级联型H桥多电平逆变器FPGA驱动脉冲系统设计

Design of FPGA Drive Pulse System for Cascaded H-bridge Multilevel Inverter

针对级联型H桥多电平逆变器的多模块化结构及在实际工程中存在调制特殊性的问题,此处以现场可编程门阵列(FPGA)为核心,利用FPGA的高速并行特点,实现载波移相调制输出。针对各功率单元与主控板间驱动信号数量庞大、存在电磁干扰等问题,提出一种对各路驱动信号进行频率编解码的光纤通信方法,提高了信号间传递的精度和稳定性,同时使用光纤传输,可有效解决低压与高压隔离的问题。最后搭建了基于数字信号处理器(DSP)和FPGA的级联型H桥多电平逆变器实验平台,实验结果验证了上述设计的正确性和可行性。

In view of the multi modular structure of cascaded H-bridge multilevel inverter and the particularity of modulation in practical engineering,field programmable gate array(FPGA)is taken as the core and the high-speed parallel characteristics of FPGA are used to realize carrier phase-shift modulation output.In view of the large number of driving signals between each power unit and the main control board and the existence of electromagnetic interference,an optical fiber communication method is proposed for frequency encoding and decoding of each driving signal,which improves the accuracy and stability of signal transmission.At the same time,the use of optical fiber transmission can effectively solve the problem of low-voltage and high-voltage isolation.Finally,an experimental platform of cascaded H-bridge multilevel inverter based on digital signal processor(DSP)and FPCA is built.The experimental results verify the correctness and feasibility of the above design.