TY - GEN
T1 - Control strategy for improved dynamic performance of variable-speed drives with the Modular Multilevel Converter
AU - Jung, Jae Jung
AU - Lee, Hak Jun
AU - Sul, Seung Ki
PY - 2013
Y1 - 2013
N2 - This paper presents a control scheme for the Modular Multilevel Converter (MMC) to drive a variable-speed AC machine, especially focusing on improving dynamic performance. Theoretically, the energy balance in the cell capacitors is prone to be unstable at startup and low frequency operation. Therefore, the MMC topology essentially requires advanced strategies for energy balancing so as to suppress the voltage pulsation of each cell capacitor. The pulsation is getting larger as the output frequency of MMC is getting lower. This paper proposes a strategy for robust dynamic response even at zero output frequency of MMC employing leg offset voltage injection. With this proposed strategy, an AC machine has been driven from standstill to rated speed without excessive cell capacitor voltage ripples. The experimental results verify that stable operation is guaranteed for both a 15r/min operation with 40% step load torque and the entire frequency operation with varying load torque.
AB - This paper presents a control scheme for the Modular Multilevel Converter (MMC) to drive a variable-speed AC machine, especially focusing on improving dynamic performance. Theoretically, the energy balance in the cell capacitors is prone to be unstable at startup and low frequency operation. Therefore, the MMC topology essentially requires advanced strategies for energy balancing so as to suppress the voltage pulsation of each cell capacitor. The pulsation is getting larger as the output frequency of MMC is getting lower. This paper proposes a strategy for robust dynamic response even at zero output frequency of MMC employing leg offset voltage injection. With this proposed strategy, an AC machine has been driven from standstill to rated speed without excessive cell capacitor voltage ripples. The experimental results verify that stable operation is guaranteed for both a 15r/min operation with 40% step load torque and the entire frequency operation with varying load torque.
KW - arm energy balancing
KW - dynamic performance
KW - inner circulating current
KW - modular multilevel converter
KW - motor drive
UR - http://www.scopus.com/inward/record.url?scp=84891057213&partnerID=8YFLogxK
U2 - 10.1109/ECCE.2013.6646880
DO - 10.1109/ECCE.2013.6646880
M3 - Conference contribution
AN - SCOPUS:84891057213
SN - 9781479903351
T3 - 2013 IEEE Energy Conversion Congress and Exposition, ECCE 2013
SP - 1481
EP - 1488
BT - 2013 IEEE Energy Conversion Congress and Exposition, ECCE 2013
T2 - 5th Annual IEEE Energy Conversion Congress and Exhibition, ECCE 2013
Y2 - 15 September 2013 through 19 September 2013
ER -