RESEARCH ON CONTROL STRATEGY OF PV STORAGE DC MICROGRID BASED ON ADAPTIVE DROOP CONTROL

The introduction of droop control often leads to a drop in bus voltage. In response to this problem, an adaptive droop control (ADC) strategy based on n-th power of batteries state of charge (SOC) is proposed, in which designs the droop coefficient during charging and discharging is designed. In the droop coefficient, the batteries Sn and the droop coefficient adjustment law based on bus voltage are introduced, and supercapacitor power compensation is added. In terms of the coordinated operation control strategy of the system, the upper level coordinated control module is designed with the bus voltageUdc and batteries SOC as control elements.Compared with traditional adaptive droop control, the proposed control strategy can elevte the dropped bus voltage, and when external environmental factor or load changes, the battery-supercapacitor hybrid energy storage system can better maintain the stability of bus voltage and improve the system′s anti-interference ability. Moreover, the system can smoothly switch between various working modes to maintain the stability of bus voltage. Finally, the effectiveness of this control strategy is verified on an PV storage DC microgrid experimental platform based on TMS320F28335. © 2024 Science Press. All rights reserved.