逆变器直流母线侧中点电位平衡的研究

Research on DC link neutral point potential balance of inverter

由于三电平逆变器存在冗余电压矢量,在选取电压矢量时既要考虑输出电压的谐波含量又要使直流母线侧电容的中点电位平衡,在分析电压矢量选取与谐波消去的本质联系后,本文研究了一种基于模糊控制的中点电位平衡方法,仿真结果表明采用模糊控制时中点电位比一般控制方法时平稳,波动小。

In three level inverter, there are lots of redundancy voltage space vector, so when choose voltage space vector, we should consider not only the harmonic distortion but also consider the balance of DC link voltage, In this paper, firstly, the neutral point potential variation is analyzed by setting up the neutral point potential model, then a novel neutral point potential technique, using fuzzy logic control strategy, was proposed.