摘要
针对逆变器死区效应引起的输出波形畸变问题,以单相电压型双极性SPWM逆变器为研究对象,提出一种以输出电压THD值最小为指标的选取逆变器开关频率的方法。首先,利用双重傅里叶变换和贝塞尔函数,推导了考虑死区效应情况下输出SPWM的傅里叶级数展开式。通过对输出SPWM电压进行频谱分析,研究了THD值和不同开关频率的关系。经研究发现,存在最优开关频率使得输出电压的THD值最小。其次,采用分段线性拉格朗日插值法,拟合不同死区时间选取最优开关频率的公式。最后,以TMS320F28335为控制芯片,搭建了单相双极性全桥逆变器试验样机,验证了理论分析与所提方法的有效性。实验结果表明,所提出的逆变器开关频率选取方法在减小输出电压THD的同时,减小了开关损耗,提高了直流侧电压利用率。
There is a problem of output waveform distortion caused by the dead-time effect of an inverter.Thus this paper takes a single-phase voltage bipolar SPWM inverter as the research object,and proposes a method to select the inverter switching frequency based on the minimum THD of the output voltage.First,using a double Fourier transform and Bessel function,the Fourier series expansion of the output SPWM is derived considering the dead-time effect.Through frequency spectrum analysis of the output SPWM voltage,the relationship between the THD and different switching frequencies is studied.It is found that there is an optimal switching frequency to minimize the THD of the output voltage.Secondly,the piecewise linear Lagrangian interpolation method is used to fit the formula for selecting the optimal switching frequency for different dead-times.Finally,using TMS320F28335 as the control chip,a single-phase bipolar full-bridge inverter test prototype is built,verifying the effectiveness of the theoretical analysis and the proposed method.Experimental results show that the proposed inverter switching frequency selection method reduces the output voltage THD,while reducing the switching loss and improving the DC side voltage utilization.
作者
巫付专
陈蒙娜
周元浩
向乃皇
WU Fuzhuan;CHEN Mengna;ZHOU Yuanhao;XIANG Naihuang(Henan Advanced Control and New Energy Technology International Joint Laboratory,Zhongyuan University of Technology,Zhengzhou 451191,China)
出处
《电力系统保护与控制》
CSCD
北大核心
2021年第24期96-104,共9页
Power System Protection and Control
基金
国家自然科学基金委面上基金资助项目(61973157)。
关键词
单相逆变器
死区效应
傅里叶变换
THD
开关频率
single-phase inverter
dead-time effect
Fourier transform
THD
switching frequency
