According to the shortcomings of photovoltaic grid connected inverter with high failure rate, high harmonic content, and complex control, a utility method of photovoltaic grid connected with DC-synchronous motor is proposed. Photovoltaic supply power is for DC motor in this photovoltaic grid connected system, and DC motor drives synchronous motor coaxial rotation, which realizes the conversion between DC and AC power. The grid connected control system includes maximum power point tracking control, motor speed control and synchronous motor terminal voltage control. The photovoltaic grid connection can be achieved when synchronous motor meets grid conditions. When connected to grid, the output of synchronous motor varies with the output of the photovoltaic. Simulative results verify the feasibility of the method based on MATLAB/Simulink. The grid voltage and current waveform are good, and active and reactive power can be provided to improve the power factor of the grid.%针对光伏并网逆变器存在故障率高、谐波含量大、控制复杂等问题，提出一种实用的光伏电源利用直流-同步电机并网的方案。该光伏并网系统中光伏电源为直流电机供电，直流电机带动同步电机同轴旋转，实现直流与交流电能之间的转换。并网控制系统包括光伏阵列最大功率跟踪控制、电机转速控制和同步电机端电压控制，当自动装置检测和判断同步电机满足并网条件时合闸并网。光伏系统并网后，同步电机的输出功率跟随光伏阵列输出功率的变化而变化。MATLAB/Simulink 仿真验证了该并网方案的可行性，该方案得到的并网电压、电流波形质量好，能够同时向电网提供有功和无功功率，有利于改善电网功率因数。
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