Photovoltaic module MPPT algorithm based on ripple association method

Abstract

The invention relates to a photovoltaic module MPPT algorithm based on a ripple association method. The algorithm is technically characterized mainly in that a photovoltaic battery model and a Boost circuit model are created; a ripple signal with the frequency equal to a switch frequency is obtained through a second-order improper integral-orthogonal signal generator; a reference voltage value isupdated, an error signal between the reference voltage value and an actual voltage value is adopted as input of a PI controller, the output of the PI controller is adopted as a duty ratio modulating signal, and a control signal obtained by means of a PWM circuit acts on a switch tube of a Boost circuit; an AND triggering threshold value of a transient state detector is created, when the radiationintensity of the sun changes suddenly, the transient state detector works, and the output of a sampling retainer is adopted as a reference voltage value of the next moment. The algorithm is reasonablein design, easy to implement and capable of enabling a photovoltaic grid-connected system to quickly track a maximum power point under different illumination, temperature and load conditions, enabling the system to stably work around the maximum power point and improving the conversion efficiency of photovoltaic batteries.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic power generation, in particular to a photovoltaic module MPPT algorithm based on a ripple correlation method. Background technique [0002] At present, environmental problems are becoming more and more prominent, and the development of new energy sources to realize the sustainable development of human society has become an important issue in the current world. As an inexhaustible renewable energy source, solar energy has been highly valued in the world today. Photovoltaic power generation has many advantages, but the low efficiency of traditional photovoltaic power generation system greatly restricts its large-scale promotion and application, and the use of maximum power point tracking technology (MPPT) can solve the above problems. [0003] The output characteristics of photovoltaic cells change with changes in ambient temperature and radiation intensity, but for specific light and temperat...

AI Technical Summary

Problems solved by technology

Commonly used MPPT algorithms, such as constant voltage method, perturbation and observation method, and hill climbing method, have disadvantages such as slow tracking speed, instability near the maximum power point, misjudgment prone to sudden changes in the external environment, complex algorithms and poor practicability, etc.

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