Balanced control strategy for multi-energy storage inverters in microgrid in paralleled with unbalanced load

作者：Liu, Fang^*; Zhang, Xing; Xu, Haizhen; Shi, Rongliang; Hu, Chao; Cao, Renxian

来源：Acta Energiae Solaris Sinica, 2016, 37(12): 3037-3044.

• Balanced control
• Circulating current
• Micro grid
• Output impedance
• Unbalanced voltages

In order to satisfy the circulating current and unbalanced voltage control requirement of the three-phase energy storage inverter in paralleled with unbalanced load operation, on the basis of positive and negative sequence transformation of single synchronous reference frame(SSRF)control system model, the positive and negative sequence output impedance of energy storage inverter was derived, the imbalance between output impedance, circulating current and voltage control was analyzed, i.e., increasing impedance could restrain circulating current while decreasing impedance could suppress unbalance. To solve the problem, a negative sequence compensation controller with reducing negative sequence output impedance appropriately was developed to suppress unbalance of output voltage based on SSRF control;on the other hand, the virtual impedance was introduced to promote control ability of circulation current, and realize proportion control of circulation current and voltage which had higher stability. The experiment results verify the validity of theoretical analysis and proposed control strategy.

• 出版日期2016
• 单位合肥工业大学