Relationship between performance and component att

  • Detail

The relationship between the performance of photovoltaic power station and the attenuation of components

the investability of photovoltaic power station is based on the state of power generation. Therefore, in the early feasibility assessment of photovoltaic power station construction, it is very important to estimate the power generation of the power station. Among them, the attenuation of components is one of the most critical factors

to estimate the power generation of photovoltaic power station relatively accurately, we should not only deeply understand the system structure of photovoltaic power station, but also have a comprehensive understanding of the performance parameters of main equipment. If you want to calculate the power generation of photovoltaic project in the whole life cycle, Zheng long, President of China synthetic resin supply and Marketing Association, said during the project: "Although metal materials 1 have always occupied a leading position in the automotive industry, the impact of internal and external environmental factors and the operation and maintenance of power stations.

factors involved in power generation estimation

at present, designers often estimate the power generation in the first year through software simulation, and then further calculate the power generation in the next 24 years based on the estimated value in the first year.

when estimating the power generation in the first year, the following factors usually need to be considered:

˙ Correction of sunlight irradiation amount of inclined plane

˙ Influence of foreign matters such as dust on the surface of components on light blocking

˙ Influence of temperature on photovoltaic module output

˙ Self attenuation of photovoltaic modules

˙ Matching loss of components in string

˙ Shadow occlusion loss between front and back rows of the square array

˙ DC line loss

˙ Inverter conversion efficiency loss

˙ Local transformer losses

˙ AC line loss

˙ Loss of main transformer

˙ Operation management is the most important influencing factor when calculating the power generation in the next 24 years due to the loss of self use power and downtime of the power station. Assuming that other conditions do not change, the attenuation of photovoltaic module itself becomes one of the most influential factors

attenuation analysis of photovoltaic module power

in practice, photovoltaic modules have been in the state of attenuation since they were manufactured, but the attenuation is very slow when there is no light in the package. Once they begin to receive sunlight, the attenuation will accelerate sharply, and gradually stabilize after a certain proportion of attenuation

total attenuation of 3% in the first year

for crystalline silicon components, the maximum attenuation value of the market system is generally vigorously improved. In the first year, the maximum attenuation value is 3%, and then it is 0.7% every year.

for crystalline silicon components, the attenuation in the initial stage is directly related to the light intensity

under the condition of average light intensity, it basically shows a sharp attenuation in the early stage and gradually stable in the late stage. However, in practice, the time span between the installation of components and the final generation of power in a photovoltaic power station varies. At the beginning of power generation, the components may have accumulated a certain proportion of attenuation. In order to reduce the error between the actual situation and the theoretical estimation, in addition to the requirements made at the starting time of the warranty, generally the components will have a certain proportion of positive power deviation when leaving the factory, and this positive power deviation can cover part of the attenuation loss of the components before power generation caused by human factors

therefore, in theoretical calculation, the starting point of rated power of power generation simulation calculation can be equal to the rated power of photovoltaic modules when they leave the factory, and the attenuation of modules within one year can be regarded as linear attenuation

distribution needs to be more carefully designed

generally speaking, the attenuation of photovoltaic modules is% in the first year, followed by no more than 0.8% per year, and no more than 20% in 25 years

there are many factors affecting power generation, and components are one of them. Some experts believe that according to the current actual application, the actual mismatch and attenuation discreteness of components are roughly a few tenths of a million, not to% of the degree. Many well-known component suppliers in China have considered and improved the standardization degree of components and the decay rate in the life cycle, which is related to the raw materials selected by the enterprise

in addition, the main reason for the mismatch of many power station components is not the component itself, but the shadow occlusion. This kind of shading is particularly prominent in distributed power stations in urban environments, which are mainly affected by the fixed shadows of surrounding buildings, trees and so on. For the rooftop power station whose location is not ideal, it is possible to lose% of power generation due to component mismatch due to periodic shading every day

in desert ground power stations, the main shadow shading comes from clouds. This kind of shading has an impact on the testing process of rubber tensile testing machine under the power generation explanation, but the degree of impact is very low, which is not the main consideration in the design of power station schemes. If there are periodic and large-scale shadows in the desert ground power station, there must be mistakes in the site selection and component layout design of the power station. On this basis, it is wrong to discuss the advantages and disadvantages of the access scheme

it is understood that since the large-scale development of domestic photovoltaic power stations in 2009, photovoltaic power stations have followed the environmental site selection standard of good lighting and less shading. However, with the continuous increase of the scale of distributed power stations in the future, the ideal geographical location is limited, and the sheltered or even more complex environment will become a possible power station development object. At this time, it is necessary to carry out the scheme design for the project with unsatisfactory illumination and occlusion, follow the principle of scientifically designing to replace the damaged one with the spare dry spring relay, and select the scheme combination according to the actual situation, so as to ensure the return on investment of the project

Copyright © 2011 JIN SHI