SOC BALANCING STRATEGY OF LOW VOLTAGE AC MICROGRIDS WITH DIFFERENT CAPACITIES BASE ON IMPROVED P-E DROOP CONTROL

Wu Qingfeng; Chu Xiaolin; Yu Shaojuan; Liu Liqun; Chen Yutong

doi:10.19912/j.0254-0096.tynxb.2021-1244

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Acta Energiae Solaris Sinica ›› 2023, Vol. 44 ›› Issue (4) : 266-275. DOI: 10.19912/j.0254-0096.tynxb.2021-1244

SOC BALANCING STRATEGY OF LOW VOLTAGE AC MICROGRIDS WITH DIFFERENT CAPACITIES BASE ON IMPROVED P-E DROOP CONTROL

Wu Qingfeng, Chu Xiaolin, Yu Shaojuan, Liu Liqun, Chen Yutong

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Abstract

Aiming at the problem that the existing state of charge （SOC） balancing scheme based on active-voltage （P-E） droop control does not consider the influence of capacity difference on SOC balancing of distributed energy storage unit （DESU） and that the SOC balancing process is accompanied by voltage quality degradation, a SOC balancing strategy for different capacity DESU is proposed. The operating characteristics of traditional P-E droop control are analyzed, and the regulation mechanism of SOC, voltage and frequency is obtained. In the P-E droop control, the SOC, voltage and frequency regulation terms are introduced, and the multiple agent technology is introduced to calculate the average value of SOC in the SOC regulation terms. The improved P-E droop control eliminates the imbalance of SOC between DESU groups with different capacities and overcomes the problems of voltage drop and frequency rise caused by load fluctuation without requiring the central controller/local pulse controller and affecting the voltage quality. The small signal model of the proposed scheme is established, and the root locus is analyzed to ensure that the set control parameters keep the system stable. The simulation and experimental results obtained by the simulation model and experimental platform confirm the feasibility of the proposed strategy.

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battery energystorage / multiple agent system / power quality / P-E droop control / SOC balancing control

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Wu Qingfeng, Chu Xiaolin, Yu Shaojuan, Liu Liqun, Chen Yutong. SOC BALANCING STRATEGY OF LOW VOLTAGE AC MICROGRIDS WITH DIFFERENT CAPACITIES BASE ON IMPROVED P-E DROOP CONTROL[J]. Acta Energiae Solaris Sinica. 2023, 44(4): 266-275 https://doi.org/10.19912/j.0254-0096.tynxb.2021-1244

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