Improved MPPT algorithm with reduced influence of partial shading on photovoltaic system

Abstract

The present invention discloses an improved MPPT algorithm with reduced influence of partial shading on a photovoltaic system. First step: a true maximum power point domain is determined, and the operating voltage of the system is shifted thereto with guaranteed celerity of tracking; given that the intersection point of the equivalent resistance line Rpm = Vpm/Ipm and the V-I characteristic curve for photovoltaic arrays under uniform light is the maximum power point, and the operating voltage at the end of the first step is determined by using the intersection point of this line and the V-I characteristic curve for photovoltaic arrays under partial shading; to prevent false tracking caused by the local minimum point and the pseudo maximum power point to the algorithm, the extreme points tracked during scanning are required to be recorded in the first step; and second step: maximum power point tracking is carried out from the operating voltage determined in the first step by using the incremental conductance algorithm. The improved MPPT algorithm with reduced influence of partial shading on a photovoltaic system may be less affected by the environment with high accuracy, less false tracking and good operating effect.

Description

technical field [0001] The invention relates to an improved MPPT algorithm for alleviating the influence of local shadows on photovoltaic systems. Background technique [0002] With the increasing energy crisis and environmental pollution, photovoltaic power generation, as an important way to utilize emerging green energy, is attracting more and more attention. However, photovoltaic cells are greatly affected by the external environment and the photoelectric conversion efficiency is low. In modern photovoltaic power generation systems, it is usually required to maintain the maximum output power of photovoltaic arrays. Therefore, the maximum power point tracking (MPPT) of photovoltaic systems has become an indispensable and important link in the process of photovoltaic power generation. [0003] At present, the commonly used MPPT algorithms mainly include: constant voltage method, disturbance observation method, conductance incremental method, open circuit voltage method, sh...

AI Technical Summary

Problems solved by technology

These algorithms have the function of global peak determination in principle, but there are certain defects in practical applications, such as: the scanning step size of the current scanning method is difficult to control, and it is easily affected by the change of its own electrical parameters, which depends too much on the algorithm, thereby reducing the The generality and transplantability of the

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