Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Dual-module VSG control strategy under unbalanced voltage conditions

  • Zhanghai Shi (School of Electrical Engineering, Southwest Jiaotong University) ;
  • Jinhao Ruan (School of Electrical Engineering, Southwest Jiaotong University) ;
  • Yunyu Hong (School of Electrical Engineering, Southwest Jiaotong University) ;
  • Mingyue Li (School of Electrical Engineering, Southwest Jiaotong University) ;
  • Dong Liu (School of Electrical Engineering, Southwest Jiaotong University)
  • Received : 2022.06.21
  • Accepted : 2022.12.25
  • Published : 2023.06.20
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Abstract

The virtual synchronous generator (VSG), as a grid-connected technology, has gain more and more attention because of its unique merits including its ability to reshape inertia and damping. These merits enable renewable energy to be smoothly integrated into the grid. Unbalance between three-phase voltage in the steady state is a common phenomenon in the grid, which distorts the output current of the VSG. However, on many occasions, inserting symmetrical current into the grid is necessary. To solve this problem, a dual-module VSG control strategy is proposed in this paper. Through this strategy, the positive and negative sequence output powers of the VSG can be correctly identified and separately controlled. Then the output current can be kept symmetrical by controlling the negative sequence output power of the VSG to be zero. Finally, the proposed strategy is verified by simulation and experimental results.

Keywords

Acknowledgement

This work was supported in part by the National Natural Science Foundation of China under Grant 51607150 and the Sichuan Science and Technology Program under Grant 2021YFH0176. All authors thank Actionpower Inc. (Xi'an, China) for providing the grid emulator, which enabled the experiments to be carried out successfully.

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