Design Of Lighting Power Supply Based On Dual Integral Sliding Mode Control

Thanks to the rapid development of LED lighting industry,LED driver power has received extensive attention and is developing towards high power factor,high performance,high efficiency and high power density.In the research of this topic,with the goal of high power factor and linear change of output,based on the two-level topology structure of the front boost circuit and the rear half bridge LLC circuit,a LED driver power supply with high power factor and output current can be linearly started and controlled will be designed.For the former Boost PFC circuit,its working principle and three current control methods are analyzed firstly,and then the mathematical model of the Boost circuit is established by the state space average method.Then the double integral sliding mode control is introduced into the boost current inner loop control for analysis and modeling,and a simulation model is built using the Simulink platform.Through the comparison of simulation waveform and data,the effect of double integral sliding mode control on improving power factor is verified.For the latter half bridge LLC circuit,the DC gain and constant current gain are analyzed and the function is derived under the FHA equivalence.Then,the operating principle of the half bridge LLC under resonance and the sufficient conditions for ZVS to work are analyzed.Then,the mathematical model of the half bridge LLC is derived through the extended description function method and the PI control loop is designed.Based on the rear half bridge LLC circuit,this paper proposes a new linear start control scheme and analyzes its working principle in detail.Using Simulink platform,a simulation model of half bridge LLC constant current output with linear start control is built to verify the control effect of linear start.Finally,a prototype with a constant output current of 10 A and a full load of 320 W is built for the research of this topic,and the calculation and selection of hardware circuit and the design idea of the program are described in detail.The test waveform obtained through the operation of the prototype proves that the prototype can achieve high power factor and achieve good linear start control effect,and verifies the correctness and practicality of the design.