中点电位平衡的三电平逆变器SVPWM简化算法及其实现

对中点钳位式三电平逆变器空间矢量调制算法和中点电位平衡控制方法进行研究,所介绍的三电平参考电压分解的空间矢量调制简化算法可避免传统开关时间的繁琐计算。中点电位的不平衡是中点钳位式三电平逆变器的一个固有问题,从矢量调制的角度分析了中点电位波动的本质和规律,并提出了一种基于简化调制算法的中点电位平衡控制方法,该方法通过调整平衡控制因子可较精确地控制中点电位的平衡。仿真分析和实验结果验证了简化算法的可行性和平衡控制的有效性。

Three-level Inverter's Neutral Point Balancing in Simplified SVPWM Algorithm and Its Implementation

A simplified algorithm to obtain the SVPWM patterns governing the operation of the neutral point clamped three-level inverter and the strategy to improve the neutral point equilibrium was focused on. The simplified SVPWM algorithm based on the reference voltage vector decomposition avoids complex and time-consuming calculations of the traditional algorithms.Because neutral point potential unbalance is an inherent problem of neutral point clamped three-level-inverter,a detailed study was performed on the fundamentals of neutral point unbalance from the view of vector modulation,and a control strategy that uses a balance control factor to more precisely balance the neutral point was proposed.The results of digital simulation and prototype experiments verified the feasibility of the simplified algorithm and the effectiveness of the balancing strategy.