最小共模电压SVPWM调制算法电压源整流器的研究(上)

Research on Minimized Common-mode Voltage SVPWM Modulation Algorithm of Voltage Source Rectifier

本文在基于三相VSR一般数学模型的基础上推导了直流侧共模电压的表达式,分析了理想情况下无死区时和实际情况下有死区时传统SVPWM算法的零矢量和非零矢量对共模电压幅值和谐波分布的影响,并在此基础上提出了一种采用非零矢量等效合成零矢量作用的最小共模电压SVPWM调制算法和共模电压不受死区影响的死区时间设置方法。以上分析得到了MATLAB/SIMULINK仿真分析和变频空调样机的定性验证。结果表明:相比传统采用零矢量的SVPWM算法,最小共模电压SVPWM算法使共模电压的幅值和变化率降低66%,减轻了共模电压干扰。

The existing modulation algorithms should be optimized to overcome the common-mode voltage problem. At first, what presented is the theoretical derivation of the DC link common-mode voltage expression based on the general mathematical model of three-phase VSR. Then the influence on the amplitude and harmonic distribution of common-mode voltage resulting from the zero-vector and non-zero vector of traditional SVPWM modulation algorithm is analyzed under ideal conditions with no dead time and actual conditions with dead time, respectively. Considering the above mentioned, the paper presents a minimized common-mode voltage SVPWM modulation algorithm using non-zero vectors to synthesize the zero vector, as well as a dead time arrangement which causes no effect on common-mode voltage. Then the above theoretical analysis is verified MATLAB/SIMULINK and inverter air-conditioner prototype. The results show that the minimized common-mode voltage SVPWM modulation algorithm can reduce the common-mode voltage amplitude and variance ratio by 66%, and can alleviate the common-mode voltage interference, when compared with the traditional SVPWM modulation algorithm.