In order to make the PV generation system more flexible and expandable, the later power circuit is composed of a high step-up converter and a pulse-width-modulation (PWM) inverter. In the dc-dc power conversion, the high step-up converter is introduced to improve the conversion efficiency in conventional boost converters and to allow the parallel operation of low-voltage PV modules. Moreover, an adaptive total sliding-mode control (ATSMC) system is designed for the current control of the PWM inverter to maintain the output current with a higher power factor (PF) and less variation under load changes. Experimental results are given to verify the validity and reliability of the high step-up converter and the PWM inverter control for a grid-connected PV generation system.