Аңдатпа
Power electronic converters for medium and high power / voltage applications employ low frequency synchronous fundamental switching to minimize semiconductor switching losses. There are two major approaches to converter switching angles determination - Selective Harmonic Elimination (SHE) and Total Harmonic Distortion (THD) minimization. For the THD minimization, converter switching angles are found to assure minimum THD criterion without taking care of frequency spectrum. For the SHE approach, all degrees of freedom due to available amount of switching angles are spent on elimination of low order harmonics. Recently suggested combined approach suggests spending some degrees of freedom on certain harmonics elimination and the rest for minimizing THD. This generalized problem formulation includes classic minimal THD and SHE problems as special cases. The paper presents comprehensive results on combined SHE and THD minimization for a staircase modulation of a single-phase converter with 5, 6, 7 and 8 switching angles (6, 7, 8 and 9 non-negative voltage levels).