Power Electronics Chapter 10 Application of Power Electronics.
POWER ELECTRONICS
description
Transcript of POWER ELECTRONICS
![Page 1: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/1.jpg)
POWER ELECTRONICS
Instructor: Eng.Moayed N. EL Mobaied
The Islamic University of GazaFaculty of EngineeringElectrical Engineering Department
الرحمن الله بسمالرحيم
EELE 5450 — Fall 2009-2010
Lecture 27
![Page 2: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/2.jpg)
Three switches conducting
The conducting sequence is as follows (each device conducts for a 180o period):
![Page 3: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/3.jpg)
![Page 4: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/4.jpg)
Three conducting devices- line voltage and current
Values of line voltage and line (also phase) current for 60o intervals are shown, from which the waveforms are constructed. The other two lines have identical values, displaced mutually by 120o
![Page 5: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/5.jpg)
Three conducting devices- line voltage and current
Values of line voltage and line (also phase) current for 60o intervals are shown, from which the waveforms are constructed. The other two lines have identical values, displaced mutually by 120o
![Page 6: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/6.jpg)
Comparing rms line currents
![Page 7: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/7.jpg)
Comparing rms line currents
Two switches conducting
![Page 8: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/8.jpg)
INVERTER HARMONICS
![Page 9: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/9.jpg)
![Page 10: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/10.jpg)
INVERTER HARMONICS
![Page 11: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/11.jpg)
INVERTER HARMONICS
![Page 12: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/12.jpg)
SINUSOIDAL PULSE-WIDTH MODULATION
One of the methods used to reduce the low frequency harmonics in the inverter waveform is sinusoidal pulse-width modulation. In this method, a reference copy of the desired sinusoidal waveform, the modulating wave, is compared to a much higher frequency triangular waveform, called the carrier wave The resulting drive signals cause multiple turn-on of the inverter switches in eachhalf-cycle with variable pulse width to produce a quasi-sine wave of load voltage. The pulse width increases from a very narrow width at the start of each cycle to a maximum width in the middle of each cycle. Then the pulse width reduces again after maximum until its minimum width at the end of the half-cycle period.
![Page 13: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/13.jpg)
SINUSOIDAL PULSE-WIDTH MODULATION
Typically in the comparator when the sine wave voltage exceeds the triangular wave voltage, the load voltage is +Vdc, and when the triangular wave voltage exceeds the sine wave voltage, the load voltage is -Vdc.
![Page 14: POWER ELECTRONICS](https://reader033.fdocuments.us/reader033/viewer/2022061502/5681427e550346895daea9ef/html5/thumbnails/14.jpg)
SINUSOIDAL PULSE-WIDTH MODULATION
End of Lecture
Problem set : (SELF-ASSESSMENT TEST, PROBLEMS) due to 6/1/2010