Photovoltaic MPPT control method based on fuzzy PI two-way linear prediction

Abstract

The invention discloses a photovoltaic MPPT control method based on fuzzy PI two-way linear prediction. The method includes the following steps that first, a power-voltage characteristic curve of a photovoltaic cell is obtained, two-way linear prediction is performed through the tangent line of the characteristic curve to approach the maximum power point, and the approximate maximum power point is obtained through calculation; second, on the basis of the approximate maximum power point, the actual maximum power point is tracked with a perturbation and observation method, and the error e(k) and the error conversion delta e(k) are calculated, wherein delta e(k)= e(k)- e(k-1), the k represents the period, P represents the power, and u represents the voltage; third, the error e(k) and the error conversion delta e(k) serve as input of a fuzzy controller, the Mamdani fuzzy reasoning method is adopted for the fuzzy controller, a fuzzy control rule is established with the target that the output power can fast reach a given value, and maximum power point tracking is achieved. The method effectively solves the problem that the tracking speed and the calculating precision can not be taken into consideration at the same time with a traditional MPPT control method, the maximum power point can be tracked fast and accurately, and the method is simple and practical.

Description

Technical field [0001] The invention belongs to the technical field of photovoltaic power generation, and more specifically, relates to a photovoltaic MPPT control method based on fuzzy PI bidirectional linear prediction. Background technique [0002] Due to the increasing lack of conventional energy sources such as petroleum, solar energy, as a renewable energy source, has ample reserves and has attracted more and more attention. Photovoltaic power generation is one of the main ways to use solar energy. However, current photovoltaic cells have defects such as low conversion efficiency and susceptibility to weather, which severely limits the large-scale promotion and application of solar energy. Therefore, how to effectively increase the output power of solar cells so as to make full use of solar energy is an important direction of photovoltaic research. [0003] The output voltage and output current of photovoltaic cells have a strong nonlinearity with changes in sunlight intensi...

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Problems solved by technology

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a photovoltaic MPPT control method based on fuzzy PI bidirectional linear prediction, which effectively solves the problem that the traditional MPPT control method cannot take into account the tracking speed and calculation accuracy, and can quickly and accurately Track the maximum power point, simple and practical

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