Variable step size perturbation observation MPPT algorithm based on dichotomy

Abstract

The invention provides a variable step size perturbation observation MPPT algorithm based on a dichotomy. The method comprises the steps that an appropriate disturbance voltage range is set, the initial disturbance step size accounts for one half of the appropriate disturbance voltage range, it can be judged whether or not reverse disturbance is needed during disturbance, if yes, the disturbance step size is halved, and if no, disturbance is carried out in the same direction with the current step size; the maximum power point is tracked through continuous iteration, a comparison method is usedduring iteration each time, the maximum power point of a system is updated by comparing the current maximum power point, a power point in the n time and a power point in the n+1 time during iteration, disturbance is stopped until the end conditions are met, and the maximum power point of the system is determined. In addition, when the external temperature and illumination change, a new maximum power point range is rapidly found through an a-time method, and then the new maximum power point is rapidly tracked by reusing the dichotomy. The variable step size perturbation observation MPPT algorithm based on the dichotomy solves the problems of most algorithms that the tracking speed is not fast enough, the maximum power point has oscillation, the algorithms are complex, and the implementation cost is high.

Description

technical field [0001] The invention relates to the technical field of maximum power point tracking algorithms in photovoltaic systems, in particular to a dichotomous method-based variable step size perturbation observation MPPT (Maximum Power Point Tracking, maximum power point tracking) algorithm. Background technique [0002] After a lot of research on the maximum power point tracking algorithms in photovoltaic systems, it is found that most of the algorithms have problems such as insufficient tracking speed, oscillation of the maximum power point, complex algorithms or high implementation costs. [0003] In photovoltaic systems, in order to quickly track to the maximum power point, improve tracking efficiency, reduce shocks, and adapt to environmental changes, a series of maximum power tracking algorithms have been proposed, mainly including the following categories of algorithms: [0004] (1) Constant voltage algorithm: According to the principle that the voltage positi...

AI Technical Summary

Problems solved by technology

[0006] The efficiency of the constant voltage algorithm is low, and the tracking accuracy is poor; it is greatly affected by the external temperature, and a large error will occur when the external temperature changes

[0007] Due to its inherent characteristics, the perturbation and observation algorithm generates oscillations near the maximum power point, and is prone to misjudgment when the external environment changes, and cannot guarantee high tracking speed and tracking accuracy at the same time.

[0008] The conductance incremental algorithm also has oscillations and misjudgments near the maximum power point, which has high requirements for sensors and system hardware, and is difficult to implement and relatively expensive

[0009] The particle swarm algorithm itself is more complicated, and there will be some oscillations near the maximum power

[0010] The structure of the neural network algorithm is relatively complex, the hardware requirements are relatively high, and it also requires a long training time

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