CN-116111003-B - Determination method for transparency of insulating material and double-sided rate of back contact assembly

CN116111003BCN 116111003 BCN116111003 BCN 116111003BCN-116111003-B

Abstract

The invention discloses a method for determining transparency of an insulating material and double-sided rate of a back contact assembly, relates to the technical field of photovoltaic cells, and aims to determine the transparency of the insulating material and improve calculation accuracy of the double-sided rate of the back contact battery or the back contact assembly. The insulating material is formed on a portion of the area of the back surface that is in back contact with the cell. The method for determining the transparency of the insulating material comprises the steps of obtaining first spectral responsivity corresponding to a first area on one side of a backlight surface of a back contact battery and second spectral responsivity corresponding to a second area under the same incident wave band. The surface of the first region is covered with an insulating material, and the surface of the second region is not covered with an insulating material. The transparency of the insulating material at the incident wavelength band is determined based on the wavelength range of the incident wavelength band, the first spectral responsivity, and the second spectral responsivity. The method for determining the double-sided rate of the back contact assembly comprises a method for determining the transparency of the insulating material.

Inventors

LIU HONGZHI
ZHAO DEBAO
ZHANG CAIXIA
CHEN JUN
LI HUA

Assignees

泰州隆基乐叶光伏科技有限公司

Dates

Publication Date: 20260512
Application Date: 20221221

Claims (7)

1. A method for determining transparency of an insulating material, wherein the insulating material is formed on a partial region of a backlight surface of a back-contact cell; the method for determining the transparency of the insulating material comprises the following steps: acquiring first spectral responsivity corresponding to a first area and second spectral responsivity corresponding to a second area on one side of a backlight surface of the back contact battery under the same incidence wave band, wherein the surface of the first area is covered with the insulating material, and the surface of the second area is not covered with the insulating material; determining a transparency of the insulating material at the incident wavelength band based on a wavelength range of the incident wavelength band, the first spectral responsivity, and the second spectral responsivity; Wherein determining the transparency of the insulating material in the incident wavelength band based on the wavelength range of the incident wavelength band, the first spectral responsivity, and the second spectral responsivity comprises: Determining a first short-circuit current density corresponding to the first region based on the wavelength range of the incident band and the first spectral responsivity; determining a second short-circuit current density corresponding to the second region based on the wavelength range of the incident band and the second spectral responsivity; the ratio of the first short-circuit current density to the second short-circuit current density is the transparency of the insulating material at the incident wavelength band.
2. The method of determining transparency of an insulating material according to claim 1, wherein the first spectral responsivity and the second spectral responsivity are acquired by a quantum efficiency tester.
3. The method of determining transparency of an insulating material according to claim 2, wherein the quantum efficiency tester has positive and negative electrodes respectively connected to adjacent one of the positive and negative bus electrodes in the back contact cell; the first region and the second region are both located within the collection range of the adjacent one of the positive bus electrode and the negative bus electrode.
4. The method for determining the transparency of an insulating material according to claim 1, wherein the electrode pattern corresponding to the first region is identical to the electrode pattern corresponding to the second region, and/or, The part of the back contact battery located in the first area is identical to the film layer structure of the part of the second area.
5. The method for determining transparency of an insulating material according to claim 1, wherein the wavelength range of the incident wavelength band is 300nm or more and 1200nm or less.
6. A method for determining a double-sided rate of a back contact assembly, comprising: acquiring an initial double-sided current ratio of a back contact battery not formed with an insulating material; Forming an insulating material on a corresponding region of a backlight surface of the back contact cell, and determining an area ratio of the insulating material on the backlight surface; sequentially laying packaging adhesive films and glass cover plates on the light-facing surface and the backlight surface of the back contact battery, and carrying out lamination treatment to obtain a back contact assembly, wherein a glaze plating layer is arranged on the glass cover plates; obtaining the transparency of the insulating material in the back contact assembly by adopting the method for determining the transparency of the insulating material according to any one of claims 1-5; correcting the initial double-sided current ratio based on structural related parameters of the double-sided current ratio of the back contact assembly, transparency of the insulating material in the back contact assembly and area occupation ratio of the insulating material on the backlight surface to obtain the double-sided current ratio of the back contact assembly; determining a double-sided rate of the back contact cell based on a double-sided current ratio of the back contact assembly; The structure related parameters of the double-sided current ratio of the back contact assembly comprise a light-facing surface current loss ratio of the back contact assembly, a backlight surface current loss ratio of the back contact assembly and a newly increased shading area ratio of the backlight surface of the back contact assembly; the structure-related parameters of the double-sided current ratio of the back contact assembly further comprise the optical gain of the glazing layer to the opposite light surface and the optical gain of the glazing layer to the backlight surface; the calculation formula of the double-sided current ratio of the back contact assembly is as follows: ; Wherein, gamma is the double-sided current ratio of the back contact battery, k is the initial double-sided current ratio, alpha is the light facing surface current loss proportion of the back contact component, beta is the backlight surface current loss proportion of the back contact component, a is the newly increased shading area proportion of the backlight surface of the back contact component, delta is the light gain of the light facing surface of the glaze plating layer, b is the area proportion of the glaze plating layer positioned on the backlight surface and the glaze plating layer positioned on the light facing surface, c is the area proportion of the insulating material on the backlight surface, and n is the transparency of the insulating material in the back contact component.
7. The method of claim 6, wherein the initial double-sided current ratio is a ratio of a short-circuit current density corresponding to a backlight surface and a light-facing surface of the back contact cell in which the insulating material is not formed.

Description

Determination method for transparency of insulating material and double-sided rate of back contact assembly Technical Field The invention relates to the technical field of photovoltaic cells, in particular to a method for determining transparency of an insulating material and double-sided rate of a back contact assembly. Background A back contact cell refers to a solar cell where both positive and negative electrode contacts are on the back (or in-vivo) of the cell and the front is not obscured by the metal electrode. Compared with a photovoltaic cell with a shielding front surface, the back contact cell has higher short-circuit current and photoelectric conversion efficiency, and is one of the technical directions for realizing the high-efficiency crystalline silicon cell at present. In addition, in the practical application process, the backlight surface of the back contact battery is usually printed with an insulating material, so that the positive electrode and the negative electrode of the back contact battery are prevented from being short-circuited through the in-string interconnection piece, and the electrical stability of the back contact battery is improved. However, the insulating material has a certain light-shielding property, and affects the light receiving effect of the back surface of the back contact battery. In contrast, when those skilled in the photovoltaic field study the double-sided rate of the back contact cell or back contact module, the light-shielding property of the insulating material is not taken into consideration, so that the calculated value and the measured value of the double-sided rate of the back contact cell or back contact module are greatly different. Disclosure of Invention The invention aims to provide a method for determining transparency of an insulating material and double-sided rate of a back contact assembly, which is used for determining the transparency of the insulating material and is beneficial to improving calculation accuracy of the double-sided rate of the back contact battery or the back contact assembly. In a first aspect, the present invention provides a method of determining the transparency of an insulating material. Wherein the insulating material is formed on a partial region of the back surface of the back contact cell. The method for determining the transparency of the insulating material comprises the following steps: And acquiring the first spectral responsivity corresponding to the first area and the second spectral responsivity corresponding to the second area on the side of the backlight surface of the back-contact battery under the same incident wave band. The surface of the first region is covered with an insulating material, and the surface of the second region is not covered with an insulating material. The transparency of the insulating material at the incident wavelength band is determined based on the wavelength range of the incident wavelength band, the first spectral responsivity, and the second spectral responsivity. Under the condition of adopting the technical scheme, because the positive electrode and the negative electrode of the back contact battery are formed on the backlight surface, and in the process of connecting at least two back contact batteries in series to form a battery string through the in-string interconnection piece, the actual placement position of the in-string interconnection piece can deviate relative to the bus electrode connected with the in-string interconnection piece, so that the insulating material is formed on the partial area of the back contact battery, the positive electrode and the negative electrode of the back contact battery can be prevented from being short-circuited or open-circuited through the in-string interconnection piece, and the electrical stability of the back contact battery is improved. In addition, in the actual determination process, the spectral responsivity of the back contact battery can be understood as the "transmittance" of the back contact battery to light rays with different wavelengths, so in the case that the back light surface of the back contact battery is formed with the insulating material, the transparency of the insulating material under the incident wave band can be obtained by acquiring and analyzing the first spectral responsivity corresponding to the first region covered with the insulating material on the back light surface side of the back contact battery and the second spectral responsivity corresponding to the second region not covered with the insulating material. In addition, the first spectral responsivity and the second spectral responsivity are obtained under the same incidence wave band, the obtained first spectral responsivity and second spectral responsivity which are not only reflected by the shading characteristic of the insulating material due to inconsistent incidence wave bands can be prevented, the determination accuracy of the transparency