MPPT control method used for photovoltaic cell

Abstract

The invention provides an MPPT control method used for a photovoltaic cell. A genetic algorithm GA and a variable acceleration perturbation method are combined to conduct MPPT tracking on the photovoltaic cell, and the largest power point is precisely tracked. In the MPPT control method, according to a photovoltaic array output characteristic curve, sectional perturbation is conducted on the photovoltaic battery, according to the value of a voltage change amount dU, an appropriate step length scale factor and a perturbation step length are chosen, according to the value of the corresponding current change amount and the ratio of the corresponding current change amount and the voltage change amount, the perturbation direction is determined, and through a mathematical expression, the accelerating process of the variable acceleration perturbation method is proved; to further improve the tracking precision and reduce the tracking time of a system, the genetic algorithm is introduced, which is used for establishing an initial search duration; the simulation shows that by using the genetic algorithm and the variable acceleration perturbation method to conduct MPPT tracking on the photovoltaic cell, the system stability and the adaptive capacity for the environment can be improved, and the fluctuation near the largest power point is reduced.

Description

technical field [0001] The present invention relates to the technical field of solar photovoltaic power generation, and more specifically, to an MPPT control method for photovoltaic cells. Background technique [0002] Photovoltaic MPPT technology research has been relatively mature, and many different methods have been derived from the initial three methods of fixed voltage, conductance increment, and disturbance observation, and have been widely used in production. The article "Research on Photovoltaic Cell Modeling and MPPT Control Strategy" in the 26th issue of "Acta Electrotechnical Society" in 2011 aimed at the shortcomings of the traditional disturbance method, and proposed a variable step size control method, according to different power changes. The step size reduces the power loss caused by voltage changes, but it cannot make a quick judgment when the light intensity changes. In the 42nd issue of "Power System Protection and Control" in 2014, the article "Analysis...

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Problems solved by technology

[0004] In order to overcome the shortcomings in the above-mentioned prior art, improve the poor adaptability of the traditional perturbation method to the external environment, reduce the oscillation of the perturbation method at the maximum power in the steady state, and improve the tracking speed of the system, a photovoltaic system is provided. The MPPT control method of the battery uses the combination of the genetic algorithm and the variable acceleration perturbation method to track the MPPT of the photovoltaic battery and accurately track the maximum power point

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