The Study And Design Of 35W Metal Halide Lamp Digital Electronic Ballast

The Metal halide lamp (MHL), it is the important light source as a high-intensity gas discharge lamp, it has the most development potential of high-tech products and representative of industrial products that have advanced technical level in electrical light sources industry. The metal halide lamps have some characteristics with high luminous efficacy, long life and good energy-saving to be widely applied at green illumination field. It is used in city roads, commercial plaza, supermarket, photographic lighting and industrial lighting in the large-scale application, it has a long-range developmental future.However, it must be matched with ballast because of the negative resistance and special characteristics of the metal halide lamps. Electronic ballasts have many advantages, its research and development is a hot spot in the power electronics industry. Traditional analog control method of MHL are often single, seems more trouble and complexity. The digital control method of MHL can make the whole circuit simplify, it is easy to adjust control signals to make better meet the security, performance and reliability requirements.Firstly, the thesis introduces control principle and structural characteristics of the metal halide lamp, analysis its startup feature and requirements of ballast, this thesis starts from key technology research and design analysis of the electronic ballast, respectively tells EMI of power, current harmonics and power factor correction, select and design method of magnetic materials, the problem of acoustic resonance and so on, and proposes solutions and reference for ballast; Secondly, This article takes the 35W metal halide lamp as research object, designs a safe and reliable electronic ballast, Selects AVR as the use of single-chip controller, designs Buck circuit to adjust output voltage, designs experiment circuit and simulation comparison with old ignition circuit and determine an appropriate start-up circuit, and this thesis designs current and voltage real-time acquisition circuit, using digital PI regulator to enable ballast to achieve constant current control so that the metal halide lamp have stability power, and this thesis designs circuit that protect the whole system based on hardware and software; Finally, this article uses PSpice simulation software to set up a metal halide lamp model, and combines the whole circuit model and the Metal Halide models, to carry out simulation analysis, which verify theoretical analysis of digital electronic ballast design correctness and reasonableness.The entire system adopts low-cost single-chip core as a controller, achieves intelligent control of electronic ballast, it is simple in structure, power stability, self-fault detection, self-protection functions, designs system to meet modern high-quality electronic ballast for the lighting requirements. It offers application value and reference in order to achieve more effective energy-saving lighting systems.