TY - JOUR
T1 - Advanced 2N+1 Submodule Unified PWM With Reduced DC-Link Current Ripple for Modular Multilevel Converters
AU - Yu, Qiang
AU - Deng, Fujin
AU - Liu, Chengkai
AU - Wang, Zheng
AU - Li, Binbin
AU - Blaabjerg, Frede
PY - 2022/4
Y1 - 2022/4
N2 - The 2 N +1 submodule unified pulsewidth modulation (SUPWM) is attractive for modular multilevel converters (MMCs). To generate 2 N +1 voltage levels, the SUPWM results in voltage pulses imposed on the arm inductors, which produces large high-frequency current ripple in the dc link of the MMC and deteriorates the dc-link performance. In this article, the dc-link high-frequency current ripple under 2 N +1 SUPWM is analyzed and a reduced dc-link current ripple control method is proposed for advanced 2 N +1 SUPWM. By regulating the phase angles of the three-phase carriers in each carrier period, the resulted voltage pulses on the arm inductors of three phases can be counteracted, and therefore the dc-link high-frequency current ripple is suppressed. With the proposed method, the MMC has much reduced dc-link current ripple, which effectively improves the performance of the MMC under 2 N +1 SUPWM. Simulations and experiments are conducted to verify the validity and effectiveness of the proposed control.
AB - The 2 N +1 submodule unified pulsewidth modulation (SUPWM) is attractive for modular multilevel converters (MMCs). To generate 2 N +1 voltage levels, the SUPWM results in voltage pulses imposed on the arm inductors, which produces large high-frequency current ripple in the dc link of the MMC and deteriorates the dc-link performance. In this article, the dc-link high-frequency current ripple under 2 N +1 SUPWM is analyzed and a reduced dc-link current ripple control method is proposed for advanced 2 N +1 SUPWM. By regulating the phase angles of the three-phase carriers in each carrier period, the resulted voltage pulses on the arm inductors of three phases can be counteracted, and therefore the dc-link high-frequency current ripple is suppressed. With the proposed method, the MMC has much reduced dc-link current ripple, which effectively improves the performance of the MMC under 2 N +1 SUPWM. Simulations and experiments are conducted to verify the validity and effectiveness of the proposed control.
KW - 2N+1 submodule (SM) unified pulsewidth modulation (SUPWM)
KW - control strategy
KW - dc-link current ripple
KW - modular multilevel converters (MMCs)
UR - http://www.scopus.com/inward/record.url?scp=85118611431&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2021.3124085
DO - 10.1109/TPEL.2021.3124085
M3 - Journal article
SN - 0885-8993
VL - 37
SP - 4261
EP - 4274
JO - I E E E Transactions on Power Electronics
JF - I E E E Transactions on Power Electronics
IS - 4
M1 - 9600570
ER -