Methods and equipment for identifying weather conditions using multi-radiometers

Abstract

A method for determining weather conditions includes: measuring horizontal irradiance; measuring irradiance on a first inclined plane and irradiance on a second inclined plane, wherein the first and second inclined planes are configured to face the sun and be symmetrical about a meridian; determining an azimuth irradiance deviation rate based on the horizontal irradiance, the first inclined plane irradiance, and the second inclined plane irradiance; and determining the weather conditions based on the horizontal irradiance, the first inclined plane irradiance, the second inclined plane irradiance, and the azimuth irradiance deviation rate. An apparatus for determining weather conditions is also provided.

Description

Technical Field

[0001] Embodiments of this disclosure relate to the meteorological field, and more specifically, to a method and apparatus for identifying weather conditions using a multi-radiometer. Background Technology

[0002] Globally, the proportion of new energy sources is gradually increasing, with photovoltaic (PV) power generation leading the global energy revolution. It is projected that by 2050, PV power generation capacity will reach 8.5 TW. Currently, PV mounting systems can be broadly categorized into fixed-tilt and tracking types. Tracking systems, with their lower cost per kilowatt-hour and higher return on investment, have seen widespread development in recent years. Single-axis tracking systems, due to their simple and practical structure and significant power generation gain, have the highest market share.

[0003] Currently, single-axis tracking photovoltaic systems typically integrate astronomical algorithms and flat-ground inverse tracking algorithms. The astronomical algorithm refers to obtaining local latitude, longitude, time and other information based on the relationship between the sun and the earth, calculating the relative position of the sun (i.e., the angle of incidence of sunlight), and obtaining the theoretical tracking angle of the single-axis tracking system based on the principle that the smaller the angle between the normal vector of the module and the incident sunlight, the higher the irradiance received by the module.

[0004] However, conventional tracking algorithms only consider maximizing the irradiance received by the components during periods of high direct radiation (sunny days). In periods of high diffuse radiation (cloudy days), they still operate using the conventional tracking algorithm, failing to fully utilize diffuse radiation and thus not fully leveraging the power generation advantages of the tracking support. Therefore, differentiating between different weather conditions and optimizing the angle accordingly is the future trend for tracking algorithms. Summary of the Invention

[0005] To address the aforementioned problems, embodiments of this disclosure provide a method and apparatus for determining weather conditions.

[0006] At least one embodiment of this disclosure provides a method for determining weather conditions, including:

[0007] Measuring horizontal irradiance;

[0008] The irradiance of the first inclined plane and the irradiance of the second inclined plane are measured, wherein the first inclined plane and the second inclined plane are set to face the sun and are symmetrical about the meridian;

[0009] The azimuth irradiance deviation rate is determined based on the horizontal irradiance, the irradiance of the first inclined plane, and the irradiance of the second inclined plane; and

[0010] The weather conditions are determined based on the horizontal irradiance, the first inclined plane irradiance, the second inclined plane irradiance, and the azimuth irradiance deviation rate.

[0011] In one embodiment of this disclosure, determining the azimuth irradiance deviation rate based on the horizontal irradiance, the first inclined plane irradiance, and the second inclined plane irradiance includes:

[0012] The ratio of the absolute value of the difference between the irradiance of the first inclined plane and the irradiance of the second inclined plane to the horizontal irradiance is defined as the azimuth irradiance deviation rate D.

[0013] In one embodiment of this disclosure, determining the weather state based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate includes:

[0014] When the horizontal irradiance is greater than the irradiance of the first inclined plane and greater than the irradiance of the second inclined plane, and the azimuth irradiance deviation rate D < 5%, the weather condition is determined to be cloudy and rainy.

[0015] In one embodiment of this disclosure, the method further includes, when the horizontal irradiance is not greater than the first inclined plane irradiance and greater than the second inclined plane irradiance, and the azimuth irradiance deviation rate D is less than 5%, the method calculates the theoretical irradiance of the first inclined plane and the theoretical irradiance of the second inclined plane based on the horizontal irradiance and the direct irradiance ratio within a preset range, according to the inclined plane irradiance calculation model.

[0016] Based on the theoretical irradiance of the first and second inclined planes, determine the azimuth irradiance theoretical deviation rate D of the theoretical irradiance of the first and second inclined planes. 理论 Based on the irradiance of the first and second inclined planes, the actual azimuth irradiance deviation rate D is determined. 实际 ;

[0017] When the actual deviation rate of the azimuth irradiation D 实际 Greater than the theoretical deviation rate D of the azimuth irradiation 理论 Under the circumstances, the weather condition is determined to be sunny; and the actual irradiance deviation rate D in the stated azimuth is... 实际 Less than or equal to the theoretical deviation rate D of the azimuth irradiation 理论 Under these circumstances, the weather condition is determined to be cloudy.

[0018] In one embodiment of this disclosure, the preset range is greater than or equal to 50% and less than or equal to 60%.

[0019] In one embodiment of this disclosure, the direct irradiation accounts for 50%.

[0020] In one embodiment of this disclosure, the method further includes:

[0021] If the horizontal irradiance is not greater than the first slope irradiance and the second slope irradiance, and the azimuth irradiance deviation rate D < 5%, based on the horizontal irradiance and multiple uniformly distributed direct irradiance proportions within the range of 0 to 100%, the theoretical irradiance of the first slope and the theoretical irradiance of the second slope under different direct irradiance proportions are calculated according to the slope irradiance calculation model.

[0022] Based on the theoretical irradiance of the first and second inclined planes under different direct irradiance ratios, and the horizontal irradiance, the theoretical azimuth irradiance deviation rate D under different direct irradiance ratios is determined. 理论 ;

[0023] Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate. 理论 The percentage of direct radiation corresponding to the theoretical deviation rate of irradiance in that azimuth is determined as the actual percentage of direct radiation; and

[0024] The weather condition is determined based on the actual percentage of direct sunlight.

[0025] In one embodiment of this disclosure, determining the current weather state based on the actual direct irradiance percentage includes: determining the weather state as sunny when the actual direct irradiance percentage is greater than a first threshold; determining the weather state as cloudy / rainy when the direct irradiance percentage is less than a second threshold; and determining the weather state as partly cloudy when the direct irradiance percentage is less than or equal to the first threshold and greater than or equal to the second threshold.

[0026] In one embodiment of this disclosure, the first threshold is 50%, and the second threshold is 10%.

[0027] At least one embodiment of this disclosure also provides an apparatus for determining weather conditions, comprising:

[0028] A first radiometer is configured to measure horizontal irradiance, wherein the measuring surface of the first radiometer is set to be horizontally placed;

[0029] The second radiometer is configured to measure the irradiance of the first inclined plane;

[0030] A third radiometer is configured to measure the irradiance of the second inclined plane, wherein the measuring surfaces of the second and third radiometers are arranged to face the sun and are symmetrical about the meridional plane; and

[0031] The processing unit is configured to receive the horizontal irradiance, the first slope irradiance, and the second slope irradiance, determine the azimuth irradiance deviation rate based on the horizontal irradiance, the first slope irradiance, and the second slope irradiance, and determine the weather condition based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate.

[0032] In one embodiment of this disclosure, the processing unit is further configured to determine the ratio of the absolute value of the difference between the first slope irradiance and the second slope irradiance to the horizontal irradiance as the azimuth irradiance deviation rate.

[0033] In one embodiment of this disclosure, the processing unit is further configured to compare the horizontal irradiance and the first sloping irradiance, and to compare the horizontal irradiance and the second sloping irradiance. If the horizontal irradiance is greater than the first sloping irradiance and greater than the second sloping irradiance, and the azimuth irradiance deviation rate D is less than 5%, the processing unit determines the weather condition as a cloudy / rainy day.

[0034] In one embodiment of this disclosure, the processing unit is further configured to, when the horizontal irradiance is greater than the first inclined plane irradiance and greater than the second inclined plane irradiance, and the azimuth irradiance deviation rate D is less than 5%, calculate the theoretical irradiance of the first inclined plane and the theoretical irradiance of the second inclined plane based on the horizontal irradiance and the direct irradiance ratio within a preset range, according to the inclined plane irradiance calculation model.

[0035] Based on the theoretical irradiance of the first and second inclined planes, determine the azimuth irradiance theoretical deviation rate D of the theoretical irradiance of the first and second inclined planes. 理论 Based on the irradiance of the first and second inclined planes, the actual azimuth irradiance deviation rate D is determined. 实际 ;

[0036] When the actual deviation rate of azimuth irradiation D 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 Under these circumstances, the weather condition is determined to be sunny; and the actual azimuth irradiance deviation rate D 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 Under these circumstances, the weather condition is determined to be cloudy.

[0037] In one embodiment of this disclosure, the preset range is greater than or equal to 50% and less than or equal to 60%.

[0038] In one embodiment of this disclosure, the direct irradiation accounts for 50%.

[0039] In one embodiment of this disclosure, the processing unit is further configured to, when the horizontal irradiance is not greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%, calculate the first slope theoretical irradiance and the second slope theoretical irradiance under different direct irradiance ratios based on the horizontal irradiance and multiple uniformly distributed direct irradiance ratios within the range of 0 to 100%, according to the slope irradiance calculation model.

[0040] Based on the theoretical irradiance of the first and second inclined planes under different direct irradiance ratios, the theoretical azimuth irradiance deviation rate D under different direct irradiance ratios is determined. 理论 ;

[0041] Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate. 理论 The theoretical deviation rate D of the irradiance in this azimuth will be... 理论 The preset direct irradiance percentage is determined as the actual direct irradiance percentage; and

[0042] The weather condition is determined based on the actual percentage of direct sunlight.

[0043] In one embodiment of this disclosure, determining the current weather state based on the actual direct irradiance percentage includes: determining the weather state as sunny when the actual direct irradiance percentage is greater than a first threshold; determining the weather state as cloudy / rainy when the direct irradiance percentage is less than a second threshold; and determining the weather state as partly cloudy when the direct irradiance percentage is between the first and second thresholds.

[0044] In one embodiment of this disclosure, the first threshold is 50%; and the second threshold is 10%.

[0045] In one embodiment of this disclosure, the device further includes a fourth radiometer and a fifth radiometer, wherein,

[0046] The fourth radiometer is configured to be symmetrical with respect to the second radiometer about a plane perpendicular to the horizontal plane and parallel to the parallel of latitude;

[0047] The fifth radiometer is configured to be symmetrical with respect to the third radiometer about a plane perpendicular to the horizontal plane and parallel to the parallel of latitude;

[0048] In the case where both the second and third radiometers are facing away from the sun, the processing unit uses the measurement data of the fourth radiometer as the first slope irradiance and the measurement data of the fifth radiometer as the second slope irradiance.

[0049] In one embodiment of this disclosure, the device further includes a rotating mechanism on which the second radiometer and the third radiometer are mounted. When both the second radiometer and the third radiometer are facing away from the sun, the rotating mechanism drives the second radiometer and the third radiometer to rotate 180 degrees in the horizontal plane, so that the second radiometer and the third radiometer face the sun again.

[0050] The embodiments of this disclosure provide an apparatus and method for determining weather conditions. Using multiple radiometers, irradiance is measured at different azimuths, and then the weather condition is identified based on the irradiance deviation rate at each azimuth. This method determines the weather condition while simultaneously measuring irradiance data, expanding the versatility of the equipment. It is simple to manufacture and install, and has low maintenance costs. Furthermore, it is applicable to all latitudes and all seasons, with low cost and high feasibility, making it widely applicable in practical engineering applications. Attached Figure Description

[0051] Figure 1 A flowchart of a method for determining weather conditions according to an embodiment of the present disclosure is shown;

[0052] Figure 2 The relationship between azimuth irradiance deviation and the proportion of direct irradiance is shown;

[0053] Figure 3 A block diagram of an apparatus for determining weather conditions according to an embodiment of the present disclosure is shown; and

[0054] Figure 4 A structural diagram of a device for determining weather conditions according to another embodiment of the present disclosure is shown. Detailed Implementation

[0055] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0056] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0057] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0058] Currently, dual-axis tracking weather stations, such as Kipp & Zonnen's RaZON+ integrated solar monitoring system, can collect data on total horizontal irradiance, diffuse horizontal irradiance, and direct horizontal irradiance by tracking the sun's position on both axes, thereby assessing the current weather conditions. However, these systems are expensive, require high tracking accuracy, have high failure and error rates, and require regular calibration, limiting their practical application.

[0059] To address this, embodiments of this disclosure provide an apparatus and method for determining weather conditions. This method uses multiple radiometers to measure irradiance at different azimuths, and then identifies the weather condition based on the irradiance deviation rate at each azimuth. By determining the weather condition simultaneously with irradiance data measurement, it expands the versatility of the equipment, simplifies manufacturing and installation, and reduces maintenance costs. Furthermore, it is applicable across all latitudes and seasons, has low cost, high feasibility, and can be widely used in practical engineering applications.

[0060] At least one embodiment of this disclosure provides a method for determining weather conditions, such as Figure 1 As shown, it includes:

[0061] Measuring horizontal irradiance;

[0062] The irradiance of the first inclined plane and the irradiance of the second inclined plane are measured, wherein the first inclined plane and the second inclined plane are set to face the sun and are symmetrical about the meridian and have the same tilt angle;

[0063] The azimuth irradiance deviation rate is determined based on horizontal irradiance, first inclined plane irradiance, and second inclined plane irradiance; and

[0064] The weather conditions are determined based on the horizontal irradiance, the first inclined plane irradiance, the second inclined plane irradiance, and the azimuth irradiance deviation rate.

[0065] Weather conditions can be determined using horizontal irradiance, first slope irradiance, and second slope irradiance. The first and second slopes are set to face the sun, are symmetrical about the meridian, and have the same tilt angle. Under different weather conditions, the irradiance distribution in each direction of the sky differs; that is, the horizontal irradiance differs from the irradiance of the first and second slopes. The closer the weather condition is to sunny, the greater the difference in irradiance between different directions; the closer the weather condition is to cloudy, the smaller the difference in irradiance between different directions. In other words, the difference in azimuthal irradiance shows a monotonic correlation with the proportion of direct sunlight. Figure 2 As shown.

[0066] The horizontal irradiance can be measured using a first radiometer set horizontally, the irradiance of the first inclined plane can be measured using a second radiometer set on the first inclined plane, and the irradiance of the second inclined plane can be measured using a third radiometer set on the second inclined plane. Figure 3 The arrangement of the first, second, and third radiometers is shown. Figure 3 As shown, the first and second inclined planes are set to face the equator (i.e., to face the sun so as to receive solar radiation). The azimuth angle of the first inclined plane is A, and the azimuth angle of the second inclined plane is B. The sum of the azimuth angles of the first and second inclined planes is 360 degrees, and the inclination angles of the first and second inclined planes are the same, that is, the angle between the first and second inclined planes and the horizontal ground is the same. The first and second inclined planes are set to face the sun and are symmetrical about the meridian.

[0067] For example, in the high latitudes of the Northern Hemisphere (north of the Tropic of Cancer, where the sun is always in the south), the azimuth of the first slope is 60° east of south, the azimuth of the second slope is 60° west of south, and the inclination is 20°. As another example, in the high latitudes of the Southern Hemisphere (south of the Tropic of Capricorn, where the sun is always in the north), the azimuth of the first slope is 60° east of north, the azimuth of the second slope is 60° west of north, and the inclination is 20°. Thus, horizontal irradiance can be measured using a horizontally positioned first radiometer, the first slope irradiance can be measured using a first slope radiometer, and the second slope irradiance can be measured using a second slope radiometer. For example, in the low latitude regions of the Northern Hemisphere and the Southern Hemisphere, for the second and third radiometers measuring the first and second inclined plane irradiance, regardless of their orientation—whether they are set to north-northeast, north-northwest, or south-east, south-west—as the sun's direct point moves between the Tropic of Cancer and the Tropic of Capricorn, the second and third radiometers will sometimes be facing away from the sun. In this case, it is necessary to set up a fourth and a fifth radiometer symmetrical to the second and third radiometers along the latitude lines, respectively, to measure the first and second inclined plane irradiance when both the second and third radiometers are facing away from the sun, thus broadening the applicability of the method for determining weather conditions according to the embodiments of this disclosure.

[0068] In one embodiment of this disclosure, determining the azimuth irradiance deviation rate based on the horizontal irradiance, the first inclined plane irradiance, and the second inclined plane irradiance includes: determining the ratio between the absolute value of the difference between the first inclined plane irradiance and the second inclined plane irradiance and the horizontal irradiance as the azimuth irradiance deviation rate D.

[0069] The closer the weather condition is to sunny, the greater the difference in irradiance between different directions; conversely, the closer the weather condition is to cloudy / rainy, the smaller the difference in irradiance between different directions. Therefore, when the difference in irradiance between the first and second slopes is very small, and the horizontal irradiance is greater than both the first and second slopes, the weather condition is close to cloudy / rainy. Actual measurement data shows that when the horizontal irradiance is greater than both the first and second slopes, and the azimuthal irradiance deviation rate D is less than 5%, the weather condition is cloudy / rainy.

[0070] Therefore, in one embodiment of this disclosure, determining the weather state based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate includes:

[0071] When the horizontal irradiance is greater than the irradiance of the first inclined plane and greater than the irradiance of the second inclined plane, and the azimuth irradiance deviation rate D < 5%, the weather condition is determined to be cloudy and rainy.

[0072] By establishing the relationship between horizontal irradiance and the irradiance of the first and second inclined planes, weather conditions can be quickly determined without the need for expensive and sophisticated equipment.

[0073] As can be seen from the above, if the horizontal irradiance is not greater than the irradiance of the first slope and not greater than the irradiance of the second slope, and the azimuth irradiance deviation rate D is less than 5%, the weather condition can be determined to be sunny or cloudy. In this case, based on the horizontal irradiance and the percentage of direct radiation within a preset range (e.g., 50%-60%), according to the slope irradiance calculation model... Calculate the theoretical irradiance of the first and second inclined planes respectively, where In represents the horizontal direct irradiance, Id represents the horizontal scattered irradiance, and ρ represents the ground reflectivity. ,in, Indicates the zenith angle of the sun. Indicates the angle of incidence of the sun.

[0074] in, Indicates solar hour angle, Indicates declination angle, Indicate latitude, Indicates the azimuth of the inclined plane, Indicates the angle of inclination of the inclined plane;

[0075] ,in The sky clarity factor, also known as the clear sky index, is a comprehensive parameter describing the influence of the atmosphere on solar shortwave radiation. It reflects not only the intensity of solar radiation reaching the ground but also the atmospheric conditions and the impact on solar radiation as it passes through the atmosphere.

[0076] After calculating the theoretical irradiance of the first and second inclined planes using the above calculation model, the ratio of the absolute value of the difference between the theoretical irradiance of the first and second inclined planes to the horizontal irradiance is determined as the azimuth irradiance theoretical deviation rate D. 理论 Based on the irradiance of the first and second inclined planes, the ratio of the absolute value of the difference between the irradiance of the first and second inclined planes to the horizontal irradiance is determined as the actual azimuth irradiance deviation rate D. 实际 Experimental data shows that when the actual deviation rate of azimuth irradiation D 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 Under the condition that the weather is clear, the actual azimuth irradiance deviation rate D 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 Under these circumstances, the weather will be mostly cloudy.

[0077] Therefore, in one embodiment of this disclosure, if the horizontal irradiance is not greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%, a preset direct irradiance percentage (e.g., 50%) within a preset range (e.g., 50%~60%) is calculated based on the slope irradiance calculation model. Calculate the theoretical irradiance of the first and second inclined planes respectively, where In represents the horizontal direct irradiance, Id represents the horizontal scattered irradiance, and ρ represents the ground reflectivity. ,in, Indicates the zenith angle of the sun. Indicates the angle of incidence of the sun.

[0078]

[0079] in, Indicates solar hour angle, Indicates declination angle, Indicate latitude, Indicates the azimuth of the inclined plane, Indicates the angle of inclination of the inclined plane;

[0080] ,in Sky clarity factor;

[0081] Based on the theoretical irradiance of the first and second inclined planes, the ratio of the absolute value of the difference between the theoretical irradiance of the first and second inclined planes to the horizontal irradiance is determined as the azimuth irradiance theoretical deviation rate D. 理论 Based on the irradiance of the first and second inclined planes, the ratio of the difference between the irradiance of the first and second inclined planes to the horizontal irradiance is determined as the actual azimuth irradiance deviation rate D. 实际 ;

[0082] When the actual deviation rate of azimuth irradiation D 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 Under these circumstances, the weather condition is determined to be sunny; and the actual azimuth irradiance deviation rate D 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 Under these circumstances, the weather condition is determined to be cloudy.

[0083] In one embodiment of this disclosure, the preset range is greater than or equal to 50% and less than or equal to 60%.

[0084] In one embodiment of this disclosure, the direct irradiation accounts for 50%.

[0085] In the above example, taking a preset direct irradiance percentage (e.g., 50%) within a preset range (e.g., 50%~60%) as an example, it is illustrated how to determine the weather state based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate D when the horizontal irradiance is not greater than the first slope irradiance and the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%.

[0086] In a more applicable example, even without knowing the proportion of horizontal direct irradiance In in the total irradiance, the weather conditions can still be determined based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate.

[0087] Without knowing the proportion of horizontal direct irradiance In in the total irradiance, multiple uniformly distributed direct irradiance proportions within the range of 0% to 100% can be used (e.g., assuming the proportions of horizontal direct irradiance In in the total irradiance are 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%). Based on the aforementioned slope irradiance calculation model, the theoretical irradiance of the first slope and the theoretical irradiance of the second slope are calculated respectively. Based on the theoretical irradiance of the first slope, the theoretical irradiance of the second slope, and the horizontal irradiance, the theoretical azimuth irradiance deviation rate D under different proportions of horizontal direct irradiance in the total irradiance is then calculated. 理论 The actual deviation rate D of azimuth irradiance is determined based on the measured horizontal irradiance, first inclined plane irradiance, and second inclined plane irradiance. 实际 Select the azimuth irradiance deviation rate D that is closest to the actual deviation rate. 实际 Theoretical deviation rate D of azimuth irradiation 理论 The theoretical deviation rate D of the azimuth irradiation 理论 The corresponding direct irradiance percentage is determined as the actual direct irradiance percentage. When a precise determination of the actual direct irradiance percentage is required, an interpolation method can be used to obtain the accurate direct irradiance percentage. Using the interpolation method can reduce the computational burden. Alternatively, the interval between direct irradiance percentages can be reduced, and the theoretical azimuth irradiance deviation rate for different direct irradiance percentages can be determined separately, then compared with the actual azimuth irradiance deviation rate to obtain the accurate direct irradiance percentage.

[0088] Once the specific percentage of direct sunlight is obtained, the current weather condition can be assessed. For example, if the percentage of direct sunlight is 30%, the current weather condition is determined to be cloudy; if the percentage of direct sunlight is 70%, the current weather condition is determined to be sunny.

[0089] Therefore, in one embodiment of this disclosure, if the horizontal irradiance is not greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%, the slope irradiance calculation model is used based on the horizontal irradiance and the proportion of multiple uniformly distributed direct irradiances within the range of 0 to 100%. The theoretical irradiance of the first and second inclined planes were calculated for different proportions of direct irradiance, where In represents horizontal direct irradiance, Id represents horizontal scattered irradiance, and ρ represents ground reflectivity. ,in, Indicates the zenith angle of the sun. This represents the solar incidence angle. The different percentages of direct irradiance refer to the different values ​​of In / (In+Id).

[0090]

[0091] in, Indicates solar hour angle, Indicates declination angle, Indicate latitude, Indicates the azimuth of the inclined plane, Indicates the angle of inclination of the inclined plane;

[0092] ,in Sky clarity factor;

[0093] The ratio of the difference between the theoretical irradiance of the first and second inclined planes under different direct irradiance ratios to the horizontal irradiance is determined as the azimuth irradiance theoretical deviation rate D under different direct irradiance ratios. 理论 ;

[0094] Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate. 理论 The proportion of direct radiation corresponding to the theoretical deviation rate of azimuth irradiance is determined as the actual proportion of direct radiation irradiance, and the weather condition is determined based on the actual proportion of direct radiation irradiance.

[0095] In one embodiment of this disclosure, determining the current weather state based on the actual direct radiation ratio includes: determining the weather state as sunny when the actual direct radiation ratio is greater than a first threshold; determining the weather state as cloudy / rainy when the direct radiation ratio is less than a second threshold; and determining the weather state as partly cloudy when the direct radiation ratio is between the first and second thresholds. For example, the first threshold is 50%; and the second threshold is 10%.

[0096] The theoretical deviation rate D of azimuth irradiance under different direct irradiance percentages was calculated. 理论And select the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate D. 理论 The direct irradiance percentage corresponding to the theoretical deviation rate of azimuth irradiance is determined as the actual direct irradiance percentage, and the weather condition is determined based on the actual direct irradiance percentage, thereby improving the applicability and accuracy of the weather condition determination method according to the embodiments of this disclosure.

[0097] At least one embodiment of this disclosure also provides an apparatus for determining weather conditions, comprising:

[0098] A first radiometer is configured to measure horizontal irradiance, wherein the measuring surface of the first radiometer is set to be horizontally placed;

[0099] The second radiometer is configured to measure the irradiance of the first inclined plane;

[0100] A third radiometer is configured to measure the irradiance of the second inclined plane, wherein the measuring surfaces of the second and third radiometers are arranged to face the sun and are symmetrical about the meridional plane; and

[0101] The processing unit is configured to receive the horizontal irradiance, the first slope irradiance, and the second slope irradiance, determine the azimuth irradiance deviation rate based on the horizontal irradiance, the first slope irradiance, and the second slope irradiance, and determine the weather condition based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate.

[0102] Figure 3 A schematic diagram of a device for determining weather conditions according to an embodiment of the present disclosure is shown. Figure 3 As shown, the device includes a first radiometer 1, a second radiometer 2, and a third radiometer 3. The measuring surface of the first radiometer 1 is positioned horizontally. The measuring surfaces of the second radiometer 2 and the third radiometer 3 are positioned facing the sun. For example, if the device is located in the Northern Hemisphere, the azimuth angle of the measuring surface of the second radiometer 2 is A (e.g., 60 degrees east of south), and the azimuth angle of the measuring surface of the third radiometer 3 is B (e.g., 60 degrees west of south). The sum of the azimuth angles of the second radiometer 2 and the third radiometer 3 is 360 degrees. The tilt angles of the measuring surfaces of the second radiometer 2 and the third radiometer 3 are the same, that is, the angle between the measuring surface of the second radiometer 2 and the horizontal ground is the same as the angle between the measuring surface of the third radiometer 3 and the horizontal ground. In other words, the measuring surfaces of the second radiometer 2 and the third radiometer 3 are both positioned facing the sun and are symmetrical about the meridian.

[0103] A first radiometer 1 is configured to measure horizontal irradiance, a second radiometer 2 is configured to measure irradiance on a first inclined plane, and a third radiometer 3 is configured to measure irradiance on a second inclined plane. All three radiometers are connected to a processing unit and transmit the measured horizontal, first, and second inclined plane irradiances to the processing unit. The processing unit determines the azimuth irradiance deviation rate based on the horizontal, first, and second inclined plane irradiances, and determines the weather conditions based on the horizontal, first, and second inclined plane irradiances and the azimuth irradiance deviation rate.

[0104] The weather condition determination device provided in this disclosure determines weather conditions while measuring irradiance data, expanding the versatility of the device. It is simple to manufacture and install, and has low maintenance costs. Furthermore, it is applicable to all latitudes and all seasons, with low cost and high feasibility, making it widely applicable in practical engineering projects.

[0105] In one embodiment of this disclosure, the processing unit determines the ratio of the absolute value of the difference between the first slope irradiance and the second slope irradiance to the horizontal irradiance as the azimuth irradiance deviation rate.

[0106] The closer the weather condition is to sunny, the greater the difference in irradiance between different directions; conversely, the closer the weather condition is to cloudy / rainy, the smaller the difference in irradiance between different directions. Therefore, when the difference in irradiance between the first and second slopes is very small, and the horizontal irradiance is greater than both the first and second slopes, the weather condition is close to cloudy / rainy. Actual measurement data shows that when the horizontal irradiance is greater than both the first and second slopes, and the azimuthal irradiance deviation rate D is less than 5%, the weather condition is cloudy / rainy.

[0107] Therefore, in one embodiment of this disclosure, the processing unit compares the horizontal irradiance and the first sloping irradiance, and compares the horizontal irradiance and the second sloping irradiance. If the horizontal irradiance is greater than the first sloping irradiance and greater than the second sloping irradiance, and the azimuth irradiance deviation rate D is less than 5%, the processing unit determines the weather condition as a cloudy / rainy day.

[0108] As can be seen from the above, if the horizontal irradiance is not greater than the irradiance of the first inclined plane and is not greater than the irradiance of the second inclined plane, and the azimuth irradiance deviation rate D is less than 5%, the weather condition can be determined to be sunny or cloudy.

[0109] In one embodiment of this disclosure, if the horizontal irradiance is not greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D < 5%, the processing unit calculates the irradiance based on the horizontal irradiance and the percentage of direct radiation within a preset range (e.g., 50%-60%), according to the slope irradiance calculation model. Calculate the theoretical irradiance of the first and second inclined planes respectively, where In represents the horizontal direct irradiance, Id represents the horizontal scattered irradiance, and ρ represents the ground reflectivity. ,in, Indicates the zenith angle of the sun. Indicates the angle of incidence of the sun.

[0110]

[0111] in, Indicates solar hour angle, Indicates declination angle, Indicate latitude, Indicates the azimuth of the inclined plane, Indicates the angle of inclination of the inclined plane;

[0112] ,in Sky clarity factor;

[0113] Based on the theoretical irradiance of the first and second inclined planes, the ratio of the difference between the theoretical irradiance of the first and second inclined planes to the horizontal irradiance is determined as the azimuth irradiance theoretical deviation rate D. 理论 The actual azimuth irradiance deviation rate D is determined by the ratio of the difference between the irradiance of the first and second inclined planes to the horizontal irradiance. 实际 ;

[0114] When the actual deviation rate of azimuth irradiation D 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 Under these circumstances, the weather condition is determined to be sunny; and the actual azimuth irradiance deviation rate D 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 Under these circumstances, the weather condition is determined to be cloudy.

[0115] In the above embodiments, taking the percentage of direct radiation within a preset range (e.g., 50%) as an example, it is explained how the processing unit determines the weather state based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate D when the horizontal irradiance is not greater than the first slope irradiance and the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%.

[0116] In one embodiment of this disclosure, the preset range is greater than or equal to 50% and less than or equal to 60%.

[0117] In one embodiment of this disclosure, the direct irradiation accounts for 50%.

[0118] By pre-setting the proportion of different horizontal direct irradiance In in the total irradiance, the weather conditions can also be determined based on the horizontal irradiance, the first inclined plane irradiance, the second inclined plane irradiance, and the azimuth irradiance deviation rate.

[0119] In one embodiment of this disclosure, the processing unit is configured to, when the horizontal irradiance is not greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D < 5%, calculate the irradiance based on the horizontal irradiance and the proportion of uniformly distributed direct irradiance within the range of 0 to 100%, according to the slope irradiance calculation model. The theoretical irradiance of the first and second inclined planes under different direct irradiance ratios were calculated, where In represents horizontal direct irradiance, Id represents horizontal scattered irradiance, and ρ represents ground reflectivity. ,in, Indicates the zenith angle of the sun. This represents the solar incidence angle. The different percentages of direct irradiance refer to the different values ​​of In / (In+Id).

[0120]

[0121] in, Indicates solar hour angle, Indicates declination angle, Indicate latitude, Indicates the azimuth of the inclined plane, Indicates the angle of inclination of the inclined plane;

[0122] ,in Sky clarity factor;

[0123] The processing unit is further configured to determine the ratio of the difference between the theoretical irradiance of the first inclined plane and the theoretical irradiance of the second inclined plane under different direct irradiance ratios to the horizontal irradiance as the azimuth irradiance theoretical deviation rate D under different direct irradiance ratios. 理论 ;

[0124] Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate D. 理论 The theoretical deviation rate D of the azimuth irradiation 理论 The corresponding percentage of direct radiation is determined to be the actual percentage of direct radiation; and

[0125] The weather condition is determined based on the actual percentage of direct sunlight.

[0126] For example, if the percentage of direct sunlight is 30%, it is considered cloudy weather; if the percentage of direct sunlight is 70%, it is considered sunny weather.

[0127] Determining the current weather state based on the actual direct radiation ratio includes: determining the weather state as sunny when the actual direct radiation ratio is greater than a first threshold; determining the weather state as cloudy / rainy when the direct radiation ratio is less than a second threshold; and determining the weather state as partly cloudy when the direct radiation ratio is less than or equal to the first threshold and greater than or equal to the second threshold.

[0128] For example, the first threshold is 50%; and the second threshold can be 10%.

[0129] The second and third radiometers in the weather condition determination device according to embodiments of this disclosure are fixed in orientation. When the device is deployed in a low-latitude region (i.e., between the Tropic of Cancer and the Tropic of Capricorn), because the subsolar point moves between the two tropics, the measuring surfaces of both the second and third radiometers may face away from the sun. The second radiometer facing away from the sun means that when the azimuth angle of the second radiometer is south-east or south-west, the subsolar point is located north of the second radiometer; conversely, when the azimuth angle of the second radiometer is north-east or north-west, the subsolar point is located south of the second radiometer. In this situation, it cannot be used to determine the weather condition.

[0130] In response, in one embodiment of this disclosure, the device for determining weather conditions further includes a fourth radiometer and a fifth radiometer. The fourth radiometer is configured to be symmetrical with respect to the second radiometer about a plane perpendicular to the horizontal plane and parallel to the latitude line, and the fifth radiometer is configured to be symmetrical with respect to the third radiometer about a plane perpendicular to the horizontal plane and parallel to the latitude line. When both the second and third radiometers are facing away from the sun, the processing unit uses the measurement data from the fourth radiometer as the first slope irradiance and the measurement data from the fifth radiometer as the second slope irradiance.

[0131] Figure 4 The structure of a device for determining weather conditions according to another embodiment of this disclosure is shown. For example... Figure 4 As shown, the device for determining weather conditions also includes a fourth radiometer 4 and a fifth radiometer 5, wherein the second radiometer 2 and the third radiometer 3 are configured in the same manner as... Figure 3The setup shown is the same: the fourth radiometer 4 and the second radiometer 2 are symmetrical about a plane that is perpendicular to the horizontal plane and parallel to the parallel of latitude; the fifth radiometer 5 and the third radiometer 3 are symmetrical about a plane that is perpendicular to the horizontal plane and parallel to the parallel of latitude; and the fourth radiometer 4 and the fifth radiometer 5 are symmetrical about the meridional plane.

[0132] After the fourth and fifth radiometers are set up, they can be activated when the second and third radiometers are facing away from the sun, and can continue to be used to determine the weather conditions.

[0133] In one embodiment of this disclosure, the device for determining weather conditions further includes a rotating mechanism, on which the second radiometer and the third radiometer are mounted. When both the second radiometer and the third radiometer are facing away from the sun, the rotating mechanism drives the second radiometer and the third radiometer to rotate 180 degrees in the horizontal plane, so that the second radiometer and the third radiometer face the sun again.

[0134] By setting up a rotating mechanism, when the point of direct sunlight is moved so that both the second and third radiometers are facing away from the sun, the second and third radiometers can be rotated 180 degrees in the horizontal plane, enabling the weather condition determination device to resume operation and improving its applicability.

[0135] The method and equipment for determining weather conditions disclosed herein measure irradiance in different azimuths, and then identify weather conditions based on the irradiance deviation rate in different azimuths. This method determines weather conditions simultaneously with irradiance data measurement, expands the versatility of equipment capabilities, simplifies manufacturing and installation, and reduces maintenance costs. Furthermore, it is applicable to all latitudes and seasons, has low cost, high feasibility, and can be widely used in practical engineering applications.

[0136] In the description of this application, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0137] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0138] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A method for determining weather conditions, comprising: Measure horizontal irradiance; The irradiance of the first inclined plane and the irradiance of the second inclined plane are measured, wherein the first inclined plane and the second inclined plane are set to face the sun and are symmetrical about the meridian; The azimuth irradiance deviation rate is determined based on the horizontal irradiance, the irradiance of the first inclined plane, and the irradiance of the second inclined plane; and The weather conditions are determined based on the horizontal irradiance, the first inclined plane irradiance, the second inclined plane irradiance, and the azimuth irradiance deviation rate.

2. The method according to claim 1, wherein, The azimuth irradiance deviation rate is determined based on the horizontal irradiance, the irradiance of the first inclined plane, and the irradiance of the second inclined plane, including: The ratio of the absolute value of the difference between the irradiance of the first inclined plane and the irradiance of the second inclined plane to the horizontal irradiance is defined as the azimuth irradiance deviation rate D.

3. The method according to claim 2, wherein, Determining weather conditions based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate includes: When the horizontal irradiance is greater than the irradiance of the first inclined plane and greater than the irradiance of the second inclined plane, and the azimuth irradiance deviation rate D is less than 5%, the weather condition is determined to be cloudy and rainy.

4. The method according to claim 2, further comprising, when the horizontal irradiance is not greater than the first inclined plane irradiance and greater than the second inclined plane irradiance, and the azimuth irradiance deviation rate D is less than 5%, obtaining the first inclined plane theoretical irradiance and the second inclined plane theoretical irradiance respectively based on the horizontal irradiance and the direct irradiance ratio within a preset range according to the inclined plane irradiance calculation model. Based on the theoretical irradiance of the first and second inclined planes, determine the azimuth irradiance theoretical deviation rate D of the theoretical irradiance of the first and second inclined planes. 理论 Based on the irradiance of the first and second inclined planes, the actual azimuth irradiance deviation rate D is determined. 实际 ; When the actual deviation rate of azimuth irradiation D 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 Under these circumstances, the weather condition is determined to be sunny; as well as Actual deviation rate D of azimuth irradiation 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 Under these circumstances, the weather condition is determined to be cloudy.

5. The method according to claim 4, wherein, The preset range is 50% to 60%.

6. The method according to claim 4, wherein, The direct radiation irradiation accounts for 50%.

7. The method according to claim 2, further comprising: Under the condition that the horizontal irradiance is greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D is less than 5%, based on the horizontal irradiance and multiple uniformly distributed direct irradiance ratios within the range of 0 to 100%, the theoretical irradiance of the first slope and the theoretical irradiance of the second slope under different direct irradiance ratios are obtained according to the slope irradiance calculation model. Based on the theoretical irradiance of the first and second inclined planes under different direct irradiance ratios, and the horizontal irradiance, the theoretical azimuth irradiance deviation rate D under different direct irradiance ratios is determined. 理论 ; Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate. 理论 The theoretical deviation rate D of the azimuth irradiation 理论 The corresponding percentage of direct radiation is determined to be the actual percentage of direct radiation. as well as The current weather condition is determined based on the actual percentage of direct sunlight.

8. The method according to claim 7, wherein, Determining the current weather condition based on the actual percentage of direct solar radiation includes: If the actual direct radiation ratio is greater than the first threshold, the weather condition is determined to be sunny. If the percentage of direct radiation is less than the second threshold, the weather condition is determined to be cloudy; and If the percentage of direct radiation is less than or equal to the first threshold and greater than or equal to the second threshold, the weather condition is determined to be cloudy.

9. The method according to claim 8, wherein, The first threshold is 50%, and the second threshold is 10%.

10. An apparatus for determining weather conditions, comprising: A first radiometer is configured to measure horizontal irradiance, wherein the measuring surface of the first radiometer is set to be horizontally placed; The second radiometer is configured to measure the irradiance of the first inclined plane; A third radiometer is configured to measure the irradiance of the second inclined plane, wherein the measuring surfaces of the second and third radiometers are arranged to face the sun and are symmetrical about the meridional plane; and The processing unit is configured to receive the horizontal irradiance, the first slope irradiance, and the second slope irradiance, determine the azimuth irradiance deviation rate based on the horizontal irradiance, the first slope irradiance, and the second slope irradiance, and determine the weather condition based on the horizontal irradiance, the first slope irradiance, the second slope irradiance, and the azimuth irradiance deviation rate.

11. The device according to claim 10, wherein, The processing unit is further configured to determine the ratio of the absolute value of the difference between the first inclined plane irradiance and the second inclined plane irradiance to the horizontal irradiance as the azimuth irradiance deviation rate.

12. The device according to claim 10, wherein, The processing unit is further configured to compare the horizontal irradiance and the first sloping irradiance and compare the horizontal irradiance and the second sloping irradiance. If the horizontal irradiance is greater than the first sloping irradiance and greater than the second sloping irradiance, and the azimuth irradiance deviation rate D is less than 5%, the processing unit determines the weather condition as a cloudy or rainy day.

13. The device according to claim 10, wherein, The processing unit is further configured to, when the horizontal irradiance is greater than the first inclined plane irradiance and greater than the second inclined plane irradiance, and the azimuth irradiance deviation rate D is less than 5%, obtain the theoretical irradiance of the first inclined plane and the theoretical irradiance of the second inclined plane based on the horizontal irradiance and the proportion of direct radiation within a preset range, according to the inclined plane irradiance calculation model. The processing unit is further configured to determine the azimuth theoretical irradiance deviation rate D of the first inclined plane theoretical irradiance and the second inclined plane theoretical irradiance based on the first inclined plane theoretical irradiance and the second inclined plane theoretical irradiance. 理论 Based on the irradiance of the first and second inclined planes, the actual azimuth irradiance deviation rate D is determined. 实际 ; Actual deviation rate D of azimuth irradiation 实际 Greater than the theoretical deviation rate D of azimuth irradiation 理论 In this case, the processing unit determines the weather condition to be sunny; And the actual deviation rate D of azimuth irradiation 实际 Less than or equal to the theoretical deviation rate of azimuth irradiation D 理论 In this case, the processing unit determines the weather condition to be cloudy.

14. The device according to claim 13, wherein, The preset range is greater than or equal to 50% and less than or equal to 60%.

15. The device according to claim 13, wherein, The direct radiation irradiation accounts for 50%.

16. The device according to claim 10, wherein, The processing unit is further configured to, under the condition that the horizontal irradiance is greater than the first slope irradiance and greater than the second slope irradiance, and the azimuth irradiance deviation rate D < 5%, obtain the first slope theoretical irradiance and the second slope theoretical irradiance under different direct irradiance ratios based on the horizontal irradiance and multiple uniformly distributed direct irradiance ratios within the range of 0 to 100%, according to the slope irradiance calculation model. The processing unit is further configured to determine the azimuth theoretical irradiance deviation rate D under different direct irradiance ratios, based on the first inclined plane theoretical irradiance, the second inclined plane theoretical irradiance, and the horizontal irradiance under different direct irradiance ratios. 理论 ; Choose the theoretical azimuth irradiance deviation rate D that is closest to the azimuth irradiance deviation rate. 理论 The selected azimuth irradiance theoretical deviation rate D 理论 The corresponding percentage of direct irradiation is determined to be the actual percentage of direct irradiation. as well as The weather condition is determined based on the actual percentage of direct sunlight.

17. The device according to claim 16, wherein, Determining the current weather condition based on the actual percentage of direct solar radiation includes: If the actual direct radiation ratio is greater than the first threshold, the weather condition is determined to be sunny. When the percentage of direct radiation is less than the second threshold, the weather condition is determined to be cloudy / rainy; and If the percentage of direct radiation is less than or equal to the first threshold and greater than or equal to the second threshold, the weather condition is determined to be cloudy.

18. The device according to claim 17, wherein, The first threshold is 50%, and the second threshold is 10%.

19. The apparatus of claim 10, further comprising a fourth radiometer and a fifth radiometer, wherein, The fourth radiometer is configured to be symmetrical with respect to the second radiometer about a plane perpendicular to the horizontal plane and parallel to the parallel of latitude; The fifth radiometer is configured to be symmetrical with respect to the third radiometer about a plane perpendicular to the horizontal plane and parallel to the parallel of latitude; In the case where both the second and third radiometers are facing away from the sun, the processing unit uses the measurement data of the fourth radiometer as the first slope irradiance and the measurement data of the fifth radiometer as the second slope irradiance.

20. The device according to claim 10, further comprising a rotating mechanism, wherein the second radiometer and the third radiometer are disposed on the rotating mechanism, and when both the second radiometer and the third radiometer are facing away from the sun, the rotating mechanism drives the second radiometer and the third radiometer to rotate 180 degrees in the horizontal plane, so that the second radiometer and the third radiometer face the sun again.

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