Selective harmonic optimization for flexible single-phase operation of Cascaded H-bridge multilevel inverters

This paper presents a generic output model of multilevel inverters formed through cascaded H-bridges and their flexibility in attaining desired harmonic levels, which could also include elimination of the selected harmonics. The signal model of the possible outputs of a multilevel inverter is mathematically represented and then compared with a conventional signal model that is based on harmonic decomposition. The mathematical relations thus obtained are used for formulation of objectives of selective harmonic optimization. An example of optimization using a stochastic algorithm is presented for validation. The content presented is an enabling step for ensuring smartness in the operation of the multilevel inverters when connected to a microgrid.