The main functions of the MPPT controller: detect the DC voltage and output current of the main circuit, calculate the output power of the solar array, and realize the tracking of the maximum power point. The disturbance resistor R and the MOSFET are connected in series. Under the condition that the output voltage is basically stable, the average current passing through the resistor is changed by changing the duty cycle of the MOSFET, so the disturbance of the current is generated.

At the same time, the output current and voltage of the photovoltaic cell will also change accordingly. By measuring the change of the output power and voltage of the photovoltaic cell before and after the disturbance, the disturbance direction of the next cycle is determined. When the disturbance direction is correct, the output power of the solar panel increases, and the lower The cycle continues to perturb in the same direction, on the contrary, perturb in the opposite direction. In this way, the perturbation and observation are repeated to make the output of the solar photovoltaic panel reach the maximum power point.