采用现场可编程门阵列的多电平D类功率放大器控制策略

介绍了一种新颖的基于级联型多电平拓扑结构的开关式的功率放大器,采用多电平技术来改善D类功率放大器输出品质,采用先进的现场可编程门阵列来实现相移PWM技术,其开关频率是单个单元开关频率的2N倍,该触发信号发生器通过数据采集单元接收A/D转换的调制波信号,通过多路载波移相控制单元产生多路相移的三角载波及其反向信号,经比较控制单元产生PWM触发信号波形,并通过死区控制单元进行死区保护控制处理.通过闭环控制保证输出信号的跟随品质,着重研究了闭环控制的控制策略,试验结果表明,采用该控制策略实现的D类功率放大器,系统带宽较宽,具有较好的瞬时响应和输出品质.

A Control Strategy of Multilevel Class-D Power Amplifier with Field Programmable Gate Array

This paper introduces a new switch-mode power amplifier based on a cascade multilevel topology.In order to im- prove the output voltage waveform,a switch-mode multilevel technology composed of several full-bridges for increasing the output voltage level is used.By adopting an advanced technology by usinge Field Programmable Gate Array to achieve class D power amplifier multipulse PWM generator.The amplifier enjoys a switching frequency which is 2N times of that of a single unit.The PWM trigger gathers the A/D transform modulated wave by the data acquiring unit,produces multi-channels phase-shifted triangle carrier waves and their reversed carrier waves by multi-channels phase-shifted tri- angle carrier waves control unit.The PWM trigger generates PWM trigger signals by compare control unit and deals with the dead area protected control by dead area control unit.The amplifier improves the output signal quality through a closed-loop control strategy.This paper lays emphasis on the closed-loop control strategy.