【摘要】 针对传统PWM控制,恒定的开关频率使电磁干扰(EMI)频谱幅值出现在开关频率及其倍频处,将数字开关频率调制技术应用于多相DC/DC中,将原本集中在开关频率基频及倍频处的能量分散到周围的频带上,从而减小频谱幅值。利用多相DC/DC消除纹波的特点,在频率调制过程中使各相相位保持恒定,从而最大程度消除总线纹波。通过MATLAB仿真,在试验平台上验证了频率调制技术对抑制EMI的作用,并对不同占空比、频率调制范围时输入总线电流频谱幅值规律进行了研究。更多还原

【Abstract】 Constant frequency PWM results in the appearance of large amplitude at switching frequency and its frequency multiplication. This paper applied digital frequency modulation technique to multi-phase DC / DC converter,the frequency spectrum is broadened,so the peak value of amplitude is reduced. Keep phase difference of every phase constant,so that the ripple of input current can be maximally counteracted. This paper realized the digital simulation of frequency modulation technique in Matlab and uses DSP,FPGA to establish digital control platform. The results show that the frequency modulation technique can effectively suppress EMI of converters.Finally,the law of input current during different duty cycle and frequency modulation range was studied.更多还原