SPWM逆变器死区影响分析  

Analysis on the Effect of Dead-time of SPWM Inverter

作　　者：李扬 李金玉 赵文逸 龚春英[1] LI Yang;LI Jin-yu;ZHAO Wen-yi;GONG Chun-ying(Nanjing University of Aeronautics&Astronautics,Nanjing 211106,China)

机构地区：[1]南京航空航天大学自动化学院,江苏南京211106

出　　处：《电力电子技术》2021年第10期69-73,79,共6页Power Electronics

摘　　要：通过建立数学模型分析正弦脉宽调制(SPWM)逆变器死区对桥臂和输出电压基波和谐波含量的影响机理,首先在开环情况下分析死区对桥臂电压基波与低次谐波的影响;接着分析闭环情况下死区影响输出电压谐波含量的关系,提出在闭环情况下理论建模时将死区的影响等效为在桥臂电压上叠加了相应谐波频率次的误差电压的分析方法并证明其正确性,进一步提出闭环情况下由于死区引起的低次谐波的估算方法,并从参数设计的角度指出减小死区影响的方法。另外提出考虑死区对基波影响后的逆变器直流母线电压(调制比)优化选取方法。通过仿真和实验验证了以上结果的正确性,研究结果可用于指导SPWM逆变器的参数优化设计。By establishing a mathematical model,the influence mechanism of dead-time of sinusoidal pulse width modulation(SPWM) inverter on the fundamental and harmonic content of bridge-arm voltage and output voltage are studied.Firstly,the influence of dead-time on the fundamental and harmonic content of bridge-arm voltage in open-loop is studied.In addition,the relationship between the dead-time and the harmonic content of the output voltage in closedloop is analyzed.And the analysis method that the effect of dead-time on output voltage can be equivalent to adding the error voltage of corresponding harmonic frequency on the bridge arm voltage is verified.Furthermore,the estimation method of harmonics caused by dead-time in closed-loop system is proposed,and the method to reduce the influence of dead time is pointed out from the angle of parameter design.Simulation verification is carried out for both openloop and closed-loop cases.At last,a design method of direct current bus voltage(modulation ratio) is proposed when considering dead-time.The above results are verified by simulation and experiment.The results can be used to guide the parameter optimization design of SPWM inverter.

关 键 词：逆变器 正弦脉宽调制 死区 调制比 谐波 

分 类 号：TM464[电气工程—电器]