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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] |
Power Transistor
A power semiconductor device is a semiconductor device used as a switch or rectifier in power electronics (for example in a switch-mode power supply). Such a device is also called a power device or, when used in an integrated circuit, a power IC. A power semiconductor device is usually used in "commutation mode" (i.e., it is either on or off), and therefore has a design optimized for such usage; it should usually not be used in linear operation. Linear power circuits are widespread as voltage regulators, audio amplifiers, and radio frequency amplifiers. Power semiconductors are found in systems delivering as little as a few tens of milliwatts for a headphone amplifier, up to around a gigawatt in a high voltage direct current transmission line. History The first electronic device used in power circuits was the electrolytic rectifier - an early version was described by a French experimenter, A. Nodon, in 1904. These were briefly popular with early radio experimenters as they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC Voltage
Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', as when they modify ''current'' or ''voltage''. Direct current may be converted from an alternating current supply by use of a rectifier, which contains electronic elements (usually) or electromechanical elements (historically) that allow current to flow only in one direction. Direct current may be converted into alternating current via an inverter. Direct current has many uses, from the charging of batteries to large power supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
HTWG Konstanz
Konstanz University of Applied Sciences () or HTWG, is a German university of applied sciences located in Konstanz, Baden-Württemberg. It is a member of Lake Constance Arts & Sciences Association. The university was established in 1906 by Alfred Wachtel and named the "Technicum Konstanz". Initially there were only three departments: engineering, technical studies, and the school for 'Werkmeister' - postgraduate work. Faculties * Architecture and Design * Civil Engineering * Electronic and Information Technology * Computer Sciences * Mechanical Engineering * Business and social sciences * College for Foreign Students (ASK) Bachelor majors * Architecture * Applied Computer Science (replaced technical computer science and software engineering) * Civil Engineering * Business Administration * Electronic and Information Technology * Communications Design * Mechanical Engineering/Construction and Development * Mechanical Engineering/Production * Transport and Environmental Techno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
