Research On Constant Power Control Of HID Lamp Based On DSP

High intensity gas discharge lamp(HID lamp)is widely used in street lamps,stage lighting,square lighting and other occasions because of its high lighting efficiency,excellent lighting effect and long life.However,the HID lamp will show negative resistance in the process of use,the voltage will decrease with the increase of the current,and the power will deviate from the nominal power.During the start-up process of HID lamp,when the power exceeds the rated value,the positive resistance characteristic of the discharge lamp will cause the temperature rise of the HID lamp to increase sharply and shorten the service life of the HID lamp seriously.In order to reduce the influence of operating conditions on the running quality and life of HID lamp,it is of great practical significance to study the constant power operation of HID lamp in the process of operation.Firstly,the paper compares the digital electronic ballast with the traditional analog electronic ballast,and expounds the advantages and disadvantages of the analog electronic ballast and the digital electronic ballast.The digital electronic ballast is analyzed theoretically,the main circuit is designed,and the parameters of the components are calculated and selected.Secondly,the equivalent model of full-bridge inverter circuit of electronic rectifier is established,and the PID control loop is designed.The simulation circuit is built by using Saber,and the simulation results show that the design parameters of the main circuit and the control loop are reasonable and can meet the constant power requirement of the system under the condition of the change of input voltage.The simulation results show that the design parameters of the main circuit and the control loop are reasonable.Finally,based on DSP chip TMS320F28335,interrupt and EPWM module are configured,sampling program,communication subroutine,protect subroutine,PID interrupt subroutine are write.The experimental circuit is set up to test and analyze the waveform of various working conditions such as the sudden increase of input voltage and sudden drop.The results show that when the input voltage fluctuates within a certain range,the circuit can maintain a stable operating power,and the power of the circuit can be kept stable when the input voltage fluctuates within a certain range.The constant power control of digital electronic ballast is realized.