Energy management strategy of microgrid energy storage unit based on adaptive droop control

Aiming at the problems of large bus voltage fluctuations and non-proportional output of energy storage unit(ESU) charging and discharging power resulting in unbalanced state of charge(SOC) in microgrid, this paper proposes an adaptive droop control(ADC) strategy based on SOC, which uses the SOC value of the ESU as the droop coefficient, and considering the fluctuation range of bus voltage, uses different control strategies for the charging and discharging of ESUs, so that the charging and discharging power of the ESU can be proportionally distributed according to its SOC value, stabilizing the fluctuating voltage, and achieving SOC balance. Energy management strategy uses a secondary control method to simultaneously monitor the bus voltage and the SOC value of the ESU. it coordinates the flexible switching between various working modes in different environments of the microgrid, effectively stabilize the bus voltage, and improve the quality of microgrid. A simulation model of the control strategy was built on the Matlab/Simulink platform, and the effectiveness of the control strategy is verified on the optical storage DC microgrid experimental platform based on TMS320F28335.