级联型多电平D类功率放大器输出滤波器设计  

Design of a Cascade Multilevel Class-D Amplifier's Output Filter

作　　者：张缨[1] 李耀华[1] 胜小松[1] 

机构地区：[1]中国科学院电工研究所,北京100080

出　　处：《电力电子技术》2006年第1期26-28,共3页Power Electronics

摘　　要：介绍了一种新颖的基于级联型多电平拓扑结构的开关式D类功率放大器,它采用相移SPWM技术,其开关频率是单个单元开关频率的2N倍,系统总的输出电压纹波较小,仅需要一个较小的滤波器即可抑制开关谐波。在分析多电平SPWM输出信号谐波的基础上,着重从系统的传递函数、输出阻抗、等效电路等方面研究了多电平D类功率放大器输出滤波器的设计方法。仿真和试验结果表明,采用该方法设计的输出滤波器简便有效,输出系统带宽较宽,具有较好的动态特性。A novel switch-mode class-D power amplifier based on a cascade muhicell multilevel circuit topology is introduced in the paper.By application of the concept of muhicell topology being operated in a phase-shifted SPWM control to switch-mode amplifier system,the effective switching of output results in 2N times the switching frequency of each full-bridge.Due to the phase-shifted SPWM control of the individual switching cells,the output voltage ripple of the total system is considerably small.Therefore,only a small output filter is required to suppress the switching frequency harmonics.The paper analyzes the output signal＇s harmonic of class-D amplifier with vary modulation index M,gives guidelines for the design of the class-D amplifier＇s LC output filter based on analyzing the system＇s transfer function, output impedance and equivalent circuits.Simulation results as well as the measurements results taken from a laboratory setup are presented,which prove the design method of output filter is simple and utility.Consequently,the proposed amplifier shows an excellent dynamic behavior and a wide bandwidth.

关 键 词：功率放大器 滤波器/多电平 相移正弦脉宽调制 

分 类 号：TN713[电子电信—电路与系统]