具有惯性支撑的混合储能直流微电网协调控制策略

Coordinated control strategy for hybrid energy storage DC microgrid with inertia support

直流微电网具有低阻尼、弱惯性特点,在受到功率扰动或负荷突变时,其抵御干扰的能力较差,直流母线电压难以维持稳定。为克服该存在的局限性,提出了具有惯性支撑能力的直流微电网混合储能协调控制策略。该策略基于混合储能互补优势基础上,在变换器侧引入虚拟惯性控制,通过建立其控制系数与直流电压的函数表达式,使系统能够通过电压波动幅度提供一定程度的惯性支撑,从而改善直流微电网的弱惯性问题。最后,基于RT-Lab硬件在环实验进行验证,结果表明所提方法可以实现各微源单元之间的平滑切换,并有效抑制母线电压波动。

DC microgrids have the characteristics of low damping and weak inertia,making them vulnerable to external disturbances and difficult to maintain stable of DC bus voltage.To address this limitation,a hybrid energy storage coordination control strategy with inertial support for DC microgrids has been proposed.This strategy is based on the complementary advantages of hybrid energy storage and introduces virtual inertia control on the battery converter side.By establishing a functional expression between its control coefficient and DC voltage,it can provide a certain amount of inertial support to the system based on the size of voltage fluctuations,thereby improving the weak inertia of DC microgrids.Finally,a experimental platform based on RT-Lab is built to verify the effectiveness of the above control method.The results show that the strategy can achieve smooth switching between operating states of each micro-source unit and rapid stabilization of the DC bus voltage.