The controlled flexible interconnection of multiple low-voltage DC microgrids can be achieved through low-voltage DC soft open point (LVDC-SOP). A key issue to address is how to achieve reasonable and flexible power exchange among sub-grids. To this end

a bidirectional droop control strategy for multi-port LVDC-SOP

which considers normalized voltage difference and power margin

is proposed. The power exchange rule based on normalized DC bus voltage difference is established. On this basis

a bidirectional droop control strategy for multi-port LVDC-SOP is developed

and a sub-grid power margin impact factor is designed. The droop coefficient can smoothly and continuously change throughout the operating range. The proposed strategy can adjust exchange power among sub-grids in real time according to changes in bus voltage and power margin of each sub-grid. At the same time

it can balance the adjustment ability of power exchange and stability of LVDC-SOP. The experimental results show that the proposed strategy can achieve reasonable

flexible power exchange among sub-grids. It can improve the adjustment capability of sub-grid to unbalanced power

and reduce the risk of exceeding the limit of DC bus voltage.