Method for intelligent control of maximum power point tracking of cascade multi-level photovoltaic grid-connected system

The invention relates to a method for intelligent control of maximum power point tracking of a cascade multi-level photovoltaic grid-connected system. The method is suitable for the cascade multi-level photovoltaic grid-connected system composed of a photovoltaic cell panel group, a cascade inverter, a signal detection module, a control module and a power grid. The method comprises a first step of establishing a mathematical model according to a topological structure of the cascade multi-level photovoltaic grid-connected system; a second step of determining the value range of the voltage modulation ratio of every inversion unit in the cascade inverter according to the mathematical model; a third step of utilizing the control module to simultaneously perform PWM control on every inversion unit in the cascade inverter; a fourth step of controlling voltage balance of inversion unit direct-current side capacitors according to the mathematical model to achieve maximum power output of the cascade multi-level photovoltaic grid-connected system. Compared with the prior art, the cascade multi-level photovoltaic grid-connected system can remarkably improve conversion efficiency, and intelligent control of the maximum power output is achieved.