一种基于FPGA的SPWM波的实时生成方法

摘要

文中基于FPGA设计了一种新型的三相SPWM波的实时生成方法.该方法以Xilinx公司的Spartan-3E系列FPGA芯片XC3SS00E作为控制核心,结合直接数字频率合成技术(DDS),利用VHDL语言实时生成三相SPWM波形.通过三个相位互差120°的正弦调制波与一个三角载波进行比较来产生三相SPWM脉冲信号,由两者的交点来确定逆变器开关时刻,其中载波频率、载波比以及死区时间可变,使牛成的三相SPWM波适应性强.通过Modesim和数字示波器验证了利用IWGA实时生成三相SPWM波的町行性,为该方法进一步应用提供了一个良好的开放平台.%Designs a new type of method for producing three-phase SPWM waveforms real-time based on FPGA. The method puts Xilinx 's Spartan-3E Series FPGA chip XC3S500E as the controlling core, and combins with the direct digital frequency synthesis ( DDS),generating three-phase SPWM waveforms real-time by VHDL language. The digital values of three sine modulating waves with 120°phase are respectively compared with the value of triangle carrier wave. The switch points are located at the intersection of the two waves. The carrier frequency, carrier ratio and dead time are variable, so that the three-phase SPWM waveforms are adaptable. Through Digital oscilloscope and Modesim, the feasibility of using FPGA implementation three-phase SPWM waveforms has been verified. This paper provides a good platform for further applications of the method.