Preparation method for improving power of photovoltaic module
By conducting reverse current testing and power-on after welding of photovoltaic modules, the power reduction problem caused by dummy welding is solved, and high-quality and high-power photovoltaic module production is achieved, reducing production costs.
Patent Information
- Application Number
- CN202411687968.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-02-18
AI Technical Summary
In the production and manufacturing of solar photovoltaic tile modules, dummy welding is prone to occur during welding, resulting in a decrease in the power of the photovoltaic module and a decrease in the filling factor, which increases the cost of the manufacturer.
Power on for at least 25 seconds by performing reverse current test on the soldered backplane and battery cells to detect battery defects and resolve the false soldering problem.
This method does not require changing the photovoltaic module production line equipment, but only needs to add about 30 seconds of reverse power-on time to the battery defect inspection process. It can be compatible with string soldering machines and printed solder paste welding to achieve high-quality and high-power photovoltaic module production. Reduced production costs.
Smart Images
Figure CN119486331A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of solar photovoltaic power generation, and in particular to a preparation method for improving the power of a photovoltaic module, which is suitable for the production and manufacture of a solar photovoltaic tile module. Background Art
[0002] In the manufacturing of solar photovoltaic tile modules, the back panel and the cells are welded to the pads using a string welding machine or printed conductive adhesive to connect the cells in series to form a circuit. However, cold solder joints are prone to occur during the welding process. If cold solder joints occur, the power of the photovoltaic module will decrease, and the fill factor will also be reduced. Low-power photovoltaic modules will cause cost losses to manufacturers. Summary of the invention
[0003] The object of the present invention is to provide a method for preparing a photovoltaic module for improving power, so as to solve the problems encountered in the above-mentioned background technology.
[0004] To achieve the above object, the technical solution of the present invention is as follows: A preparation method for improving the power of a photovoltaic module, comprising the steps of: passing a reverse current through a back plate and a cell after welding, while testing for cell defects, and applying power with the reverse current for at least 25 seconds. As a preferred solution, the reverse current application time is 25-45 seconds, and the conductive adhesive is a solder strip or solder paste.
[0005] During specific implementation, the operating procedures for the backplane are: first, a layer of adhesive film is laid on the backplane, and a copper film is laid on the adhesive film, and then a layer of IEC film is laid on the copper film; the operating procedures for the battery cell are: first, the battery cell is printed with conductive glue on a printing machine, and the conductive glue is located in the pad of the battery cell; the operating procedures for reverse current energization are: the printed battery cell is laid on the IEC film, and the pad and the conductive glue are aligned with the IEC film so that the conductive glue is in contact with the copper film to form a circuit of the battery assembly; the circuit of the arranged battery assembly is energized with reverse current for at least 25 seconds.
[0006] In the above scheme, it should be noted that: when using reverse current to energize, the voltage is adjusted to between 25-28 volts, and the voltage range cannot exceed the open circuit voltage Voc of the battery cell multiplied by the number of battery cells n.
[0007] Compared with the prior art, the beneficial effects of the present invention are: in this solution, there is no need to modify the photovoltaic module production line equipment, only need to increase the reverse power-on time by about 30 seconds in the battery defect inspection process, it is compatible with string welding machines and printed solder paste welding, and high quality and high power can be achieved at low cost, thereby reducing the production cost of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them: Figure 1 It is a schematic diagram of the arrangement structure of the back plate in the present invention; Figure 2 It is a schematic diagram of the structure of the battery cell in the present invention; Figure 3 for Figure 2 Schematic diagram of the enlarged structure of part B in the middle.
[0009] Numbers in the figure: 1-backplane; 2-adhesive film; 3-copper film; 4-IEC film; 5-battery cell; 6-soldering pad; 7-conductive adhesive. DETAILED DESCRIPTION
[0010] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is now further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the relevant components of the present invention.
[0011] According to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and the accompanying drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the entirety of the present invention or as a limitation or restriction to the technical solution of the present invention.
[0012] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0013] like Figures 1 to 3 As shown, a preparation method for improving the power of a photovoltaic module is performed by the steps of: passing a reverse current through the back plate 1 and the battery cell 5 after the welding process while testing the battery defects, and using the reverse current to energize for at least 25 seconds. As a preferred solution, the reverse current energization time is 25-45 seconds, preferably about 30 seconds. Among them, the conductive glue 7 is a solder strip or solder paste.
[0014] After the welding process, the battery defect is tested by reverse current, which plays the role of detecting the yield of battery components. Normally, it takes 1-3 seconds to complete the power-on. However, in this battery defect detection, it takes more than 25 seconds to power on. The main reasons for this are: Due to long-term power-on, the resistance of the cold solder joint will increase and generate heat. During the heating process, the heat will slightly decompose and melt the solder strip or solder paste to form better contact with the battery cell 5, thus solving the cold solder joint caused by the string soldering machine or printed conductive glue 7 to the battery component series circuit.
[0015] Current battery defect detection mainly focuses on the quality of the battery cell 5. This solution uses reverse power supply to extend the power-on time through battery defect detection, which solves the low power caused by poor soldering of photovoltaic modules, improves the power of photovoltaic modules, and reduces user manufacturing costs.
[0016] During specific implementation, the operating procedure for the backplane 1 is as follows: first, a layer of adhesive film 2 is laid on the backplane 1, and a copper film 3 is laid on the adhesive film 2, and then a layer of IEC film 4 is laid on the copper film 3; the operating procedure for the battery cell 5 is as follows: first, a conductive adhesive 7 is printed on the battery cell 5 on a printing machine, and the conductive adhesive 7 is located in the pad 6 of the battery cell 5; the operating procedure for reverse current energization is as follows: the printed battery cell 5 is laid on the IEC film 4, and the pad 6 and the conductive adhesive 7 are aligned with the IEC film 4 so that the conductive adhesive 7 is in contact with the copper film 3 and is conductive, so as to form a circuit of the battery assembly; the circuit of the arranged battery assembly is energized with reverse current for at least 25 seconds.
[0017] It should be noted that when reverse current is used for power supply, the voltage is adjusted to between 25-28V, and the voltage range cannot exceed the open circuit voltage Voc of the battery cell 5 multiplied by the number n of the battery cells 5. The open circuit voltage Voc is the maximum voltage that the solar cell can generate.
[0018] When reverse current is applied, some conductive glue 7 on the cell 5 will heat up. At this time, the conductive glue 7 is semi-dry. When heated, the conductive glue 7 will melt and come into better contact with the copper film 3. Since the fill factor is the ratio of the product of the current and voltage when the battery has the maximum output power to the product of the short-circuit current and the open-circuit voltage, the increase in power will also increase the fill factor.
[0019] Heating principle: When reverse power is applied, the resistance of the virtual printing or virtual soldering area will increase and generate heat. Through the heating principle, the printed semi-dry conductive glue 7 will be melted and diluted, and the connection with the copper film 3 will be better to form better conductivity, thereby improving the filling factor. The reverse-powered battery defect detection component is covered with a layer of adhesive film 2 and a front transparent plate and put into the laminator. After lamination, the junction box is connected to complete the production of the photovoltaic module.
[0020] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for improving the power of a photovoltaic module, characterized in that: Perform the following steps: After the welding process, the back sheet and the battery cell are energized by reverse current for at least 25 seconds while testing the battery defects.
2. A method for improving the power of a photovoltaic module according to claim 1, characterized in that: The reverse current conduction time is 25-45 seconds.
3. A method for improving the power of a photovoltaic module according to claim 1, characterized in that: The operation process for the backplane is as follows: first, lay a layer of adhesive film on the backplane, then lay a copper film on the adhesive film, and then lay a layer of IEC film on the copper film; The operation process for the battery cell is as follows: first, the battery cell is printed with conductive glue on a printer, and the conductive glue is located in the pad of the battery cell; The operating procedures for reverse current power supply are as follows: lay the printed battery cells on the IEC film, align the pads and the conductive glue with the IEC film, make the conductive glue contact and conduct with the copper film, and form the circuit of the battery assembly; power the circuit of the arranged battery assembly with reverse current for at least 25 seconds.
4. A method for improving the power of a photovoltaic module according to claim 3, characterized in that: When reverse current is used for power supply, the voltage is adjusted to between 25 and 28 volts, and the voltage range cannot exceed the open circuit voltage Voc of the battery cell multiplied by the number of battery cells n.
5. A method for improving the power of a photovoltaic module according to claim 3, characterized in that: The conductive adhesive is a soldering tape or solder paste.