Research And Design On Digital Metal Halide Lamps Electronic Ballast

Since the beginning of the21st century, the non-renewable energy become shortage gradually, energy saving must be of concern for global industrial development. Because of the good color, high light efficiency, long life, and many other features make the Metal Halide occupy an important position in the field of green lighting. Metal halide is a superior performance light source can be widely used in stadiums, workshop pier occasions. Currently, halide electronic ballasts still use traditional inductive or analog control mode on the market, digital control and digital power is bound to become the development trend of the future. Therefore, the study of the digital electronic ballasts is significance in this thesis.Firstly, the problems of inductive and analog control electronic ballast are analyzed in the dissertation, and the digital electronic ballast solution is put forward. According the startup characteristic of the metal halide and the demanding of the digital control, he classical three stage topology is adopted which include the PFC circuit, the BUCK circuit and the full-bridge inverter circuit.Secondly, according the nonlinear negative resistance load characteristic of the metal halide, a digital program control algorithm is designed. A piecewise control method is adopted, including the soft start scheme which can reduce the starting current, the piecewise constant power control of the transition process, and the constant power control of the steady state. The digital control method is realized by PI algorithm, which can match different metal halide and realize the abnormal situation protection.At last, according to the previous theoretical research, a70W digital metal halide lamp electronic ballast of high power factor is given in the dissertation. And, the experiment data is shown which can be verified the rationality of the design scheme...