A fire early warning system powered by photovoltaic energy

Abstract

This invention relates to the field of early warning systems and discloses a fire early warning system utilizing photovoltaic power. The system includes a data acquisition module for acquiring operational data of a photovoltaic device at fixed locations and fixed time intervals. The operational data includes illumination images of the photovoltaic device, installation location data of the photovoltaic device's power cables, and environmental parameter data of the photovoltaic device's installation environment, including wind speed, wind direction, temperature, and light intensity. A first analysis module processes the illumination images to identify shadow areas, illuminated areas, and illumination angles, and determines the illuminated area of ​​the photovoltaic device based on the illuminated areas. It then calculates the input power of the photovoltaic device based on the illumination angle, illuminated area, and light intensity. A second analysis module divides the power cables into several segments based on the shadow and illuminated areas in the illumination images and the installation location data of the power cables.

Description

Technical Field

[0001] This invention relates to the field of early warning systems, and more specifically, to a fire early warning system that utilizes photovoltaic power. Background Technology

[0002] Existing photovoltaic systems are typically equipped with heat dissipation devices to handle the heat generated during operation. However, power cables, due to their length limitations, have poor heat dissipation, especially under the scorching summer sun, where heat accumulation can easily lead to overheating and even fires. To monitor the temperature of power cables, current technology usually involves installing temperature sensors at multiple locations along the cable. However, due to the long length of power cables, this method requires installing a large number of temperature sensors, increasing costs and posing significant challenges to maintenance and management. Summary of the Invention

[0003] This invention provides a fire early warning system that utilizes photovoltaic power, thus solving the technical problems mentioned in the background art.

[0004] This invention provides a fire early warning system utilizing photovoltaic power, comprising:

[0005] The data acquisition module is used to collect data at fixed locations and at fixed time intervals. Acquire operational data of the photovoltaic (PV) device, including illumination images of the PV device, installation location data of the PV device's power cables, and environmental parameter data of the PV device's installation environment, including wind speed, wind direction, temperature, and light intensity.

[0006] The first analysis module is used to process the illumination image to identify the shadow area, illumination area and illumination angle, and determine the illumination area of ​​the photovoltaic device based on the illumination area. Based on the illumination angle, illumination area and illumination intensity, the input power of the photovoltaic device is calculated.

[0007] The second analysis module is used to divide the power cable into several segments based on the shadow and light areas in the illumination image and the installation location data of the power cable; combined with wind speed, wind direction and temperature, it calculates the transmission efficiency of each segment and sums them up to obtain the total transmission efficiency of the power cable.

[0008] The data verification module is used to predict the output power of the photovoltaic device based on the input power of the photovoltaic device and the total transmission efficiency of the power cable, and compare the predicted output power with the actual output power of the photovoltaic device to generate a prediction deviation.

[0009] The early warning module is used to assess the heat accumulation risk of power cables based on prediction deviation; when the heat accumulation risk reaches a preset threshold, it generates a fire prevention early warning signal and issues an early warning.

[0010] Further processing of the illumination image to identify shadow and illuminated areas includes:

[0011] Step 1: Perform semantic segmentation on the illumination image to obtain several photovoltaic panel segmentation images in the illumination image, and convert the photovoltaic panel segmentation images to grayscale to obtain the grayscale value of each pixel in the photovoltaic panel segmentation images;

[0012] Step 2: Compare the gray values ​​of adjacent pixels to determine several edges of the photovoltaic panel segmentation map, and filter all the edges of the photovoltaic panel, removing non-straight edges;

[0013] Step 3: Combine all the photovoltaic panel segmentation images and the edges of the corresponding straight lines in the photovoltaic panel segmentation images to identify the shaded areas and the illuminated areas, as follows:

[0014] Extend both ends of the straight lines in the photovoltaic panel segmentation diagram by a length equal to the photovoltaic panel installation spacing. If the edges of the extended lines intersect, the corresponding edges are connected and retained; otherwise, the non-connected edges are discarded to obtain a connected geometry graph. The connected geometry graph is mapped onto the illumination image, and the gray values ​​of the pixels inside and outside the connected geometry graph in the illumination image are compared to obtain the shadow area and the illumination area.

[0015] Furthermore, identifying the lighting angle includes:

[0016] Step 4: Obtain the latitude and longitude of the photovoltaic device installation location, and the date and time of the sunlight image capture;

[0017] Step 5: Calculate the angle of the Sun relative to the Earth's equatorial plane. The formula is as follows:

[0018] ;in, Indicates the date the image was taken. It indicates the number of days since the vernal equinox. This represents the maximum value of the Earth's obliquity (the angle between the Earth's ecliptic and the Earth's

[0019] Calculate the angle between the sun and the location directly above the photovoltaic installation site. The formula is as follows:

[0020] ; in, Indicates the latitude of the photovoltaic device installation location. Indicates the time when the illumination image was captured. This indicates the angle of the sun's movement per hour;

[0021] Calculate the horizontal angle of the sun relative to the north. The formula is as follows:

[0022] ;in, This indicates the operation of calculating inverse trigonometric functions;

[0023] Calculate the angle between sunlight and the horizontal line on the ground based on atmospheric refraction of light. The formula is as follows:

[0024] ;in, express, Indicates the refraction correction value;

[0025] Step 6, calculate the illumination angle The calculation formula is as follows:

[0026] ;in, This indicates the adjustment coefficient for increasing the solar declination.

[0027] Furthermore, determining the illuminated area of ​​the photovoltaic device based on the illuminated region includes:

[0028] Step 7: Determine the total number of pixels of the photovoltaic panels in the illuminated area based on the shaded area and the illuminated area. and the total number of pixels of the photovoltaic panels in the shaded area. ;

[0029] Step 8: Obtain the total area of ​​photovoltaic panels. ;

[0030] Step 9, according to The illuminated area of ​​the photovoltaic device is obtained as follows .

[0031] Furthermore, based on the illumination angle, illumination area, and illumination intensity, the input power of the photovoltaic device is calculated using the following formula:

[0032] ;

[0033] ;

[0034] ;

[0035] ;

[0036] in, Indicates the input power of the photovoltaic device. A unit vector representing the position of the sun. The unit vector representing the direction of the photovoltaic panel. Represents the correction matrix. Indicates light intensity. Indicates the tilt angle of the photovoltaic panel. Indicates the orientation angle of the photovoltaic panel. This indicates the photoelectric conversion efficiency of the photovoltaic panel. This indicates the transpose operation. This indicates the calculation operation of the modulus. This represents the weighting coefficient.

[0037] Furthermore, based on the shadow and illumination areas in the illumination image, and the installation location data of the power cables, the power cables are divided into several sub-segments, including:

[0038] Step 10: Divide the power cable into two segments based on the illuminated and shaded areas to obtain illuminated and shaded segments.

[0039] Step 11: Obtain the installation location data of the power cable. The installation location data includes the thermal conductivity and heat absorption rate of the material used to fix and adhere the power cable. Based on the installation location data, the power cable is further divided into illuminated and shaded segments to obtain several illuminated and shaded segments.

[0040] Furthermore, considering wind speed, wind direction, and temperature, the transmission efficiency of each segment is calculated separately, and the total transmission efficiency of the power cable is obtained by summing these parameters, including:

[0041] Step 12, calculate the temperature rise of the i-th sub-segment, as follows:

[0042] If the i-th sub-segment is a light-illuminated sub-segment, then the formula for calculating the temperature rise of the i-th sub-segment is as follows:

[0043] ;

[0044] If the i-th sub-segment is a shaded sub-segment, then the formula for calculating the temperature rise of the i-th sub-segment is as follows:

[0045] ;

[0046] in, This indicates the temperature rise of the illuminated segment. This indicates the temperature rise of the shaded sub-segment. Indicates the current in the cable. This represents the resistance per unit length of power cable. This indicates the heat absorption rate of the material used in power cables. Indicates light intensity. This represents the surface area of ​​the illuminated or shaded sub-segment. Indicates wind speed. This indicates the angle between the wind direction and the light or shadow sub-segment. Indicates the reflectivity of power cables. This represents the Stefan Boltzmann constant. Indicates the temperature of the environment in which the photovoltaic device is installed;

[0047] Among them, the surface area of ​​the illuminated sub-segment or the shaded sub-segment The calculation process is as follows:

[0048] Obtain the total length of the power cable Total number of pixels in the outline of the power cable And the total number of pixels of the outline of the lighting sub-segment or the shadow sub-segment. ;

[0049] Calculate the surface area of ​​the illuminated or shaded sub-segment. , ;in, This indicates the cross-sectional radius of the power cable. Indicates the length of the illuminated or shaded sub-segment;

[0050] Step 13, calculate the transmission efficiency of the i-th sub-segment, as follows;

[0051] ;

[0052] ;

[0053] in, This represents the transmission efficiency of the i-th illumination sub-segment. This represents the transmission efficiency of the i-th shaded segment. This represents the coefficient of resistance as a function of temperature. Indicates the input voltage of the power cable;

[0054] Step 14: Summarize the total transmission efficiency of the power cables, as follows:

[0055] ;

[0056] in, This indicates the overall transmission efficiency of the power cable. Indicates the number of illuminated segments. An index representing the number of illuminated segments. This represents the transmission efficiency of the g-th illuminated sub-segment. This represents the length of the g-th illuminated segment. Indicates the number of shaded segments. An index representing the number of shaded subfields. Indicates the first The transmission efficiency of the shadow sub-segment Indicates the first The length of each shaded sub-segment.

[0057] Furthermore, the output power of the photovoltaic device is predicted, and the predicted output power is compared with the actual output power of the photovoltaic device to generate prediction bias, including:

[0058] The output power of the photovoltaic (PV) device is predicted, and the predicted output power is compared with the actual output power of the PV device to generate prediction bias, including:

[0059] Step 15: Predict the output power of the photovoltaic device. The calculation formula is as follows:

[0060] ;in, Indicates the predicted output power;

[0061] Step 16: Compare the predicted output power with the actual output power to obtain the difference between the predicted output power and the actual output power, and use the difference as the prediction deviation.

[0062] Furthermore, based on prediction bias, the risk of heat accumulation in power cables is assessed, including:

[0063] Step 17, adjust the prediction bias and fixed time interval. Weighting is applied to obtain additional calories;

[0064] Step 18: Based on all the segments of the power cable, determine the shortest segment;

[0065] Step 19: Calculate the additional temperature rise of the shortest segment by concentrating the extra heat according to the heat capacity formula, and add the temperature of the photovoltaic device installation environment to the additional temperature rise to obtain the final temperature of the shortest segment.

[0066] Step 20: Define the heat accumulation risk based on the final temperature and the warning temperature threshold, specifically including:

[0067] If the final temperature is greater than or equal to the warning temperature threshold, the risk of heat accumulation is abnormal; otherwise, it is normal.

[0068] Furthermore, early warnings will be issued, including:

[0069] Step 21: Determine the deviation between the final temperature and the warning temperature threshold. The deviation is the ratio of the final temperature to the warning temperature threshold.

[0070] Step 22, if If so, then the first process is initiated. If so, then the second process will be initiated.

[0071] The beneficial effects of this invention are as follows: by combining light image processing with dynamic data analysis, the operating environment of photovoltaic devices (such as light intensity, wind speed, wind direction, etc.) and the physical characteristics of power cables (such as heat conduction and heat absorption) are fully integrated, realizing real-time monitoring, refined modeling and dynamic risk assessment, so as to accurately calculate the potential risks of local heat accumulation in cables, and improve the system's safety, reliability and ability to adapt to complex environmental changes. Attached Figure Description

[0072] Figure 1 This is an architectural diagram of a fire early warning system that utilizes photovoltaic power according to the present invention. Detailed Implementation

[0073] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0074] like Figure 1 As shown, a fire early warning system utilizing photovoltaic power includes:

[0075] The data acquisition module is used to collect data at fixed locations and at fixed time intervals. Acquire operational data of the photovoltaic (PV) device, including illumination images of the PV device, installation location data of the PV device's power cables, and environmental parameter data of the PV device's installation environment, including wind speed, wind direction, temperature, and light intensity.

[0076] The first analysis module is used to process the illumination image to identify the shadow area, illumination area and illumination angle, and determine the illumination area of ​​the photovoltaic device based on the illumination area. Based on the illumination angle, illumination area and illumination intensity, the input power of the photovoltaic device is calculated.

[0077] The second analysis module is used to divide the power cable into several segments based on the shadow and light areas in the illumination image and the installation location data of the power cable; combined with wind speed, wind direction and temperature, it calculates the transmission efficiency of each segment and sums them up to obtain the total transmission efficiency of the power cable.

[0078] The data verification module is used to predict the output power of the photovoltaic device based on the input power of the photovoltaic device and the total transmission efficiency of the power cable, and compare the predicted output power with the actual output power of the photovoltaic device to generate a prediction deviation.

[0079] The early warning module is used to assess the heat accumulation risk of power cables based on prediction deviation; when the heat accumulation risk reaches a preset threshold, it generates a fire prevention early warning signal and issues an early warning.

[0080] In one embodiment of the invention, processing an illumination image to identify shadow areas and illuminated areas includes:

[0081] Step 1: Perform semantic segmentation on the illumination image to obtain several photovoltaic panel segmentation images in the illumination image, and convert the photovoltaic panel segmentation images to grayscale to obtain the grayscale value of each pixel in the photovoltaic panel segmentation images;

[0082] Step 2: Compare the gray values ​​of adjacent pixels to determine several edges of the photovoltaic panel segmentation map, and filter all the edges of the photovoltaic panel, removing non-straight edges;

[0083] Step 3: Combine all the photovoltaic panel segmentation images and the edges of the corresponding straight lines in the photovoltaic panel segmentation images to identify the shaded areas and the illuminated areas, as follows:

[0084] Extend both ends of the straight lines in the photovoltaic panel segmentation diagram by a length equal to the photovoltaic panel installation spacing. If the edges of the extended lines intersect, the corresponding edges are connected and retained; otherwise, the non-connected edges are discarded to obtain a connected geometry graph. The connected geometry graph is mapped onto the illumination image, and the gray values ​​of the pixels inside and outside the connected geometry graph in the illumination image are compared to obtain the shadow area and the illumination area.

[0085] Specifically, in step 1, semantic segmentation of the illumination image can include:

[0086] The illumination image is acquired at a fixed location, so the positions of entities in the illumination image do not change. By selecting any one illumination image as the reference image, and then annotating the entities in the reference image, a reference image for manual semantic segmentation is obtained. The reference image and any illumination image are then superimposed, that is, the annotation results in the reference image are mapped to the any illumination image, thus achieving automated semantic segmentation.

[0087] Step 1 yields a photovoltaic panel segmentation image. For this image, the grayscale values ​​differ depending on whether a shadow is cast on the top of the photovoltaic panel or when sunlight shines on it. Therefore, the photovoltaic panel segmentation image is converted to grayscale to obtain a grayscale version. If a shadow exists in the photovoltaic panel segmentation image, a boundary for the grayscale value will be present in the grayscale image.

[0088] For shadows to significantly affect the power generation efficiency of photovoltaic panels, the shadows must exist in patches. Therefore, the boundaries of the grayscale values ​​of each photovoltaic panel segment are extended. If a connection is successful, the shadows on the two photovoltaic panels are considered to be connected, and thus considered as a single patch of shadow affecting power generation efficiency. Through the joint judgment of the shadows of the photovoltaic panels, the identified shadow areas and illuminated areas are obtained.

[0089] In one embodiment of the present invention, identifying the illumination angle includes:

[0090] Step 4: Obtain the latitude and longitude of the photovoltaic device installation location, and the date and time of the sunlight image capture;

[0091] Step 5: Calculate the angle of the Sun relative to the Earth's equatorial plane. The formula is as follows:

[0092] ;in, Indicates the date the image was taken. It indicates the number of days since the vernal equinox. This represents the maximum value of the Earth's obliquity (the angle between the Earth's ecliptic and the Earth's

[0093] Calculate the angle between the sun and the location directly above the photovoltaic installation site. The formula is as follows:

[0094] ;in, Indicates the latitude of the photovoltaic device installation location. Indicates the time when the illumination image was captured. This indicates the angle of the sun's movement per hour;

[0095] Calculate the horizontal angle of the sun relative to the north. The formula is as follows:

[0096] ;in, This indicates the operation of calculating inverse trigonometric functions;

[0097] Calculate the angle between sunlight and the horizontal line on the ground based on atmospheric refraction of light. The formula is as follows:

[0098] ;in, express, Indicates the refraction correction value;

[0099] Step 6, calculate the illumination angle The calculation formula is as follows:

[0100] ;in, This indicates the adjustment coefficient for increasing the solar declination.

[0101] Specifically, the process involves obtaining the following basic data (Step 4): Latitude and longitude: The geographical location of the photovoltaic device, used to determine the relative position of the sun. Date and time of shooting: Used to calculate the sun's position in the sky that day. Solar angle calculation (Step 5): Angle of the sun relative to the Earth's equatorial plane: Calculated based on the date, using the formula for solar declination. This formula relates to the sun's position relative to the Earth throughout the year. Angle between the sun and directly overhead: Combining latitude, longitude, and time, the solar altitude angle is calculated, reflecting the angle between sunlight and the vertical direction of the ground. Horizontal angle of the sun relative to north: This is the horizontal component of the sun's direction relative to the ground, typically used to calculate the direction of shadows. Refraction correction: Due to the influence of atmospheric refraction on light, the directly calculated angle needs correction to improve accuracy. The refraction correction formula corrects the actual solar angle to the ground-viewed angle. Illumination angle calculation (Step 6): Combining the above data, the actual illumination angle of the photovoltaic device is obtained by adjusting the correction coefficient for solar declination. The formula includes adjustments to the sun's position angle to ensure the angle calculation matches the installation orientation of the photovoltaic device. The entire process utilizes astronomical formulas for calculating the position of sunlight, combined with specific geographical and temporal data, as well as atmospheric effects, to accurately calculate the angle of illumination.

[0102] In one embodiment of the present invention, determining the illumination area of ​​a photovoltaic device based on the illumination region includes:

[0103] Step 7: Determine the total number of pixels of the photovoltaic panels in the illuminated area based on the shaded area and the illuminated area. and the total number of pixels of the photovoltaic panels in the shaded area. ;

[0104] Step 8: Obtain the total area of ​​photovoltaic panels. ;

[0105] Step 9, according to The illuminated area of ​​the photovoltaic device is obtained as follows .

[0106] In one embodiment of the present invention, the input power of the photovoltaic device is calculated based on the illumination angle, illumination area, and illumination intensity, using the following formula:

[0107] ;

[0108] ;

[0109] ;

[0110] ;

[0111] in, Indicates the input power of the photovoltaic device. A unit vector representing the position of the sun. The unit vector representing the direction of the photovoltaic panel. Represents the correction matrix. Indicates light intensity. Indicates the tilt angle of the photovoltaic panel. Indicates the orientation angle of the photovoltaic panel. This indicates the photoelectric conversion efficiency of the photovoltaic panel. This indicates the transpose operation. This indicates the calculation operation of the modulus. This represents the weighting coefficient.

[0112] Specifically, the number of pixels in the illuminated and shaded areas is determined (step 7). Image processing techniques are used to identify the illuminated and shaded areas on the photovoltaic panel. The total number of pixels in the illuminated and shaded areas of the photovoltaic panel is then counted. This is to further determine the relative proportion of each area on the photovoltaic panel.

[0113] Total photovoltaic panel area acquisition (step 8). Using the physical properties of the photovoltaic device (such as the known area of ​​the photovoltaic panels), the pixel information in the image is mapped to the actual area. This requires establishing the proportional relationship between image pixels and actual area.

[0114] Calculate the illuminated area (step 9). Calculate the actual illuminated area of ​​the photovoltaic device by combining the pixel ratio of the illuminated area and the total photovoltaic panel area, and then calculate the input power.

[0115] The combination of image processing and photovoltaic panel characteristics integrates image processing with physical modeling. By using image processing technology, the illuminated and shaded areas of the photovoltaic panel can be acquired in real time. This method can dynamically reflect environmental changes during the operation of the actual photovoltaic device and is a more accurate approach than traditional static parameter measurements.

[0116] The dynamic nature of the calculation of the illuminated area, which determines the actual illuminated area of ​​the photovoltaic panel by dynamically determining the pixel ratio in the image, significantly improves the flexibility and accuracy of the calculation, especially when the illumination conditions are complex and changing (such as cloudy, local shadows, etc.).

[0117] The integrated modeling of the sun and the orientation of the photovoltaic panel incorporates the geometric relationship between the direction of sunlight and the normal vector of the photovoltaic panel into the input power calculation, reflecting the influence of the actual angle at which the photovoltaic panel receives sunlight. This method, which combines vector geometry and physical parameters, can more accurately reflect the actual input power.

[0118] Environmental impact correction involves introducing a correction matrix into the input power calculation to correct for the effects of non-ideal environments (such as reflection and refraction) on the input power.

[0119] In one embodiment of the present invention, based on the shadow area and the illuminated area in the illumination image, and the installation location data of the power cable, the power cable is divided into several sub-segments, including:

[0120] Step 10: Divide the power cable into two segments based on the illuminated and shaded areas to obtain illuminated and shaded segments.

[0121] Step 11: Obtain the installation location data of the power cable. The installation location data includes the thermal conductivity and heat absorption rate of the material used to fix and adhere the power cable. Based on the installation location data, the power cable is further divided into illuminated and shaded segments to obtain several illuminated and shaded segments.

[0122] Specifically, traditional methods typically rely on fixed environmental assumptions to calculate cable temperature rise and transmission efficiency, while this invention dynamically determines the illuminated and shaded areas through real-time analysis of illumination images.

[0123] By considering both material and environmental factors, this invention incorporates data on the installation location of power cables (such as the thermal conductivity and endothermic properties of the materials) into heat transfer analysis. This innovation makes the calculation of heat accumulation and temperature rise more realistic, especially when there are significant differences in the performance of cable bonding materials.

[0124] Refined segment division: Traditional methods for calculating cable heat conduction and energy transfer often rely on the assumption of uniformity across the entire area. However, this invention further divides the cable into multiple smaller segments, enabling a more accurate evaluation of the performance of each part.

[0125] For example, if a power cable passes through a lit area and a shaded area, the lit area and the shaded area are divided into segments. For the lit segment, it is installed and fixed on a cement surface and a black rubber surface. Since the cement surface and the black rubber surface have very different heat absorption and radiation capabilities, the cement surface and the black rubber surface are further divided into segments.

[0126] In one embodiment of the present invention, the transmission efficiency of each segment is calculated by combining wind speed, wind direction, and temperature, and the total transmission efficiency of the power cable is obtained by summing the results, including:

[0127] Step 12, calculate the temperature rise of the i-th sub-segment, as follows:

[0128] If the i-th sub-segment is a light-illuminated sub-segment, then the formula for calculating the temperature rise of the i-th sub-segment is as follows:

[0129] ;

[0130] If the i-th sub-segment is a shaded sub-segment, then the formula for calculating the temperature rise of the i-th sub-segment is as follows:

[0131] ;

[0132] in, This indicates the temperature rise of the illuminated segment. This indicates the temperature rise of the shaded sub-segment. Indicates the current in the cable. This represents the resistance per unit length of power cable. This indicates the heat absorption rate of the material used in power cables. Indicates light intensity. This represents the surface area of ​​the illuminated or shaded sub-segment. Indicates wind speed. This indicates the angle between the wind direction and the light or shadow sub-segment. Indicates the reflectivity of power cables. This represents the Stefan Boltzmann constant. Indicates the temperature of the environment in which the photovoltaic device is installed;

[0133] Among them, the surface area of ​​the illuminated sub-segment or the shaded sub-segment The calculation process is as follows:

[0134] Obtain the total length of the power cable Total number of pixels in the outline of the power cable And the total number of pixels of the outline of the lighting sub-segment or the shadow sub-segment. ;

[0135] Calculate the surface area of ​​the illuminated or shaded sub-segment. , ;in, This indicates the cross-sectional radius of the power cable. Indicates the length of the illuminated or shaded sub-segment;

[0136] Step 13, calculate the transmission efficiency of the i-th sub-segment, as follows;

[0137] ;

[0138] ;

[0139] in, This represents the transmission efficiency of the i-th illumination sub-segment. This represents the transmission efficiency of the i-th shaded segment. This represents the coefficient of resistance as a function of temperature. Indicates the input voltage of the power cable;

[0140] Step 14: Summarize the total transmission efficiency of the power cables, as follows:

[0141] ;

[0142] in, This indicates the overall transmission efficiency of the power cable. Indicates the number of illuminated segments. An index representing the number of illuminated segments. This represents the transmission efficiency of the g-th illuminated sub-segment. This represents the length of the g-th illuminated segment. Indicates the number of shaded segments. An index representing the number of shaded subfields. Indicates the first The transmission efficiency of the shadow sub-segment Indicates the first The length of each shaded sub-segment.

[0143] Specifically, this step first considers the temperature rise of each power cable segment (sub-segment) due to environmental and its own operating conditions. Factors influencing temperature rise include the cable's own heat generation and solar radiation heat. Heat dissipation factors include radiative heat dissipation, convective heat dissipation, and ambient temperature. In shaded sub-segments, since solar radiation heat is minimal, only the balance between self-heating and heat dissipation is considered.

[0144] The determination of surface area is crucial, as it is closely related to heat transfer. Using image processing techniques and considering the geometric properties of the power cable (such as radius and length), the surface area of ​​illuminated or shaded segments can be accurately calculated. The size of the surface area directly affects the efficiency of heat dissipation and absorption.

[0145] The calculation of segment transmission efficiency is based on the results of temperature rise calculations, as the power transmission efficiency of each segment is affected by temperature. Increased temperature leads to increased resistance: the resistance of the material increases with increasing temperature. This results in decreased efficiency: higher resistance leads to increased energy loss, reducing the transmission efficiency of the segment. The specific efficiency of each segment is calculated by using the relationship between temperature rise and resistance change.

[0146] The overall transmission efficiency is then summarized, and finally, the transmission efficiencies of all segments are weighted and summed. The length and efficiency of the illuminated and shaded segments together determine the overall transmission efficiency of the power cable.

[0147] In one embodiment of the present invention, the output power of a photovoltaic device is predicted, and the predicted output power is compared with the actual output power of the photovoltaic device to generate a prediction deviation, including:

[0148] Step 15: Predict the output power of the photovoltaic device. The calculation formula is as follows:

[0149] ;in, Indicates the predicted output power;

[0150] Step 16: Compare the predicted output power with the actual output power to obtain the difference between the predicted output power and the actual output power, and use the difference as the prediction deviation.

[0151] Specifically, through modeling analysis, the theoretical output power of the photovoltaic system is calculated based on the operating conditions of the photovoltaic device (such as irradiance, illuminated area, illumination angle, and cable transmission efficiency). This predicted power reflects the output capability of the photovoltaic device under ideal conditions and current environmental conditions.

[0152] The actual output power of the photovoltaic system is obtained using real measuring devices. This is the power output result under the actual operating conditions of the system.

[0153] The predicted theoretical output power is compared with the actual measured output power to obtain the deviation value between the two. This deviation reflects possible operational anomalies in the photovoltaic system (such as local heat accumulation).

[0154] Based on the magnitude of the deviation, it is possible to assess whether the photovoltaic device has any performance abnormalities or potential hazards. When the deviation is large, the system can issue an alarm, providing a basis for timely maintenance measures.

[0155] In one embodiment of the present invention, assessing the heat accumulation risk of power cables based on prediction deviation includes:

[0156] Step 17, adjust the prediction bias and fixed time interval. Weighting is applied to obtain additional calories;

[0157] Step 18: Based on all the segments of the power cable, determine the shortest segment;

[0158] Step 19: Calculate the additional temperature rise of the shortest segment by concentrating the extra heat according to the heat capacity formula, and add the temperature of the photovoltaic device installation environment to the additional temperature rise to obtain the final temperature of the shortest segment.

[0159] Step 20: Define the heat accumulation risk based on the final temperature and the warning temperature threshold, specifically including:

[0160] If the final temperature is greater than or equal to the warning temperature threshold, the risk of heat accumulation is abnormal; otherwise, it is normal.

[0161] Specifically, prediction deviation reflects the difference between the actual operation of the photovoltaic system and theoretical predictions, a difference stemming from heat accumulation. The prediction deviation is weighted by a fixed time interval to obtain the accumulated heat due to the prediction deviation. This weighting method considers the impact of time on heat accumulation. Among all power cable segments, a maximization judgment is made, assuming all heat accumulates in the shortest segment; if the shortest segment is normal, the entire system is considered normal. Based on the heat capacity formula, the temperature rise caused by the additional heat due to the prediction deviation is calculated. The temperature rise caused by the additional heat concentrated in the shortest segment is calculated. The initial temperature of the photovoltaic installation environment is superimposed on the additional temperature rise to obtain the final temperature of the shortest segment. This step reflects the combined impact of the local cable environment and operating conditions on heat accumulation. By comparing the final temperature of the shortest segment with a preset safe temperature threshold, the heat accumulation risk of that segment is assessed. If the final temperature is greater than or equal to the warning temperature threshold, the heat accumulation risk is considered abnormal, triggering a warning signal. If the final temperature is below the threshold, the risk status is normal.

[0162] In one embodiment of the present invention, providing an early warning includes:

[0163] Step 21: Determine the deviation between the final temperature and the warning temperature threshold. The deviation is the ratio of the final temperature to the warning temperature threshold.

[0164] Step 22, if If so, then the first process is initiated. If so, then the second process will be initiated.

[0165] Specifically, the first approach is to not report the fire and let the person in charge of the photovoltaic system handle the situation themselves. The second approach is to report the fire and let the fire department handle the situation.

[0166] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. A fire early warning system utilizing photovoltaic power, characterized in that, include: The data acquisition module is used to collect data at fixed locations and at fixed time intervals. Acquire operational data of the photovoltaic (PV) device, including illumination images of the PV device, installation location data of the PV device's power cables, and environmental parameter data of the PV device's installation environment, including wind speed, wind direction, temperature, and light intensity. The first analysis module is used to process the illumination image to identify the shadow area, illumination area and illumination angle, and determine the illumination area of ​​the photovoltaic device based on the illumination area. Based on the illumination angle, illumination area and illumination intensity, the input power of the photovoltaic device is calculated. The second analysis module is used to divide the power cable into several sub-segments based on the shadow and illumination areas in the illumination image and the installation location data of the power cable, including: Step 10: Divide the power cable into two segments based on the illuminated and shaded areas to obtain illuminated and shaded segments. Step 11: Obtain the installation location data of the power cable. The installation location data includes the thermal conductivity and heat absorption rate of the material used to fix and adhere the power cable. Based on the installation location data, the power cable is divided into two sub-segments: the illuminated sub-segment and the shaded sub-segment, to obtain several illuminated sub-segments and shaded sub-segments. Combining wind speed, wind direction, and temperature, the transmission efficiency of each segment is calculated separately, and the total transmission efficiency of the power cable is obtained by summing them up. This includes step 12, calculating the temperature rise of the i-th segment, as follows: If the i-th segment is a light-illuminating segment, the formula for calculating the temperature rise of the i-th segment is as follows: If the i-th sub-segment is a shaded sub-segment, then the formula for calculating the temperature rise of the i-th sub-segment is as follows: ;in, This indicates the temperature rise of the illuminated segment. This indicates the temperature rise of the shaded sub-segment. Indicates the current in the cable. This represents the resistance per unit length of power cable. This indicates the heat absorption rate of the material used in power cables. Indicates light intensity. This represents the surface area of ​​the illuminated or shaded sub-segment. Indicates wind speed. This indicates the angle between the wind direction and the light or shadow sub-segment. Indicates the reflectivity of power cables. This represents the Stefan Boltzmann constant. This indicates the temperature of the environment in which the photovoltaic device is installed; where the surface area of ​​the illuminated or shaded sub-segment is... The calculation process is as follows: Obtain the total length of the power cable. Total number of pixels in the outline of the power cable And the total number of pixels of the outline of the lighting sub-segment or the shadow sub-segment. ; Calculate the surface area of ​​the illuminated or shaded sub-segment , ;in, This indicates the cross-sectional radius of the power cable. Indicates the length of the illuminated or shaded sub-segment; Step 13, calculate the transmission efficiency of the i-th sub-segment, as follows; ; ;in, This represents the transmission efficiency of the i-th illumination sub-segment. This represents the transmission efficiency of the i-th shaded segment. This represents the coefficient of resistance as a function of temperature. This indicates the input voltage of the power cable; Step 14, summarize the total transmission efficiency of the power cable as follows: ;in, This indicates the overall transmission efficiency of the power cable. Indicates the number of illuminated segments. An index representing the number of illuminated segments. This represents the transmission efficiency of the g-th illuminated sub-segment. This represents the length of the g-th illuminated segment. Indicates the number of shaded segments. An index representing the number of shaded subfields. Indicates the first The transmission efficiency of the shadow sub-segment Indicates the first The length of each shaded sub-segment; The data verification module is used to predict the output power of the photovoltaic device based on the input power of the photovoltaic device and the total transmission efficiency of the power cable, and compare the predicted output power with the actual output power of the photovoltaic device to generate a prediction deviation. This includes step 15, predicting the output power of the photovoltaic device using the following formula: ;in, Indicates the predicted output power; Step 16, compare the predicted output power with the actual output power to obtain the difference between the predicted output power and the actual output power, and use the difference as the prediction deviation; The early warning module is used to assess the heat accumulation risk of power cables based on prediction deviation; when the heat accumulation risk reaches a preset threshold, a fire prevention early warning signal is generated and an early warning is issued, including step 17, which involves analyzing the prediction deviation and fixed time interval. Step 18: Based on all power cable segments, determine the shortest segment; Step 19: According to the heat capacity formula, calculate the additional temperature rise of the shortest segment due to the additional heat, and add the temperature of the photovoltaic device installation environment to the additional temperature rise to obtain the final temperature of the shortest segment; Step 20: Define the heat accumulation risk based on the final temperature and the warning temperature threshold, specifically including: if the final temperature is greater than or equal to the warning temperature threshold, the heat accumulation risk is abnormal; otherwise, it is normal.

2. A fire early warning system utilizing photovoltaic power as described in claim 1, characterized in that, Processing the illumination image to identify shadow and illuminated areas includes: Step 1: Perform semantic segmentation on the illumination image to obtain several photovoltaic panel segmentation images in the illumination image, and convert the photovoltaic panel segmentation images to grayscale to obtain the grayscale value of each pixel in the photovoltaic panel segmentation images; Step 2: Compare the gray values ​​of adjacent pixels to determine several edges of the photovoltaic panel segmentation map, and filter all the edges of the photovoltaic panel, removing non-straight edges; Step 3: Combine all the photovoltaic panel segmentation images and the edges of the corresponding straight lines in the photovoltaic panel segmentation images to identify the shaded areas and the illuminated areas, as follows: Extend both ends of the straight lines in the photovoltaic panel segmentation diagram by a length equal to the photovoltaic panel installation spacing. If the edges of the extended lines intersect, the corresponding edges are connected and retained; otherwise, the non-connected edges are discarded to obtain a connected geometry graph. The connected geometry graph is mapped onto the illumination image, and the gray values ​​of the pixels inside and outside the connected geometry graph in the illumination image are compared to obtain the shadow area and the illumination area.

3. A fire early warning system utilizing photovoltaic power according to claim 2, characterized in that, Identifying the angle of illumination, including: Step 4: Obtain the latitude and longitude of the photovoltaic device installation location, and the date and time of the sunlight image capture; Step 5: Calculate the angle of the Sun relative to the Earth's equatorial plane. The formula is as follows: ;in, Indicates the date the image was taken. It indicates the number of days since the vernal equinox. This represents the maximum value of the Earth's obliquity (the angle between the Earth's ecliptic and the Earth's Calculate the angle between the sun and the location directly above the photovoltaic installation site. The formula is as follows: ;in, Indicates the latitude of the photovoltaic device installation location. Indicates the time when the illumination image was captured. This indicates the angle of the sun's movement per hour; Calculate the horizontal angle of the sun relative to the north. The formula is as follows: ;in, This indicates the operation of calculating inverse trigonometric functions; Calculate the angle between sunlight and the horizontal line on the ground based on atmospheric refraction of light. The formula is as follows: ;in, express, Indicates the refraction correction value; Step 6, calculate the illumination angle The calculation formula is as follows: ;in, This indicates the adjustment coefficient for increasing the solar declination.

4. A fire early warning system utilizing photovoltaic power according to claim 3, characterized in that, Determining the illuminated area of ​​a photovoltaic device based on the illuminated region includes: Step 7: Determine the total number of pixels of the photovoltaic panels in the illuminated area based on the shaded area and the illuminated area. and the total number of pixels of the photovoltaic panels in the shaded area. ; Step 8: Obtain the total area of ​​photovoltaic panels. ; Step 9, according to The illuminated area of ​​the photovoltaic device is obtained as follows .

5. A fire early warning system utilizing photovoltaic power according to claim 4, characterized in that, The input power of a photovoltaic device can be calculated based on the angle of illumination, the area illuminated, and the intensity of light, using the following formula: ； ； ； ； in, Indicates the input power of the photovoltaic device. A unit vector representing the position of the sun. The unit vector representing the direction of the photovoltaic panel. Represents the correction matrix. Indicates light intensity. Indicates the tilt angle of the photovoltaic panel. Indicates the orientation angle of the photovoltaic panel. This indicates the photoelectric conversion efficiency of the photovoltaic panel. This indicates the transpose operation. This indicates the calculation operation of the modulus. This represents the weighting coefficient.

6. A fire early warning system utilizing photovoltaic power according to claim 5, characterized in that, Issue early warnings, including: Step 21: Determine the deviation between the final temperature and the warning temperature threshold. The deviation is the ratio of the final temperature to the warning temperature threshold. Step 22, if If so, then the first process is initiated. If so, then the second process will be initiated.

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