三电平NPC整流器控制及中点电位平衡控制技术

摘要

The operating principle of three-level NPC rectifier is analyzed and its mathematical model based on switching functions is founded. The dq axis decoupling control is presented and the dual closed loop control system is designed for the decoupled current and voltage,resulting in the zero-error adjustment of active and reactive currents and the stability of DC voltage. A combined control strategy based on simplified three-level SVPWM is proposed to optimize the active time of small vector according to the direction of input current and the ripple of neutral point potential. The effectiveness of rectifier control strategy and the performance of neutral point potential control strategy are verified by experiments.%通过分析三电平中点箝位式整流器工作原理,建立了基于开关函数的三电平整流器的数学模型,提出了一种基于dq轴解耦的控制策略,对解耦后的电流以及电压进行双闭环控制系统设计,实现了有功电流和无功电流的无差调节以及直流侧电压的稳定.在简化三电平空间矢量脉宽调制(SVPWM)算法的基础上,提出了一种根据三相输入电流和中点电位的波动,优化小矢量作用时间的组合控制策略,减小中点电位波动.最后通过实际系统实验,验证了整流器控制策略的正确性以及中点电位控制策略的优异性.