Power Regulation And Constant Control Of Electronic Ballast For HID Lamp

High intensity discharge(HID)lamps has the advantages of high luminous efficiency,good color rendering,and long life.It has become the key research object in green lighting engineering,due to the negative resistance characteristics of HID lamps,it needs to be used together with ballast.According to the different requirements of the surrounding environment for HID lamp,the output power of the electronic ballast is adjusted,so that the HID lamp can work in the state of half power or full power,which can achieve the purpose of dimming and save energy.At the same time,for HID lamp power fluctuations caused by different lamp models and lamp aging,etc,constant power control of HID lamps can extend the service life of the lamp.Based on the PL3106 chip and the SG3525 drive control chip,this paper designs a 250 W HID lamp two-stage electronic ballast prototype,on the basis of the original analog circuit,the digital control is used to replace the analog control,and the frequency modulation and dimming control mode is selected,by adjusting the frequency of the output drive signal of the SG3525 chip,the conduction frequency of the switch tube of the half-bridge inverter circuit is changed,and realizes the dimming control of the 250 W HID lamp power from half power to full power and constant power control under the rated power state.By studying the two-stage electronic ballast,using Saber simulation software to model and simulate the main circuit and control circuit of the HID lamp electronic ballast,to verify the theoretical control principle,write debugging software program based on PL3106 chip,make debugging hardware circuit,The experimental results show that the electronic ballast can operate in the state of half power or full power,and the dimming control is realized.When the load power fluctuates,the HID lamp can work in the state of constant power,and the constant power control is realized.