两相并联LCL-nT谐振型多路均流LED驱动器研究

摘要

针对大功率发光二极管(LED)应用场合下需要多路输出及各路电流均衡的问题,提出一种具有多路输出均流的两相并联LCL-nT谐振型电路拓扑结构,详细分析两相并联LCL-nT型谐振变换器的恒流特性、多路并联输出的均流特性以及移相调光控制策略;推导出恒流工作频率表达式和能够实现多路均流的负载范围,并对谐振网络的阻抗特性和电压增益特性进行了分析,在此基础上给出一种兼顾输出功率和开关管零电压开关(zero voltage switching,ZVS)的参数设计方法.最后设计1台200 W的实验样机,实验结果验证了所提出的电路拓扑具有良好的恒流特性和均流特性,并且能实现对LED的全范围调光.%A two-phase parallel LCL-nT resonant converter topology with multi-output current balancing was proposed for the needs of multi-output with current balancing in high-power light emitting diode (LED) applications.The constant current characteristic of the two-phase parallel LCL-nT resonate con-verter,the characteristic of parallel multi-output current balancing and the phase-shift dimming control strategy were analyzed in detail;Then the expression of constant current working frequency and the load range were deduced under which the output current is reliably balanced .Meanwhile ,the impedance char-acteristic and the voltage gain of the resonant network were analyzed .Based on it , a parameter design method which balances the output power and zero voltage switching ( ZVS) was given.Finally,a 200 W laboratory prototype was built .The experimental results confirm that the topology presented has good char-acteristic of constant current and current balancing ,and it can realize full-range dimming of the LED .