考虑混合储能荷电状态的独立光伏系统控制策略

Control strategy of the stand-alone photovoltaic system considering SOC of the hybrid energy storage system

独立光伏系统中配备由蓄电池与超级电容组成的混合储能系统可以实现功率平滑、能量平衡以及提高电能质量。在同时考虑蓄电池与超级电容各自的荷电状态以及不同重要等级负荷的情况下,提出了对混合储能的能量管理及对应Buck/Boost双向功率变换器的控制策略。该能量管理方案可以在保证微网的正常运行下维持储能元件在合理的荷电状态;该控制策略可以保证蓄电池的阶段式恒流充电和过充过放保护以及对直流母线电压的稳定快速控制。建立了独立光伏系统的模型,给出了变换器的控制策略,仿真结果验证了所提能量管理方案及控制策略的有效性。

Stand-alone photovoltaic（ PV） system with hybrid energy storage system（ HESS） including battery and super-capacitor can filter the fluctuating power,balance the energy and improve the power quality. A novel energy management scheme of the HESS and a control strategy for the Buck / Boost bidirectional converter are proposed when considering SOCs of the battery and super-capacitor. The energy management scheme can keep SOCs reasonable state of charge when the micro-grid works normally. The control strategy can guarantee the battery charge and discharge with stepped current,and it contains the function of over charge and discharge protection and can achieve fast and stable control of the DC bus voltage. Each part of the stand-alone PV system model is established,and results of the simulation show the effectiveness of the proposed energy management scheme and control strategy.