Photovoltaic variable-step MPPT control method based on prediction technology

Abstract

The invention provides a photovoltaic variable step size MPPT control method based on a prediction technology, and belongs to the technical field of photovoltaic MPPT rapid tracking. The control system of the control method comprises a photovoltaic battery pack, an MPPT controller, a load and a DC-DC circuit connected with the load. According to the control method, the working state of the controller can be analyzed according to the sampling voltage and current value obtained by each sampling period of the controller, and the voltage and current value of the maximum power point (MPP point) on the output characteristic curve of the battery under the corresponding illumination intensity can be predicted when the illumination intensity changes, so that the optimal output duty ratio is calculated, the maximum power point (GMPP point) of the system can be quickly reached by the aid of the variable step size, the MPP point can be quickly and stably tracked from the GMPP point in combination with the variable step size, the problem that misjudgment is easy to occur when the illumination intensity of the MPPT controller is changed can be solved, and the response speed and the steady-state precision of the MPPT controller can be considered at the same time.

Description

Technical field [0001] The present invention relates to the technical field of photovoltaic power generation, and more particularly to a method of rapid tracking of photovoltaic MPPT. Background technique [0002] Energy is an important substance foundation for human production and survival. In order to meet the development of industrial, there are a large number of fossil fuels such as coal, oil, natural gas. Due to the non-renewableness of these fossil energy, many countries have faced energy depletion, in order to solve energy crisis countries are looking for alternative energy. As a clean energy, solar energy has a wide range of use in the world than wind energy solar energy has a better stability, service life, and simple maintenance. [0003] The power generation efficiency of the photovoltaic cell has been influenced by many people-uncontrollable external environment, light intensity, temperature, etc., wherein the change in light intensity has the greatest effect on the o...

AI Technical Summary

Problems solved by technology

The traditional P&O and INC algorithms both use a fixed step size for disturbance. Since the set value of the step size is fixed, the tracking effect is not good.

When the step size is set larger, larger shocks will occur in a stable state; when the step size is set smaller, it cannot be quickly disturbed to the maximum power point when the environment changes

At the same time, when the cloud layer moves to block the sunlight, resulting in continuous and slow changes in the light intensity, the traditional algorithm is prone to continuous misjudgment, and it is easy to cause a large energy loss at this time.

Images