一种无桥高增益单级LED驱动电路及其混合控制策略  

Bridgeless high gain single-stage LED driver and its hybrid control strategy

作　　者：刘光清 林维明[1] 陈欣玮 LIU Guangqing;LIN Weiming;CHEN Xinwei(Fujian Key Laboratory of New Energy Generation and Power Conversion,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学、福建省新能源发电与电能变换重点实验室,福建福州350108

出　　处：《电机与控制学报》2024年第1期105-119,共15页Electric Machines and Control

基　　金：福建省科技厅高校产学重大项目(2014H6012)。

摘　　要：中小功率的LED驱动电源中,传统两级LED驱动电源存在体积大、成本高以及传统Boost PFC电路在低压输入时导通损耗大等问题。为此提出一种由无桥二次型Boost PFC电路和DC-DC LLC电路集成的无桥高增益单级LED驱动电路,实现了高电压增益、功率开关器件软开关、一套控制电路和高电路转换效率。针对单级电路在电网输入电压变化引起直流母线电压变动范围大等问题,设计一种适用于所提电路的APWM-PFM混合控制策略,并对混合控制原理和控制过程进行详细分析。最后设计一台200 W的实验样机,在输入电压80~120 Vrms范围内,占空比最大为0.5,最大电压增益为6.7,直流母线电压基于网侧特性和LLC电路特性设计在700 V以内,样机的功率因数值均高于0.990,THD均低于15%。在满载条件下,110 Vrms输入时,样机效率为93.20%,相比于传统无桥PFC,电压增益提高了2.21倍,实现了高电压增益和软开关,有效提升了在低压输入条件下的电路转换效率。仿真和实验结果验证了所提出电路和控制方法的有效性。The traditional two-stage LED driver is usually used in the small and medium power LED drivers,resulting in some problems such as large in size and high in cost,and a large conduction loss at low voltage input,etc.To solve the above problems,a bridgeless high gain single-stage LED driver integrated by a bridgeless quadratic Boost PFC circuit and DC-DC LLC circuit was proposed,in which high voltage gain and soft switching can be realized,a set of control circuit is needed and the circuit efficiency can be improved.Aiming at the problem that the DC bus voltage variation range of the proposed single-stage circuit needs to be regulated,the APWM-PFM hybrid control strategy suitable for the proposed circuit was proposed and analyzed and the hybrid control principle and the control process were analyzed in detail.Finally,computer simulation was carried out and a 200 W experimental prototype was built up.In the range of input voltage 80-120 Vrms,when the duty cycle is 0.5,the maximum voltage gain is obtained to be 6.7,the power factor value of the prototype can be achieved to be higher than 0.990 in all line voltage ranges,the THD can be reduced to be lower than 15%and the DC bus voltage is regulated to be under 700 V to equilibrate the line characteristics and LLC performance.Under full load condition,the prototype efficiency can reach up to 93.20%when the input voltage is 110 Vrms.Compared with the traditional two-stage converter,the voltage gain is increased by 2.21 times,high voltage gain and soft switching are achieved,the efficiency under low-voltage input condition is effectively improved.The proposed circuit and control method have been proved to be effective by the simulation and experimental results.

关 键 词：LED驱动电路 功率因数校正 高增益Boost与LLC电路集成 混合控制策略 软开关 

分 类 号：TM46[电气工程—电器]