Photovoltaic Module Analysis Techniques
Multiple different photovoltaic module analysis techniques are available and necessary for the inspection of photovoltaic (PV) solar panel, modules, the detection of occurring degradation and the analysis of cell properties. The analysis of PV modules during production and operation is an important part in ensuring Reliability engineering, reliability and thus energy Electrical efficiency, efficiency of the PV technology. Therefore, it is crucial for solar module quality assurance. During their lifetime, PV modules experience severe changes in weather and working conditions, leading to large temperature variations (day - night, summer - winter, irradiance) and mechanical stress (wind, snow, hail). This can lead to an enhanced degradation compared to the usual wearing-out of materials over time, resulting in degradation modes (DMs), which can have an (negative) effect on lifetime and power production. To predict the impact of DMs on a PV module or even a photovoltaic system, PV sy ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Nominal Power (photovoltaic)
Nominal power (or peak power) is the nameplate capacity of photovoltaic (PV) devices, such as solar cells, modules and systems. It is determined by measuring the electric current and voltage in a circuit, while varying the resistance under precisely defined conditions. The nominal power is important for designing an installation in order to correctly dimension its cabling and converters.Die Verwirrung um das Watt-Peak The confusion around watt-peak, 14 August 2009. Nominal power is also called peak power because the test conditions at which it is determined are similar to the maximum irradiation from the sun. Thus this quantity approximates the theoretical maximum production of the panel on a clear sunny day with the panel oriented perpendicular to the sun. The no ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Theory Of Solar Cells
The theory of solar cells explains the process by which light energy in photons is converted into electric current when the photons strike a suitable semiconductor device. The theoretical studies are of practical use because they predict the fundamental limits of a solar cell, and give guidance on the phenomena that contribute to losses and solar cell efficiency. Working explanation # Photons in sunlight hit the solar panel and are absorbed by semi-conducting materials. # Electrons (negatively charged) are knocked loose from their atoms as they are excited. Due to their special structure and the materials in solar cells, the electrons are only allowed to move in a single direction. The electronic structure of the materials is very important for the process to work, and often silicon incorporating small amounts of boron or phosphorus is used in different layers. # An array of solar cells converts solar energy into a usable amount of direct current (DC) electricity. Photogeneration ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Fill Factor (solar Cell)
Solar-cell efficiency is the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell. The efficiency of the solar cells used in a photovoltaic system, in combination with latitude and climate, determines the annual energy output of the system. For example, a solar panel with 20% efficiency and an area of 1 m2 produces 200 kWh/yr at Standard Test Conditions if exposed to the Standard Test Condition solar irradiance value of 1000 W/m2 for 2.74 hours a day. Usually solar panels are exposed to sunlight for longer than this in a given day, but the solar irradiance is less than 1000 W/m2 for most of the day. A solar panel can produce more when the Sun is high in Earth's sky and produces less in cloudy conditions, or when the Sun is low in the sky. The Sun is lower in the sky in the winter. Two location dependent factors that affect solar PV yield are the dispersion and intensity of solar radiation. These ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Maximum Power Point
Maximum power point tracking (MPPT), or sometimes just power point tracking (PPT), is a technique used with variable power sources to maximize energy extraction as conditions vary. The technique is most commonly used with photovoltaic (PV) solar systems but can also be used with wind turbines, optical power transmission and thermophotovoltaics. PV solar systems have varying relationships to inverter systems, external grids, battery banks, and other electrical loads. The central problem addressed by MPPT is that the efficiency of power transfer from the solar cell depends on the amount of available sunlight, shading, solar panel temperature and the load's electrical characteristics. As these conditions vary, the load characteristic ( impedance) that gives the highest power transfer changes. The system is optimized when the load characteristic changes to keep power transfer at highest efficiency. This optimal load characteristic is called the ''maximum power point'' (MPP). MPPT is ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Short-circuit Current
A short circuit (sometimes abbreviated to short or s/c) is an electrical network, electrical circuit that allows a Electric current, current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit. The opposite of a short circuit is an open circuit, which is an infinite Electrical resistance and conductance, resistance (or very high impedance) between two nodes. Definition A short circuit is an abnormal connection between two nodes of an electric circuit intended to be at different voltages. This results in an electric current limited only by the Thévenin's theorem, Thévenin equivalent resistance of the rest of the network which can cause circuit damage, Overheating (electricity), overheating, fire or explosion. Although usually the result of a Electrical fault, fault, there are cases where short circuits are caused intentionally, for example, for the purpose of voltage-sensing Crowbar (circ ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Open-circuit Voltage
Open-circuit voltage (abbreviated as OCV or VOC) is the voltage, difference of electrical potential between two Terminal (electronics), terminals of an electronic device when disconnected from any Electric Circuit, circuit. There is no External electric load, external load connected. No external electric current flows between the terminals. Alternatively, the open-circuit voltage may be thought of as the voltage that must be applied to a solar cell or a Electric battery, battery to stop the current. It is sometimes given the symbol Voc. In network analysis (electrical circuits), network analysis this voltage is also known as the Thévenin's theorem, Thévenin voltage. The open-circuit voltages of batteries and solar cells are often quoted under particular conditions (state-of-charge, illumination, temperature, etc.). The potential difference mentioned for batteries and cells is usually the open-circuit voltage. The value of the open-circuit voltage of a transducer equals its e ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Series And Parallel Circuits
Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology. Whether a two-terminal "object" is an electrical component (e.g. a resistor) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has the same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current through the network is equal to the sum of the currents thr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Maximum Power Point Tracker
Maximum power point tracking (MPPT), or sometimes just power point tracking (PPT), is a technique used with variable power sources to maximize energy extraction as conditions vary. The technique is most commonly used with photovoltaic (PV) solar systems but can also be used with wind turbines, optical power transmission and thermophotovoltaics. PV solar systems have varying relationships to inverter systems, external grids, battery banks, and other electrical loads. The central problem addressed by MPPT is that the efficiency of power transfer from the solar cell depends on the amount of available sunlight, shading, solar panel temperature and the load's electrical characteristics. As these conditions vary, the load characteristic ( impedance) that gives the highest power transfer changes. The system is optimized when the load characteristic changes to keep power transfer at highest efficiency. This optimal load characteristic is called the ''maximum power point'' (MPP). MPPT is ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Inverter
A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the opposite of rectifiers which were originally large electromechanical devices converting AC to DC. The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. The inverter does not produce any power; the power is provided by the DC source. A power inverter can be entirely electronic or maybe a combination of mechanical effects (such as a rotary apparatus) and electronic circuitry. Static inverters do not use moving parts in the conversion process. Power inverters are primarily used in electrical power applications where high currents and voltages are present; circuits that perform the same function for electronic signals, which usually have very low currents and vol ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Semiconductor Curve Tracer
A curve tracer is a specialised piece of electronic test equipment used to analyze the characteristics of discrete electronic components, such as diodes, transistors, thyristors, and vacuum tubes. The device contains voltage and current sources that can be used to stimulate the device under test (DUT). Operation The function is to apply a swept (automatically continuously varying with time) voltage to two terminals of the device under test and measure the amount of current that the device permits to flow at each voltage. This so-called I–V (current versus voltage) data is either directly displayed on an oscilloscope screen, or recorded to a data file for later processing and graphing with a computer. Configuration includes the maximum voltage applied, the polarity of the voltage applied (including the automatic application of both positive and negative polarities), and the resistance inserted in series with the device. The main terminal voltage can often be swept up to several ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), with the third being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |