Desempeño de un controlador de carga en condiciones de sombreado parcial en la ciudad de Manizales

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 Performance of a charge controller in partial shading conditions in the city of Manizales

Desempeño de un controlador de carga en condiciones de sombreado parcial en la ciudad de Manizales

ABSTRACT

In the use of autonomous photovoltaic systems, optimizing them is vitally important, so that they deliver the maximum available power at all times. Under shading conditions and non-uniform solar irradiation, the power and voltage curve of these systems is more complex, with the appearance of multiple points of local maximum power (LMPP). Under these conditions it is important to know the behavior of the charge controller, and to determine to what extent it can identify the point of maximum global power (MPP) of the system. This research evaluated the operation and performance of a maximum power charge controller (MTTP) for two types of photovoltaic technology: mono and polycrystalline silicon, under different shading and solar irradiation conditions in the city of Manizales-Colombia. It was found that the controller performance varies depending on the shading percentage, the shading shape, the irradiation level, and the type of solar panel technology. During the design stage of autonomous systems, it is necessary to study the shading configurations that the system will undergo. This could affect the decision on the type of solar panel technology to be installed. Likewise, it will also influence the orientation of the string, and how they are spatially arranged in the installation area. We consider this is a relevant contribution to the state of the art regarding the design and installation of stand-alone photovoltaic systems.

Keywords: photovoltaic modules, maximum power controllers, solar irradiation, renewable energies.

RESUMEN

En el uso de sistemas fotovoltaicos autónomos es de vital importancia la optimización de los mismos, para que en todo momento entreguen la máxima potencia disponible. Bajo condiciones de sombreado e irradiación solar no uniforme, la curva de potencia y corriente de estos sistemas resulta más compleja, con la aparición de múltiples puntos de potencia máxima local (LMPP). Bajo estas condiciones es importante conocer el comportamiento del controlador de carga, y determinar hasta qué punto puede identificar el punto de máxima potencia global (MPP) del sistema. Esta investigación evaluó el funcionamiento y desempeño de un controlador de carga máxima potencia (MTTP) para dos tipos de tecnología fotovoltaica: silicio mono y policristalino, bajo diferentes condiciones de sombreado e irradiación solar en la ciudad de Manizales. Se encontró que el rendimiento del controlador varía dependiendo del porcentaje de sombreado, la forma de sombreado, el nivel de irradiación, y el tipo de tecnología de panel solar. Durante la etapa de diseño de sistemas autónomos, es necesario estudiar las configuraciones de sombreado que sufrirá el sistema. Esto podría afectar la decisión del tipo de tecnología de paneles solares a instalar. Así mismo, también influirá en la orientación de las cadenas de series, y cómo están dispuestas espacialmente en el área de instalación. Se considera que esto es un aporte relevante al estado del arte, respecto al diseño e instalación de los sistemas fotovoltaicos autónomos.

Palabras clave: módulos fotovoltaicos, controladores de máxima potencia, irradiación solar, energías renovables.

Received: June 08 th 2021

Accepted: January __th 20xx

Introduction^[1] [2]

Solar energy has become a source of great importance in the world, driven by the need to satisfy a growing energy demand and the social pressure to protect the environment. The continuous climatic changes, the limited traditional energies, pollution, among other factors, have led mankind to carry out research processes focused on renewable energies. Photovoltaic solar energy has become a viable alternative within renewable energies.

Solar energy is energy obtained from solar radiation that reaches the earth in the form of light, heat or ultraviolet rays. It is a type of clean and renewable energy, because its source, the sun, is an unlimited resource. To transform solar energy into electric energy, electromagnetic radiation from the sun is collected by different means (thermal collectors, photovoltaic cells, etc.). Photovoltaic conversion is the process by which solar energy is transformed directly into electricity. The device or element that mediates in the process is the solar cell or photovoltaic cell. Photovoltaic systems allow the transformation of sunlight into electric energy, that is, the conversion of a particle with light energy (photon) into electromotive energy (voltaic).

The efficiency of a photovoltaic system as an electric power generator is determined by variables that influence it. The solar radiation that affects photovoltaic modules varies greatly depending on the specific conditions of the environment. For example, some shadows during the day that may be predictable, the case of a building located in the vicinity of the panel installation. Other shadows are more difficult to predict, for example, those produced by clouds. These conditions require constantly determining, moment by moment, the point on the voltage and current characteristic of the photovoltaic generator, at which the power generated is maximum.

For these reasons, it is proposed to develop the present investigation of the operation and performance of a maximum power controller for photovoltaic modules of two types of materials: monocrystalline, polycrystalline. We worked in different shading and irradiation conditions in the city of Manizales. To achieve the objective, it is necessary to thoroughly analyze the factors that affect the capture and transformation of solar energy and understand the behavior of maximum power point controllers (MPPT).

Methodology

For the analysis of the behavior of the components in the system, two panels in monocrystalline and polycrystalline were used connected in series the MPPT controller, as well as the curve plotter, the total power of the panels is 300W, in the following table is the technical data of the solar panels.

Table 1. Solar Panel Spec Datasheet

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Source: Authors

The taking of measures is stipulated every 15 minutes for a period of 6 hours in the hours of 9:00 in the morning to 15:00, for a total of 24 data in the day, through the collection of the data can vary the time or the amount of data taken. At this point it is important to note that during most working days it was not possible to carry out the 24 measures, due to variable weather conditions in the city of Manizales.

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