FPGA控制的不对称多电平逆变器的设计

Design of a Hybrid Cascade Asymmetrical Multilevel Inverter Based on FPGA

随着多电平技术在大容量场合的应用,不同结构的多电平拓扑结构不断被提出。论文研究一种混合级联式不对称多电平逆变器,该结构逆变器将传统H桥逆变器进行改进,与H桥相比使用相同器件时,该结构能够输出更多的电平数,或者在输出相同电平数的情况下比传统H桥级联结构使用更少的器件。该多电平逆变器由两个不对称四电平逆变器级联而成,输出电平数最少时为七电平,可以用于独立电源供电的系统中,如列车牵引和大型舰船推进系统以及工业自动化应用中。文中对直流侧为独立直流电源供电的混合级联式不对称多电平逆变器进行分析,所采用的调制方法为载波层叠PWM调制方法,通过FPGA编程输出PWM控制信号,调试搭建了硬件电路,从而验证了理论的正确性。

With the application of multilevel inverters in high power occasions,various multilevel inverter topologies have been proposed.A hybrid cascade asymmetric multilevel inverter scheme is validated,in which the traditional H-bridge inverter is improved to output more level numbers using the same devices or output the same level number using less devices.The asymmetric inverter consists of two asymmetric four multilevel inverters and outputs seven levels at least.This scheme can be used in independent power supply system,such as electric vehicle motor drive and shipborne propulsion system.Hybrid cascaded asymmetric multilevel inverter with separated DC supplies is analyzed.The Phase Opposition Disposition PWM（PODPWM） modulation method is employed.FPGA logic device is chosen to produce PWM signal.Finally,the validity of the design was confirmed by debugging the built hardware circuit.