The invention provides a high-efficiency stable photovoltaic single-phase grid connected control method with double MPPT functions and belongs to the technical field of photovoltaic generating control. The method is characterized in that: a high-speed
digital signal processor and a C-language dynamic
fixed point algorithm are utilized for forming a high-performance high-reliability
control algorithm for an overall photovoltaic single-phase grid connected
control system; by using a two-stage type grid connected control structure, a maximum power point tacking strategy of double MPPT rapid
smoothing, and a grid connected current prediction dead-beat
control algorithm, multiple strings of
photovoltaic arrays are enabled to be at optimization operation states and the maximum energy emitted by the
photovoltaic arrays is transformed through a stable bipolar type structure for outputting to a local
electrical network; and at the time when the multiple strings of
photovoltaic arrays are provided with double MPPT maximum power point tacking and grid connected current prediction dead-beat control, photovoltaic grid connected current is enabled to be completely consistent with a local single-phase
voltage phase. The advantages are as follows: the
power factor is 1, and the grid connected current
harmonic wave
distortion rate is lower than 3%, thus the
system operation is safe and reliable.