Journal of Engineering (Jan 2021)

A Multiport Electric Energy Routing Scheme Applied to Battery Energy Storage System

  • Guanglin Sha,
  • Qing Duan,
  • Wanxing Sheng,
  • Aiqiang Pan,
  • Zhe Liu,
  • Chunyan Ma,
  • Caihong Zhao,
  • Jiaxun Teng,
  • Lumin Fu,
  • Yi Zheng

DOI
https://doi.org/10.1155/2021/6637926
Journal volume & issue
Vol. 2021

Abstract

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In this paper, the research status of topology and control strategy of energy storage grid-connected system is analyzed, and aiming at the working characteristics of the repurposed battery, a cascade power electronic transformer (CPET) with independent DC output is proposed. The working principle of current fed isolated bidirectional DC-DC converter (CF-IBDC) and cascaded H-bridge (CHB) is analyzed, and the decoupling control strategy is designed. In this paper, a hierarchical control strategy is designed for the repurposed battery energy storage (RBES) grid-connected system based on CPET, which consists of three layers: energy layer, power layer, and state of charge (SOC) layer. The energy layer responds to active and reactive power scheduling instructions, the power layer controls the grid-connected current and tracks the grid voltage, and the SOC layer equates the charged state of repurposed batteries. A 3 MVA/12 kV three-phase grid-connected simulation system was established, and a 1 kW single-phase system experiment platform was designed. The simulation and experimental results can verify the correctness of the theoretical analysis and the feasibility of the control strategy.