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Soft-switching Three-level Inverter
A soft-switching three-level inverter (S3L inverter) is a high-efficiency power electronics, power electronic inverter intended, in particular, for use with three-phase drives, as a grid-tie inverter for photovoltaic installations or wind turbines and in power supplies. The topology was developed in 2009 at HTWG Konstanz (Constance University of Applied Sciences). Operating principle Inverters are used for converting DC voltage into AC voltage. Their construction typically makes use of power transistors and diodes. These are operated as electronic switches. In conventional designs using "hard" switching, this gives rise to Peter R. W. Martin (editor): Applikationshandbuch IGBT- und MOSFET-Leistungsmodule. ISLE Verlag, 1998, , Section 1.2.3 Qualitatives Schaltverhalten von MOSFET und IGBT beim harten Schalten (PDF version). which, especially for high values of the switching frequency, cause a reduction in their energy conversion efficiency. To improve their efficiency, high-power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Electronics
Power electronics is the application of electronics to the control and conversion of electric power. The first high-power electronic devices were made using mercury-arc valves. In modern systems, the conversion is performed with semiconductor switching devices such as diodes, thyristors, and power transistors such as the power MOSFET and IGBT. In contrast to electronic systems concerned with the transmission and processing of signals and data, substantial amounts of electrical energy are processed in power electronics. An AC/DC converter (rectifier) is the most typical power electronics device found in many consumer electronic devices, e.g. television sets, personal computers, battery chargers, etc. The power range is typically from tens of watts to several hundred watts. In industry, a common application is the Adjustable-speed drive, variable speed drive (VSD) that is used to control an induction motor. The power range of VSDs starts from a few hundred watts and ends at ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AC Voltage
Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', respectively, as when they modify ''current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa (the full period is called a '' cycle''). "Alternating current" most commonly refers to power distribution, but a wide range of other applications are technically alternating curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hirofumi Akagi
Hirofumi Akagi (赤木 泰文, ''Akagi Hirofumi'', born August 1951) is a Japanese electrical engineer and professor. He is widely recognized for his pioneering contributions to the field of power electronics, particularly for developing the instantaneous reactive power theory (p-q theory) and his work on active power filters. Early life Hirofumi Akagi was born in Okayama, Japan, in August 1951. He was born and grew up in Okayama city, where his father worked for the Japanese National Railways. Living near the station, he was regularly exposed to steam engine locomotives. A memorable family trip included a glimpse of the "Kodama 151 series," a newest limited express train at Kyoto station, which left a lasting impression on him. His early interest in engineering began in childhood, where he enjoyed making rubber-band-powered paper airplanes and meticulously adjusting them to achieve stable and long flights. This early experience fostered his fascination with manufacturing. Educ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Conversion Efficiency
Energy conversion efficiency (''η'') is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The input, as well as the useful output may be chemical, electric power, mechanical work, light (radiation), or heat. The resulting value, ''η'' (eta), ranges between 0 and 1. Overview Energy conversion efficiency depends on the usefulness of the output. All or part of the heat produced from burning a fuel may become rejected waste heat if, for example, work is the desired output from a thermodynamic cycle. Energy converter is an example of an energy transformation. For example, a light bulb falls into the categories energy converter. \eta = \frac Even though the definition includes the notion of usefulness, efficiency is considered a technical or physical term. Goal or mission oriented terms include effectiveness and efficacy. Generally, energy conversion efficiency is a dimensionless number between 0 and 1.0, or 0% to 100%. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switching Frequency
In electronics, switching frequency refers to the rate at which an electronic switch performs its function. Switching frequency is an important design and operating parameter in systems such as: * The Class-D amplifier, an audio power amplifier with a switched-mode output. * Various types of electric power conversion equipment: ** Boost converter ** Buck–boost converter ** Buck converter ** Chopper ** Switched-mode power supply ** Power inverter * Motor controls, such as Variable-frequency drive A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor, AC motor drive (sys ...s {{Electronics-stub Electrical parameters This frequency is also used in different types of DC-DC converters like Battery Discharge Regulator, Universal Bus Regulator, Auxiliary Bus Regulator etc., switching frequency refers the sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode
A diode is a two-Terminal (electronics), terminal electronic component that conducts electric current primarily in One-way traffic, one direction (asymmetric electrical conductance, conductance). It has low (ideally zero) Electrical resistance and conductance, resistance in one direction and high (ideally infinite) resistance in the other. A semiconductor diode, the most commonly used type today, is a Crystallinity, crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. It has an Exponential function, exponential current–voltage characteristic. Semiconductor diodes were the first Semiconductor device, semiconductor electronic devices. The discovery of asymmetric electrical conduction across the contact between a Crystal, crystalline mineral and a metal was made by German physicist Ferdinand Braun in 1874. Today, most diodes are made of silicon, but other semiconducting materials such as gallium arsenide and germanium are also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
