Reserch On Dimmable LED Digital Drive Power Supply Based On LoRa

LED lighting has been widely used in the lighting field.However,the existing LED drive power supply mostly adopts integrated circuit control system,with relatively complex circuit structure and no wireless communication function.For highway tunnel lighting and urban road lighting,it is difficult to meet the demand of smart lighting and green energy saving.Based on LoRa wireless technology and digital control technology,this paper designs a dimmable LED digital drive power supply with wireless communication function to realize intelligent functions such as wireless dimming and LED lamp fault diagnosis,which greatly reduces the difficulty of installation and construction of lamps and line complexity,increase the level of green lighting and energy saving in highway tunnel lighting and urban road lighting.First of all,The theory of Boost type APFC circuit and Flyback type DC/DC converter circuit of the main circuit of LED drive power supply and the principle of digital PID constant current dimming control are analyzed,and the theoretical calculation formula is derived;Based on theoretical analysis and circuit design specification,the design and parameter calculation of the Boost APFC main circuit and the Flyback DC/DC main circuit are completed;An APFC control circuit with OB6561 P chip as the core is designed to realize power factor correction;The OB2203 chip is used as the core for the DC/DC conversion control circuit to realize the quasi-resonant control of the Flyback type DC/DC main circuit;Designed a digital LED constant current control and wireless dimming control circuit based on microcontroller STM8 and LoRa wireless module ZM470SX-M,feedback control the DC/DC circuit to realize LED constant current and dimming,and combined with LoRa wireless module to realize Wireless control function of LED drive power.Based on the hardware design of digital LED constant current control and wireless dimming control circuit,the STM8 program was written,which mainly includes the main program,PID control program and LoRa wireless control program.A series of initialization operations of the system are realized in the main program;The PID control program implements the digital PID control algorithm and performs constant current dimming control and constant voltage control on the LED drive power;The LoRa wireless control program operates the LoRa wireless module to realize LoRa wireless communication of the LED drive power,and realizes wireless dimming control,LED lamp fault diagnosis,parameter configuration and otherfunctions by analyzing the wireless control commands.Prototype and test platform for LED drive power were built,On the test platform,The circuit performance of the APFC circuit,DC/DC conversion circuit and digital LED constant current control and wireless dimming control circuit of the LED drive power supply designed in this paper were tested.At the same time,the LoRa wireless control function was tested.According to the test results,The power factor and power efficiency of the designed LED drive power supply meet the design specifications.The functions such as wireless dimming of LED drive power and fault diagnosis of lamps are normally realized,and the wireless communication is stable and reliable.The LED drive power designed in this paper has been used in some tunnel lighting renovation projects,and the actual lighting and energy-saving effects are better tested on site.