18-09-2017, 03:52 PM
Power electronics is the application of solid state electronics for the control and conversion of electric power. The first high-powered electronic devices were mercury arc valves. In modern systems the conversion is performed with semiconductor switching devices such as diodes, thyristors and transistors, initiated by R. D. Middle-brook and others since the 1950s. Unlike electronic systems related to the transmission and processing of signals and data, substantial quantities of electrical energy are processed in power electronics. An AC / DC converter (rectifier) is the most typical electronic power device found in many consumer electronic devices, televisions, 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 speed variator (VSD) that is used to control an induction motor. The power range of the VSDs starts from a few hundred watts and ends up in tens of megawatts.
Power conversion systems can be classified according to the type of input and output power
• AC to DC (rectifier)
• DC to AC (inverter)
• DC to DC (DC-DC converter)
• AC to AC (AC to AC converter)
Power electronics began with the development of mercury arc rectifier. Invented by Peter Cooper Hewitt in 1902, it was used to convert alternating current (AC) to direct current (DC). From the 1920s, research continued to apply thyratrons and grid-controlled mercury arc valves to power transmission. One Lamm developed a mercury valve with rating electrodes that make them suitable for high voltage direct current transmission. In 1933 selenium rectifiers were invented.
In 1947, the bipolar point-contact transistor was invented by Walter H. Brattain and John Bardeen under the direction of William Shockley at Bell Labs. In 1948, Shockley's invention of the bipolar junction transistor (BJT) improved stability and performance of transistors, and reduced costs. In the 1950s, higher-power semiconductor diodes were available and began to replace vacuum tubes. In 1956, the silicon-controlled rectifier (SCR) was introduced by General Electric, greatly increasing the range of power electronics applications.
In the 1960s, the improved switching speed of bipolar junction transistors had enabled high-frequency DC / DC converters. In 1976 power MOSFETs became commercially available. In 1982 the insulated gate bipolar transistor (IGBT) was introduced.
Power conversion systems can be classified according to the type of input and output power
• AC to DC (rectifier)
• DC to AC (inverter)
• DC to DC (DC-DC converter)
• AC to AC (AC to AC converter)
Power electronics began with the development of mercury arc rectifier. Invented by Peter Cooper Hewitt in 1902, it was used to convert alternating current (AC) to direct current (DC). From the 1920s, research continued to apply thyratrons and grid-controlled mercury arc valves to power transmission. One Lamm developed a mercury valve with rating electrodes that make them suitable for high voltage direct current transmission. In 1933 selenium rectifiers were invented.
In 1947, the bipolar point-contact transistor was invented by Walter H. Brattain and John Bardeen under the direction of William Shockley at Bell Labs. In 1948, Shockley's invention of the bipolar junction transistor (BJT) improved stability and performance of transistors, and reduced costs. In the 1950s, higher-power semiconductor diodes were available and began to replace vacuum tubes. In 1956, the silicon-controlled rectifier (SCR) was introduced by General Electric, greatly increasing the range of power electronics applications.
In the 1960s, the improved switching speed of bipolar junction transistors had enabled high-frequency DC / DC converters. In 1976 power MOSFETs became commercially available. In 1982 the insulated gate bipolar transistor (IGBT) was introduced.