Investigation of the losses of photovoltaic solar systems during operation under partial shading

Abstract

The article deals with research in solar power plants and Renewable Energy Laboratory. The purpose of research was to study the influencing of partial shading on the energy efficiency of photovoltaic installations in various connection options. As the title implies the article describes a study of the possibilities of increasing their energy efficiency when operating under different conditions. It is spoken in detail about replacement of "block connection" panels to the "in-line connection", in case of partial shading by the previous string. It is shown that substitution allows to obtain a significantly higher power - up to 8 times. It is examined that the horizontal arrangement of the panels instead of the vertical, under the same conditions, also allows up to 5 times the power of the partially shaded array in the case "in-line connection" and by 34% in the case of a "block connection". It is analyzed that parallel connection of partially shaded photovoltaic array with normally illuminated, requires voltage matching, for the selection of electrical energy at the point of maximum power, which makes it possible to obtain much more energy from the shaded array. It is experimentally shown that when using the "Intelligent maximum power selection device" that implements the voltage matching, it is possible to increase the array power up to 4 times with partial shading of 3 panels of 18. It should be noted that the choice of methods that allow receiving energy from shaded panels through individual matching converters does not permit significantly increasing the energy production of partially shaded array. It is experimentally shown that as a result of their use the array power does not increase by more than 2.5%. The results of research can be used in the design of new installations based on photovoltaic cells and the modernization of existing ones.