一种新型不对称三相三电平逆变器

A novel three-phase three-level inverter with asymmetrical legs

提出了一种新型的不对称桥臂的三相三电平逆变电路,对该拓扑结构及工作原理进行了详细的分析。在控制算法上,对传统的三电平SVPWM算法进行了改进,将传统的两电平和现有的三电平算法联系起来并线性转化到三电平,避免大量的三角运算。在此基础上将该算法与新的电路拓扑结构结合起来,对中点电位的不平衡问题进行分析并给出了对策,利用Matlab/Simulink仿真工具对该拓扑和算法的正确性进行了验证。实验结果表明,该新型三电平逆变器能够很好地完成逆变,且改进算法也非常适用于此新型结构,中点电位波动小,总的谐波畸变率低,性能稳定。

A novel three-phase three-level inverter circuit with asymmetrical legs was proposed. The topology of the proposed inverter and operating mechanism were analyzed. The traditional three-level SVPWM algorithm was improved, combining traditional two-level with three-level algorithm and linearly transforming to the two-level algorithm to avoid large number of triangular operation. Combined the new algorithm with the new circuit topology,the root cause of the neutral-point-potential imbalance was analyzed, and the solution of this problem was proposed.Simulation study using Matlab/Simulink was conducted to demonstrate the validity of the proposed new topology and SVPWM algorithm.The simulation results show the new three-level inverter could effectively finish inverting, and the improved algorithm is very suitable for the new topology. The neutral point potential fluctuations are small, and total harmonic distortion is small, leading stable performance.