Optical filter for ultraviolet pretreatment test of photovoltaic module and preparation method thereof
Technical Field
The application relates to the technical field of optical filters, in particular to an optical filter for ultraviolet pretreatment test of a photovoltaic module and a preparation method thereof.
Background
Ultraviolet rays are the general term for radiation with the wavelength of 10-400nm in electromagnetic spectrum, and can be divided into long-wave ultraviolet rays, medium-wave ultraviolet rays and short-wave ultraviolet rays according to the difference of the wavelengths of the ultraviolet rays, wherein the wavelength of the long-wave ultraviolet rays is 320-400nm, the wavelength of the medium-wave ultraviolet rays is UVB, the wavelength of the medium-wave ultraviolet rays is 280-320nm, the wavelength of the short-wave ultraviolet rays is UVC, and the wavelength of the short-wave ultraviolet rays is 200-280nm.
In the ultraviolet pretreatment test of the photovoltaic module, the metal halogen lamp is a commonly used ultraviolet pretreatment test light source of the photovoltaic module, and is suitable for stress screening due to the ultra-high ultraviolet intensity; however, the problem of light source duty ratio is always a technical problem, if the test conditions of the four types of photovoltaic cell components, namely 280-385nm, are defined as total ultraviolet, c-si, CIGS, cdTe, a-si, require that the duty ratio of UVB in the total ultraviolet is 3-10%, the test conditions of the cell components except for the four types require that the proportion of UVB in the total ultraviolet is more than or equal to 1/3, and as UVB to UVA are continuous spectrums, if duty ratio mismatch can cause the problem of stress screening distortion, the current common practice in the industry is that UVB and UVA are respectively subjected to two experiments, namely the UVB and UVA light sources respectively irradiate a sample once, and the accumulated values respectively reach the standard requirements, so that the light sources need to be switched in the test process, and the test energy consumption and the test period are prolonged.
Disclosure of Invention
In order to enable the occupation ratio of 280-320nm to 280-385nm to meet the test requirement of the photovoltaic module, the application provides an optical filter for the ultraviolet pretreatment test of the photovoltaic module and a preparation method thereof.
In a first aspect, the present application provides a filter for an ultraviolet pretreatment test of a photovoltaic module, which adopts the following technical scheme:
ultraviolet pretreatment test for photovoltaic moduleThe experimental optical filter comprises a substrate and a film layer arranged on the surface of the substrate, wherein the film layer is formed by alternately stacking materials with high refractive index and low refractive index, and has a film system structure (HL) 7 Wherein H is a high refractive index material; l is a low refractive index material and 7 is the number of times high refractive index and low refractive index materials are alternately stacked together.
Optionally, the high refractive index material is HFO 2 The low refractive index material is SiO 2 The raw materials and thickness distribution of the film layer are as follows:
the thickness error of the whole film layer is in the range of 1 nm.
By adopting the technical scheme, the initial thickness of the thickness distribution of the film layer is thinner, and the film layers are stacked together and alternately for 4 times in the middle and are all of the thickness HFO 2 =56.58 nm, thickness SiO 2 =77.05 nm, while a film layer made with a thicker final thickness helps to ensure spectral accuracy and transmittance.
Optionally, the thickness of the substrate is 2mm, and the substrate adopts high borate.
Through adopting above-mentioned technical scheme, substrate thickness can influence the shortwave light transmissivity, and this application adopts 2 mm's high borate substrate can absorb nearly 100% UVC, makes the UVC occupation ratio accord with the basic condition of photovoltaic module ultraviolet ray pretreatment test.
Optionally, a metal halogen lamp is used as a light source for a solar ultraviolet rapid aging test, and the average transmittance T of the optical filter at the wave band of 250-280nm is less than 0.1 percent (the coating film is high in transmittance and the substrate is absorbed); the mean transmittance t=92% over the wavelength band 280-385nm allows a deviation of ±3%.
By adopting the technical scheme, the metal halogen lamp is used as a solar ultraviolet rapid aging test light source, and the metal halogen lamp has low relative light energy loss and is more suitable for being used as a test light source because the ultraviolet energy of the metal halogen lamp accounts for about half of the full spectrum.
Alternatively, UV band 280-385nm is defined as 100% and UV band 280-320nm is 33.5%.
By adopting the technical scheme, the ultraviolet band 280-320nm (namely the medium-wave ultraviolet rays) accounts for 33.5 percent (namely not less than 1/3 and infinitely close to 1/3) of the ultraviolet band 280-400nm (namely the medium-wave ultraviolet rays and the long-wave ultraviolet rays), so that UVB deficiency can be prevented, UVB superscalar can be prevented, and the proportion of UVB to total ultraviolet required by test conditions of battery components except the c-si, CIGS, cdTe, a-si type can be met.
In a second aspect, the present application provides a method for preparing an optical filter for an ultraviolet pretreatment test of a photovoltaic module, which adopts the following technical scheme:
the preparation method of the optical filter for the ultraviolet pretreatment test of the photovoltaic module comprises the following steps:
heating high refractive index material and low refractive index material, plating on the surface of substrate by vacuum sputtering, controlling error of film thickness less than 1%, and vacuum degree of 3×10 -3 Pa。
By adopting the technical scheme, the filtering can be carried out on different ultraviolet wave bands by combining the coating process, the material selection and thickness adjustment of the substrate and the film layer, and different test samples can be dealt with in proportion serialization; according to the relative spectral intensity distribution of the metal halogen lamp light source, a matched filter is designed, so that the ultraviolet light passing through the filter is close to the standard value regulated by the international electrotechnical commission standard.
In summary, the present application includes at least one of the following beneficial technical effects:
1. the optical filter can filter different ultraviolet wave bands, and meets the requirements of coping with different test samples;
2. according to the relative spectral intensity distribution of the metal halogen lamp light source, a matched filter is designed, so that the ultraviolet light passing through the filter is close to the standard value regulated by the international electrotechnical commission standard;
the spectral filter with the filtering characteristic is used, the ultraviolet band 280-385nm is defined as 100%, and the ultraviolet band 280-320nm accounts for 33.5%.
Drawings
FIG. 1 is a graph of UV spectrum design for a UVB 33.5% ratio using a metal halide lamp as the test light source.
Detailed Description
The present application is described in further detail below with reference to examples.
Example 1
The optical filter for the ultraviolet pretreatment test of the photovoltaic module comprises a substrate and a film layer arranged on the surface of the substrate, wherein the film layer is formed by alternately stacking materials with high refractive index and materials with low refractive index, and the film system structure is (HL) 7 Wherein H is a high refractive index material; l is a low refractive index material, and 7 is the number of times that high refractive index and low refractive index materials are alternately stacked together;
the thickness of the substrate is 2mm, and the substrate is high borate;
the high refractive index material is HFO 2 The low refractive index material is SiO 2 The raw materials and thickness distribution of the film layer are as follows:
the thickness error of the whole film layer is in the range of 1 nm.
The preparation method of the optical filter for the ultraviolet pretreatment test of the photovoltaic module comprises the following steps:
heating high refractive index material and low refractive index material, plating on the surface of substrate by vacuum sputtering, controlling error of film thickness less than 1%, and vacuum degree of 3×10 -3 Pa, and obtaining the optical filter.
Performance test
1. The metal halogen lamp is used as a light source for the solar ultraviolet rapid aging test, and average transmittance measured in the wave bands of 250-280nm, 280-320nm and 320-385nm are tested for multiple times respectively.
The filter test results of example 1 are shown in FIG. 1.
The first graph shows that the average transmittance T of the filter at the wave band of 250-280nm is less than 0.1 percent (the coating film is high in transmittance and the substrate absorbs); the mean transmittance t=92% over the wavelength band 280-385nm allows a deviation of ±3%.
Calibration test: the spectral irradiance distribution of the ultraviolet test box is measured by an optical fiber spectrometer, the spectral irradiance data is derived, and the UVB (280-320 nm) ultraviolet integral irradiance and the (UVA+UVB) (280-385 nm) total integral irradiance are calculated by the formula: f=e UVB /E UVA +E UVB X 100% and the proportion of UVB irradiance to (uva+uvb) irradiance was calculated.
Calibration results: the proportion of UVB (280-320 nm) ultraviolet integrated irradiance to (UVA+UVB) (280-385 nm) total integrated irradiance is: 33.5%.
2. Application of optical filter to ultraviolet pretreatment test of photovoltaic module
The test results are shown in Table 1.
TABLE 1 comparison of filter characteristics and parameters defined by International electrotechnical Commission standards
As can be seen by combining example 1 and Table 1, the ultraviolet band 280-320nm (i.e., mid-wave ultraviolet) accounts for 33.5% of the ultraviolet band 280-385nm (i.e., mid-wave ultraviolet and long-wave ultraviolet) (i.e., not less than 1/3 and infinitely close to 1/3), which can prevent UVB deficiency and UVB superscalar, and can meet the ratio of UVB to total ultraviolet required by the test conditions of the battery pack except for the c-si, CIGS, cdTe, a-si category.
The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.