1. By Caisang Huang Yingying Han

2. Major contents  What is electric generator?  Major component of generator  Electromagnetic induction  How the generator work?  What I lean?  Bibliography

3. What is an electric generator?  Due to the law of conservation of energy, energy cannot be created, but energy can only be transferred from one type of energy to another.  In power industry, an electric generator is the device to convert mechanical energy to electrical energy.  The mechanical energy can be transferred from chemical, nuclear or thermal energy.  It is based on the phenomenon of electromagnetic induction.

5. Major components ( 1) Engine: the source of input mechanical energy (2) Alternator: to produce electrical output (3) Fuel System: fuel tank to keep generator operate (4) Voltage Regulator: to control the output voltage of generator (5) Cooling and Exhaust Systems: to deal with heat produced in the process and dispose the exhaust gases to keep normal operation (6) Lubrication System: to keep moving part of generator be smooth and durable for long time. (7) Battery Charger: to supply generator with a precise ‘float’ voltage. (8) Control Panel: to control electrical outlets by people (9) Main Assembly / Frame: to provide structural support

7. In 1830 Joseph Henry and Faraday observed that an electric magnetic field was created in a coil whenever the flux through the coil changes. The electric magnetic field causes a current to flow when changing magnetic force. Electric magnetic field created in the coil is called "induced electric magnetic field” and the current produced is "Induced Current". Experiments show the magnitude of electric magnetic field depends on the rate at which the flux through the coil changes and the number of turns on the coil.

8. FARADAY’S LAW OF ELECTROMAGNETIC INDUCTION Faraday was the first scientist to carry out a large amount of experiments to discover the electromagnetic induction, he formulated the following law: When magnetic flux changes through a circuit, an electric magnetic field is induced in it which lasts only as long as the change in the magnetic flux through the circuit continues. Average electric magnetic field = -N △ ф/ △ t

9. Principle : A.C. generators operates on the same fundamental principles of electromagnetic induction as D.C. generators. Alternating voltage can be generated by rotating a magnetic field within a stationary coil or rotating a coil in the magnetic field. The value of the voltage generated depends on- ◇ strength of the field. ◇ the number of turns in the coil. ◇ the speed at which the coil or magnetic field rotates.

12. Bibliography  http://www.foxpowerequipment.com/ http://www.foxpowerequipment.com/  http://www.dieselserviceandsupply.com/how_generators_work.aspx http://www.dieselserviceandsupply.com/how_generators_work.aspx  http://www.electric-motorsprice.info/electric-generator/ http://www.electric-motorsprice.info/electric-generator/  http://www.ncert.nic.in/html/learning_basket/electricity/electricity/machine/ac_ generator.htm http://www.ncert.nic.in/html/learning_basket/electricity/electricity/machine/ac_ generator.htm  http://image.baidu.com/i?ct=503316480&z=&tn=baiduimagedetail&word=%B7 %A8%C0%AD%B5%DA&in=5128&cl=2&lm=-1&st=- 1&pn=2&rn=1&di=121059516165&ln=1971&fr=&fm=result&fmq=1334453343487 _R&ic=0&s=0&se=1&sme=0&tab=&width=&height=&face=0&is=&istype=2#pn2 &- 1&di121059516165&objURLhttp%3A%2F%2Fjpk.sdju.edu.cn%2Fwuli%2FArticle %2FUploadFiles%2F201003%2F2010032513143534.jpg&fromURLhttp%3A%2F% 2Fjpk.sdju.edu.cn%2Fwuli%2Farticle%2Fprint.asp%3Farticleid%3D63&W153&H 199&T9089&S6&TPjpg%3D63&W153&H 199&T9089&S6&TPjpg  http://image.baidu.com/i?ct=503316480&z=&tn=baiduimagedetail&word=%B5 %E7%B4%C5%B8%D0%D3%A6&in=9489&cl=2&lm=- 1&st=&pn=2&rn=1&di=77041487130&ln=1979&fr=&fm=&fmq=1334453181169_R &ic=&s=&se=&sme=0&tab=&width=&height=&face=&is=&istype=#pn2&- 1&di77041487130&objURLhttp%3A%2F%2Ffile.qlteacher.com%2Fupload%2Fgz 2010%2Fimages%2F1007%2F26%2F153341198.JPG&fromURLhttp%3A%2F%2F gz2010.qlteacher.com%2Fsubmission%2Fwuli%2F4071270&W350&H200&T880 6&S12&TPjpg350&H200&T880 6&S12&TPjpg  http://www.citycollegiate.com/xii_chpxiv6.htm http://www.citycollegiate.com/xii_chpxiv6.htm