Circulating current control for modular multilevel converter based on selective harmonic elimination with ultra-low switching frequency
Author/s
Perez-Basante, Angel; Ceballos, Salvador; Konstantinou, Georgios; Liserre, Marco; Pou, Josep; [et al.]Date
2016Keywords
Harmonic analysis
Switches
Modulation
Capacitors
Switching frequency
Voltage control
Current control
Abstract
Multilevel converters (MCs) are utilized in medium voltage (MV) high power applications due to its higher efficiency than two level converters. On the other hand, modular multilevel converters (MMCs) provide several advantages with regard to other MCs, such as higher scalability, reliability and no requirement of a common DC capacitor. Particularly, low switching frequency modulations, such as (2N+1) selective harmonic elimination (SHE) - pulse width modulation (PWM), may improve the efficiency of MMCs when they are utilized in MV and high power applications, where the number of sub-modules is not high. This work presents a new circulating current control for MMC when (2N+1) SHE-PWM is utilized. Therefore, it is possible to operate the converter simultaneously with low switching frequency and low capacitor voltage ripple at every sub-module besides a correct energy balance between arms. In addition, a new method to implement (2N+1) SHE-PWM for MMCs, which is also valid to implement ...
Type
conferenceObject