Based on traditional photovoltaic combiner box, Hopewind C&D PV grid connected scheme adds DC/DC boost converter hardware units and MPPT control software units, realizes the function of maximum 4 PV strings (2 PV strings for standard) corresponding to 1 MPPT point. The scheme greatly reduces the efficiency loss caused by inconsistent of component parameters, partial shade, elevation difference. At the same time, the output voltage of improved PV combiner box (PV controller) rises to 820V~1000V, the output voltage of the inverter rises to 520V, reducing the transmission loss of AC/DC line and the heat loss of the inverter.