基于模糊-下垂控制的光伏直流微电网混合储能功率分配及母线稳压研究

针对离网型光伏直流微电网中光伏输出功率与负载消耗功率不匹配引起的母线电压波动问题,通常采用蓄电池和超级电容相结合的混合储能装置进行补偿,一般通过下垂控制对储能装置进行功率分配,传统下垂控制很难实现下垂系数按照不同频率特性的功率波动进行有效调节,其分配特性还会受线路阻抗等其它因素的影响。文章在传统下垂控制的基础上提出了模糊-下垂控制策略,实时优化下垂系数,平抑系统内部因素所引起的负面影响,实现直流微电网中不平衡功率在蓄电池和超级电容间的合理分配。通过MATLAB/Simulink仿真证明,所提出的模糊-下垂控制策略能够有效实现直流微电网中的功率调节,抑制母线电压的波动,提高了系统的鲁棒性。

Research on hybrid energy storage power distribution and bus voltage stabilization of photovoltaic DC microgrid based on fuzzy-droop control

In order to solve the problem of bus voltage fluctuation caused by the mismatch between photovoltaic output power and load consumption power in off grid photovoltaic DC microgrid, the hybrid energy storage device combining battery and super capacitor is usually used to compensate the power of the system. Generally, the power distribution of the energy storage device is carried out through droop control. The traditional droop control is difficult to achieve the droop coefficient according to different frequency characteristics, the distribution characteristics of power fluctuation can also be affected by line impedance and so on. Based on the traditional droop control, this paper proposes a fuzzy droop control strategy, which optimizes the droop coefficient in real time, suppresses the negative influence caused by the internal factors of the system, and realizes the reasonable distribution of the unbalanced power between the battery and the super capacitor in the DC microgrid. Matlab/Simulink simulation shows that the proposed fuzzy droop control strategy can effectively realize the power regulation in DC microgrid, suppress the fluctuation of bus voltage, and improve the robustness of the system.