Communication-free power distribution method of hybrid energy storage system in isolated DC microgrid

In an island DC microgrid, sudden load changes can cause DC bus voltage instability. Hybrid energy storage is usually used to suppress DC bus voltage fluctuations. DC bus voltage recovery depends on the coordinated power distribution method between different types of energy storage. To address this problem, this paper proposes a flywheel-battery hybrid energy storage communication-free power distribution method, which solves the problem that the traditional fixed-division coefficient energy storage power distribution method cannot take into account both voltage recovery and power distribution effects. Given the relationship between voltage deviation and energy storage power division coefficient, a droop control method for adaptive power division coefficient is proposed. Finally, simulation and experimental results verify the effectiveness and superiority of the proposed control method.