A maximum power point tracking method under partial shading of photovoltaic arrays

Abstract

The invention discloses a maximum power point tracking method for a partially shielded photovoltaic array. The method comprises steps of carrying out modeling analysis for the partially shielded photovoltaic array by avoiding power consumption caused by scanning of (i)P-V( / i) curves; introducing constraint conditions into the MPPT method, and intelligently judging contracting direction and size of search region; and taking three points in the search region according to the (i)P-V( / i) curves to roughly describe trend of the (i)P-V( / i) curves. If it is judged that the rough trend is a peak graph, the maximum power point occurs in the middle of the search region, so 1 / 2 of region should be contacted bilaterally from outside to inside, otherwise, the maximum power points occur on two ends of the search region, so by computing the sum of power of the three points on each of the ends, unilateral contract direction can be precisely grasped, thereby avoiding falling into the partial maximum power point. The invention provides the MPPT method combining unilateral contraction and bilateral contraction, so by intelligently adjusting contraction speed, falling into the local maximum power point is avoided, and while the tracking precision of the overall maximum power point is ensured, tracking speed is increased.

Description

technical field [0001] The invention relates to a method for tracking a maximum power point of a photovoltaic array, in particular to a method for tracking a maximum power point of a photovoltaic array under partial shading. Background technique [0002] Maximum Power Point Tracking (MPPT) is a key technology that enables photovoltaic arrays to output more power by adjusting the operating voltage of circuit modules. Because it can detect the output voltage of the photovoltaic array in real time and quickly track the maximum power point, so that the system can output electric energy with the highest efficiency, its research has received extensive attention. So far, many classic MPPT methods have been proposed, such as constant voltage method, perturbation and observation method (Perturb and Observe, referred to as P&O), admittance incremental method (Incremental Conductance, referred to as IncCond), and other improved methods. However, due to the complexity of the environmen...

AI Technical Summary

Problems solved by technology

Since Jaya Agrawal and Ramaprabha use the method of unilaterally reducing the scanning range to determine the global maximum power point, when the complexity of illumination intensity increases, once the global maximum power point is missed in the early stage, it will be difficult to make up for it in the later stage

Therefore, the above two methods cannot guarantee the tracking of the global maximum power point when dealing with two or more local maximum power points with similar values.

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