For 3-level flying capacitor photovoltaic (PV) inverter (FCPI), carrier-based phase-shifted method has the disadvantage of high line voltage harmonics and incapable of controlling flying capacitor voltage flexibly. This paper presents a grid-connected PV power generation system using novel carrier-based disposition PWM method which can balance flying capacitor voltage manually and reduce line voltage harmonics through adding zero-level vectors. This paper presents a 3-level FCPI grid-connected power generation system with proposed method, describes the basic principles of the proposed method and analyses the advantage of reducing line voltage total harmonic distortion (THD). Through Matlab/Simulink digital simulation and experiments, the results prove that the system has a fast response with capabilities of achieving maximum power point tracking (MPPT), stabling DC voltage and reducing line voltage of FCPI using the proposed method.