A Decentralized Optimal Load Current Sharing Method for Power Line Loss Minimization in MT-HVDC Systems

  • Liu, Yiqi (College of Mechanical and Electrical Engineering, Northeast Forestry University) ;
  • Song, Wenlong (College of Mechanical and Electrical Engineering, Northeast Forestry University) ;
  • Li, Ningning (School of Electrical Engineering and Automation, Harbin Institute of Technology) ;
  • Bai, Linquan (Electrical Engineering and Computer Science Department, University of Tennessee) ;
  • Ji, Yanchao (School of Electrical Engineering and Automation, Harbin Institute of Technology)
  • Received : 2015.06.26
  • Accepted : 2016.07.01
  • Published : 2016.11.20


This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.


Supported by : Central Universities


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