Photovoltaic grid-connected control method under unbalanced terminal voltage of three-phase distribution line

The invention relates to a photovoltaic grid-connected control method under unbalanced terminal voltage of a three-phase distribution line. A voltage Hall sensor is used for sampling the voltage of a power grid, and a voltage signal under a static coordinate system is obtained through 3/2 conversion. Respectively moving the voltage signal forward and backward by 1/4 period under the static coordinate system to obtain a delayed voltage signal, generating a current reference instruction by using the active power reference value, the reactive power reference value, the voltage component under the static coordinate system and the delayed voltage signal, sampling the output current of the photovoltaic grid-connected inverter by using a current Hall sensor, and calculating the output current of the photovoltaic grid-connected inverter. And a current signal under a static coordinate system is obtained through 3/2 conversion. And subtracting the current signal from the current reference instruction to obtain an error