基于随机SVPWM的PMSM谐波频谱展开研究

Harmonic Frequency Spectra Spread of PMSM Based on Random Space Vector Pulse Width Modulation

在电压源逆变器供电的永磁同步电机(PMSM)驱动系统中,传统空间矢量脉宽调制(SVPWM)的逆变器输出电压和电流在开关频率及其倍频附近存在较大幅值的谐波。为了有效地降低此种电压和电流谐波,将随机SVPWM方法应用于谐波频谱展开。该方法可以改变谐波分布,降低局部较高幅值谐波,从而减小电机的噪声、振动和电磁干扰,提高电机的控制性能。分别对单随机载波空间矢量脉宽调制(SRVSVPWM)和混沌空间矢量脉宽调制(Chaotic SVPWM)两种方法进行了介绍,并利用Matlab/Simulink进行仿真,结果表明了两种方法对频谱展开的有效性。为了进一步证明随机载波SVPWM对谐波频谱展开的性能,将谐波展开因子和总谐波畸变作为性能指标对随机载波法进行了评估。

In the voltage source inverter fed permanent magnet synchronous motor(PMSM) driving system,there exists a large amount of voltage and current harmonic components concentrating around the switching frequency and its integer multiples for the traditional space vector pulse width modulation(SVPWM). In order to reduce the voltage and current harmonics of the inverter, the random carrier SVPWM is applied to spread the frequency spectra. This method can change the distribution of the harmonic components of the VSI and alleviate the acoustic noise, undesirable vibration and electromagnetic interference, which improves the control performance of the motor. Single random carrier space vector pulse width modulation(SRCSVPWM) and chaotic SVPWM are introduced. Simulation results in Matlab/Simulink show the effectiveness of the control method. In order to further prove the effectiveness of the random SVPWM on the frequency spectra spread, this paper evaluates the method by using the harmonic expansion factor(HSF) and the total harmonic distortion(THD).