摘要
考虑到滤波电感、开关器件寄生参数和控制延迟等影响因素,整流器可能工作于非单位功率因数状态。此时,整流器若采用传统基于载波的脉宽调制(Carrier-based pulse width modulation,CB-PWM)策略,则会产生电压电流极性不一致的区域,进而导致开关管误动作、降低整流器性能。为此,基于传统CB-PWM策略提出一种改进载波脉宽调制策略(Modified carrier-based pulse width modulation,MCB-PWM)来改善整流器过零点畸变现象。首先,基于三相Vienna整流器工作原理,建立两相旋转(d-q)坐标系下的数学模型;其次,详细分析传统CB-PWM策略引起网侧电流过零点处波形畸变的原因,设计补偿措施,给出所提MCB-PWM策略的具体原理;此外,结合传统双闭环控制,形成系统整体控制框图;最后,利用Matlab/Simulink仿真,将传统CB-PWM策略与所提MCB-PWM策略进行对比,结果表明,所提MCB-PWM策略能显著改善输入电流过零点畸变现象,理论分析的正确性和有效性得到了验证。
Considering the influence factors such as filter inductance,parasitic parameters of switching devices and control delay,so the rectifier may work in the state of non-unity power factor.At this time,if the rectifier adopts the traditional carrier-based pulse width modulation(CB-PWM)strategy,an area with inconsistent voltage and current polarity will be generated,which may cause the switching tubes to malfunction and the performance of the rectifier to decrease.For this reason,a modified carrier-based pulse width modulation strategy(MCB-PWM)is proposed based on the traditional CB-PWM strategy to improve the zero-crossing distortion of the rectifier.First,based on the working principle of the three-phase Vienna rectifier,a mathematical model is established in a two-phase rotating(d-q)coordinate system;secondly,the causes of waveform distortion at the grid-side current zero-crossing point caused by the traditional CB-PWM strategy is analyzed in detail,the compensation measure is designed,and the specific principle of the MCB-PWM strategy is given;in addition,the overall control block diagram of the system is formed by combining the traditional double closed-loop control;finally,the traditional CB-PWM strategy is compared with the MCB-PWM strategy by the simulation in Matlab/Simulink.The results show that the input current zero-crossing distortion phenomenon can be significantly improved by using the MCB-PWM strategy,and the correctness and effectiveness of the theoretical analysis are verified.
作者
陈岚
肖蕙蕙
郭强
向文凯
CHEN Lan;XIAO Huihui;GUO Qiang;XIANG Wenkai(School of Electrical and Electronic Engineering,Chongqing University of Technology,Chongqing 400054;Chongqing Energy Internet Engineering Technology Research Center,Chongqing 400054)
出处
《电气工程学报》
CSCD
2021年第4期143-150,共8页
Journal of Electrical Engineering
基金
重庆市教委科学技术研究(KJQN202001128)
重庆理工大学研究生创新重点(clgycx20201004)资助项目。
