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型功率放大器,采用相移PWM技术,其开关频率是单个单元开关频率的2N倍,总的输出电压波纹很小,只需要一个较小的滤波器来抑制开关谐波。文中对多电平PWM输出信号的谐波进行分析,重点研究采用滑模电流电压双闭环控制的设计要点并推导其参数,之后研制一台2kW级联型多电平滑模控制的电流电压双闭环D类功率放大器。试验研究结果表明:采用滑模电流电压双闭环控制的级联型多电平D类功率放大器,明显提高了系统带宽,使系统不仅对阻性负载而且对桥式整流负载都具有良好的快速性和跟踪性能,很好的瞬时响应和稳定性,较高的效率和低的输出信号谐波总畸变率值。
A novel switch-mode power amplifier based on cascade multicell multilevel circuit topology is introduced in the paper. By application of the concept of multicell topology being operated in a phase-shifted PWM 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 PWM control of individual switching cells, the output voltage ripple of entitre system is considerably small. Therefore, only a small output filter is required to suppress the switching frequency harmonics. The paper analyzes harmonic of class-D amplifier＇s output signal with vary modulation index M. The main subject is design of sliding mode controller of current and velocity dual feedback loops control of class-D amplifier and the guidelines of controller parameters, then a 2kW cascade multilevel class-D power amplifier based on sliding mode controller of current and velocity dual feedback loops control is built in the laboratory. The results of measurements taken from a laboratory setup are presented, which prove the proposed amplifier obviously increase bandwidth. The system shows excellent transient response and stability, a good quick response and following characteristic, a higher efficiency and lower THD of output signal, especially if under resistive load or rectifier load.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2007年第36期103-108,共6页
Proceedings of the CSEE
