降压Cuk/LLC单级LED驱动电路及其控制  

Research on Step-down Cuk/LLC Single-stage LED Driver Circuit and Control

作　　者：曾璐 林维明[1] ZENG Lu;LIN Wei-ming(Fujian Key Laboratory of New Energy Power Generation Technology,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学电气工程与自动化学院福建省新能源发电技术重点实验室

出　　处：《电力电子技术》2019年第7期85-88,共4页Power Electronics

基　　金：福建省科技厅重大项目(2014H6012)~~

摘　　要：提出一种结合降压Cuk电路和半桥LLC电路,以适用于特定高压输入场合,该电路采用半桥LLC作为单级变换器的DC/DC隔离单元,针对所提电路,设计采用非对称脉宽调制-脉冲频率调制(APWM-PFM)混合控制策略以解决传统的PFM控制策略所导致该单级电路输入特性不太理想的问题并保持了LLC电路的软开关特性。因此提出的单级谐振变换器具有输入输出电压电流纹波小、开关管应力低及整机效率高等优点。详细分析了混合控制策略工作原理,进行了关键参数分析设计。研制了一台100 W的实验样机,验证了所提方案的可行性。在整个输入电压范围内,电路实现了开关管零电压开关(ZVS)开通及次级二极管零电流开关(ZCS)关断,对于额定负载情况,在310 V有效输入电压时,电路效率最高达91.65%。An integrated step-down Cuk circuit and half-bridge LLC circuit is proposed to be used in high voltage input applications.The circuit uses a half-bridge LLC as a DC/DC isolation unit of the single-stage converter and adopts an asymmetric pluse width modulation-pluse frequency modulation(APWM-PFM)hybrid control strategy to solve the problem that the conventional PFM control strategy leads to unsatisfactory input characteristics of the single-stage cir-cuit and keep the LLC circuit's soft switching characteristics.Therefore,the single-stage resonant converter proposed has the advantages of low input and output current ripple,low stress of the switch tube and high machine efficiency.The working principle of the hybrid control strategy is analyzed and the analysis of key parameters is carried out.A 100 W experimental prototype is developed,which verifies the feasibility of the proposed scheme.Within the entire input voltage range,the zero voltage switch(ZVS)on of the switch and the zero current switch(ZCS)shutdown of the secondary diode are obtained.In the rated load condition,the circuit efficiency achieves 91.65%at the 310V input voltage.

关 键 词：变换器 混合控制 效率 

分 类 号：TM46[电气工程—电器]