The Research On Digital Controlled Dimmable Electronic Ballast For High Intensity Discharge Lamps

Because of the shortage of non-renewable energy, energy saving has become a world-wide topic. Being part of it, green lighting projects are attracting more and more attention. As a high efficacy, long life time lighting source, High Intensity Discharge (HID) lamp plays an important role in it. Therefore the development of the drive circuit of the lamp, namely ballast has become an important research point. Because of excellence in energy saving, lighting weight, etc., electronic ballast will gradually take the place of traditional electromagnetic (EM) ballast.Active power factor correction (APFC) technology can restrain humorous waves of input current, and improve the power factor (PF) of electronic ballast efficiently. The dissertation introduces transition mode(TM) Boost PFC circuit and offers basis to design the parameters in the circuit suitably.The dissertation introduces the theory of acoustic resonance and the injection of low-frequency into high-frequency modulation can eliminate acoustic resonance in majority of metal halide (MH) lamps.The dissertation presents a digital controlled electronic ballast for high pressure sodium lamps. Its digital controller includes some functions for soft starting, lamp fault protection, power control for dimming, frequency modulation. The circuit offers the capability of dimming the lamp power from 100% to 50%.The experimental results are given by testing digital electronic ballast for 400W HPS lamps.The dissertation designs the hardware and software of hand controlled dimming, including designing a novel accessorial DC source for electronic ballast. In the end, a practical dimmable electronic ballast for 250W HPS lamps, is developed successfully on the base of above research.