Research of SPWM of Single Phase Cascade Full-bridge Inverter Based on DSP

Research and realization of topology and control strategy of cascaded multilevel inverter are important parts of high voltage power converter with large power.In the paper,main circuit of 2H bridge cascaded five-level inverter was introduced in which carrier phase shift SPWM technology was adopted.The working principle and control rules of the circuit were analyzed and then the analytical expression of output voltage was deduced.TMS320F2812 controller of TI was used for control circuit.The results of experiment of output voltage wave and frequency spectrum of 2H bridge cascaded five-level inverter verify the theoretical analysis and experimental results are consistent,which proves correctness of the control method and convenience of the DSP used for realizing the phase shift SPWM technology.