TY - GEN
T1 - Defining the exact number of sub-module transitions in fundamental frequency modulated modular multilevel converters
AU - Konstantinou, Georgios
AU - Pou, Josep
AU - Darus, Rosheila
AU - Ceballos, Salvador
AU - Agelidis, Vassilios G.
N1 - Publisher Copyright:
© 2015 IEEE.
PY - 2015/6/16
Y1 - 2015/6/16
N2 - The large number of voltage levels and high quality of a modular multilevel converter (MMC) output voltage and current makes modulation at fundamental frequency a viable alternative. However, a staircase output voltage does not necessarily translate to fundamental switching frequency of the MMC submodules (SMs). This is because the voltage balancing algorithm usually requires several SMs to switch at any sampling period. This paper proposes a voltage balancing algorithm capable of controlling the exact number of SM transitions that are allowed within the arms of an MMC enabling improved regulation of the SM capacitor voltages. The proposed implementation can be extended to any modulation and circulating current control method. It is also shown that enabling the minimum additional transitions within the arm offers the best compromise between SM capacitor voltage ripple and increase in the switching frequency. The proposed method is verified for all operating points with extensive simulation results and demonstrated in an experimental prototype with five SMs per arm.
AB - The large number of voltage levels and high quality of a modular multilevel converter (MMC) output voltage and current makes modulation at fundamental frequency a viable alternative. However, a staircase output voltage does not necessarily translate to fundamental switching frequency of the MMC submodules (SMs). This is because the voltage balancing algorithm usually requires several SMs to switch at any sampling period. This paper proposes a voltage balancing algorithm capable of controlling the exact number of SM transitions that are allowed within the arms of an MMC enabling improved regulation of the SM capacitor voltages. The proposed implementation can be extended to any modulation and circulating current control method. It is also shown that enabling the minimum additional transitions within the arm offers the best compromise between SM capacitor voltage ripple and increase in the switching frequency. The proposed method is verified for all operating points with extensive simulation results and demonstrated in an experimental prototype with five SMs per arm.
KW - Modular multilevel converter
KW - Multilevel converters
KW - Pulse-width modulation
UR - http://www.scopus.com/inward/record.url?scp=84937716198&partnerID=8YFLogxK
U2 - 10.1109/ICIT.2015.7125549
DO - 10.1109/ICIT.2015.7125549
M3 - Conference contribution
AN - SCOPUS:84937716198
T3 - Proceedings of the IEEE International Conference on Industrial Technology
SP - 3052
EP - 3057
BT - 2015 IEEE International Conference on Industrial Technology, ICIT 2015
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2015 IEEE International Conference on Industrial Technology, ICIT 2015
Y2 - 17 March 2015 through 19 March 2015
ER -