Chopper working and Application
In this article we will discuss about the chopper working and application. We will also learn about the AC chopper. We will also know SCR working and their application.
Chopper Working and Application
Working principle of Chopper
A chopper is high speed on/off semiconductor switch. It connect source to load and disconnect load from source at high speed. In other word the principle of chopper is application of fixed dc Voltage intermittently to the load.
This is achieved by continuously triggering on and off the power switch (SCR) at fast speed. The duration for which the SCR remain on and off are called as on time and off time. By varying on time and off time, the average voltage across the loaf can be varied. Power semiconductor devices used in chopper circuit are unidirectional devices. A chopper can operate in any of the four quadrants by an appropriate arrangement of semiconductor devices. This characteristic of their operation in any of the four quadrants forms the basis of their classification as type-A, type-B, type-C, type D, type-E.
A chopper is a static device that converts fixed dc into a variable dc output voltage. A chopper may be as dc equivalent of an ac transformer since they behave in an identical manner. As chopper involve one stage conversion they are more efficient in compare of ac link chopper are now being used all over the world for rapid transit system. These are also used in trolley cars, fork lift, trucks etc. These systems have smooth control, high efficiency, fast response, and regeneration
Application of Chopper
Many industrial applications require power from D.C. voltage sources. Several of this application performs better in case if they are feed from variable d.c voltage sources. Example of such dc system is subway car, trolley buses, battery operated vehicles, battery charging etc. From ac supply system variable dc output voltage can be obtained through the use of phase control converters or motor generator set. The conversion of fixed d.c. voltage to an adjustable d.c output voltage through the use of semiconductor devices.
Chopper is two types-
1) A.C. link chopper
In the ac link chopper, dc is first converted to ac by an inverter. Ac is step up or step down by a transformer which is them converted back to dc by a diode rectifier as a conversion is in two stages that’s why ac link chopper is costly, bulky and less efficient.
Hence these are Chopper working and application if will find any incorrect in above article you must comment below in comment box.
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