照明用大功率无桥LED驱动电路输入电流谐波分析

本文对文献［3］介绍的照明用大功率无桥LED驱动电路的输入交流工频电流波形在设定电路条件后利用电脑对它的频谱和谐波含量进行了分析和计算，其结果是在电路的最低工作频率以下的频率范围内基本不存在谐波成分，电路输入电流的总谐波含量决定的THD随最小输入电流脉冲宽度T0(min) 增大而上升，随电路的输出直流电压与输入交流电压有效值的比U0/Ui的增大而下降。并指出在电路的输入端需要一个滤波电路，分析了滤波电路的滤波效果，给出了滤波电路的设计方法

An Input Current Harmonic Analysis of High-power Non-bridge LED Drive Circuit in the Illumination Use

The essay focuses on a Fourier analysis of high-power non-bridge LED drive circuit in the illumination use, which Document 3] gives. Under the given circuit conditions, the content of its frequency spectrum and harmonic has been calculated. The result is that there basically exists no harmonic in the frequency range below the lowest working frequency of the circuit. THD, the content of the total harmonic of the circuit input current, rises with the minimum input current pulse width T0(min) broaden and comes down with effective value ratio of circuit output direct voltage vs input alternating voltage Uo/Ui enhanced. It indicates that a filter circuit is needed at the input port of the circuit and gives its analysis of the effect. It also displays the designing way of the filter circuit