• CSCD核心库收录期刊
  • 中文核心期刊
  • 中国科技核心期刊

ELECTRIC POWER CONSTRUCTION ›› 2022, Vol. 43 ›› Issue (7): 87-95.doi: 10.12204/j.issn.1000-7229.2022.07.010

• Smart Grid • Previous Articles     Next Articles

Research on Distributed Control of Multiple Energy Storage Systems with Different SOC in DC Microgrid

MA Haining1(), WANG Luyang1, QIU Cheng2, QIAO Lu1, JI Mingcheng1   

  1. 1. School of Electrical Engineering, Shanghai Electric Power University, Shanghai 200090, China
    2. State Grid Shanghai Economic Research Institute, Shanghai 200233, China
  • Received:2021-12-15 Online:2022-07-01 Published:2022-06-30
  • Contact: MA Haining E-mail:1131617582@qq.com
  • Supported by:
    project from Shanghai Green Energy Grid Connection Engineering Technology Research Center(13DZ2251900)

Abstract:

A DC microgrid needs the energy storage system to maintain its stable operation when it is off-grid. In the case of multiple energy-storage converters in parallel, the line impedance mismatch will lead to the SOC of each energy-storage unit cannot be balanced and the output current of the converter cannot be accurately distributed. At the same time, the bus voltage deviation caused by the “virtual impedance” also needs to be compensated. Aiming at a series of problems, an improved SOC equalization control strategy is proposed to adaptively adjust the “virtual impedance” to realize SOC equalization, and a distributed secondary control strategy is proposed to construct a transfer factor containing multiple information λ, thus generating a unique voltage compensation term that can both eliminate the influence of line impedance and restore bus voltage at the same time, so that the communication pressure of the system can be alleviated. In order to obtain the global average information, a distributed dynamic average algorithm controller is designed by using low bandwidth communication to exchange information between adjacent converters according to consistency algorithm. A photovoltaic multi-energy storage system model is built. Simulation and experiments verify the effectiveness and accuracy of the control strategy.

Key words: DC microgrid, state of charge (SOC), bus voltage recovery, dynamic average algorithm

CLC Number: