Power flow interactive sharing between two DC nanogrids photovoltaic local branch dynamic systems at Island operation

摘要

Nowadays DC nanogrid topologies are going spread with the deployment of distributed generation. Therefore, the investigation of interactive sharing between DC nanogrid branches is mandatory to realize a continuous operation of the photovoltaic considering: maximum power tracking, Off-maximum power point tracking, load sharing, and battery charge sharing. This paper discusses the power flow interaction among two DC nanogrids in island mode. To demonstrate that, a detailed dynamic branch modeling systems is proposed. The MPPT and Off-MPPT control are tested on this nanogrid dynamic model; the MPPT is working continuously unless the two BSS are fully charged which is known by the reference indicator state of charge (SOC) value. If the BSS reaches SOC 100 %, the Off-MPPT control will be operated to stop extraction of more power. The objective of interactive sharing is proposed by a control approach for the bidirectional converter utilized in charging and discharging of BSS. This control approach with the support of simple nanogrid controller transfers power via transmission line to performs load sharing and BSS charging of the nanogrid. The power transfer between the two buses will be performed by rising the sending bus voltage above the receiving bus.