An Improved Clonal Selection Algorithm for Optimizing PWM Switching Sequences of Inverters

To minimize the total harmonic distortion (THD) in the pulse width modulation (PWM) switching sequence of an inverter for generating a standard sine waveform, an enhanced clonal selection algorithm (ICSA), based on the traditional clonal selection algorithm (CSA) framework, is proposed. This optimization aims to refine the PWM switching sequence. We introduce a nonparametric mutation operator and a gene immigration strategy to boost the exploration and exploitation capabilities of the CSA. The ICSA has been applied to a single-phase full-bridge inverter to validate its optimization performance, with comparisons made against three existing algorithms. Experimental results demonstrate that the PWM switching sequence optimized by ICSA produces higher quality power output compared to those optimized by the other three algorithms, reducing the total THD to 2.19%. Additionally, numerous odd-order harmonics are effectively eliminated. The proposed nonparametric mutation operator and gene immigration strategy significantly enhance the global search capability of the algorithm.