An immune-algorithm-based dead-time elimination PWM control strategy in a single-phase inverter

In this paper, an immune algorithm is developed for optimization of the harmonic performance of a single-phase inverter under a novel dead-time elimination PWM control strategy. The proposed scheme is based on the division of reference current and constraining switching states, and executes the conventional dead-time elimination in most of the reference current fundamental period but switches to the novel dead-time elimination around the zero crossing point. Meanwhile, the presented algorithm employs the immune approach as the search method for finding the best optimal control sequence to minimize the objective function (OB) of the Total Harmonic Distortion (THD) of the output voltage waveforms. Additionally, an experimental platform based on DSP and FPGA is built. The simulation and experimental results verify the best dead-time elimination control sequences generated by IA compared with the existing conventional control strategies, not only effectively and safely eliminate the effect of dead-time, but also significantly reduce the output waveforms of THD and increase the amplitude of the fundamental voltage.