Research On Ballast For High-Power Metal-Halide Lamps

Metal halide lamps have wide application in the field of lighting, because of their high efficacy, good color rendition, long life and other advantages. High wattage metal halide lamps are widely used in gyms, plant workshops and other large-scale lighting places. Analog control methods are used in the most ballast fit for large-power MH lamps in market now. But the digital control methods are adopted merely. The characteristics of the large-power HM lamps are studied thoroughly in this thesis. And proper topology is selected and digital controlled system is designed based on DSP.This thesis introduces the starting-process of the large-power MH lamps, several proper topologies and control methods.Furthermore, three stage circuits are designed. Small signal model analysis is adopted to optimize the system parameters. Tow-loop digital control method is adopted according to the advantage of digital control system.4000W test machine is designed and relevant test is done to improve its performance.