三电平网侧变流器预测电流控制及其与两电平变流器比较

将预测电流控制方法从两电平推广至三电平,对三电平系统中需要注意的脉宽调制方法、中点电位平衡等进行研究,提出适合三电平的预测电流控制策略。通过计算机仿真,对两电平和三电平系统采用同样的控制方法进行模拟,仿真结果说明预测电流控制同样可以应用于三电平网侧变流器,且能够保证中点电位的平衡。在相同条件下与两电平系统相比,三电平系统要求的器件耐压和网侧谐波含量更小,适合用于高压大容量的电力牵引传动系统。

Predictive Current Control of Three-Level Line-Side Converter and Comparison with Two-Level Converter

Predictive current control(PCC) method is extended from two-level to three-level.Some points in three-level system are studied,such as pulse width modulation,neutral-point potential balancing etc.The implement strategy of PCC which is suitable to three-level is presented.Two-level and three-level systems are simulated,and both are controlled by PCC.The simulated results show that PCC can be applied to three-level line-side converter and that the neutral-point potential is balanced.Compared with two-level system under the same condition,the sustaining voltage of switch devices and total harmonic distortion(THD) of line current are lower in three-level system which is fit for high-voltage large-capacity traction drive system.