In this paper, a photovoltaic module integrated microinverter with gradationally controlled voltage sources and a series connected buck converter or a full bridge inverter as an active filter is proposed. Recently, typical commercially used microinveter can achieve high efficiency. By using microinverter system, high Maximum Power Point Tracking (MPPT) efficiency by its small photovoltaic area can be achieved. The proposed circuit is a combination of a gradationally controlled voltage source with low switching frequency, a series connected active filter with high switching frequency and an unfolding circuit. The power to be converted in this circuit can be reduced to 1/8 as compared with a conventional full power conversion inverter. The circuit construction, the controller for the proposed circuits are described. In addition, the grid connected operations are verified by circuit simulation.