Multi-Objective Distributed Secondary Control Method for Multi-VSG Independent Microgrid

When a power grid composed of multiple virtual synchronous generators (abbr. VSGs) experiences external disturbances, traditional VSG control can lead to issues such as frequency and voltage deviations, low accuracy in reactive power sharing, and active power oscillations, which can easily cause system overload and instability. To address these problems, firstly, the droop characteristics and reasons for power oscillations of VSGs were analyzed. Secondly, a multi-objective coordinated secondary control strategy was proposed. In this strategy, the consistency frequency restoration control strategy for active power was used to adaptively adjust the reference value of active power to achieve frequency restoration and accurate proportional sharing of active power, the consistency and average voltage restoration control strategy for reactive power was used to adaptively compensate for voltage to achieve voltage restoration and accurate proportional sharing of reactive power. Finally, the effectiveness and robustness of this control strategy are verified through simulation.