Research On The Radio Frequency Electronic Ballast And Magnetic Component

As a high efficacy, long life, and high color rending lighting source, High Intensity Discharge (HID) lamps play an important role in green lighting. Therefore development of the electronic ballast has become important research object. Because of the excellence in energy saving, relatively little weight, easy control, etc., the electronic ballast will gradually take the place of the traditional electromagnetic (EM) ballast. High efficiency, high credibility, little weight, and low cost are the aims of the electronic ballast research.At the beginning of the thesis, the principle, electrical characteristic, and acoustic resonance phenomenon of the HID lamp are introduced. Three main research aspects for the electronic ballast: Suppression of acoustic resonance, Dimming, and Start-up control are summarized respectively.Acoustic resonance is the inherence characteristic of the HID lamp, and it may cause serious problems, such as arc instability, light fluctuation, color variations, and arc extinction, even arc tube crack. So suppression of acoustic resonance is one important research aspect of electronic ballast. Making the ballast working upon the highest frequency of the acoustic resonance is one of the promising approaches to avoid the acoustic resonance of the HID lamps. Chapter II introduces a method of design dimmable electronic ballast with T-type resonant inverter at radio frequency, which can improve the efficiency and credibility.Easy dimming control is a merit of the electronic ballast, energy saving and other method can be achieved by dimming. A dimmable radio frequency electronic ballast based on T-type filter with Bi-frequency control is presented in Chapter III. It is easy control, and the EMI is low.The switching losses of the switches can be reduced with reasonable parameters design. However, the losses of the magnetic components become seriously at radio frequency, it becomes the main factor which affect the efficiency of ballast. Chapter IV gives a detail analysis of the magnetic components design consideration used in the ballast.