Model ◽  
Internal Structure ◽  
Photovoltaic Module ◽  
Partial Shading ◽  
Photovoltaic Modules ◽  
Pv Module ◽  
Current Voltage ◽  
Replacement Model ◽  
Current Voltage Characteristics ◽  
Matlab Package

In this paper, the usefulness of photovoltaic modules built of half cells for partially obstructed photovoltaic (PV) installations was analyzed based on verified simulation studies. The parameters of these modules are similar to the classic, but the internal structure is different. Instead of 60 cells in a typical classic PV module, there are twice as many cells in modules with half cells. A simulation model was built in the Matlab/Simulink engineering calculations package, using the “Solar Cell” component, which is a double-diode PV cell replacement model. The simulation model reflects the internal structure of the PV module from half cells so that the output current is divided into two equal parts inside, and the structure of the module is divided into six sections. Simulation tests were performed for the same parameters that were measured during actual measurements of the current–voltage characteristics of the partially shaded PV module. Verification tests were carried out for the photovoltaic module—JAM60S03-320/PR—using the I–V 400 meter. Four different cases of partial shading of the module were verified and one for the case of no shading, but in conditions different from the standard, given by the manufacturer.

scholarly journals Application of the Double Diode Model of Photovoltaic Cells for Simulation Studies on the Impact of Partial Shading of Silicon Photovoltaic Modules on the Waveforms of Their Current–Voltage Characteristic

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2421 ◽  
Author(s):  
Mariusz T. Sarniak ◽  
Jacek Wernik ◽  
Krzysztof J. Wołosz
Keyword(s):  
Computer Simulation ◽  
Classical Method ◽  
Photovoltaic Cells ◽  
Photovoltaic System ◽  
Partial Shading ◽  
Photovoltaic Modules ◽  
Solar Radiation Intensity ◽  
Current Voltage ◽  
Pv Modules ◽  
The Impact

Photovoltaics (PV) is the phenomenon of converting sun energy into electric energy by using photovoltaic cells. Furthermore, solar energy is the major renewable energy source. PV modules are systematically more efficient and manufacturing costs decrease at the same time. The PV module performance is affected by ambient temperature, humidity, wind speed, rainfall, incident solar radiation intensity and spectrum, dust deposition, pollution, and shading, which are environmental factors. The problem of partial shading of the generator often arises when designing photovoltaic installations. If it is not possible to avoid this phenomenon, its impact on the operation of the photovoltaic system should be estimated. The classical method is to measure the current–voltage characteristics, but it requires switching off the installation for the duration of the measurements. Therefore, this paper proposes a method using a computer simulation in the Matlab package with the implemented component “Solar Cell” for this purpose. Three cases of partial shading of photovoltaic modules with different degrees of shading were analyzed. The obtained results of the computer simulation were verified for two types of silicon PV modules: Mono- and polycrystalline.

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