Method and device for controlling photovoltaic grid-connected inverter, and apparatus

The invention discloses a method for controlling a photovoltaic grid-connected inverter. The method comprises: obtaining output voltage and output power of a photovoltaic cell at preset moment; according to variation trends of the output voltage and output power, performing iterative computation on an output current set value, until an output current reference value of a maximum power point tracking (MPPT) control module at a maximum power point of the photovoltaic cell is obtained; according to the output current reference value, calculating to obtain a current set value of a current inner loop, finally, based on a proportional resonance (PR) control strategy, realizing maximum power point tracking and photovoltaic inverter grid connected. Through the variation trends of the output voltage and output power of the photovoltaic cell, iterative computation is directly performed on the output current set value, and finally the current set value of the current inner loop is obtained. Compared with the prior art,