Street Lamp Dimming Control Technology Based On Cuk AC/AC Converter

High pressure sodium lamp has been widely applied in the field of street and venue lighting owing to its advantages of high luminance,long device aging,and strong fog-penetrability capacity.However,when applied to the practical applications,the traditional high-pressure sodium lamp and inductance ballast do not have the function of dimming,resulting in the meaningless waste of energy.Meanwhile,owing to the line loss,the voltage across the street lamp at the terminal of power lines is too low,resulting in the street lamp difficult to start or even cannot start.Beyond that,the complexity of the power system will cause the voltage fluctuation on the electrical equipment to exceed the national standard,which will reduce the service life of the lamp.Based on this,street lamp dimming controller based on AC chopper is designed to meet the high requirements of high voltage sodium lamp for voltage stability and speediness in actual operation.A scheme of light adjustment controller with continuous adjustable output voltage is proposed in this pape.the principle which Cuk circuit topology can increase or decrease the output voltage is applied to the energy saving technology of street lamp dimming control.At first,the principle of Cuk AC chopper is analyzed in this paper.Then the design method of the main circuit topology of Cuk AC chopper is given.Finally,the open loop simulation verification is carried out on the MATLAB/Simulink platform.This process has theoretically proved the superiority of Cuk AC chopper in the field of energy saving and dimming in road illumination.Aiming at the problem of slow response of voltage effective value feedback control,the mathematical model of Cuk AC/AC converter is established based on the state space averaging method,and a double-feedforward compound control strategy is put forward in this paper.The closed loop simulation experiment in MATLAB/Simulink shows that the Cuk AC/AC light control controller with compound control strategy can achieve stability in two to three frequency cycles under the condition of the input voltage rise and drop suddenly,and has the advantage of fast dynamic response speed.In view of the complicated working conditions of HP lamps,this paper proposes a scheme of dimming controller based on STM32,which contains multiple circuit modules.The 400 W high-pressure sodium lamp is tested and analyzed.The experimental results show that the output voltage range of the controller can reach 160V~280V,the harmonic distortion is less than 2%,the energy saving rate is 16%.It has the advantages of small volume and simple structure.The experimental results of this paper verify the correctness of the theory.The scheme has certain practical significance for the dimming control of the same kind of high intensity discharge lamp.