Claims:We claim:
1. A system for determining real-time temperature of a photovoltaic module (102), said system comprising:
a solar cell string layer (110) stacked between encapsulation layers (108/1 and 108/2);
a groove (202) on said encapsulation layer (108/2);
a temperature sensor (114) accommodated inside said groove (202); and
a contact made between the solar cell string layer (110) and the temperature sensor (114).

2. The system as claimed in claim 1, wherein a sensing element (204) integrated inside the temperature sensor (114), wherein real-time temperature of the photovoltaic module (102) is determined through resistance value of the sensing element (204).

3. The system as claimed in claim 1, wherein a glass sheet layer (106) is stacked above the encapsulation layer (108/1) and a back sheet layer (112) is stacked below the encapsulation layer (108/2).

4. The system as claimed in claim 2, wherein a metal frame (104) is stacked on the glass sheet layer (106).

5. The system as claimed in claim 1, wherein the contact is between a backside metal of the solar cell string layer (110) and the temperature sensor (114) through soldering or through a thermally conductive paste.

6. The system as claimed in claim 4, wherein the temperature sensor (114) is a platinum resistance thermometer Pt100 which makes a direct contact with the solar cell string layer (110).

7. The system as claimed in claim 1, wherein a Resistance Temperature Detector integrated in the temperature sensor (114) is configured to determine real-time temperature values of the photovoltaic module (102) through the measured resistance value of the sensing element (204).

8. A method for manufacturing a photovoltaic module (102), said method comprising:
stacking a solar cell string layer (110) between encapsulation layers (108/1 and 108/2);
accommodating a temperature sensor (114) inside a groove (202) on said encapsulation layer (108/2); and
creating a contact between the solar cell string layer (110) and the temperature sensor (114);

9. The method as claimed in claim 7, wherein the method comprises:
stacking a glass sheet layer (106) on the encapsulation layer (108/1);
stacking the encapsulation layer (108/2) on a back sheet layer (112);
stacking a metal frame on the glass sheet layer (106); and
attaching a connection cable (206) with the temperature sensor (114) to transmit data towards a monitor (208).

10. A method for measuring real-time temperature of a photovoltaic module (102), said method comprising:
stacking a solar cell string layer (110) between encapsulation layers (108/1 and 108/2);
accommodating a temperature sensor (114) inside a groove (202) on the encapsulation layer (108/2);
creating a contact between the solar cell string layer (110) and the temperature sensor (114), wherein the contact provides thermal conduction between the solar cell string layer (110) and the temperature sensor (114);
measuring resistance value of a sensing element (204) integrated inside the temperature sensor (114), wherein the sensing element is in contact with the solar cell string layer (110); and
determining the real-time temperature of the photovoltaic module (102) through the measured resistance value.

11. The method as claimed in claim 14, wherein the method comprises determining real-time temperature values of the photovoltaic module (102) through the measured resistance value of the sensing element (204) by using a Temperature Detector integrated in the temperature sensor (114).

12. The method as claimed in claim 7, wherein the method comprises transmitting data of real-time temperature value of the photovoltaic module (102) obtained from the temperature sensor (114), to the monitor (208) through the connection cable (206).
, Description:FIELD OF INVENTION
[001] The field of invention generally relates to photovoltaic modules. More specifically, it relates to a method of determining real-time temperature of a photovoltaic module by using a sensor embedded in the photovoltaic module.

BACKGROUND
[002] The temperature of components in photovoltaic modules plays an important role in measuring and analyzing their performance. Inaccurately measured heating of photovoltaic module components may severely affect the working efficiency and performance parameters of such devices. Consequently, the generated output may also vary from the expected output, and may not produce results as expected.
[003] Further, constant and accurate temperature monitoring is required in order to prevent malfunctions and accidents. Therefore, it is very important to provide efficient temperature measurement and monitoring in photovoltaic modules.
[004] In case of temperature monitoring of a large solar power plant, where temperatures of components in the solar power plant may reach high values due to direct sunlight, conventional techniques do not succeed in measuring accurate temperatures of the photovoltaic modules in said solar plant. The existing systems makes use of a temperature sensor that is placed outside the photovoltaic module to measure the temperature of the respective photovoltaic module. However, faulty or worn out connections of components may result in over-heating of the photovoltaic module and may directly impact the temperature sensors that are placed outside the photovoltaic module. Further, temperature sensors placed outside the photovoltaic module may also be influenced by external factors such as atmospheric conditions, thereby resulting in a false measurement of temperature.
[005] Other existing techniques have tried to address the aforementioned problem. However, their scope was limited to determining the temperature at various points of the photovoltaic module and measuring the over-heat temperature of the components of the photovoltaic module.
[006] Thus, in light of the above discussion, it is implied that there is a need for a system and method to determine the accurate temperature of the photovoltaic modules, which is reliable and does not face the problems mentioned above.
OBJECT OF INVENTION
[007] A principal objective of this invention is to provide a method for placing a temperature sensor inside a photovoltaic module without affecting photovoltaic module structure.
[008] Another objective of the invention is to provide a method for determining accurate temperature of a photovoltaic module.
[009] Another objective of the invention is to provide a method of integrating a temperature sensor between stacks of various layers to form a photovoltaic module.
[0010] A further objective of the invention is to provide a method for measuring a real-time temperature data of a photovoltaic module.
[0011] Another objective of the invention is to provide a method for tracking low performing photovoltaic modules.

BRIEF DESCRIPTION OF FIGURES
[0012] This invention is illustrated in the accompanying drawings, throughout which, like reference letters indicate corresponding parts in the various figures.
[0013] The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0014] Figure 1adepicts/illustrates a side view of a photovoltaic module comprising a temperature sensor, in accordance with an embodiment of the invention;
[0015] Figure 1b depicts/illustrates a structure of the photovoltaic module, in accordance with an embodiment of the invention;
[0016] Figure 2 depicts/illustrates an arrangement of a temperature sensor, in accordance with an embodiment of the invention;
[0017] Figure3 illustrates a flowchart of a method for determining accurate temperature of the photovoltaic module, in accordance with an embodiment of the invention.
STATEMENT OF INVENTION
The present invention provides a system and method for determining real-time temperature of a photovoltaic module in a solar power plant. The system comprises a temperature sensor which is embedded within a solar cell string layer such that the temperature sensor is in direct contact with the solar cell string layer. The temperature sensor is accommodated in a groove in an encapsulation layer of the photovoltaic module. The temperature sensor is embedded into the solar cell string layer without affecting the performance and structure of the photovoltaic module. The embedding of the temperature sensor inside the photovoltaic module allows the temperature sensor to be in direct contact with the solar cell strings, thereby enabling a direct measurement of the real-time temperature of solar cells of said photovoltaic module. The temperature sensor may comprise a sensing element whose resistance enables the measurement of temperature. A Temperature Detector may use the measured resistance value of the sensing element to determine the real-time temperature of the photovoltaic module.
DETAILED DESCRIPTION
[0018] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and/or detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0019] The present invention discloses a system and method for determining accurate temperature of a photovoltaic module by embedding a temperature sensor between layers stacked inside the photovoltaic module. A temperature sensor, is embedded inside the photovoltaic module without affecting the performance and structure of the photovoltaic module. The temperature of the photovoltaic module is determined accurately by measuring real-time temperature of the solar cells within the photovoltaic module. The real-time temperature values are further utilized to identify one or more of irradiance received by respective photovoltaic modules, low-performing, faulty or worn-out photovoltaic modules in a solar power plant.
[0020] In the present invention, each layer of the photovoltaic module is stacked one above the other and a metal frame is stacked on one side of the stacked layers. The temperature sensor is embedded in such a way that the temperature sensor is integrated between two layers of the photovoltaic module. The temperature of the photovoltaic module is measured by a sensing element integrated inside the temperature sensor. An efficient and accurate temperature determination is achieved when the temperature sensor measures a real-time value of the solar cell’s temperature. Subsequently, accurate temperature data of the photovoltaic module can be transmitted from the temperature sensor to external device(s). Further, the external device may be configured to display the determined accurate temperature of the photovoltaic module.
[0021] Throughout the description, a system and method for determining the accurate temperature of the photovoltaic module by embedding the temperature sensor between the stacked layers of the photovoltaic module, are disclosed. This embodiment should not be read as a limitation of this invention and the scope of this description covers other embodiments where the temperature sensor or a method of placing the temperature sensors may be utilized.
[0022] Referring now to the drawings, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0023] Figure 1a depicts/illustrates a side view 100/1 of a photovoltaic module 102, in accordance with an embodiment of the invention.
[0024] In an embodiment of the invention, the photovoltaic module 102 comprises a metal frame 104, a glass sheet layer 106, a first encapsulation layer108/1, a second encapsulation layer108/2, a solar cell string layer 110, and a back sheet layer 112. The metal frame 104 is placed on one side of the stacked layers. The photovoltaic module 102 is embedded with a temperature sensor 114 to measure accurate real-time temperature of the solar cells within the photovoltaic module 102.
[0025] In an embodiment of the invention, the metal frame 104 may comprise one or more metals. In an embodiment, the metal frame 104 may comprise a durable metal such as, but not limited to, aluminium. The metal frame 104 provides high durability to the photovoltaic module 102.
[0026] Further, in the present invention, the glass sheet layer 106 may be a sheet made of tempered glass.
[0027] In an embodiment, the glass sheet layer 106 may be heavier in weight than other sheets stacked in the photovoltaic module 102. In a preferred embodiment, the glass sheet layer 106 is devised to provide protection and durability to the photovoltaic module 102.
[0028] In an embodiment of the invention, the first and second encapsulation layers 108/1 and 108/2 include a thermoplastic encapsulant material, such as, but not limited to, Ethylene Vinyl Acetate (EVA).The encapsulation layers 108/1 and 108/2 provide strong adhesion to its overlapping layers, such as the glass sheet layer 106, the solar cell string layer 110, and the back sheet layer 112. The encapsulation layers 108/1 and 108/2 also act as a stable laminate to the photovoltaic module 102.
[0029] In an embodiment of the invention, the back sheet layer 112 may comprise a polymer or a combination of polymers devised to protect the photovoltaic module 102 from UV radiations, penetration of moisture, etc. The back sheet layer 112 also acts as an electrical insulation for the photovoltaic module 102 and provides durability to the photovoltaic module 102.
[0030] In an embodiment of the invention, one side of the second encapsulation layer 108/2 is stacked on the back sheet layer 112. Subsequently, the solar cell string layer 110 is stacked on another side of the second encapsulation layer 108/2. The glass sheet layer 106 is stacked on one side of the first encapsulation layer 108/1 and further, another side of the first encapsulation layer 108/1 is stacked on the solar cell string layer 110. Further, the metal frame 104 is stacked on the glass sheet layer 106.
[0031] In an embodiment of the invention, the temperature sensor 114 embedded inside the photovoltaic module 102, may comprise an electronic component such as, but not limited to, a pt100 temperature sensor, among other types of temperature sensors. The temperature sensor 114 is stacked between the solar cell string layer 110 and the second encapsulation layer 108/2. Thus, advantageously, the temperature sensor 114 provides real-time data of the temperature of the photovoltaic module 102 by measuring the real-time temperature of solar cells of the photovoltaic module 102.
[0032] In conventional techniques, a temperature sensor is placed outside the photovoltaic module to measure the temperature of said photovoltaic module. The delta difference between the actual temperature and measured temperature will be high in such cases, as the temperature measured by the sensor is influenced by several external factors such as climate, weather, type of photovoltaic installations, other adjacent photovoltaic modules, etc. The delta difference is the difference in temperature values between the measured and actual temperature of the photovoltaic module. Therefore, an accurate temperature of the photovoltaic module is not obtained.
[0033] In the present invention, the temperature sensor 114 is embedded inside the photovoltaic module 102 advantageously, by enabling the accurate temperature measurement of the photovoltaic module 102, irrespective of any impact from external factors. Additionally, the accurately measured temperature of the photovoltaic module 102, when compared with the obtained temperature from conventional shows a real-time measurement with an additional gain of approximately 10 degrees in temperature when the temperature sensor 114 is embedded inside the photovoltaic module 102. Further, the real-time measurement enables the calculation of accurate energy is generated by any photovoltaic modules in large solar power plants, thereby identifying low-performing photovoltaic modules.
[0034] Figure 1b depicts/illustrates a structure 100/2 of the photovoltaic module 102, in accordance with an embodiment of the invention.
[0035] In an embodiment of the invention, the solar cell string layer 110 is stacked between the first and second encapsulation layers 108/1 and 108/2. The second encapsulation layer 108/2 is further stacked on the back sheet layer 112. Subsequently, a glass sheet layer 106 is stacked on the first encapsulation layer 108/1. Further, a metal frame 104 is stacked on the glass sheet layer 106.
[0036] Further in the embodiment, the temperature sensor 114 is embedded between the solar cell string layer 110 and the second encapsulation layer 108/2 without affecting the structure 100/2 of the photovoltaic module 102 and the performance of the photovoltaic module 102.
[0037] Figure 2 depicts/illustrates an arrangement 200 of the temperature sensor 114, in accordance with an embodiment of the invention.
[0038] In an embodiment of the invention, the solar cell string layer 110 is stacked between the first and second encapsulation layers 108/1 & 108/2. The second encapsulation layer 108/2 comprises a groove 202 to accommodate the temperature sensor 114.
[0039] In an embodiment, the temperature sensor 114 is embedded such that the embedding creates an area of contact between the temperature sensor 114 and the back side of the solar cell string layer 110. The area of contact is made through a connection laid between the temperature sensor 114 and metallic element (not shown in figure) of the solar cell string layer 110.
[0040] In an embodiment, the area of contact may comprise a permanent connection made between the temperature sensor 114 and the back side of the solar cell string layer 110. The connection may be made through one or more of soldering, adhesive, and a thermally conductive paste, among others. The embedding of the temperature sensor 114 inside the photovoltaic module 102 provides a thermal conduction between the solar cell string layer 110 and the temperature sensor 114.
[0041] In an embodiment of the invention, the temperature sensor 114 is insulated from all other parts of the photovoltaic module 102, apart from the area of contact made with the solar cell string layer 110.
[0042] In a preferred embodiment of the invention, the temperature sensor 114 may further comprise a sensing element 204, and a connection cable 206. The sensing element 204 may comprise a resistor whose resistance value varies based on variations in the temperature of the solar cell string layer 110, as temperature and resistance are directly proportional to each other..
[0043] In an embodiment, any change in the temperature value of the solar cells in the solar cell string layer 110 is reflected simultaneously as the temperature sensor 114 is in direct contact with the solar cell string layer 110.
[0044] Further, in an embodiment, a Temperature Detector (not shown in figure) may be integrated inside the temperature sensor 114 to measure the real-time temperature of the solar cells through the sensed resistance value. The temperature sensor may comprise one or more components such as one or more of electronic components, electric components, circuits, processors, etc.
[0045] Subsequently, accurate temperature data of the photovoltaic module 102 may be transmitted from the temperature sensor 114 to one or more external devices such as a monitor 208 through the connection cable 206. The monitor 208 may be configured to display the determined accurate temperature of the photovoltaic module 102. Additionally, change in temperature values and low performing photovoltaic modules may be determined by observing the temperature values in the monitor 102. The monitor 208 may be a stand-alone device or may be attached to the photovoltaic module 102.
[0046] Figure 3 illustrates a flowchart of a method 300 for determining accurate temperature of the photovoltaic module 102, in accordance with an embodiment of the invention.
[0047] The method 300 for determining the accurate temperature of the photovoltaic module begins at step 302 by initiating the stacking of various layers of the photovoltaic module with a metal frame. The metal frame is stacked on the glass layer, as depicted at step 304. The metal frame provides high durability to all the subsequent layers that are stacked below the metal frame in the photovoltaic module. At step 306, the method 300 discloses the stacking of the solar cell string layer between the first and second encapsulation layers and stacking of the tempered glass layer on the first encapsulation layer.
[0048] Further, the method 300 discloses the stacking of the second encapsulation layer on the back sheet layer of the photovoltaic module, as depicted at step 308. A groove is created on the second encapsulation layer to accommodate a temperature sensor, as depicted at step 310. Embedding the temperature sensor on the created groove in the second encapsulation layer is depicted at step 312, wherein the temperature sensor is embedded between the solar cell string layer and the second encapsulation layer. A resistance value of the sensing element integrated inside the temperature sensor is measured. Thereafter, accurate temperature of the photovoltaic module is determined by using an Temperature Detector to analyze the measured resistance values of the sensing element, as depicted at step 314. Finally, at step 316, the determined accurate temperature of the photovoltaic module is transmitted to a monitor through a connection cable, wherein the monitor is configured to display the determined accurate temperature of the photovoltaic module.
[0049] An advantage of the present invention is to identify and track low performing photovoltaic modules in a large solar power plant.
[0050] Another advantage of the invention is to determine the accurate, real-time temperature of the photovoltaic module.
[0051] Another advantage of the invention is to integrate a temperature sensor inside the photovoltaic module, thereby eliminating any false value in the measurement of temperature due to any external factors.
[0052] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described here.