TY - GEN
T1 - Analysis on the Arm Power Imbalance in Modular Multilevel Matrix Converter with Frequency Ratio near One-third
AU - Liu, Shenquan
AU - Zhao, Boyang
AU - Wang, Xifan
N1 - Publisher Copyright:
© 2020 IEEE.
PY - 2020/11/6
Y1 - 2020/11/6
N2 - Fractional frequency transmission system (FFTS) is a promising integration method for long-distance offshore wind farms. The modular multilevel matrix converter serves as the frequency converter between the 50/3 Hz FFTS and the 50 Hz main grid; however, constant circulating current component for inter-arm energy balancing is observed when the M3C operates with frequency ratio near one-third. This paper investigates the origin and compensation method for this arm power imbalance. The 3rd-order harmonics in M3C is modelled utilizing the two-dimensional phasor method proposed by the authors in previous research. Subsequent analysis shows that the arm power imbalance is generated by coupling between 3rd-order harmonic neutral-point voltage and the system-side fundamental-frequency arm current component. Then, compensation method is proposed to eliminate the 3rd-order harmonic neutral-point voltage, which resultantly retains the arm power balance and suppresses the constant circulating current. At last, the proposed model and compensation strategy is verified by simulation studies carried out in MATLAB/Simulink environment.
AB - Fractional frequency transmission system (FFTS) is a promising integration method for long-distance offshore wind farms. The modular multilevel matrix converter serves as the frequency converter between the 50/3 Hz FFTS and the 50 Hz main grid; however, constant circulating current component for inter-arm energy balancing is observed when the M3C operates with frequency ratio near one-third. This paper investigates the origin and compensation method for this arm power imbalance. The 3rd-order harmonics in M3C is modelled utilizing the two-dimensional phasor method proposed by the authors in previous research. Subsequent analysis shows that the arm power imbalance is generated by coupling between 3rd-order harmonic neutral-point voltage and the system-side fundamental-frequency arm current component. Then, compensation method is proposed to eliminate the 3rd-order harmonic neutral-point voltage, which resultantly retains the arm power balance and suppresses the constant circulating current. At last, the proposed model and compensation strategy is verified by simulation studies carried out in MATLAB/Simulink environment.
KW - control
KW - fractional frequency transmission system
KW - modular multilevel matrix converter
UR - https://www.scopus.com/pages/publications/85099450508
U2 - 10.1109/HVDC50696.2020.9292731
DO - 10.1109/HVDC50696.2020.9292731
M3 - 会议稿件
AN - SCOPUS:85099450508
T3 - 2020 4th International Conference on HVDC, HVDC 2020
SP - 577
EP - 582
BT - 2020 4th International Conference on HVDC, HVDC 2020
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 4th International Conference on HVDC, HVDC 2020
Y2 - 6 November 2020 through 9 November 2020
ER -