基于电压下垂法的独立直流微网混合储能系统控制策略改进

针对独立直流微网中混合储能单元使用寿命问题，基于电压下垂控制的混合储能单元控制策略，提出了混合储能系统控制策略的改进措施。首先采用基于超级电容荷电状态的稳态功率修正策略，使超级电容在工作一段时间后荷电状态能够恢复至初始额定值，避免超级电容过充或者过放。其次，针对电池使用寿命问题，提出基于混合储能荷电状态的能量管理策略，以达到延长电池使用寿命的目的。最后通过Matlab/Simulink仿真分析，证明该方法在光伏输出功率改变条件下可有效延长电池与超级电容使用寿命。

Improvement of Hybrid Energy Storage System Control Strategy of Independent DC Microgrid Based on Voltage Sag Method

Aiming at the service life of hybrid energy storage units in independent DC microgrids， the control strategy of hybrid energy storage units based on voltage droop control is proposed， and the improvement measures of the control strategy of hybrid energy storage system are proposed. Firstly， steady-state power correction strategy based on supercapacitor state of charge is used to restore the charge state of supercapacitor to the initial rating after a period of operation，so as to avoid overcharge or over-discharge of supercapacitor. Secondly，in view of battery service life，an energy management strategy based on the charged state of mixed energy storage is proposed to achieve the purpose of prolonging the battery service life . Finally，through Matlab/Simulink simulation analysis，it is proved that the proposed method can effectively extend the service life of batteries and supercapacitors under the condition of changing the photovoltaic output power.