Title :
Control and Experiment of a Modular Multilevel Cascade Converter Based on Triple-Star Bridge Cells
Author :
Kawamura, Wataru ; Hagiwara, Manabu ; Akagi, Hirofumi
Author_Institution :
Dept. of Electr. & Electron. Eng., Tokyo Inst. of Technol., Tokyo, Japan
Abstract :
This paper presents a modular multilevel cascade converter based on triple-star bridge cells (MMCC-TSBC), devoting itself to control and experiment. The TSBC is one of the direct ac-to-ac power converters capable of bidirectional power flow with three-phase sinusoidal currents with any power factor at both supply (input) and motor (output) sides. Therefore, it is suitable for medium-voltage high-power motor drives with regenerative braking, intended to replace a conventional line-commutated cycloconverter using thyristors. This paper provides an intensive discussion on how to control the whole TSBC system, how to regulate and balance the dc mean voltages of all the dc capacitors, and how to mitigate their ac voltage fluctuations. The validity and effectiveness of the proposed control strategy and tactics are verified by a three-phase 400-V 15-kW downscaled model.
Keywords :
AC-AC power convertors; bridge circuits; capacitors; load flow; motor drives; power factor; regenerative braking; thyristors; MMCC-TSBC; ac-to-ac power converters; bidirectional power flow; dc capacitors; medium-voltage high-power motor drives; modular multilevel cascade converter; power 15 kW; power factor; regenerative braking; three-phase downscaled model; three-phase sinusoidal currents; thyristors; triple-star bridge cells; voltage 400 V; voltage fluctuation; AC motors; Bridge circuits; Capacitors; Equations; Medium voltage; Pulse width modulation; Voltage control; Direct ac-to-ac power conversion; medium-voltage motor drives; modular multilevel cascade converters (MMCCs);
Journal_Title :
Industry Applications, IEEE Transactions on
DOI :
10.1109/TIA.2014.2311759
