Management system, power generation system, and managing method for solar panel

Abstract

To estimate the maximum power of a solar panel with high precision.SOLUTION: A power control system includes a temperature estimation unit 62 that estimates an estimated panel temperature Tb of a solar panel 30 on the basis of a solar radiation intensity Ra of the solar panel 30, a radiation estimation unit 63 that estimates a solar radiation intensity Rb of the solar panel 30 on the basis of an operating point X of the solar panel 30 and the estimated panel temperature Tb, and a power estimation unit 51C that estimates a maximum power Pmax of the solar panel 30 on the basis of the estimated panel temperature Tb and the radiation intensity Rb.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to techniques for managing solar panels. [Background technology]

[0002] Power systems that supply power generated by solar panels to a power grid have been proposed. To increase the power generated by solar panels in emergencies such as when the power grid frequency drops, a suppression operation is envisioned, in which solar panels are operated at an operating point lower than the maximum power they can generate. For suppression operation, it is necessary to estimate the maximum power of the solar panels. However, the maximum power of a solar panel depends on various factors, such as the solar irradiance on the panel or the panel temperature.

[0003] For example, Patent Document 1 discloses a configuration for estimating the power generation reserve capacity of a solar panel by comparing a first maximum power corresponding to a first current-voltage characteristic previously obtained for the solar panel with a second maximum power corresponding to a second current-voltage characteristic estimated based on fluctuations in the output voltage of the solar panel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-9116 Summary of the Invention [Problem to be solved by the invention]

[0005] For appropriate suppression operation, it is important to estimate the maximum power with high accuracy. Although the technology of Patent Document 1 can estimate the power generation reserve capacity, there is room for further improvement in the accuracy of estimating the maximum power of the solar panel. In consideration of the above circumstances, one aspect of the present disclosure aims to estimate the maximum power of the solar panel with high accuracy. [Means for solving the problem]

[0006] In order to solve the above problems, a management system according to one embodiment of the present disclosure includes a temperature estimation unit that estimates an estimated panel temperature of the solar panel in accordance with a first solar radiation intensity of the solar panel, a solar radiation estimation unit that estimates a second solar radiation intensity of the solar panel in accordance with an operating point of the solar panel and the estimated panel temperature, and a power estimation unit that estimates the maximum power of the solar panel in accordance with the estimated panel temperature and the second solar radiation intensity.

[0007] A power generation system according to one embodiment of the present disclosure includes a solar panel and a management system that manages the solar panel, and the management system includes a temperature estimation unit that estimates an estimated panel temperature of the solar panel based on a first solar radiation intensity of the solar panel, a solar radiation estimation unit that estimates a second solar radiation intensity of the solar panel based on an operating point of the solar panel and the estimated panel temperature, and a power estimation unit that estimates a maximum power of the solar panel based on the estimated panel temperature and the second solar radiation intensity.

[0008] In one embodiment of the present disclosure, a solar panel management method includes a management system that manages solar panels, which estimates an estimated panel temperature of the solar panel based on a first solar radiation intensity of the solar panel, estimates a second solar radiation intensity of the solar panel based on the operating point of the solar panel and the estimated panel temperature, and estimates the maximum power of the solar panel based on the estimated panel temperature and the second solar radiation intensity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating a configuration of a power generation system. [Figure 2] 1 is a graph of voltage-power characteristics. [Figure 3] 1 is a graph of voltage-power characteristics. [Figure 4] FIG. 2 is a block diagram illustrating an example of the functional configuration of the power control system. [Figure 5] FIG. 2 is an explanatory diagram relating to the relationship between voltage-power characteristics and an operating point. [Figure 6]FIG. 4 is an explanatory diagram of the operation of the operation control unit. [Figure 7] FIG. 4 is an explanatory diagram of the operation of the operation control unit. [Figure 8] 4 is a flowchart of a control process in the first embodiment. [Figure 9] FIG. 10 is a block diagram illustrating an example of the functional configuration of a power control system according to a second embodiment. [Figure 10] 10 is a flowchart of a control process in the second embodiment. [Figure 11] FIG. 10 is a block diagram illustrating an example of the functional configuration of a power control system according to a third embodiment. [Figure 12] FIG. 10 is a block diagram illustrating the configuration of a temperature estimation unit in a third embodiment. [Figure 13] 10 is a flowchart of a control process in a third embodiment. [Figure 14] 10 is a graph showing voltage-current characteristics in a modified example. [Figure 15] FIG. 10 is a block diagram of a power generation system according to a modified example. [Figure 16] FIG. 10 is a block diagram of a power generation system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following description of an embodiment of the present disclosure will be given with reference to the accompanying drawings. Note that the embodiment described below is an exemplary embodiment that may be envisioned when implementing the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0011] 1. First embodiment 1 is a block diagram of a power generation system 20 according to a first embodiment. The power generation system 20 is a system that exchanges electric power (AC power) with a power system 10. The power system 10 is, for example, a distribution system or a transmission system that supplies electric power generated by a power generation facility (not shown) such as a thermal power plant or a nuclear power plant to consumers such as business facilities or ordinary homes.

[0012] The power generation system 20 is a power facility that exchanges power with the power grid 10 and is connected to the power grid 10. As illustrated in FIG. 1 , the power generation system 20 of the first embodiment is a solar power generation system that includes a solar panel 30 and a power control system 40.

[0013] The solar panel 30 is a power generation facility that converts the light energy of sunlight into electrical energy. Specifically, the solar panel 30 is a collection of cells, which are the basic units of solar cells. Specifically, the solar panel 30 is a cluster made up of multiple cells, a module made up of multiple clusters, a string made up of multiple modules, or an array made up of multiple strings.

[0014] 2 and 3 are graphs showing the relationship (hereinafter referred to as "voltage-power characteristics Cp") between the voltage V output by the solar panel 30 and the power P(V) generated by the solar panel 30. The voltage-power characteristics Cp are characteristics according to the specifications of the solar panel 30 (for example, open circuit voltage, short circuit current, temperature characteristics, etc.).

[0015] The solar panel 30 can operate at any point (hereinafter referred to as "operating point X") on the voltage-power characteristic Cp. The operating point X refers to a combination of voltage V and power P(V). At a specific operating point X (hereinafter referred to as "optimum operating point Xmax") on the voltage-power characteristic Cp, the power P(V) reaches a maximum value (hereinafter referred to as "maximum power Pmax"). In other words, the optimal operating point Xmax is the local maximum point of the power P(V).

[0016] 2 also shows the voltage-power characteristics Cp for each of a number of cases where the solar radiation intensity R on the solar panel 30 is different. The solar radiation intensity R is an index of the amount of light energy (W / m) that reaches the unit area of ​​the solar panel 30 from the sun. 2 2, the voltage-power characteristic Cp depends on the solar radiation intensity R. Specifically, the higher the solar radiation intensity R, the greater the maximum power Pmax.

[0017] FIG. 3 also shows the voltage-power characteristics Cp for multiple cases where the temperature of the solar panel 30 (hereinafter referred to as "panel temperature T") is different. As can be seen from FIG. 3, the voltage-power characteristics Cp depend on the panel temperature T. Specifically, the higher the panel temperature T, the smaller the maximum power Pmax. As explained above, the voltage-power characteristics Cp of the solar panel 30 change depending on the solar radiation intensity R and the panel temperature T.

[0018] 1 is a PCS (Power Conditioning System) that controls the solar panel 30. For example, the power control system 40 converts DC power generated by the solar panel 30 into AC power and supplies it to the power grid 10. The power control system 40 also controls the operating point X of the solar panel 30. The power control system 40 includes a control device 41 and a storage device 42.

[0019] The control device 41 is composed of one or more processors that control each element of the power control system 40. Specifically, the control device 41 is composed of one or more types of processors, such as a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC).

[0020] The storage device 42 is one or more memories that store programs executed by the control device 41 and data used by the control device 41. The storage device 42 is configured with a known storage medium such as a magnetic storage medium or a semiconductor storage medium. The storage device 42 may also be configured with a combination of multiple types of storage medium. A portable storage medium that can be attached to and detached from the power control system 40 may also be used as the storage device 42.

[0021] 4 is a block diagram illustrating an example of the functional configuration of the power control system 40. The control device 41 executes a program stored in the storage device 42 to realize a plurality of functions for controlling the solar panel 30 (a power estimation unit 51A, an operation control unit 52).

[0022] The power estimation unit 51A estimates the maximum power Pmax based on the current operating point X of the solar panel 30, and the current solar radiation intensity R and panel temperature T of the solar panel 30. The solar radiation intensity R is an actual measurement value measured by a pyranometer 31 installed on the solar panel 30. The panel temperature T is an actual measurement value measured by a thermometer 32 installed on the solar panel 30.

[0023] As mentioned above, the voltage-power characteristic Cp varies depending on the solar radiation intensity R or the panel temperature T. Therefore, as illustrated in Fig. 5, an infinite number of voltage-power characteristics Cp that pass through a specific operating point X are possible. However, once the solar radiation intensity R or the panel temperature T is determined, one voltage-power characteristic Cp that passes through the specific operating point X is identified.

[0024] Taking the above circumstances into consideration, the power estimation unit 51A of the first embodiment identifies a voltage-power characteristic Cp that passes through the current operating point X and corresponds to the solar radiation intensity R and the panel temperature T. Then, the power estimation unit 51A identifies a maximum power Pmax that corresponds to an optimal operating point Xmax on the voltage-power characteristic Cp identified from the operating point X, the solar radiation intensity R, and the panel temperature T. The power estimation unit 51A is a mathematical model that approximately represents the relationship between the voltage-power characteristic Cp, the solar radiation intensity R, and the panel temperature T.

[0025] The operation control unit 52 in Fig. 4 controls the solar panel 30 according to the maximum power Pmax estimated by the power estimation unit 51A. Specifically, the operation control unit 52 controls the operating point X of the solar panel 30 so that the difference ΔP (ΔP = Pmax - P(V)) between the maximum power Pmax and the power P(V) corresponding to the current operating point X approaches a predetermined reference value Prsv (rsv: reserve power). The reference value Prsv is a numerical value set in advance. For example, the reference value Prsv is set by an instruction from an administrator of the power control system 40 or an instruction from an external device such as an EMS (Energy Management System).

[0026] 6 and 7 are explanatory diagrams of the operation of the operation control unit 52. As illustrated in FIG. 6, when the difference ΔP between the maximum power Pmax and the power P(V) exceeds the reference value Prsv (i.e., when the power generation reserve capacity is excessive), the operation control unit 52 controls the operating point X of the solar panel 30 so that the power P(V) increases. On the other hand, as illustrated in FIG. 7, when the difference ΔP between the maximum power Pmax and the power P(V) falls below the reference value Prsv (i.e., when the power generation reserve capacity is insufficient), the operation control unit 52 controls the operating point X of the solar panel 30 so that the power P(V) decreases. As can be understood from the above explanation, according to the first embodiment, suppressed operation is realized while ensuring a power generation reserve capacity equivalent to the reference value Prsv.

[0027] As a result of the suppression operation exemplified above, in an emergency such as when the power frequency drops due to a shortage of power supply to the power grid 10, the power supply shortage in the power grid 10 is resolved by utilizing the power generation reserve, and the drop in frequency is suppressed. For example, by bringing the power P(V) of the solar panel 30 closer to the maximum power Pmax, the power supply to the power grid 10 is supplemented by the power generation system 20.

[0028] 8 is a flowchart of a process (hereinafter referred to as a "control process") executed by the power control system 40. For example, the control process is started in response to an instruction from the administrator of the power control system 40.

[0029] When the control process starts, the control device 41 (power estimation unit 51A) acquires the solar radiation intensity R and the panel temperature T (Sa1). Specifically, the control device 41 receives the solar radiation intensity R from the pyranometer 31 and the panel temperature T from the thermometer 32. The control device 41 (power estimation unit 51A) identifies the voltage-power characteristic Cp according to the current operating point X, the solar radiation intensity R, and the panel temperature T (Sa2). Then, the control device 41 (power estimation unit 51A) estimates the maximum power Pmax from the voltage-power characteristic Cp (Sa3). Furthermore, the control device 41 (operation control unit 52) ​​controls the operating point X of the solar panel 30 according to the maximum power Pmax (Sa4).

[0030] The control device 41 determines whether a predetermined termination condition is met (Sa5). The termination condition is, for example, when a termination command is received from the administrator of the power control system 40. If the termination condition is not met (Sa5: NO), the control device 41 transitions the process to step Sa1. That is, estimation of the current maximum power Pmax (Sa1-Sa3) and control of the solar panel 30 (Sa4) are repeated until the termination condition is met. If the termination condition is met (Sa5: YES), the control device 41 ends the control process.

[0031] As explained above, in the first embodiment, in addition to the current operating point X of the solar panel 30, the solar radiation intensity R and the panel temperature T of the solar panel 30 are taken into consideration. Therefore, the maximum power Pmax of the solar panel 30 can be estimated with high accuracy compared to, for example, a mode in which the maximum power Pmax is estimated based only on the operating point X.

[0032] 2. Second embodiment A second embodiment will be described. Note that, for elements in the following exemplary aspects that have the same functions as those in the first embodiment, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0033] 9 is a block diagram illustrating an example of the functional configuration of a power control system 40 according to the second embodiment. A control device 41 executes a program stored in a storage device 42 to realize a plurality of functions for controlling the solar panel 30 (a power estimation unit 51B, an operation control unit 52).

[0034] The power estimation unit 51B estimates the maximum power Pmax according to the current operating point X of the solar panel 30 and the gradient G of the voltage-power characteristic Cp at the operating point X. The gradient G is the inclination of the tangent to the voltage-power characteristic Cp at the operating point X. In other words, the gradient G is the ratio (dP / dV) of the change dP in the power P to the change dV in the voltage V of the solar panel 30.

[0035] As mentioned above, the voltage-power characteristic Cp varies depending on various factors such as the solar radiation intensity R or the panel temperature T. However, once the operating point X through which the voltage-power characteristic Cp passes and the gradient G at the operating point X are determined, one voltage-power characteristic Cp can be identified.

[0036] Taking the above circumstances into consideration, the power estimation unit 51B of the second embodiment identifies a voltage-power characteristic Cp that passes through the current operating point X and has a tangent angle at the operating point X with a gradient G. The power estimation unit 51B is, for example, a mathematical model that approximately represents the voltage-power characteristic Cp.

[0037] The operation control unit 52 controls the solar panel 30 according to the maximum power Pmax estimated by the power estimation unit 51B. Specifically, similar to the first embodiment, the operation control unit 52 controls the operating point X of the solar panel 30 so that the difference ΔP (ΔP=Pmax−P(V)) between the maximum power Pmax and the power P(V) corresponding to the current operating point X approaches a predetermined reference value Prsv.

[0038] 10 is a flowchart of the control process in the second embodiment. When the control process starts, the control device 41 (power estimation unit 51B) acquires the gradient G at the operating point X (Sb1). For example, the control device 41 varies the voltage V of the solar panel 30 by a small amount of change dV, and calculates the gradient G (G=dP / dV) from the amount of change dV in the voltage V and the amount of change dP in the power P(V) linked to the variation. Note that when the power of the power control system 40 varies due to, for example, a frequency or voltage disturbance in the power grid 10, the operating point X of the solar panel 30 varies in conjunction with the variation. The control device 41 may calculate the gradient G from the variation in the operating point X (variations in the voltage V and the power P(V)) described above.

[0039] The control device 41 (power estimation unit 51B) identifies the voltage-power characteristic Cp according to the current operating point X and the gradient G (Sb2). Then, the control device 41 (power estimation unit 51B) estimates the maximum power Pmax from the voltage-power characteristic Cp (Sb3). Furthermore, the control device 41 (operation control unit 52) ​​controls the operating point X of the solar panel 30 according to the maximum power Pmax (Sb4).

[0040] The control device 41 determines whether a predetermined termination condition is met (Sb5). If the termination condition is not met (Sb5: NO), the control device 41 proceeds to step Sb1 and repeats the estimation of the maximum power Pmax (Sb1-Sb3) and the control of the solar panel 30 (Sb4). If the termination condition is met (Sb5: YES), the control device 41 ends the control process.

[0041] As described above, in the second embodiment, in addition to the current operating point X of the solar panel 30, the gradient G at the operating point X is taken into consideration. Therefore, the maximum power Pmax of the solar panel 30 can be estimated with high accuracy compared to, for example, a mode in which the maximum power Pmax is estimated based only on the operating point X.

[0042] Furthermore, in the second embodiment, the maximum power Pmax is estimated according to the operating point X and the gradient G. Therefore, the actinometer 31 that measures the solar radiation intensity R and the thermometer 32 that measures the panel temperature T are not required. This also has the advantage that the configuration and operation of the power generation system 20 are simplified.

[0043] 3. Third embodiment 11 is a block diagram illustrating an example of the functional configuration of a power control system 40 according to the third embodiment. The control device 41 executes a program stored in the storage device 42 to realize a plurality of functions for controlling the solar panel 30 (an initial estimation unit 61, a temperature estimation unit 62, a solar radiation estimation unit 63, a power estimation unit 51C, and an operation control unit 52).

[0044] The initial estimation unit 61 estimates the current irradiance intensity Ra and estimated panel temperature Ta of the solar panel 30 according to the current operating point X of the solar panel 30 and the gradient G of the voltage-power characteristic Cp at the operating point X. The initial estimation unit 61 is a mathematical model that approximately expresses the relationship between the operating point X and the gradient G and the irradiance intensity Ra and the estimated panel temperature Ta. As described above, the voltage-power characteristic Cp depends on the irradiance intensity R and the panel temperature T. Therefore, once the voltage-power characteristic Cp is identified from the operating point X and the gradient G, it is possible to estimate the irradiance intensity R and panel temperature T corresponding to the voltage-power characteristic Cp. The initial estimation unit 61 identifies the voltage-power characteristic Cp from the operating point X and the gradient G, and identifies the irradiance intensity Ra and estimated panel temperature Ta corresponding to the voltage-power characteristic Cp.

[0045] Incidentally, the gradient G may contain errors. For example, (1) Errors due to noise in the power control system 40; (2) Errors due to the electrical hysteresis characteristics of the solar panel 30 (3) Errors caused by sudden and temporary changes in the solar radiation intensity R, for example, when the solar panel 30 is hidden in the shadow of various objects such as an aircraft. The gradient G is subject to errors due to factors such as:

[0046] In order to reduce the influence of the errors described above, the temperature estimation unit 62 of the third embodiment estimates the estimated panel temperature Tb of the solar panel 30 according to the solar radiation intensity Ra estimated by the initial estimation unit 61. Specifically, the temperature estimation unit 62 estimates the estimated panel temperature Tb of the solar panel 30 according to the solar radiation intensity Ra estimated by the initial estimation unit 61, meteorological data D related to the weather in the environment in which the solar panel 30 is installed (hereinafter referred to as the "installation environment"), and the power P(V) generated by the solar panel 30.

[0047] The weather data D is information provided by a weather observation system (not shown). The weather observation system generates the weather data D using the results of observations by various observation facilities, such as meteorological satellites or AMeDAS. The weather data D includes an outside temperature Dt and a wind speed Dw. The outside temperature Dt is the outdoor temperature in the installation environment. The wind speed Dw is the speed of wind occurring in the installation environment. The temperature estimation unit 62 repeatedly acquires the weather data D from the weather observation system at a predetermined cycle.

[0048] Fig. 12 is a block diagram illustrating the configuration of temperature estimation unit 62. As illustrated in Fig. 12, temperature estimation unit 62 is a mathematical model including calculation units 71, 72, 73, 74, and 75.

[0049] The calculation unit 71 calculates the estimated panel temperature Tb by adding the outside air temperature Dt and the temperature change ΔT. The temperature change ΔT is the amount of change in the estimated panel temperature Tb caused by the exchange of energy in the solar panel 30. The temperature change ΔT can also be expressed as the difference between the outside air temperature Dt and the estimated panel temperature Tb.

[0050] The calculation unit 72 estimates the radiant energy E1 dissipated from the solar panel 30 into the installation environment. Specifically, the calculation unit 72 includes an adder 721, a multiplier 722, and a converter 723. The adder 721 adds the wind speed Dw of the weather data D to a predetermined adjustment value A. The adjustment value A is a predetermined numerical value corresponding to the cooling of the solar panel 30 due to natural convection in the installation environment and the cooling of the solar panel 30 due to thermal radiation, and is set in advance, for example, statistically or experimentally. In other words, the sum (Dw+A) of the wind speed Dw and the adjustment value A simulates factors (e.g., wind or convection) that affect the cooling of the solar panel 30.

[0051] The multiplication unit 722 multiplies the sum (Dw+A) of the wind speed Dw and the adjustment value A by the temperature change ΔT. The conversion unit 723 converts the result of the calculation by the multiplication unit 722 into radiant energy E1. Specifically, the conversion unit 723 calculates the radiant energy E1 by multiplying the result of the calculation by the multiplication unit 722 (ΔT(Dw+A)) by a predetermined coefficient k1.

[0052] The calculation unit 73 converts the solar radiation intensity Ra estimated by the initial estimation unit 61 into supply energy E2. The supply energy E2 is energy supplied to the solar panel 30 by irradiation with sunlight. Specifically, the calculation unit 73 calculates the supply energy E2 by multiplying the solar radiation intensity Ra by a predetermined coefficient k2.

[0053] The calculation unit 74 calculates the stored energy E3 by subtracting the radiant energy E1 and the power P(V) from the supplied energy E2. The power P(V) corresponds to the energy used by the solar panel 30 for power generation. As can be understood from the above explanation, the stored energy E3 is the energy stored in the solar panel 30. Note that, because the power P(V) is substantially proportional to the solar radiation intensity Ra, the subtraction of the power P(v) by the calculation unit 74 may be replaced by the multiplication of the solar radiation intensity Ra by a coefficient k2 (calculation unit 73).

[0054] The calculation unit 75 converts the stored energy E3 into a temperature change ΔT of the solar panel 30. Specifically, the calculation unit 75 calculates the temperature change ΔT by multiplying the stored energy E3 by an adjustment value (1 / (k3·s)). The coefficient k3 is a predetermined value proportional to the heat capacity of the solar panel 30. The larger the coefficient k3, the smaller the temperature change ΔT. In other words, the larger the coefficient k3, the more the fluctuations in the panel temperature T are suppressed.

[0055] The panel temperature T of the solar panel 30 changes over time due to various factors such as the solar radiation intensity R, the outside air temperature Dt, and the wind speed Dw. However, the panel temperature T tends to be less susceptible to sudden changes compared to the solar radiation intensity R, the outside air temperature Dt, the wind speed Dw, etc. (hereinafter referred to as "temperature change tendency").

[0056] The temperature estimation unit 62 illustrated in Fig. 12 is a mathematical model that simulates the temperature change trend due to solar radiation intensity Ra, outside air temperature Dt, wind speed Dw, etc. On the other hand, the estimated panel temperature Ta estimated by the initial estimation unit 61 is a numerical value corresponding to the operating point X and gradient G, and does not reflect the temperature change trend. Considering the above, it can be said that the estimated panel temperature Tb estimated by the temperature estimation unit 62 is a more accurate temperature that takes into account the temperature change trend compared to the estimated panel temperature Ta. In other words, if the estimated panel temperature Tb and the estimated panel temperature Ta differ significantly, it can be interpreted that the estimation accuracy of the estimated panel temperature Ta has decreased due to an error in the gradient G described above.

[0057] In consideration of the above circumstances, in the third embodiment, the estimated panel temperature Tb estimated by the temperature estimator 62 is applied to the estimation of the maximum power Pmax. Therefore, the influence of errors in the gradient G is reduced, and as a result, the maximum power Pmax can be estimated with high accuracy.

[0058] The solar radiation estimator 63 in FIG. 11 estimates the solar radiation intensity Rb of the solar panel 30 based on the operating point X of the solar panel 30 and the estimated panel temperature Tb estimated by the temperature estimator 62. The solar radiation estimator 63 is a mathematical model that approximately represents the relationship between the operating point X, the estimated panel temperature Tb, and the solar radiation intensity Rb. That is, the solar radiation estimator 63 estimates the solar radiation intensity Rb corresponding to the operating point X and the estimated panel temperature Tb. As described above, the estimated panel temperature Tb is more accurate than the estimated panel temperature Ta. Therefore, the solar radiation intensity Rb estimated from the estimated panel temperature Tb has a smaller error than the solar radiation intensity Ra estimated together with the estimated panel temperature Ta. That is, the temperature estimator 62 and the solar radiation estimator 63 function as elements that correct the initial solar radiation intensity Ra to an accurate solar radiation intensity Rb. Note that the solar radiation intensity Ra is an example of a "first solar radiation intensity," and the solar radiation intensity Rb is an example of a "second solar radiation intensity."

[0059] The power estimation unit 51C estimates the maximum power Pmax based on the solar radiation intensity Rb estimated by the solar radiation estimation unit 63 and the estimated panel temperature Tb estimated by the temperature estimation unit 62. Specifically, the power estimation unit 51C identifies the voltage-power characteristic Cp corresponding to the solar radiation intensity Rb and the estimated panel temperature Tb, and identifies the maximum power Pmax corresponding to the optimal operating point Xmax of the voltage-power characteristic Cp. The power estimation unit 51C is a mathematical model that approximately represents the relationship between the voltage-power characteristic Cp, the solar radiation intensity R, and the panel temperature T. As described above, the solar radiation estimation unit 63 and the power estimation unit 51C function as elements that estimate the maximum power Pmax based on the operating point X of the solar panel 30 and the estimated panel temperature Tb estimated by the temperature estimation unit 62.

[0060] The operation control unit 52 controls the solar panel 30 according to the maximum power Pmax estimated by the power estimation unit 51C. Specifically, similar to the first embodiment, the operation control unit 52 controls the operating point X of the solar panel 30 so that the difference ΔP (ΔP=Pmax−P(V)) between the maximum power Pmax and the power P(V) corresponding to the current operating point X approaches a predetermined reference value Prsv.

[0061] 13 is a flowchart of the control process in the third embodiment. When the control process is started, the control device 41 (initial estimation unit 61) estimates the solar radiation intensity Ra and the estimated panel temperature Ta of the solar panel 30 according to the current operating point X and the gradient G at the operating point X (Sc1). The control device 41 (temperature estimator 62) estimates the estimated panel temperature Tb of the solar panel 30 according to the solar radiation intensity Ra (Sc2).

[0062] The control device 41 (solar radiation estimation unit 63) estimates solar radiation intensity Rb according to the operating point X and the estimated panel temperature Tb (Sc3). The control device 41 (power estimation unit 51C) estimates maximum power Pmax according to the solar radiation intensity Rb and the estimated panel temperature Tb (Sc4). Then, the control device 41 (operation control unit 52) ​​controls the operating point X of the solar panel 30 according to the maximum power Pmax (Sc5).

[0063] The control device 41 determines whether a predetermined termination condition is met (Sc6). If the termination condition is not met (Sc6: NO), the control device 41 shifts the process to step Sc1 and repeats the estimation of the maximum power Pmax (Sc1-Sc4) and the control of the solar panel 30 (Sc5). If the termination condition is met (Sc6: YES), the control device 41 ends the control process.

[0064] As described above, in the third embodiment, the estimated panel temperature Tb is estimated according to the solar radiation intensity Ra, and the solar radiation intensity Rb is estimated according to the operating point X of the solar panel 30 and the estimated panel temperature Tb. Furthermore, the maximum power Pmax of the solar panel 30 is estimated according to the solar radiation intensity Rb and the estimated panel temperature Tb. Therefore, the maximum power Pmax of the solar panel 30 can be estimated with high accuracy compared to a form in which the maximum power Pmax is estimated according to the solar radiation intensity Ra and the estimated panel temperature Ta estimated by the initial estimation unit 61.

[0065] In particular, in the third embodiment, in addition to the solar radiation intensity Ra of the solar panel 30, the outside air temperature Dt in the installation environment of the solar panel 30, the wind speed Dw in the installation environment of the solar panel 30, and the power P(V) generated by the solar panel 30 are used to estimate the estimated panel temperature Tb. Therefore, compared to a form in which the estimated panel temperature Tb is estimated based only on the solar radiation intensity Ra, the maximum power Pmax of the solar panel 30 can be estimated with high accuracy.

[0066] Furthermore, in the third embodiment, the solar radiation intensity Ra is estimated according to the operating point X of the solar panel 30, so the solar radiation intensity Ra can be acquired without the need for the actinometer 31. This simplifies the configuration and operation of the power generation system 20. In particular, in the third embodiment, in addition to the operating point X of the solar panel 30, the gradient G of the power P(V) relative to the voltage V at the operating point X is used to estimate the solar radiation intensity Ra. This allows the solar radiation intensity Ra (and therefore the maximum power Pmax) to be estimated with high accuracy, compared to a configuration in which the solar radiation intensity Ra is estimated only according to the operating point X of the solar panel 30.

[0067] 4. Variations Specific modified embodiments that can be added to each of the embodiments exemplified above are exemplified below. Two or more embodiments arbitrarily selected from the following examples may be combined as appropriate within the scope of not being mutually contradictory.

[0068] (1) The voltage-power characteristic Cp in each of the above-described embodiments may be replaced with the voltage-current characteristic Ci illustrated in Fig. 14. The voltage-current characteristic Ci is the relationship between the voltage V and the current I(V) in the solar panel 30.

[0069] In a configuration that uses the voltage-current characteristic Ci, the gradient G is the angle of the tangent to the voltage-current characteristic Ci at the operating point X. In other words, the gradient G may be the relative ratio (dI / dV) of the amount of change dI in the current I(V) to the amount of change dV in the voltage V of the solar panel 30. As can be understood from the above explanation, the gradient G is comprehensively expressed as the rate of change of the power P(V) or the current I(V) with respect to the voltage V of the solar panel 30 at the operating point X.

[0070] (2) In the third embodiment, the temperature estimator 62 estimates the estimated panel temperature Tb based on the outside air temperature Dt in the installation environment of the solar panel 30, the wind speed Dw in the installation environment, and the power P(V) generated by the solar panel 30. However, the information used to estimate the estimated panel temperature Tb is not limited to the above examples. Furthermore, the use of at least two of the outside air temperature Dt, the wind speed Dw, and the power P(V) may be omitted. That is, the temperature estimator 62 may estimate the estimated panel temperature Tb based on at least one of the outside air temperature Dt, the wind speed Dw, and the power P(V). The temperature estimator 62 may estimate the estimated panel temperature Tb based only on the solar radiation intensity Ra.

[0071] (3) In each of the above-described embodiments, for convenience, an example is given in which the power control system 40 controls one solar panel 30. However, as illustrated in FIG. 15, the power control system 40 may control multiple solar panels 30.

[0072] In an embodiment in which a plurality of solar panels 30 are installed, the processes exemplified in the above-described embodiments (estimation of maximum power Pmax, control of solar panels 30 according to maximum power Pmax) are executed in parallel for each of the plurality of solar panels 30. Note that, although one power control system 40 is illustrated for the plurality of solar panels 30 in Fig. 15, a power control system 40 may be installed individually for each solar panel 30.

[0073] Furthermore, the power control system 40 may estimate the maximum power Pmax for some of the solar panels 30 among the multiple solar panels 30, and control all of the solar panels 30 according to the estimated maximum power Pmax. The solar panels 30 for which the maximum power Pmax is to be estimated may be one or more solar panels 30.

[0074] (4) In the above-described embodiments, the power control system 40 of the power generation system 20 estimates the maximum power Pmax of the solar panel 30. However, the device that estimates the maximum power Pmax is not limited to the power control system 40. For example, an information processing system 80 illustrated in FIG. 16 may implement the functions of the power control system 40 in the above-described embodiments (FIGS. 4, 9, and 11). The information processing system 80 is a server system that can communicate with the power control system 40 via a communication network 81 such as a dedicated line. An example of the information processing system 80 is an external device such as an EMS. The power control system 40 in the above-described embodiments and the information processing system 80 illustrated in FIG. 16 are collectively referred to as a management system that controls the solar panel 30.

[0075] (5) As described above, the functions of the power control system 40 according to each of the above embodiments are realized by cooperation between one or more processors constituting the control device 41 and a program stored in the storage device 42. The programs exemplified above can be provided in a form stored on a computer-readable recording medium and installed on a computer. The recording medium is, for example, a non-transitory recording medium, such as an optical recording medium (optical disk) such as a CD-ROM, but also includes any known type of recording medium, such as a semiconductor recording medium or a magnetic recording medium. Note that a non-transitory recording medium includes any recording medium other than a transitory, propagating signal, and does not exclude volatile recording media. Furthermore, in a configuration in which a distribution device distributes a program via a communication network, the recording medium storing the program in the distribution device corresponds to the non-transitory recording medium described above.

[0076] (6) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position or order of each element based on the term "nth."

[0077] 5. Additional Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0078] A management system according to one aspect (aspect 1) of the present disclosure includes a temperature estimation unit that estimates an estimated panel temperature of a solar panel according to a first solar irradiance intensity (including solar radiation amount) of the solar panel, a solar radiation estimation unit that estimates a second solar irradiance intensity of the solar panel according to an operating point of the solar panel and the estimated panel temperature, and a power estimation unit that estimates a maximum power of the solar panel according to the estimated panel temperature and the second solar irradiance intensity. In the above aspect, the estimated panel temperature of the solar panel is estimated according to the acquired first solar irradiance intensity, and the second solar irradiance intensity is estimated according to the operating point of the solar panel and the estimated panel temperature of the solar panel. Furthermore, the maximum power of the solar panel is estimated according to the estimated panel temperature of the solar panel and the second solar irradiance intensity. Therefore, the maximum power of the solar panel can be estimated with higher accuracy compared to an aspect in which the maximum power of the solar panel is estimated according to the first solar irradiance intensity.

[0079] In a specific example (Aspect 2) of Aspect 1, the temperature estimator estimates the estimated panel temperature in accordance with at least one of the outside air temperature in the environment where the solar panel is installed, the wind speed in the environment where the solar panel is installed, and the power generated by the solar panel. In the above aspect, in addition to the first solar irradiance intensity of the solar panel, at least one of the outside air temperature in the environment where the solar panel is installed, the wind speed in the environment where the solar panel is installed, and the power generated by the solar panel is used to estimate the estimated panel temperature. Therefore, the maximum power of the solar panel can be estimated with higher accuracy than in an aspect in which the estimated panel temperature is estimated in accordance with only the first solar irradiance intensity.

[0080] In a specific example (Aspect 3) of Aspect 1 or Aspect 2, the solar panel further includes an initial estimation unit that estimates the first solar irradiance intensity according to the operating point of the solar panel. In the above aspect, the first solar irradiance intensity used to estimate the estimated panel temperature is estimated according to the operating point of the solar panel. Therefore, the first solar irradiance intensity can be obtained without the need for a pyranometer.

[0081] In a specific example (Aspect 4) of Aspect 3, the initial estimation unit estimates the first solar irradiance intensity according to a gradient of power or current relative to voltage of the solar panel at the operating point. In the above aspect, in addition to the operating point of the solar panel, the gradient of power or current relative to voltage at the operating point is used to estimate the first solar irradiance intensity. Therefore, the first solar irradiance intensity can be estimated with higher accuracy than in an aspect in which the first solar irradiance intensity is estimated only according to the operating point of the solar panel.

[0082] In a specific example (Aspect 5) of any one of Aspects 1 to 4, an operation control unit is further provided that controls the operating point of the solar panel so that the difference between the maximum power and the power corresponding to the operating point approaches a predetermined reference value. According to the above aspect, when the difference between the maximum power and the power of the operating point exceeds the reference value (i.e., when the power generating reserve capacity is excessive), the operating point of the solar panel is controlled so that the power of the operating point increases. On the other hand, when the difference between the maximum power and the power of the operating point falls below the reference value (i.e., when the power generating reserve capacity is insufficient), the operating point of the solar panel is controlled so that the power of the operating point decreases. Therefore, suppressed operation is realized while maintaining a predetermined power generating reserve capacity.

[0083] A power generation system according to one aspect (aspect 6) of the present disclosure includes a solar panel and a management system that manages the solar panel, and the management system includes a temperature estimation unit that estimates the estimated panel temperature based on a first solar radiation intensity of the solar panel, a solar radiation estimation unit that estimates a second solar radiation intensity of the solar panel based on the operating point of the solar panel and the estimated panel temperature, and a power estimation unit that estimates the maximum power of the solar panel based on the estimated panel temperature and the second solar radiation intensity.

[0084] A management method according to one aspect (aspect 7) of the present disclosure includes a management system for managing solar panels, which estimates the estimated panel temperature based on a first solar radiation intensity of the solar panel, estimates a second solar radiation intensity of the solar panel based on the operating point of the solar panel and the estimated panel temperature, and estimates the maximum power of the solar panel based on the estimated panel temperature and the second solar radiation intensity.

[0085] In addition, a management system according to another aspect of the present disclosure includes a power estimation unit that estimates the maximum power of a solar panel based on an operating point of the solar panel and a gradient of the power or current relative to the voltage of the solar panel at the operating point. In the above aspect, since the gradient at the operating point is taken into account in addition to the operating point of the solar panel, the maximum power of the solar panel can be estimated with high accuracy compared to, for example, a configuration in which the maximum power is estimated based only on the operating point. [Explanation of symbols]

[0086] 10...power system, 20...power generation system, 30...solar panel, 31...pyranometer, 32...thermometer, 40...power control system, 41...control device, 42...memory device, 51A, 51B, 51C...power estimation unit, 52...operation control unit, 61...initial estimation unit, 62...temperature estimation unit, 63...solar radiation estimation unit, 80...information processing system.

Claims

1. a temperature estimation unit that estimates an estimated panel temperature of the solar panel in accordance with a first solar radiation intensity of the solar panel; a solar radiation estimator that estimates a second solar radiation intensity of the solar panel according to an operating point of the solar panel and the estimated panel temperature; a power estimation unit that estimates a maximum power of the solar panel in accordance with the estimated panel temperature and the second solar radiation intensity; A management system comprising:

2. The temperature estimation unit estimates the estimated panel temperature in accordance with at least one of an outside air temperature in an environment where the solar panel is installed, a wind speed in an environment where the solar panel is installed, and a power generation electric power of the solar panel. The management system of claim 1.

3. an initial estimation unit that estimates the first solar radiation intensity according to the operating point of the solar panel; 3. The management system according to claim 1 or 2, further comprising:

4. The initial estimation unit estimates the first solar radiation intensity according to a gradient of power or current with respect to a voltage of the solar panel at the operating point. The management system of claim 3.

5. an operation control unit that controls the operating point of the solar panel so that the difference between the maximum power and the power corresponding to the operating point approaches a predetermined reference value; The management system of claim 1 further comprising:

6. Solar panels and A management system for managing the solar panels, The management system includes: a temperature estimation unit that estimates an estimated panel temperature of the solar panel in accordance with a first solar radiation intensity of the solar panel; a solar radiation estimator that estimates a second solar radiation intensity of the solar panel according to an operating point of the solar panel and the estimated panel temperature; a power estimation unit that estimates a maximum power of the solar panel in accordance with the estimated panel temperature and the second solar radiation intensity; Power generation system.

7. The management system that manages solar panels Estimating an estimated panel temperature of the solar panel according to a first solar radiation intensity of the solar panel; estimating a second solar radiation intensity of the solar panel according to an operating point of the solar panel and the estimated panel temperature; A maximum power of the solar panel is estimated according to the estimated panel temperature and the second solar radiation intensity. How to manage solar panels.

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