Electronic Science and Technology ›› 2020, Vol. 33 ›› Issue (4): 35-42.doi: 10.16180/j.cnki.issn1007-7820.2020.04.007

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VSC-HVDC System with Improved Deadbeat Control when Voltage is Unbalanced

FU Ziyi,DU Tianyu   

  1. School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454150,China
  • Received:2019-03-11 Online:2020-04-15 Published:2020-04-23
  • Supported by:
    National Key Research and Development Program(2016YFC06009)


In the case of unbalanced grid voltage, the output power and DC bus voltage of the VSC-HVDC will induce double frequency fluctuation, which affects the stable operation of the system. Aiming to solve the problem, the improved deadbeat control strategy for flexible DC transmission systems under voltage imbalance was studied. The positive and negative sequence reference current expressions were derived by taking the instantaneous active power fluctuation component as zero. Aiming at the control delay of the traditional deadbeat control algorithm and the poor robustness of the change of the inductance parameters on the AC side, an improved deadbeat control strategy was proposed. The control strategy used Lagrangian interpolation to predict the reference current at the next sampling time, then linearly predicted the grid voltage and nonlinearly predicts the grid side current. Finally, the corresponding simulation model was built by MATLAB/Simulink platform. The simulation results proved the correctness and effectiveness of the control strategy.

Key words: flexible HVDC transmission, deadbeat control, Lagrange interpolation, unbalanced grid, control delay

CLC Number: 

  • TP29