基于预测电流控制的三电平4象限变流器研究

为了实现变流器网侧电流正弦化,输入端高功率因数和开关器件承受低电压应力,介绍了一种单相三电平4象限变流器的电路,分析了其工作模式,推导了其数学模型,为了易于数字化处理器实现,探讨了一种类似于SVPWM控制的新型预测电流控制策路.该控制算法不仅能够离散化实现,而且能够弥补三电平变流器直流侧电容电压不平衡的先天性缺陷.仿真结果表明:该控制策略能有效地抑制注入电网的谐波,实现交流输入端高功率因数和能量的双向流动,系统具有很好的动态特性.

Research on 3-level 4-quadrant Converter Based on Predictive Current Control

To draw a sinusoidal line current and to achieve high power factor and low voltage stress of power switches,a single-phase 3-level 4-quadrant converter was introduced,the working state was analyzed in detail,the mathematic model of the rectifier was derived,and a new predictive current control technique just like SVPWM for the converter was adopted in order to be easily carried out by digital processor.The adopted control method is not only effective in discrete implementation but also able to cope with the voltage unbalancing problem of DC capacitors,which is inherent in the 3-level converter.Simulation results show that the harmonics are suppressed effectively,the high power factor is achieved on the AC input terminal,the bi-directional flowing of power is implemented,the dynamic performance is excellent.