新型低压非隔离十七电平变流器及控制策略研究

A Novel Low Voltage Seventeen-level Converter and Control Strategy

为了减少高阶多电平变流器开关器件的数量,提出一种仅需要12个开关器件和2个飞跨电容的十七电平变流器拓扑,分析电路的工作原理及模态。通过与几种典型的十七电平逆变器拓扑比较,提出的十七电平逆变器在开关器件数量、飞跨电容数量、驱动电路数量等方面具有明显优势,其中最突出的是电流流经的开关器件的数量是最少的。这使得所提出的十七电平变流器具有更小的器件损耗。另外,采用有限控制集模型预测控制方法,实现了对输出电流、直流母线电容电压和飞跨电容电压等变流器核心参数的控制。通过仿真验证所提出十七电平变流器的工作原理的正确性及其控制策略的可行性。最后,搭建硬件实验平台,进一步验证所提出变流器及其控制算法的有效性。

In order to reduce the number of switching devices in high-order multi-level converters,a 17-level converter topology with only 12 switching devices and 2 flying capacitors was proposed,and the working principle and mode of the circuit were analyzed.Compared with several typical 17-level inverters,the proposed 17-level inverter have advantages in the number of switching devices,the number of flying capacitors and the number of driving circuits.The most important is that the number of switching devices through which current flows is the least,which makes the proposed 17-level converter have the smallest device losses.In addition,the core parameters of converter,such as output current,DC bus capacitor voltages and flying capacitor voltages,are controlled by finite control set model predictive control strategy.The effectiveness of the proposed 17-level converter and the feasibility of the capacitor voltage balance control strategy were verified by simulation.Finally,a hardware platform was built to further verify the effectiveness of the proposed converter and its control strategy.