Global Optimal Solving Algorithm for Power Distribution Based on Selective Harmonic Elimination in Cascaded H-Bridge...

The conventional power distributions methods face many challenges, such as high switching frequency, multiple carrier cycles, and single power distribution. To address the above issues, a novel power distribution based on the selective harmonic elimination (PD-SHE) strategy is proposed to achieve arbitrary power distribution and selective harmonic elimination but with low switching frequency and single carrier cycle. Firstly, the novel PD-SHE model is established based on the principles of SHE and power calculation theory, where distribution ratio is introduced to adjust power distribution arbitrarily and its constraints have been deduced. In addition, the issue of redundancy of solution is also analyzed and solved by adding valid constraints. Finally, polynomial homotopy continuation (PHC) algorithm is applied to solve the novel PD-SHE model. Then, all the physically realizable solutions can be found without choosing the initial value in the full range of modulation index. The results of simulation analysis show the effectiveness of PD-SHE strategy and the superiority of PHC algorithm in solving the global optimal solution. Moreover, the reliability of the global optimal solution for PD-SHE strategy is verified via physical experiments in terms of harmonic elimination and active power distribution.