SOLAR POWER PHOTOVOLTAIC THREE-PHASE MICRO-INVERTER SYSTEM AND METHOD FOR IMPROVING CONVERSION EFFICIENCY THEREOF

摘要

A solar power photovoltaic three-phase micro-inverter system and a method for improving conversion efficiency thereof.The solar power photovoltaic three-phase micro-inverter system (500) includes a plurality of three-phase micro-inverters (501), with each three three-phase micro-inverters being one group connected to a three-phase alternating current grid (504).Each three-phase micro-inverter includes three single-phase inverter circuits (502), each single-phase inverter circuit including two sets of conversion circuits (A1, A2; B1, B2; C1, C2), and each set of conversion circuits corresponding to one phase in the three-phase alternating current grid.The alternating current outputs of the same set of conversion circuits in the three micro-inverters within one group are respectively connected to the three-phase live wires (L1, L2, L3) of the three-phase alternating current grid.When the power summation decreases from a full load, each three-phase micro-inverter will turn off the same single set of conversion circuits successively so as to improve the conversion efficiency in a low power state.