【摘要】 对于三相逆变器而言,不同调制方法对负载中性点波动的影响也不尽相同,而中性点的电位波动,会给绝缘和电气安全带来负面影响。为此,从分析正弦脉宽调制(SPWM)的本质入手,建立了PWM脉冲模型,推导了PWM方法和中点电位波动的关系;提出了一种考虑负载中点电位波动的PWM调制方法,并应用DSP2407型控制芯片予以实现。实验表明,使用该方法既能实现不同调制方法间的合理切换,也能降低中点电位波动带来的不利影响,提高电气安全。更多还原

【Abstract】 As for the three phase full bridge inverter,different modulation methods have various effects on neutral point of the load,which will be dangerous to the load and people.This paper constructs a model for PWM by analyzing the theory of PWM,and also presents a general modulation method realized in TI 2407 DSP.The results of simulation and experiment show that switching between SVM and SPWM without interrupting DSP,which can decrease the floating of the three phase load center,is easy.And in this method the computation are vastly decreased compared with the traditional method.The calculation accuracy is also increased correspondingly.More CPU resources are saved,which can optimize the inverter output and makes control more effectively.And also,this method can provide a good reference for the DSP appliance in power model and other control systems.So it is a practicable modulation method.更多还原