PROJECT TITLE :

(2N+1) Selective Harmonic Elimination-PWM for Modular Multilevel Converters: A Generalized Formulation and A Circulating Current Control Method - 2017

ABSTRACT:

The performance of modular multilevel converters (MMCs) in medium-voltage applications, where the amount of required submodules is not high, will be improved utilizing low switching frequency modulations like (2N+1) selective harmonic elimination-pulse width modulation (SHE-PWM), that provides tight control of lower order harmonics and low switching losses. This paper proposes a calculation methodology, that is predicated on a unique formulation, to unravel the SHE-PWM downside. In explicit, MMCs with (2N+1) phase output voltage levels are considered, obtaining a (2N+1) SHE-PWM waveform. This method utilizes a distinctive system of equations that's valid for any possible waveform. Therefore, it's ready to calculate simultaneously, without predefined waveforms, each the switching patterns and also the associated firing angles that solve the (2N+1) SHE-PWM downside. Consequently, the search method is simplified and optimized. Furthermore, this paper conjointly proposes a circulating current management technique, that can be applied along with (2N+one) SHE-PWM without disturbing the section output voltage. Simulation results and experimental tests obtained with one-part laboratory prototype prove the validity of the novel (2N+one) SHE-PWM implementation technique and the proposed circulating current control technique.