Research On Electronic Ballast Used For High Pressure Sodium Lamp

The implementation of national green lighting engineering urges the development of different types of light source with green, efficiently, longer life and good lighting color. The high intensity gaseous discharge lamp (HID) is the most typical new light source. Because of its advantages in lighting efficiency, life, lighting color and lighting penetrability, the high pressure sodium lamp (HPS) is more broadly applicated in the family of HID lamp. But the inductance ballast, with lower power factor , much more loss and large physical volume etc, makes the HPS lamp can't satisfy people's request for lighting equipment of green and energy saving. The development for some kinds of electronic ballast, having high power factor, less loss and smaller physical volume etc, has become insistent requirement. The research work in this thesis is carried out according to this viewpoint.A number of domestic and international technique data releated to HID lamp and its lighting technology have been refered, analyzed and comprehensively synthesized firstly. The working principle and characteristic of HID lamp are cognized. The problem involved in the application practice of HID lamp is fundamentally understood. And, the technique research works about HID lamp and its application practice carried out by former researcher are simply summaried.Based on the analysing about the merits and shortcomings of present HID lamp's mathematical model, the author makes some trial research works on the mathematical model of HID lamp. According to the analysis for the applicable frequency range and defects of two mathematical models used for electric arc discharges within high voltage switch, the author presents a kind of mathematical model for normally worked HID lamp. Compared with former models, this model has the advantage of less parameters, wide applicable frequency range and easy method of parameter settle etc. Simulation research shows that this model has the same performance of former complicated model in aspect of describing the exterior electric characteristics of HID lamp. This model can be used in various situations in which the exterior electric performance of HID lamp is concerned.As an application of the HID lamp's mathematical model put forward in thesis, according to the voltage and current waveforms acquired from a test of a 250W high pressure sodium lamp working at 50Hz, this HPS lamp's mathematical model has been established. In Matlab's Simulink environment, this model is sued in the simulation of the inverter which is the main part of the electronic ballast circuit designed for the HPS lamp. Combined with the design for the driving and controlling circuit of the inverter, the pulse-up circuit of the lamp and the power factor correction circuit of the whole electronic ballast, the author completed the design work of electronic ballast used for the HPS lamp. And the technique route run through this design process can be completely used for the design work of other types of HID lamp's electronic ballast.