中文摘要：

针对传统电力电子拓扑结构中开关器件耐压值不够高，与电力系统中高压范围不能直接匹配的问题，研究了基于FPGADSP的改进型混合级联多电平变换器的高性能控制系统。该改进型的级联多电平拓扑是将具有相同母线电压的一个二极管钳位拓扑与若干个H桥级联，输出波形由级联模块的输出电压叠加而成。并针对该拓扑提出了其混合调制的调制策略，使较高开关频率的开关器件与高耐压值的器件协同工作在一起，充分发挥开关器件各自的特性。由于多电平变换器开关管数量众多，专用DSP芯片已经不能完全满足设计要求，为此专门设计了基于FPGA-DSP的通用控制系统，用以实现多电平电路的专用PWM控制电路的功能，该控制系统稳定可靠，易于扩展。仿真与实验结果充分证明了该设计方案的可行性和有效性。

英文摘要：

We focused on an improved hybrid cascade multilevel converter based on FPGA DSP control system. In this topology, a Neutral-Point-Clamped （NPC） converter and several identical H-Bridge converters with equal DC bus voltage were series connected, and the multilevel waveform was synthesized by adding of each converter output voltage. Accordingly, a hybrid modulation method was employed to make higher voltage devices and faster devices operation in synergism, so that the distinct characters of the different switch devices were colligated. The special DSP could not satisfy the PWM control demands of the multilevel converter, so a system based on DSP-FPGA , which could simplify circuit-design, guarantee the reliability and the extension of the system, was designed to be the multilevel converters＂ particular PWM control circuit. The modulation and concretely realization of the control module was expatiated. The feasibility and the validity of the proposed system were adequately verified by the simulation and experiment results.