Flexible Power Control for Stand-alone Interlinking Converter in PV and Storage System Application

The stand-alone interlinking converter is promising in residential PV systems due to its multiport, high power density, multifunction and power control flexibility. To exhibit the multifunction of the stand-alone interlinking converter, this paper proposes a flexible power control strategy with changeable operations. After configuring the grid-connected PV and storage system with the stand-alone converter, a flexible control method is proposed to enable the stand-alone converter to act as a DC-DC converter, a single-phase inverter, or an interlinking converter. In that case, the PV and storage system can flexibly operate under the PV+Battery mode, the Battery+Grid mode, and the PV+Battery+Grid mode. Experiments have been carried out on a hybrid grid-connected PV and storage system to validate the good performance in terms of versatility and flexible power controllability of the proposed control strategy.