Maximum power point tracing method for photovoltaic array

Abstract

The invention relates to a maximum power point tracing method for a photovoltaic array. On the basis of the fundamental principles of the constant pressure method and the perturbation and observation method, the constant pressure method and the perturbation and observation method are combined together, and therefore photovoltaic array maximum power point tracing is achieved. When the photovoltaic array is far away from the maximum power point, larger perturbation step length is adopted to improve the tracing speed; when the photovoltaic array is near the maximum power point, the smaller perturbation step length is adopted; power oscillation of the photovoltaic array on the maximum power point is effectively reduced. The maximum power point tracing method for the photovoltaic array solves the contradiction between an original perturbation and observation method and power oscillation, and also solves the problem that the constant pressure method is not the maximum power point tracing method indeed.

Description

technical field [0001] The invention belongs to a method for tracking a maximum power point of a photovoltaic array, and in particular relates to a commonly used tracking algorithm for a maximum power point of a photovoltaic array such as a constant voltage method and a disturbance observation method. Background technique [0002] At a certain temperature, the voltage corresponding to the maximum power point of the photovoltaic array is almost distributed on both sides of a fixed voltage value under different light intensities. The constant voltage method believes that if the photovoltaic array is operated at this fixed voltage, it can be approximately considered that the photovoltaic array at this time is operating at the maximum power point. It can be seen from the principle that this method is not a real maximum power point tracking method, but because it only needs to detect the output voltage of the photovoltaic array, the detection parameters are few, and the control i...

AI Technical Summary

Problems solved by technology

If the selected disturbance step size D is large, the output voltage of the photovoltaic array will change greatly before and after the disturbance, and the response speed of the photovoltaic array to changes in the external environment will be faster, but a large disturbance step will also make the photovoltaic array The array produces a large power oscillation near the maximum power point; when the disturbance step size D is small, the output voltage of the photovoltaic array does not change much before and after the disturbance, which weakens the power oscillation near the maximum power point, but if the disturbance step size is small, the It will slow down the response speed of the photovoltaic power generation system to changes in external environmental factors

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