基于FPGA的混合级联27电平控制策略研究

Control Strategy Study of a Hybrid Cascaded 27-level Based on FPGA

介绍了一种新型的基于级联3-H桥的27电平逆变器电路拓扑结构,直流侧采用单直流电源,避免了多电源导致电路结构复杂,同时输出电压经过变压器短路阻抗滤波能够接近单位功率因数。采用简单的基于FPGA的控制方法,避免了传统控制方法的复杂性。采用Matlab软件对电路拓扑结构及控制策略进行了仿真研究.仿真和实验结果很好的证明了新型3-H桥多电平电路结构及调制方法的有效性,具有良好的谐波特性。

A new circuit topology of cascaded 27-level inverter based on 3-H bridges is introduced.A single DC power is adopted at DC side to avoid the complexity of multi-power circuits and to get unity power factor by using the short-circuit impedance of transformer to filter the output voltage.A simple control method based on FPGA is adopted to avoid the complexity of traditional controlling methods.Matlab software is used to conduct simulation study on the topology and the control strategy.The experimental and simulation results show that the new multilevel circuit with 3- H bridges and the modulation method are both effective and it has good harmonic characteristics.