TY - GEN
T1 - Enhanced Voltage Injection Control for Capacitor Voltage Balancing of MMC Under Low-Frequency Operation
AU - Lee, Seung Yong
AU - Cui, Shenghui
AU - Jung, Jae Jung
N1 - Publisher Copyright:
© 2023 The Korean Institute of Power Electronics.
PY - 2023
Y1 - 2023
N2 - In this study, a control approach is presented that is designed for the Modular Multilevel Converter (MMC) to drive low frequency AC devices, such as motors that run at low speeds. The main objective is to improve the converter's dynamic performance, which is crucial for stable operation of motor drives. Theoretical analysis suggests that energy balance in cell capacitors used in motor drive applications may lead to instability during startup and low-frequency operation. Furthermore, the capacitors' energy pulsation is inversely proportional to the output frequency, resulting in significant pulsation at low frequency. Therefore, effective MMC operation requires advanced energy balancing techniques to reduce voltage fluctuations in individual cell capacitors. This paper introduces an enhanced strategy that injects leg offset voltage for low-frequency MMC operation, which is more efficient than existing methods. The proposed approach is evaluated through simulation with a low-frequency MMC output, and the results demonstrate its effectiveness by comparing and analyzing the size of the capacitor voltage ripple before and after the control is applied.
AB - In this study, a control approach is presented that is designed for the Modular Multilevel Converter (MMC) to drive low frequency AC devices, such as motors that run at low speeds. The main objective is to improve the converter's dynamic performance, which is crucial for stable operation of motor drives. Theoretical analysis suggests that energy balance in cell capacitors used in motor drive applications may lead to instability during startup and low-frequency operation. Furthermore, the capacitors' energy pulsation is inversely proportional to the output frequency, resulting in significant pulsation at low frequency. Therefore, effective MMC operation requires advanced energy balancing techniques to reduce voltage fluctuations in individual cell capacitors. This paper introduces an enhanced strategy that injects leg offset voltage for low-frequency MMC operation, which is more efficient than existing methods. The proposed approach is evaluated through simulation with a low-frequency MMC output, and the results demonstrate its effectiveness by comparing and analyzing the size of the capacitor voltage ripple before and after the control is applied.
KW - Arm energy balancing
KW - circulating current
KW - low frequency operation
KW - modular multilevel converter (MMC)
KW - offset voltage
UR - http://www.scopus.com/inward/record.url?scp=85170646735&partnerID=8YFLogxK
U2 - 10.23919/ICPE2023-ECCEAsia54778.2023.10213656
DO - 10.23919/ICPE2023-ECCEAsia54778.2023.10213656
M3 - Conference contribution
AN - SCOPUS:85170646735
T3 - ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia: Green World with Power Electronics
SP - 2643
EP - 2648
BT - ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 11th International Conference on Power Electronics - ECCE Asia, ICPE 2023-ECCE Asia
Y2 - 22 May 2023 through 25 May 2023
ER -