Solar cell control method and solar cell control device

Abstract

To accurately estimate maximum output operation points of solar batteries installed in regions of a mobile 2 different in height and suppress an opportunity loss of power generation during search for the maximum output operation points.SOLUTION: A shadow pattern applied on a first solar battery B1 is estimated by using output power of second and third solar batteries B2 and B3 which are installed ahead of the first solar battery B1 mounted on the mobile body 2 in an advancing direction of a mobile 2 and also installed in regions of the mobile 2 different in height from the ground. A maximum output operation point at which the output power of the first solar battery becomes maximum is estimated on the estimated shadow pattern, and an operation point of the first solar battery B1 is controlled on the basis of the estimated maximum output operation point.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a solar cell and a device for controlling a solar cell. [Background technology]

[0002] Conventionally, an on-board solar power generation system in which multiple solar cell panels (solar cells) are arranged in parallel in the direction of travel of the vehicle has been known (Patent Document 1). The on-board solar power generation system described in Patent Document 1 is based on the premise that the ambient environment of the solar cell arranged at the front in the direction of travel of the vehicle will move to the position of the solar cells arranged behind it as the vehicle travels. For this reason, the on-board solar power generation system described in Patent Document 1 applies the operating conditions of the front solar cell, i.e., the operating point (maximum output operating point) at which the power generated by the front solar cell is maximized, to the second and subsequent solar cells counting from the front. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-229481 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the onboard solar power generation system described in Patent Document 1 does not take into consideration the height of the solar cells arranged on the vehicle. Therefore, if the heights of the first solar cell and the second and subsequent solar cells are different, the influence of the surrounding environment on the first solar cell and the second and subsequent solar cells may differ. For example, even if the shadow of the same structure falls on the first solar cell and the second and subsequent solar cells, if the heights of the first solar cell and the second and subsequent solar cells are different, the position of the shadow falling on the first solar cell may differ from the position of the shadow falling on the second and subsequent solar cells depending on the position of the sun. Therefore, if the operating point of the first solar cell is applied directly to the second and subsequent solar cells, it may not be optimal as the operating point for the second and subsequent solar cells.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a solar cell control method and a solar cell control device that can accurately estimate the maximum power operating point of solar cells installed in areas of moving bodies at different heights, and can reduce the opportunity loss of power generation due to the search for the maximum power operating point. [Means for solving the problem]

[0006] A solar cell control method according to one aspect of the present invention is a solar cell control method for controlling an operating point of a first solar cell mounted on a mobile body. The method estimates the pattern of a shadow cast on the first solar cell using the output power of a second solar cell and a third solar cell, which are installed in areas of the mobile body ahead of the first solar cell in the direction of travel of the mobile body and at different heights above ground. Based on the estimated shadow pattern, the method estimates a maximum power operating point, which is the operating point at which the output power of the first solar cell is maximized, and controls the operating point of the first solar cell based on the estimated maximum power operating point. [Effects of the Invention]

[0007] According to the present invention, it is possible to accurately estimate the maximum power operating point of solar cells installed in areas of moving bodies at different heights, and to reduce loss of power generation opportunities due to searching for the maximum power operating point. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a solar cell control device according to this embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the arrangement of solar cells according to the first embodiment. [Figure 3A] FIG. 3A is a schematic diagram showing a shadow pattern. [Figure 3B] FIG. 3B is a schematic diagram showing an example of a method for estimating a shadow pattern. [Figure 4A] FIG. 4A is a schematic diagram illustrating the definition of the solar radiation angle. [Figure 4B] FIG. 4B is a schematic diagram showing parameters used to calculate the solar radiation angle. [Figure 4C] FIG. 4C is a schematic diagram showing the relationship between the solar radiation angle and the shadow offset amount. [Figure 4D] FIG. 4D is a schematic diagram showing a method for calculating the width of the shadow. [Figure 5] FIG. 5 is a flowchart showing an example of processing by the solar cell control device according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the arrangement of solar cells according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The embodiments will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0010] (First embodiment) [Configuration of solar cell control device] The configuration of a solar cell control device 1 according to the first embodiment will be described with reference to Figures 1 and 2. The solar cell in this embodiment is synonymous with a solar cell panel, a photovoltaic power generation panel, and a solar power generation module, and is made up of semiconductors that convert light energy such as sunlight into electrical energy. Specifically, the solar cell is made up of a plurality of solar cell cells arranged in the direction of travel F of the moving body (vehicle 2) and in the left-right direction facing the direction of travel F.

[0011] In this embodiment, the first solar cell B1 and the third solar cell B3 are arranged in the area of ​​the roof portion 23 of the vehicle 2, and the second solar cell B2 is arranged in the area of ​​the hood portion 22 of the vehicle 2. The height above ground of the first solar cell B1 and the third solar cell B3 is h3, and the height above ground of the second solar cell B2 is h2. Note that in this embodiment, the first solar cell B1 and the third solar cell B3 are installed in areas of the roof portion 23 of the vehicle 2 at the same height, but the first solar cell B1 and the third solar cell B3 may be installed in areas of the vehicle 2 at different heights above ground. Alternatively, the first solar cell B1, the second solar cell B2, and the third solar cell B3 may each be individual solar cell panels, and the first solar cell B1, the second solar cell B2, and the third solar cell B3 may be installed in areas of the vehicle 2 at different heights above ground. Alternatively, the first solar cell B1 and the third solar cell B3, which are arranged adjacent to each other in areas of the roof portion 23 at the same height above ground, may be configured as a single solar cell panel. For example, the first solar cell B1 and the third solar cell B3 may be configured by dividing a control region for controlling the operating point in one solar cell panel into a front and a rear in the traveling direction F of the vehicle 2.

[0012] The first solar cell B1 includes a plurality of solar cells, the operating points of which can be individually controlled, arranged in the left-right direction in the traveling direction F of the vehicle 2. The second solar cell B2 and the third solar cell B3 each include a plurality of solar cells, the operating points of which can be individually controlled, arranged in the left-right direction in the traveling direction F of the vehicle 2. The number of solar cells included in each of the first solar cell B1, the second solar cell B2, and the third solar cell B3 is set to the maximum number that can be controlled by the power converter that controls the solar cells mounted on the vehicle 2. At least one of the second solar cell B2 or the third solar cell B3 may have a structure in which photodiodes are arranged in the vehicle width direction.

[0013] The solar cell control device 1 is mounted on the vehicle 2. The solar cell control device 1 can individually control the operating points of multiple solar cells (B1, B2, B3) provided on the vehicle 2. The solar cell control device 1 estimates the pattern of shadow cast on the first solar cell B1 using the output power of the second solar cell B2 and the third solar cell B3, which are installed in areas of the vehicle 2 further forward in the direction of travel F of the vehicle 2 and at different heights above ground than the first solar cell B1. Based on the estimated shadow pattern, the solar cell control device 1 estimates a maximum power operating point, which is the operating point at which the output power of the first solar cell B1 is maximum, and controls the operating point of the first solar cell B1 based on the estimated maximum power operating point.

[0014] The solar cell control device 1 is a general-purpose microcomputer equipped with a CPU (Central Processing Unit), memories (storage units) such as RAM and ROM, and an input / output unit. A computer program for causing the microcomputer to function as the solar cell control device 1 is installed in the microcomputer. By executing the computer program, the microcomputer functions as multiple information processing circuits (11, 12, 13) provided in the solar cell control device 1. Note that in this embodiment, an example is shown in which the multiple information processing circuits (11, 12, 13) provided in the solar cell control device 1 are realized by software, but it is also possible to configure the information processing circuits by providing dedicated hardware for executing each information processing. Furthermore, the multiple information processing circuits may be configured as individual hardware. The solar cell control device 1 is equipped with a shadow pattern estimation unit 11, an operating point estimation unit 12, and a power control unit 13 as the multiple information processing circuits.

[0015] The shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the first solar cell B1 (hereinafter simply referred to as the "shadow pattern"). Specifically, when the shadow pattern estimation unit 11 detects a change in the output power of the second solar cell B2, it starts estimating the shadow pattern. The shadow pattern cast on the first solar cell B1 can be classified into one of the following two patterns. The shadow pattern estimation unit 11 estimates which of the following two patterns the shadow pattern cast on the first solar cell B1 is.

[0016] Here, the pattern of the shadow cast on the first solar cell B1 will be described with reference to FIG. 3A. In FIG. 3A, the pattern of the shadow cast on the first solar cell will be described with reference to the shadow S cast on the second solar cell B2 (B2-1 to B2-5) and the third solar cell B3 (B3-1 to B3-5) used when estimating the shadow pattern. Each of B2-1 to B2-5 indicates a solar cell provided in the second solar cell B2, and each of B3-1 to B3-5 indicates a solar cell provided in the third solar cell B3. FIG. 3A shows the shapes of the shadow S cast on the vehicle 2 in the first and second patterns, respectively, and shows a perspective view pv, a first top view tv1, and a second top view tv2 from the left side of the page. The first top view tv1 and the second top view tv2 differ in the position of the vehicle 2 relative to the structure (St1 or St2). The second top view tv2 shows the state of the shadow at time t=tv when the shadow S1 that was cast on the second solar cell B2 in the first top view tv1 is cast on the third solar cell B3 due to the movement of the vehicle 2 in the direction of travel F.

[0017] The first pattern is a pattern in which a shadow S cast by a structure St1, such as a utility pole, falls on the vehicle 2. When the vehicle 2 passes through the shadow S cast by such a structure St1, the shadow S cast on the second solar cell B2 (B2-1 to B2-5) arranged in an area at a height h2 above the ground of the vehicle 2 flows backward in the traveling direction F of the vehicle 2 as seen from the vehicle 2. Specifically, as shown in the first top view tv1 of the first pattern, at time t=0, the shadow S1 falls on the solar cell cells (B2-1 and B2-2) of the second solar cell B2. In contrast, as shown in the second top view tv2 of the first pattern, at time t=tv, the shadow S2 that was cast on the solar cell cells (B2-1 and B2-2) of the second solar cell B2 now falls on the solar cell cells (B3-1 and B3-2) of the third solar cell B3. In other words, the shadow S cast on the second solar cell B2 flows backward in the traveling direction F of the vehicle 2 as it is. Therefore, the first pattern is a pattern in which the shadow S cast on the second solar cell B2 falls on the first solar cell B1 without being offset in the left-right direction in the traveling direction F of the vehicle 2.

[0018] The second pattern is a pattern in which a shadow S cast by a structure St2 that is horizontal to the ground, such as an electric wire, falls on the vehicle 2. When the vehicle 2 passes through the shadow S cast by such a structure St2, the shadow S cast on the second solar cell B2 (B2-1 to B2-5) arranged in an area at height h2 above the ground of the vehicle 2 is offset left and right with respect to the traveling direction F of the vehicle 2 and flows backward in the traveling direction F when it falls on the third solar cell B3 and the first solar cell B1 arranged in an area at a different height at height h3 above the ground, as seen from the vehicle 2. Specifically, as shown in the first top view tv1 of the second pattern, at time t=0, the shadow S1 falls on the solar cell of the second solar cell B2 (part of B2-3 and all of B2-4). In contrast, as shown in the second top view tv2 of the second pattern, at time t=tv, the shadow S1 that was cast on the solar cells of the second solar cell B2 (part of B2-3 and all of B2-4) now casts on the solar cells of the third solar cell B3 (all of B3-3 and part of B3-4). In other words, the shadow S cast on the second solar cell B2 is offset when it casts on an area at a different height, and flows backward in the direction of travel F of the vehicle 2. Therefore, the second pattern is a pattern in which the shadow S cast on the second solar cell B2 is offset left and right in the direction of travel F of the vehicle 2 and casts on the first solar cell B1.

[0019] The shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the first solar cell B1 using the output power of the second solar cell B2 installed on the hood portion 22 and the third solar cell B3 installed on the roof portion 23, which are regions of the vehicle 2 that are further forward in the direction of travel F of the vehicle 2 than the first solar cell B1 and at a different height above ground. Specifically, the shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the first solar cell B1 by comparing the output power of the second solar cell B2 with the output power of the third solar cell B3. The shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the first solar cell B1 based on the power output from each of the multiple solar cell units included in the second solar cell B2 and the third solar cell B3.

[0020] Here, with reference to Fig. 3B, the method by which the shadow pattern estimation unit 11 estimates a shadow pattern will be described in detail. Fig. 3B shows power values ​​(P2-1 to P2-5) output from each of the multiple solar cell units included in the second solar cell B2 at time t = 0 in the first and second patterns. Fig. 3B also shows power values ​​(P3-1 to P3-5) output from each of the multiple solar cell units included in the third solar cell B3 at time t = tv in the first and second patterns. Note that the power values ​​output from the solar cell units B2-1 to B2-5 included in the second solar cell B2 correspond to P2-1 to P2-5, and the power values ​​output from the solar cell units B3-1 to B3-5 of the third solar cell B3 correspond to P3-1 to P3-5. Time t=tv is the time when the shadow S cast on the solar cells (B2-1 to B2-5) of the second solar cell B2 at time t=0 falls on the solar cells (B3-1 to B3-5) of the third solar cell B3.

[0021] When the power output from each of the plurality of solar cell units (B2-1 to B2-5) included in the second solar cell B2 changes (time t=0), the shadow pattern estimation unit 11 acquires the power values ​​(P2-1 to P2-5) output from each of the plurality of solar cell units included in the second solar cell B2. The shadow pattern estimation unit 11 acquires the power values ​​(P3-1 to P3-5) output from each of the plurality of solar cell units included in the third solar cell B3 at time t=tv. The shadow pattern estimation unit 11 compares the distribution of the power values ​​(P2-1 to P2-5) output from each of the plurality of solar cell units included in the second solar cell B2 at time t=0 with the distribution of the power values ​​(P3-1 to P3-5) output from each of the plurality of solar cell units included in the third solar cell B3 at time t=tv. If the shadow pattern estimation unit 11 determines that the distribution of the power values ​​(P2-1 to P2-5) output from each of the solar cells included in the second solar cell B2 is the same as the distribution of the power values ​​(P3-1 to P3-5) output from each of the solar cells included in the third solar cell B3, it estimates that the shadow pattern is the first pattern. If the shadow pattern estimation unit 11 determines that the distribution of the power values ​​(P2-1 to P2-5) output from each of the solar cells included in the second solar cell B2 is not the same as the distribution of the power values ​​(P3-1 to P3-5) output from each of the solar cells included in the third solar cell B3, it estimates that the shadow pattern is the second pattern.

[0022] As shown in FIG. 3B, the first pattern shows a state in which a shadow S is cast on the two solar cells (B2-1 and B2-2) on the left side of the second solar cell B2, and then, at time t = tv, a shadow S passing through the second solar cell B2 casts on the two solar cells (B3-1 and B3-2) on the left side of the third solar cell B3. Therefore, the power values ​​output from the solar cells of the second solar cell B2 and the third solar cell B3 all match, and the distributions of the power values ​​are consistent. Therefore, it can be determined that the shadow S cast on the second solar cell B2 casts on the first solar cell B1 without being offset left or right in the traveling direction F of the vehicle 2. The second pattern shown in FIG. 3B shows a state in which a shadow S is cast on the third and fourth solar cells (B2-3 and B2-4) from the left of the second solar cell B2, and then, at time t = tv, a shadow S passing through the second solar cell B2 casts on the third solar cell (B3-3) from the left of the third solar cell B3. Therefore, the power values ​​output from the solar cells of the second solar cell B2 and the third solar cell B3 do not match, and the distribution of power values ​​is offset to the left. Therefore, it can be determined that the shadow S cast on the second solar cell B2 is offset to the left when viewed from the traveling direction F of the vehicle 2 when it casts on the third solar cell B3, and casts on the first solar cell B1.

[0023] If the estimated shadow pattern is a predetermined pattern (second pattern), the shadow pattern estimation unit 11 calculates the solar radiation angle, which is the angle between the horizontal plane and the sun projected onto a plane perpendicular to the traveling direction F of the vehicle 2. Here, with reference to FIG. 4A, the definition of the solar radiation angle φ will be explained schematically. FIG. 4A shows a plane p1 perpendicular to the traveling direction F of the vehicle 2 and a horizontal plane hp. The solar radiation angle φ is defined as the angle between the sun T projected onto the plane p1 perpendicular to the traveling direction F of the vehicle 2 and the horizontal plane hp. The shadow pattern estimation unit 11 calculates the solar radiation angle φ based on the output power of the second solar cell B2, the height h2 of the second solar cell B2 above ground, and the output power of the third solar cell B3, and the height h3 of the third solar cell B3 above ground. The solar radiation angle φ is calculated using the following equation (1). FIG. 4B shows parameters used to calculate the solar radiation angle φ. The parameters used to calculate the solar radiation angle φ are the height h2 of the second solar cell B2 above ground, the height h3 of the third solar cell B3 above ground, the width x2 of the shadow cast by the second solar cell B2, and the width x3 of the shadow cast by the third solar cell B3. The width x2 of the shadow cast by the second solar cell B2 is calculated based on the output power of the second solar cell B2, and the width x3 of the shadow cast by the third solar cell B3 is calculated based on the output power of the third solar cell B3.

[0024]

number

[0025] The width of the shadow cast on the solar cell is a parameter required when calculating the solar radiation angle φ. The shadow pattern estimation unit 11 identifies the solar cell that is cast by the shadow S based on the output power of the solar cell, and calculates the width of the shadow. Specifically, the shadow pattern estimation unit 11 calculates the width of the shadow based on the power value output by each of the multiple solar cell cells provided in the solar cell. The shadow pattern estimation unit 11 compares the power values ​​output from each solar cell provided in the solar cell, and identifies the solar cell that outputs less power than the other solar cell. In other words, the shadow pattern estimation unit 11 identifies the solar cell that is cast by the shadow S. The shadow pattern estimation unit 11 sets the width of the identified solar cell that outputs less power than the other solar cell as the shadow width.

[0026] Here, with reference to FIG. 4D, the method by which the shadow pattern estimation unit 11 calculates the width of the shadow cast on the solar cell will be described in detail. As shown in FIG. 4D, the power values ​​output by each of the solar cell cells (B2-1 to B2-5) arranged in the left-right direction of the second solar cell B2 decrease from the first solar cell B2-1 to the fourth solar cell B2-4. Therefore, the shadow pattern estimation unit 11 identifies the first solar cell B2-1 to the fourth solar cell B2-4 as solar cell cells with decreased power values. When solar cell cells with decreased power values ​​are adjacent to each other, the shadow pattern estimation unit 11 calculates the width x2 of the shadow cast on the second solar cell B2 by multiplying the pre-stored solar cell width by the number of solar cell cells with decreased power values ​​(four). Alternatively, the shadow pattern estimation unit 11 may identify the maximum value from the power values ​​output by each solar cell and identify solar cell cells whose output power value is less than half of the maximum value as solar cell cells with decreased power. This prevents the second solar cell B3-2 of the third solar cell B3 from being included in the shadow width x3, even though the output power value P3-2 is reduced, as the second solar cell B3-2 is not completely covered by the shadow S, and allows the shadow width x3 to be calculated more accurately.

[0027] Based on the calculated solar radiation angle φ, the shadow pattern estimation unit 11 calculates an offset amount Δx1 (hereinafter simply referred to as "offset amount Δx1") in the left-right direction in the traveling direction F of the vehicle 2 that occurs when the shadow that was cast on the second solar cell B2 falls on the first solar cell B1. The offset amount Δx1 of the shadow cast on the first solar cell B1 is calculated using the following mathematical formula (2). FIG. 4C shows the relationship between the solar radiation angle φ and the offset amount Δx1 in the left-right direction in the traveling direction F of the vehicle 2 that occurs when the shadow S cast on the second solar cell B2 falls on the first solar cell B1. Note that in this embodiment, the height h3 above ground of the third solar cell B3 is the same as the height h1 above ground of the first solar cell B1, and h1 in mathematical formula (2) is the same value as the height h3 above ground of the third solar cell B3.

[0028]

number

[0029] Note that if the shadow S on the vehicle 2 is uniformly cast across the entire left-right direction in the traveling direction F of the vehicle 2, or if there is no shadow on the vehicle 2 at all, the shadow pattern estimation unit 11 cannot estimate the width of the shadow cast on the solar cell. In other words, the shadow pattern estimation unit 11 cannot calculate the solar radiation angle φ. Therefore, if the power output from all solar cell cells included in at least one of the second solar cell B2 and the third solar cell B3 is the same value, the shadow pattern estimation unit 11 stops estimating the shadow pattern. If the power output from the multiple solar cell cells included in the second solar cell B2 is different values ​​and the power output from the multiple solar cell cells included in the third solar cell B3 is different values, the shadow pattern estimation unit 11 resumes estimating the shadow pattern. Note that if the power output from all solar cell cells included in at least one of the second solar cell B2 and the third solar cell B3 is the same value, the shadow pattern estimation unit 11 estimates that the shadow pattern cast on the first solar cell B1 is the first pattern.

[0030] The power point estimator 12 estimates a maximum power power point, which is an operating point at which the output power of the first solar cell B1 is maximized, based on the estimated pattern of the shadow cast on the first solar cell B1. Specifically, the power point estimator 12 estimates a maximum power power point for each of the plurality of solar cells included in the first solar cell B1 based on the estimated pattern of the shadow.

[0031] 3A, when the shadow pattern is the first pattern, the shadow S1 that was cast on the solar cell (B2-1 and B2-2) of the second solar cell B2 at time t=0 moves rearward in the traveling direction F of the vehicle 2 as the vehicle 2 moves. Therefore, the power point estimator 12 determines that the shadow S1 is cast on the solar cell of the first solar cell B1, which is disposed rearward in the traveling direction F of the solar cell (B2-1 and B2-2) of the second solar cell B2 that is cast by the shadow S1. The power point estimator 12 estimates that, at the time when the shadow S1 that was cast on the second solar cell B2 casts on the first solar cell B1, the maximum power operating point of the solar cell that is cast by the shadow S1 will be the same as the solar cell (B2-1 and B2-2) of the second solar cell B2 at time t=0. The time at which the shadow S1 that was cast on the solar cells (B2-1 and B2-2) of the second solar cell B2 casts on the solar cells of the first solar cell B1 is calculated based on the distance between the solar cells of the second solar cell B2 and the first solar cell B1 and the moving speed of the vehicle 2. The maximum power operating points of the second solar cell B2 and the third solar cell B3 are identified by a known maximum power operating point tracking method.

[0032] As shown in FIG. 3A, when the shadow pattern is the second pattern, the shadow S1 that was cast on the solar cell (part of B2-3 and all of B2-4) of the second solar cell B2 at time t=0 is offset to the left as viewed from the traveling direction F of the vehicle 2 when it casts on the third solar cell B3 and the first solar cell B1. The shadow pattern estimation unit 11 determines that the solar cell of the second solar cell B2 that is cast by the shadow S1 at time t=0 is B2-4. The operating point estimation unit 12 identifies the solar cell of the first solar cell B1 that is cast by the shadow S1 that was cast on the solar cell B2-4 of the second solar cell B2 at time t=0. Specifically, when the shadow pattern is the second pattern, the operating point estimation unit 12 identifies the solar cell B2-3 of the second solar cell B2 that is located at a position that is separated in the left-right direction by an offset amount Δx1 from the solar cell B2-4 of the second solar cell B2 that is cast by the shadow S1. Then, the power point estimation unit 12 identifies the solar cell of the first solar cell B1 arranged behind the solar cell B2-3 of the second solar cell B2 in the traveling direction F as the solar cell cast by the shadow S1. The power point estimation unit 12 estimates that at the time when the shadow S1 that was cast on the second solar cell B2 at time t=0 casts on the first solar cell B1, the maximum power power point of the solar cell of the first solar cell B1 cast by the shadow S1 will be the same as that of the solar cell B2-4 of the second solar cell B2 at time t=0.

[0033] Power control unit 13 controls the power points of the plurality of solar cells included in first solar cell B1 based on the maximum power power point for each of the plurality of solar cells included in first solar cell B1. Specifically, power control unit 13 controls the output voltage of first solar cell B1 so that the power point of first solar cell B1 becomes the maximum power power point.

[0034] [Solar cell control method] Next, an example of the processing of the solar cell control device 1 shown in Fig. 1 will be described with reference to Fig. 5. The processing of the solar cell control device 1 shown in the flowchart of Fig. 5 continues as long as power is supplied to the solar cell control device 1.

[0035] In step S10, the shadow pattern estimation unit 11 determines whether the width of the shadow can be estimated. Specifically, if the power output from all solar cells included in at least one of the second solar cell B2 and the third solar cell B3 is the same value, the shadow pattern estimation unit 11 determines that the width of the shadow cannot be estimated. For example, if all solar cells arranged in the horizontal direction are shaded, or if all solar cells arranged in the horizontal direction are exposed to sunlight, the output power from all solar cells will be the same value, and therefore the shadow width is determined to be unable to be estimated. If the shadow pattern estimation unit 11 determines that the width of the shadow cannot be estimated (NO in step S10), the process proceeds to step S80. If the shadow pattern estimation unit 11 determines that the width of the shadow can be estimated (YES in step S10), the process proceeds to step S20.

[0036] In step S20, the shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the first solar cell B1. Specifically, the shadow pattern cast on the first solar cell B1 is estimated using the output power of the second solar cell B2 and the third solar cell B3, which are installed in an area of ​​the vehicle 2 further ahead in the direction of travel of the vehicle 2 and at a different height above ground than the first solar cell B1. If the shadow pattern cast on the first solar cell B1 is the second pattern (YES in step S30), the process proceeds to step S40. If the shadow pattern cast on the first solar cell B1 is not the second pattern (NO in step S30), the process proceeds to step S80.

[0037] In step S40, the shadow pattern estimation unit 11 estimates the solar radiation angle φ. Specifically, the shadow pattern estimation unit 11 calculates the solar radiation angle φ based on the width x2 of the shadow cast on the second solar cell B2 and the height h2 of the second solar cell B2 above ground, and the width x3 of the shadow cast on the third solar cell B3 and the height h1 of the third solar cell B3 above ground. In step S50, the shadow pattern estimation unit 11 calculates, based on the calculated solar radiation angle φ, an offset amount Δx1 in the left-right direction toward the traveling direction F of the vehicle 2 that occurs when the shadow cast by the second solar cell B2 casts on the first solar cell B1.

[0038] In step S60, the power point estimator 12 estimates the maximum power power point of the first solar cell B1. Specifically, the power point estimator 12 estimates the maximum power power point of each of the plurality of solar cells included in the first solar cell B1 based on the travel speed of the vehicle 2 and an offset amount Δx1 that occurs when a shadow that was cast on a solar cell of the second solar cell B2 falls on a solar cell of the first solar cell B1. In step S70, the power control unit 13 controls the power points of the plurality of solar cells included in the first solar cell B1 based on the estimated maximum power power points for each of the plurality of solar cells included in the first solar cell B1.

[0039] In step S80, the power point estimator 12 estimates the maximum power point of the first solar cell B1. Specifically, the power point estimator 12 determines that the shadow that was cast on the second solar cell B2 will now fall on the solar cells of the first solar cell B1 that are located behind the solar cells of the second solar cell B2 in the direction of travel F of the vehicle 2 that is cast in the shadow. The power point estimator 12 estimates that, at the time when the shadow that was cast on the solar cells of the second solar cell B2 falls on the solar cells of the first solar cell B1, the maximum power point of the solar cells of the first solar cell B1 that are cast in the shadow will be the same as the maximum power point of the solar cells of the second solar cell B2 that were cast in the shadow. In other words, at the time when the shadow that was cast on the second solar cell B2 falls on the first solar cell B1, the power point estimator 12 estimates that the maximum power point of each of the multiple solar cells of the first solar cell B1 will be the same as the maximum power point of each of the multiple solar cells of the second solar cell B2 when the second solar cell B2 was in the shadow. In step S90, the power control unit 13 controls the operating points of the plurality of solar cells included in the first solar cell B1 based on the estimated maximum output operating point for each of the plurality of solar cells included in the first solar cell B1.

[0040] [Action and effect] As described above, the first embodiment provides the following advantageous effects.

[0041] The solar cell control device 1 estimates the pattern of the shadow cast on the first solar cell B1 using the output power of the second solar cell B2 and the third solar cell B3, which are installed in areas of the vehicle 2 further forward in the direction of travel F of the vehicle 2 than the first solar cell B1 and at different heights above ground. This allows the pattern of the shadow cast on the first solar cell B1 to be estimated, and based on the estimated pattern of the shadow cast on the first solar cell B1, it can estimate the maximum power operating point, which is the operating point at which the output power of the first solar cell B1 is maximized. Furthermore, the maximum power operating point of the first solar cell B1 is estimated based on the shadow pattern estimated from the output power of the second solar cell B2 and the third solar cell B3, which are installed further forward in the direction of travel F of the vehicle 2 than the first solar cell B1. This allows the solar cell control device 1 to set the operating point of the first solar cell B1 in a feedforward manner before the first solar cell B1 is shaded, thereby reducing the opportunity loss of power generation due to the search for the maximum power operating point.

[0042] The solar cell control device 1 estimates the pattern of the shadow cast on the first solar cell B1 by comparing the output power of the second solar cell B2 with the output power of the third solar cell B3. This allows the solar cell control device 1 to estimate the pattern of the shadow cast on the first solar cell B1 by comparing the output power of the second solar cell B2 with the output power of the third solar cell B3, which are installed in areas of the vehicle 2 at different heights above ground.

[0043] The solar cell control device 1 determines whether the estimated shadow pattern is a predetermined pattern. If it determines that the estimated shadow pattern is a predetermined pattern, it calculates the solar radiation angle φ, which is the angle between the sun T projected onto a plane p1 perpendicular to the direction of travel F of the vehicle 2 and the horizontal plane hp. If the shadow pattern on the first solar cell B1 is the second pattern, when the shadow cast on the second solar cell B2 casts on the first solar cell B1, an offset occurs in the left-right direction in the direction of travel F of the vehicle 2. Therefore, if the shadow pattern on the first solar cell B1 is the second pattern, the solar cell control device 1 can calculate the solar radiation angle φ to calculate the offset amount Δx1 that occurs when the shadow cast on the second solar cell B2 casts on the first solar cell B1. The shape of the shadow cast by a certain structure varies depending on the height above ground of the object that casts the shadow and the solar radiation angle φ. Therefore, if the height above ground of the solar cell is known in advance, it is possible to predict how the shadow will be cast on the solar cell at any height above ground by calculating the solar radiation angle φ. Furthermore, the solar cell control device 1 estimates the maximum power operating point of the first solar cell B1 based on the solar radiation angle φ and the vehicle's moving speed, thereby enabling the solar cell control device 1 to estimate the maximum power operating point at the time when the shadow of the second solar cell B2 falls on the first solar cell B1.

[0044] The solar cell control device 1 calculates the solar radiation angle φ based on the output power of the second solar cell B2 and its height above ground h2, and the output power of the third solar cell and its height above ground h3. This allows the solar cell control device 1 to calculate the solar radiation angle φ.

[0045] The first solar cell B1 includes a plurality of solar cells arranged in the left-right direction facing the traveling direction F of the vehicle 2, and each of which has an individually controllable operating point. The solar cell control device 1 estimates a maximum power operating point for each of the plurality of solar cells included in the first solar cell B1 based on the estimated shadow pattern, and individually controls the operating points of the plurality of solar cells based on the estimated maximum power operating point. This allows the solar cell control device 1 to control the operating point in accordance with the position of the shadow falling on the first solar cell B1. In other words, the solar cell control device 1 can reduce the loss of power generation opportunities caused by a deviation in the operating point.

[0046] The second solar cell B2 and the third solar cell B3 each include a plurality of solar cell cells that individually output power and are arranged in the left-right direction facing the traveling direction F of the vehicle 2. The solar cell control device 1 estimates the pattern of the shadow falling on the first solar cell B1 based on the power output from each of the plurality of solar cell cells of the second solar cell B2 and the third solar cell B3. This allows the solar cell control device 1 to determine whether the shadows between the second solar cell B2 and the third solar cell B3 are offset, and to estimate the shadow pattern.

[0047] The number of solar cells included in each of the first solar cell B1, the second solar cell B2, and the third solar cell B3 is the maximum number that can be controlled by the power converter that controls the solar cells mounted on the vehicle 2. This makes it possible to maximize the resolution within the range of performance given to the vehicle 2.

[0048] The solar cell control device 1 stops estimating the shadow pattern when the power output from all solar cell cells included in at least one of the second solar cell B2 and the third solar cell B3 is the same value. Furthermore, the solar cell control device 1 resumes estimating the shadow pattern when the power output from the solar cell cells included in the second solar cell B2 is different and the power output from the solar cell cells included in the third solar cell B3 is different. When the shadow S on the vehicle 2 is uniformly cast across the entire left-right direction in the traveling direction F of the vehicle 2, or when there is no shadow S on the vehicle 2 at all, the solar cell control device 1 cannot estimate the width of the shadow cast on the solar cell. In other words, the solar cell control device 1 cannot calculate the solar irradiation angle φ. Therefore, the solar cell control device 1 determines whether the solar irradiation angle φ can be calculated, and if the solar irradiation angle φ cannot be calculated, stops the process of estimating the maximum power power point, thereby allowing the maximum power power point to be appropriately determined using a different method.

[0049] In the solar cell control device 1, at least one of the second solar cell B2 and the third solar cell B3 may have a structure in which photodiodes are arranged. This allows the solar cell control device 1 to estimate the shadow pattern more inexpensively compared to when the second solar cell B2 and the third solar cell B3 are used to estimate the shadow pattern. In other words, the solar cell control device 1 can estimate the maximum power operating point of the first solar cell B1 more inexpensively.

[0050] (Second embodiment) [Configuration of solar cell control device] The configuration of a solar cell control device 1 according to a second embodiment will be described with reference to Figure 6. Compared to the first embodiment, the second embodiment further includes a fourth solar cell B4 and a fifth solar cell B5, and the structures of the fourth solar cell B4 and the fifth solar cell B5 differ from those of the first to third solar cells, but the other points are common. Therefore, only the differences will be described, and a description of the other common points will be omitted.

[0051] The solar cell control device 1 according to the second embodiment includes a fourth solar cell B4 installed in the bumper section 24, which is an area of ​​the vehicle 2 that is further forward in the direction of travel F of the vehicle 2 than the second solar cell B2 and at a different height above the ground, and a fifth solar cell B5 arranged above the front grill section 25. The fourth solar cell B4 and the fifth solar cell B5 are structured so that photodiodes are arranged in the left-right direction facing the direction of travel F of the vehicle 2.

[0052] [Solar cell control method] Differences from the processing in the first embodiment will be described with reference to FIG. 5. In the second embodiment, in step S20, the shadow pattern estimation unit 11 estimates the pattern of the shadow cast on the second solar cell B2 using the output power of the fourth solar cell B4 and the fifth solar cell B5, which are installed in an area of ​​the vehicle 2 further forward in the direction of travel F of the vehicle 2 than the second solar cell B2 and at a different height above ground. In step S60, the power point estimation unit 12 estimates the maximum power power point for each of the plurality of solar cells included in the second solar cell B2, the third solar cell B3, and the first solar cell B1 based on the estimated shadow pattern. In step S70, the power control unit 13 controls the power points of the plurality of solar cells included in the second solar cell B2, the third solar cell B3, and the first solar cell B1 based on the maximum power power point for each of the plurality of solar cells included in the second solar cell B2, the third solar cell B3, and the first solar cell B1.

[0053] [Action and effect] As described above, according to the second embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.

[0054] The solar cell control device 1 can control the operating points of the second solar cell B2, the third solar cell B3, and the first solar cell B1, which are installed further rearward in the direction of travel F of the vehicle 2 than the fifth solar cell B5, in a feedforward manner, thereby further reducing loss of power generation opportunities. Furthermore, the fourth solar cell B4 and the fifth solar cell B5 have a structure in which photodiodes are arranged in the left-right direction in the direction of travel F of the vehicle 2. This allows the solar cell control device 1 to estimate shadow patterns at a lower cost than when estimating shadow patterns using solar cells. [Explanation of symbols]

[0055] 1. Solar cell control device 2. Mobile B1 1st solar cell B2 2nd solar cell B3 Third solar cell φ solar radiation angle

Claims

1. A solar cell control method for controlling an operating point of a first solar cell mounted on a moving object, comprising: using the output power of a second solar cell and a third solar cell installed in an area of ​​the moving body that is further forward in the moving body's direction of travel and at a different height above ground than the first solar cell, to estimate whether the pattern of the shadow cast by the first solar cell is a first pattern in which the shadow flows backward in the moving body's direction of travel without being offset in the left-right direction with respect to the moving body's direction of travel, or a second pattern in which the shadow flows backward in the moving body's direction of travel with an offset in the left-right direction; estimating a maximum output power point, which is an operating point at which the output power of the first solar cell is maximized, based on the estimated shadow pattern; The operating point of the first solar cell is controlled based on the estimated maximum output operating point. How to control solar cells.

2. A pattern of a shadow cast on the first solar cell is estimated by comparing the output power of the second solar cell with the output power of the third solar cell. The method for controlling a solar cell according to claim 1 .

3. A method for controlling an operating point of a first solar cell mounted on a mobile object, comprising: estimating a pattern of a shadow cast on the first solar cell using output power of a second solar cell and a third solar cell that are installed in an area of ​​the moving body that is forward in a direction of travel of the moving body and at a different height above ground than the first solar cell; determining whether the estimated shadow pattern is a predetermined pattern; If it is determined that the estimated shadow pattern is a predetermined pattern, a solar radiation angle is calculated, which is the angle between the sun projected onto a plane perpendicular to the traveling direction of the moving body and a horizontal plane; estimating a maximum output operating point, which is an operating point at which the output power of the first solar cell is maximized, based on the solar radiation angle and the moving speed of the mobile object; The operating point of the first solar cell is controlled based on the estimated maximum output operating point. How to control solar cells.

4. The solar radiation angle is calculated based on the output power of the second solar cell and the height above ground of the second solar cell, and the output power of the third solar cell and the height above ground of the third solar cell. The method for controlling a solar cell according to claim 3 .

5. the first solar cell includes a plurality of solar cell cells arranged in a left-right direction in a traveling direction of the moving body, the solar cell cells being capable of individually controlling the operating points; The control method includes: estimating the maximum power operating point for each of the plurality of solar cells based on the estimated shadow pattern; The operating points of the plurality of solar cells are individually controlled based on the estimated maximum output operating point. The method for controlling the solar cell according to claim 1 .

6. the second solar cell and the third solar cell each include a plurality of solar cell units that are arranged in a left-right direction in a traveling direction of the moving body and that individually output electric power, The control method includes: A pattern of a shadow cast on the first solar cell is estimated based on the power output from each of the plurality of solar cells of the second solar cell and the third solar cell. A method for controlling the solar cell according to any one of claims 1 to 5.

7. The number of the plurality of solar cells included in each of the first solar cell, the second solar cell, and the third solar cell is the maximum number that can be controlled by a power converter included in the mobile object. The method for controlling a solar cell according to claim 5 or 6.

8. stopping the estimation of the shadow pattern when the power output from all solar cells included in at least one of the second solar cell and the third solar cell is the same value; When the powers output from the plurality of solar cell units included in the second solar cell are different values ​​and the powers output from the plurality of solar cell units included in the third solar cell are different values, the estimation of the shadow pattern is resumed. The method for controlling a solar cell according to claim 6 or 7.

9. A solar cell control device that controls an operating point of a first solar cell mounted on a moving object, a shadow pattern estimation unit that estimates, using output power of a second solar cell and a third solar cell installed in an area of ​​the moving body forward of the moving body in the direction of travel and at a different height above ground than the first solar cell, whether the pattern of a shadow cast on the first solar cell is a first pattern that flows backward in the moving body's direction of travel without being offset in the left-right direction with respect to the moving body's direction of travel, or a second pattern that flows backward in the moving body's direction of travel with an offset in the left-right direction; an operating point estimating unit that estimates a maximum output operating point, which is an operating point at which the output power of the first solar cell is maximized, based on the estimated shadow pattern; a power control unit that controls the operating point of the first solar cell based on the estimated maximum output operating point. Solar cell control device.

10. A solar cell control device that controls an operating point of a first solar cell mounted on a mobile body, comprising: a shadow pattern estimation unit that estimates a pattern of a shadow cast on the first solar cell using output power of a second solar cell and a third solar cell that are installed in an area of ​​the moving body that is further forward in the moving body's direction of travel than the first solar cell and at a different height above ground; an operating point estimating unit that estimates a maximum output operating point, which is an operating point at which the output power of the first solar cell is maximized, based on the estimated shadow pattern; a power control unit that controls an operating point of the first solar cell based on the estimated maximum power operating point, At least one of the second solar cell and the third solar cell has a structure in which photodiodes are arranged. Solar cell control device.

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