An isolated household grid-connected photovoltaic power system

An isolated grid-connected photovoltaic (PV) power system for household is proposed and the control strategy of the system is presented in this paper. The proposed PV system employs an interleaved boost converter as the first power-processing stage, which can boost a low voltage of PV array up to a high dc-bus voltage. In the traditional isolated PV system, industrial low-frequency transformers are often used for electrical isolation. However, with the shortage of large volume, great weight and high noise, it is not suitable for household application. In this paper, dual active bridge (DAB) is used as the second power-processing stage to achieve high-frequency isolation and a fullbridge inverter is used as the third power-processing stage which can stabilize the dc-bus voltage and shape the output current. At last, a 1.5KW prototype has been built and verify the design presented in this paper.