Power Coordinated Control Strategy for Grid-Connected DC Microgrid Considering State of Charge

doi:10.12096/j.2096-4528.pgt.24010

Abstract

Abstract:

Objectives Existing research on decentralized coordinated control strategies mainly focuses on power distribution within DC microgrid, with limited consideration given to the operation of grid-connected DC microgrids. To address this, a power coordinated control strategy for grid-connected DC microgrids, considering the state of charge (SOC), is proposed. Methods The proposed strategy treats the interconnecting converter as a dispatchable resource. It regulates the output power of the energy storage unit and interconnecting converter based on the DC bus voltage while keeping the bus voltage and SOC of the energy storage unit within allowable limits. Results The proposed strategy can achieve decentralized power coordination between the energy storage unit and the interconnecting converter, as well as SOC balancing among energy storage units. It also prevents overvoltage and overcharge/overdischarge conditions for the energy storage units. Conclusions The proposed control strategy ensures reasonable power distribution in grid-connected DC microgrids and guarantees the stable operation of the system.

Key words: DC microgrid, coordinated control strategy, decentralized control, power distribution, energy storage unit, SOC balancing

CLC Number:

TK 01

Guangyu WEI, Xiaodong YING, Yanjun YAO, Xiaofang YANG, Chudi WENG, Yonggang PENG, Hailong LI. Power Coordinated Control Strategy for Grid-Connected DC Microgrid Considering State of Charge[J]. Power Generation Technology, 2025, 46(4): 788-796.

Figures/Tables 1

Tab. 1 Simulation parameters

参数	数值
直流母线电压额定值 $U *$ /V	500
直流负荷初始功率 $P L$ /kW	10
储能容量 $C S k$ /C	250
下垂系数之比 $r I C$ ∶ $r E 1$ ∶ $r E 2$	1∶1∶1

Tab. 1 Simulation parameters

参数	数值
直流母线电压额定值 $U *$ /V	500
直流负荷初始功率 $P L$ /kW	10
储能容量 $C S k$ /C	250
下垂系数之比 $r I C$ ∶ $r E 1$ ∶ $r E 2$	1∶1∶1

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