Abstract: A three-port topology for the photovoltaic-storage system is proposed,which extends the battery port on the basis of the partial power processing phase-shifted full-bridge converter to solve the disadvantage of the poor anti-input disturbance ability of the partial power processing converter. Its battery port has the power control function,which is beneficial to improve the power density of the optical storage system. The paper first gives the circuit establishment process,and gives the mathematical description of power transmission and small signal model,and presents the control strategy of the converter. The simulation and experiment results show that the voltage stability of the converter is improved,and the functions of maximum power point tracking,charge and discharge control and load voltage regulation are realized,and the converter has good dynamic performance when the load changes.