The invention discloses a novel
photovoltaic inverter control method based on BP neural network and dual-mode structure
repetitive control. According to the invention the output of the photovoltaic grid-connected
inverter is connected to a power network after LCL filtering to carry out a sampling link. The phase theta extracted by the improved PLL is fed into the dqalpha beta transform. The difference between the reference
voltage of the DC side and the actual
voltage of the DC side is inputted into the PI controller; Obtaining the actual current
signal ig through abcalpha beta transformationfrom the sampled current of the power network side. The difference between the
reference grid-connected current ig and the actual current
signal ig in the alpha beta coordinate
system after the dqalpha beta transformation is subjected to the alpha beta abc transformation, and then is fed into the
composite controller together with the actual current
signal ig and the
reference grid-connected current ig. The signal processed by the
composite controller is sent to the notch filter for
processing, and then the processed signal is sent to the SVPWM module, so as to generate periodic switching signals for controlling the grid-connected
photovoltaic inverter, thereby suppressing the
harmonics of the grid-connected
photovoltaic inverter into the
power grid. The
compensation effect of the invention is superior to the traditional photovoltaic grid-connected
inverter.