Introduction:
Power Electronics is defined as control and conversion of large amounts of electrical power .
Why control and conversion is required
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A power electronics system consists of an electrical source , load , and a power electronic circuit .
PE circuit containing switches , energy storage elements and control functions .
Power electronic applications deal with the flow of power .
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However , majority of applications in PEs are based on switching the power flow in order to improve efficiency .
consequently , one must use power semiconductor devices with an emphasis on using them as PE switches .
Few of the common power semiconductor switches are diodes , BJTs , MOSFETs , IFBTs.
Power MOSFETs and IGBTs have a large role to play in modern power control equipment’s and hence their study is emphasised.
Power electronics is a vast , complex and interdisciplinary subject that has undergone through a rapid technological evolution during the last 50 years .
Due to advancement in technology with decreased apparatus cost and improved reliability , the application of PE are expanding in industrial , commercial , aerospace , residential , military , and utility environments .
Many innovations in the field of power semiconductor devices , converter topologies , electric machine drives , control etc
The frontier of this technology has been further advanced by the versatile use of AI techniques , such as fuzzy logic and the artificial neural network .
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In 1957 , the silicon-controlled rectifier (SCR) was introduced , and later other power semiconductor devices have been developed with the advancement in the semiconductor technology .
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Power diodes are available up to the ratings of 3000V , 3500A and 1KHz , whereas thyristors are available up to 6000V , 3500A , 1KHz
BJTs are available in the market up to the ratings of 1200V , 400A and 10KHz .
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Power MOSFETs have relatively low ranges of approximately 1000V and 50A with high frequency of 100KHz.
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IGBTs are available up to ower ratings of 1200V , 400A and 20KHz.
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DIODE RECTIFIERS
A diode rectifier circuit converts AC input voltage into a fixed DC voltage.
The input voltage may be single phase or three phase.
Diode rectifiers find wide use in, electric traction battery charging, power supplies, welding, and UPS systems.
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Password : PowerElectronicsBala
pdf made by Dr M Balasubbareddy