Abstract: This paper presented the charge/discharge stage in the solar power system which is used by a multiple-winding bidirectional flyback converter. The maximum energy extraction from photovoltaic panels, battery charging and discharging dynamic control, and high voltage step-up to the inverter DC bus, also operating with soft-switching capability. In the normal operation of solar panels, the energy can be charged to the battery module. When one or more solar panels are out of order, the battery module supplies the energy to the load through the bidirectional flyback converter without affecting the operation of the load. Generally, one solar-energy maximum-power-point tracking circuit is with one battery module. So more tracking circuits need more battery modules. However, for the multiple-winding bidirectional flyback converter presented in this paper, it uses only one battery module and can be applied to the multiple solar energy maximum-power-point tracking circuits. Furthermore, about the charge way of battery, the interleaved energy charge method used to this bidirectional flyback converter is proposed in this paper. All the above mentioned functions are realized with digital signal processor to integrate the complete system. In order to capture the maximum energy from the PV module, solar inverters must guarantee that the PV module is operated at the MPP. This is accomplished by the maximum power point control loop known as the Maximum Power Point Tracker (MPPT).

Keywords: Flyback converter, photovoltaic array, single Energy storage, Maximum Power Point Tracker.