A modified voltage balancing sorting algorithm for the modular multilevel converter: Evaluation for staircase and phase-disposition PWM

• Published in: Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC
• Main Author: Darus R.; Pou J.; Konstantinou G.; Ceballos S.; Agelidis V.G.
• Format: Conference paper
• Language: English
• Published: Institute of Electrical and Electronics Engineers Inc. 2014
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900419732&doi=10.1109%2fAPEC.2014.6803318&partnerID=40&md5=34c30ccae4d3b919bd4b6a0f639df8d6

This paper introduces a low complexity implementation of the voltage balancing sorting algorithm to reduce the switching frequency of the power devices in modular multilevel converters (MMCs). Two modulation techniques are evaluated; staircase modulation and phase-disposition pulse-width modulation (PD-PWM) under the conventional and the proposed algorithm. Using a circulating current controller in an MMC with 12 sub-modules per arm, PD-PWM yields better results compared to the staircase modulation technique. The test condition for this comparison is such that the power devices operate at a similar switching frequency and produce similar amplitudes to the capacitor voltage ripples in both modulation techniques. The results are verified through extensive simulations and experimentally using a phase-leg MMC laboratory prototype. © 2014 IEEE.