We put forward a system of the grid integration of photovoltaic（PV） power based on the module cascaded converter topology. Each PV module is connected to a half-bridge of the cascaded converter

which is integrated to the AC grid by an inverter. A constant DC voltage control is utilized to ensure the power balance between the AC and DC sides. In the presence of the cascaded half-bridge converter

the high-voltage level for the DC transmission purpose is built by series connections of low-voltage PV modules. The switching of half-bridges is determined according to the DC capacitor voltages of the PV modules. Thus

the output power of each PV module can be regulated accordingly

and the corresponding DC capacitor voltage is controlled at the desired value. Thus

the DC chopper in each PV module is able to convert the constant DC voltage from the related DC capacitor to a desired value for the maximum power point track（MPPT） of the PV array. The effectiveness of the proposed PV integration scheme is validated by detailed time-domain simulation results. Each PV array is operated at its maximum power point independently

and the DC voltages of the PV modules are kept to be balanced during unbalanced irradiance

which increases the efficiency of the PV integration.