Photovoltaic power generation output estimation device, photovoltaic power generation output estimation method, and photovoltaic power generation output estimation program

Abstract

To obtain a device for estimating the output of sunlight power generation that can predict whether a sunlight power generation facility as a target of estimation of power generation output is excessively loaded.SOLUTION: The present invention includes: a power generation output estimation unit 140 for estimating power generation output of a sunlight power generation facility by using solar radiation intensity information showing the solar radiation intensity in a distance preset by the sunlight power generation facility; and an excessive loading estimation unit 150 for calculating an excessive load determination coefficient showing the correlation between solar radiation intensity information and a residual demand as an apparent power consumption of a demander with a sunlight power generation facility, and determining whether the sunlight power generation facility is excessively loaded by using the excessive load determination coefficient.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a photovoltaic power generation output estimation device, a photovoltaic power generation output estimation method, and a photovoltaic power generation output estimation program that estimate the power generation output of a photovoltaic power generation facility. [Background technology]

[0002] In recent years, the importance of expanding the use of renewable energy has been increasing, and an increasing number of consumers are installing distributed power sources such as solar power generation facilities and supplying power to a power transmission system or a power distribution system (hereinafter, these are referred to as power systems). Meanwhile, power companies and the like that operate the power systems are aware of the power output of some solar power generation facilities, but are unable to grasp the power output of many solar power generation facilities. For this reason, a device that estimates the power output of solar power generation facilities installed by each consumer has been proposed (see, for example, Patent Document 1). Note that the above-mentioned solar power generation facilities that can grasp the power output are solar power generation facilities that are subject to a contract under the full amount purchase system (hereinafter, referred to as a full amount purchase contract), and the solar power generation facilities that cannot grasp the power output are solar power generation facilities that are subject to a contract under the surplus power purchase system (hereinafter, referred to as a surplus purchase contract). This is because consumers who own solar power generation facilities that are subject to full purchase agreements are equipped with separate smart meters that measure the amount of electricity generated by the solar power generation facilities and the amount of electricity consumed by the load within the consumer's facility, whereas consumers who own solar power generation facilities that are subject to surplus purchase agreements are equipped with only a smart meter that measures the combined amount of electricity generated by the solar power generation facilities and the amount of electricity consumed by the load.

[0003] Patent Document 1 discloses a photovoltaic power output estimation device that estimates photovoltaic power output, which is the power output at a predetermined time point of a photovoltaic power generation facility that supplies power to a load connected to a power system, and is characterized by including a power output estimation unit that estimates photovoltaic power output using the solar radiation intensity at a predetermined point and the active power of the power system during a period before the predetermined time point when the sun's noon altitude is within a predetermined range from the noon altitude at the predetermined time point. This photovoltaic power output estimation device estimates the power output of a photovoltaic power generation facility connected to a power system using the solar radiation intensity measured by a pyranometer or the like installed around a substation and the active power measured by a measuring instrument installed at the substation or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-139270 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a large number of photovoltaic power generation facilities are introduced in a situation where electric power companies and the like are unable to grasp the power output of many photovoltaic power generation facilities, various problems arise in the operation of the power system. Although electric power companies and the like can measure the power consumption of the apparent power system load (hereinafter referred to as the "apparent load") that takes into account the power output of the photovoltaic power generation facilities at substations under their jurisdiction using meters and the like, they are unable to accurately grasp the power consumption of the actual load (hereinafter referred to as the "actual load") because the total power output of all photovoltaic power generation facilities connected to the power system is unknown. For this reason, for example, when planning the formation of power distribution facilities, it is necessary to predict the current flow through the future power distribution facilities based on the actual values ​​of the past actual loads. However, when the photovoltaic power generation output is unknown, the actual load is also unknown, so accurate current prediction is not possible, making it difficult to formulate an appropriate facility formation plan. In addition, when a large number of photovoltaic power generation facilities are introduced, the risk of supply and demand control increases because the prediction error of the power consumption of the actual load, which is predicted using multiple regression analysis, increases, and the risk of system control increases because restoration operations after a system accident are hindered.

[0006] For this reason, it is necessary to accurately estimate the power output of the photovoltaic power generation equipment. On the other hand, some photovoltaic power generation equipment are called overloaded photovoltaic power generation equipment. Overloaded photovoltaic power generation equipment is a photovoltaic power generation equipment in which the rated capacity of the PCS (Power Conditioning System: power conditioner) is smaller than the capacity of the solar panel. According to the photovoltaic power generation output estimation device of Patent Document 1, the power generation output is estimated using a coefficient that converts the solar radiation intensity into the power generation output of the photovoltaic power generation equipment. However, in an overloaded photovoltaic power generation equipment, when the rated capacity of the PCS is reached, the power generation output is saturated, so the correlation between the power generation output and the solar radiation intensity may be low. The photovoltaic power generation output estimation device described in Patent Document 1 estimates the power generation output using the same method as that of a photovoltaic power generation equipment that is not overloaded without distinguishing the overloaded photovoltaic power generation equipment, so there is a problem that the estimation accuracy of the power generation output of the overloaded photovoltaic power generation equipment is reduced. For this reason, it is desired to estimate whether the photovoltaic power generation equipment to be estimated for the power generation output is overloaded or not.

[0007] The present disclosure has been made in consideration of the above, and aims to provide a photovoltaic power generation output estimation device that can estimate whether or not a photovoltaic power generation facility that is the subject of power generation output estimation is overloaded. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the objective, the photovoltaic power generation output estimation device according to the present disclosure includes a power generation output estimation unit that estimates the power generation output of the photovoltaic power generation equipment using solar radiation intensity information that indicates the solar radiation intensity within a predetermined distance from the photovoltaic power generation equipment, and an overload estimation unit that calculates an overload determination coefficient that indicates the correlation between the solar radiation intensity information and residual demand, which is the apparent power consumption of a consumer in which the photovoltaic power generation equipment is installed, and determines whether the photovoltaic power generation equipment is overloaded using the overload determination coefficient. Effect of the Invention

[0009] Advantageous Effects of Invention The present disclosure provides an advantage in that it is possible to estimate whether or not a photovoltaic power generation facility that is a target for estimating power generation output is overloaded. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a photovoltaic power generation output estimation system according to a first embodiment. [Diagram 2] FIG. 1 is a block diagram showing an example of a functional configuration of a photovoltaic power generation output estimation device according to a first embodiment. [Diagram 3] FIG. 1 is a diagram showing an example of the configuration of a computer system that realizes a photovoltaic power generation output estimation device according to a first embodiment. [Figure 4] A flowchart showing an example of a processing procedure for estimating a second photovoltaic power generation output by the photovoltaic power generation output estimating device according to the first embodiment. [Diagram 5] FIG. 2 is a diagram showing a schematic diagram of the geographical location of each customer's photovoltaic power generation facility indicated by the location information data of the first embodiment; [Figure 6] FIG. 1 is a diagram showing the correspondence between a photovoltaic power generation facility that is the subject of estimation of power output in the first embodiment and a photovoltaic power generation facility that is used for the estimation. [Figure 7] FIG. 1 shows an example of a moving window according to the first embodiment. [Figure 8] FIG. 13 is a diagram showing an example of a calculation result of an overload determination coefficient according to the first embodiment; [Figure 9] FIG. 13 is a diagram showing an example of an estimation result of a saturation value according to the first embodiment; [Figure 10] FIG. 1 is a diagram showing an example of overload estimation data according to the first embodiment; [Figure 11] 11 is a flowchart showing an example of a first covariance calculation process procedure in a first covariance calculation unit. [Figure 12] 1 is a flowchart showing an example of a procedure for calculating a second covariance by a second covariance calculation unit according to the first embodiment. [Figure 13] A flowchart showing an example of a processing procedure in a power generation output estimation unit according to the first embodiment. [Figure 14] FIG. 13 is a diagram showing an example of an estimation result of a second photovoltaic power generation output displayed by a display unit according to the first embodiment; [Figure 15] FIG. 13 is a diagram showing an example of an estimation result of a second photovoltaic power generation output displayed by a display unit according to the first embodiment; [Figure 16] FIG. 13 is a diagram showing an example of a screen for selecting an area for displaying the determination result of an overloaded photovoltaic power generation facility according to the first embodiment. [Figure 17] FIG. 13 is a diagram showing an example of a display screen of a determination result of an overloaded photovoltaic power generation facility according to the first embodiment. [Figure 18] FIG. 13 is a diagram showing an example of an enlarged display screen of a determination result of an overloaded photovoltaic power generation facility according to the first embodiment. [Figure 19] FIG. 13 is a diagram showing an example of a display screen on which the determination result of an overloaded photovoltaic power generation facility according to the first embodiment is displayed in text form. [Figure 20] FIG. 13 is a diagram showing an example of a coefficient α in a case where photovoltaic power generation facilities of a plurality of customers are subject to estimation in the first embodiment. [Figure 21] A flowchart showing an example of a processing procedure for estimating a second photovoltaic power generation output by the photovoltaic power generation output estimating device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A photovoltaic power generation output estimating device, a photovoltaic power generation output estimating method, and a photovoltaic power generation output estimating program according to embodiments will be described below in detail with reference to the accompanying drawings.

[0012] Embodiment 1 Fig. 1 is a diagram showing a configuration example of a photovoltaic power generation output estimation system according to a first embodiment. A photovoltaic power generation output estimation system 10 of the present embodiment is configured such that a photovoltaic power generation output estimation device 100 and various facilities installed under a plurality of consumers are connected via a communication network 50. In Fig. 1, solid lines represent the flow of power, and dashed lines represent the flow of information.

[0013] FIG. 1 illustrates a consumer 200-1, a consumer 200-2, a consumer 200-3, a consumer 200-4, . . . , a consumer 200-m, . . . , and a consumer 200-n as a plurality of consumers. A load 201 and a photovoltaic power generation facility (abbreviated as PV (PhotoVoltaic) in the figure) 202 are connected to each of the consumers 200-1 to 200-n. Note that in the example illustrated in FIG. 1, n is an integer of 6 or more, and m is an integer of 5 or more and less than n, but the values ​​of n and m are not limited to the example illustrated in FIG. 1. Also, the load 201 of each of the consumers 200-1 to 200-n indicates one or more facilities that consume power, and in general, the specific facilities that constitute the load 201 are not the same for all the consumers 200-1 to 200-n. Similarly, in general, the photovoltaic power generation facilities 202 are not the same for all the consumers 200-1 to 200-n.

[0014] The photovoltaic power generation facility 202 installed in the consumer 200-1 is a photovoltaic power generation facility subject to a full purchase contract. The photovoltaic power generation facilities 202 installed in the consumers 200-2 to 200-n are photovoltaic power generation facilities subject to surplus purchase contracts.

[0015] The photovoltaic power generation facility 202 is, for example, a photovoltaic power generation facility installed on the roof of a building owned by the consumers 200-1 to 200-n, and includes not only small-scale photovoltaic power generation facilities but also large-scale photovoltaic power plants such as so-called mega solar power plants. The photovoltaic power generation facility 202 is connected to the power system 20 and supplies generated power to the power system 20. In addition, as shown in Fig. 1, loads 201 of the consumers 200-1 to 200-n are connected to the power system 20. The loads 201 receive power from the power system 20 and consume the power.

[0016] Consumers 200-1 to 200-n, which are provided with a load 201 and a photovoltaic power generation facility 202, receive power from the power system 20 and supply power generated by the photovoltaic power generation facility 202 to the power system 20. Therefore, the apparent power consumption of each consumer 200-1 to 200-n seen from the power system 20 depends on both the actual power consumption of the load 201 and the power generation output by the photovoltaic power generation facility 202. When the power consumption by the load 201 is exceeded by the power generation output by the photovoltaic power generation facility 202, the power generation output of the consumer is supplied to the power system 20 from the perspective of the power system 20, and the apparent power consumption becomes a negative value. Hereinafter, the apparent power consumption of each consumer 200-1 to 200-n seen from the power system 20 is referred to as a residual demand.

[0017] The consumers 200-2 to 200-n who have concluded a surplus purchase contract are each equipped with a smart meter (abbreviated as SM (Smart Meter) in the figure) 205. When i is an arbitrary integer from 2 to n, the smart meter 205 of the consumer 200-i measures the power generation output P PVi (t) and the power consumption P by the load 201 LiThe smart meter 205 measures the power obtained by adding up the power consumption (t) and the power consumption (t) of the photovoltaic power generation output estimation device 100. That is, the power measured by the smart meter 205 is the residual demand described above, and is the amount obtained by subtracting the power generation output of the photovoltaic power generation facility 202 from the power consumption of the load 201 for each of the consumers 200-2 to 200-n. The measurement data of the residual demand measured by the smart meter 205 is sent to the photovoltaic power generation output estimation device 100 via the communication network 25 and the communication network 50.

[0018] For example, in the consumer 200-2, the smart meter 205 measures the power generation output P PV2 (t) and the power consumption P by the load 201 L2 The sum of this and (t) is measured and recorded as the residual demand. Then, the smart meter 205 transmits the measurement data of the residual demand of the consumer 200-2 to the photovoltaic power generation output estimating device 100 via the communication networks 25 and 50. In this manner, the photovoltaic power generation output estimating device 100 acquires the measurement data of the residual demand, which is the measurement value of the smart meters 205 installed in the consumers 200-2 to 200-n that own the photovoltaic power generation facilities 202 that are the subject of the surplus purchase contract.

[0019] In addition, the customer 200-3 is provided with a power generation output P PV3 The measuring instrument 206 is provided to measure the power output P(t). The measuring instrument 206 may be a part of a device such as a PCS or a HEMS (Home Energy Management System) that controls the photovoltaic power generation facility 202, or may be a separately provided measuring instrument. The measuring instrument 206 measures the power output P PV3 The measurement data (t) is sent to the photovoltaic power generation output estimating device 100 via the communication network 25 and the communication network 50. Note that, although an example in which the measuring instrument 206 is provided at the consumer 200-3 will be described here, the number of consumers provided with the measuring instrument 206 among the consumers 200-2 to 200-n may be zero or more.

[0020] A smart meter 203 and a smart meter 204 are installed in a consumer 200-1 that has concluded a full-amount purchase contract. The smart meter 203 is a meter that measures the consumption output P L1 The smart meter 204 measures and records the power output P PV1 The measurement data of the power output of the photovoltaic power generation facility 202 of the customer 200-1 measured by the smart meter 204 is sent to the photovoltaic power generation output estimating device 100 via the communication network 25 and the communication network 50. In this way, the photovoltaic power generation output estimating device 100 estimates the power output P PV1 The measurement data of the smart meter 203 is also sent to the photovoltaic power generation output estimating device 100 via the communication network 25 and the communication network 50. At least one of the smart meter 203 and the smart meter 204, or a device not shown in place of these devices, may measure (or calculate) the apparent power consumption, which is the sum of the measurement data of the smart meter 203 and the measurement data of the smart meter 204, that is, the residual demand, and transmit the measured (or calculated) residual demand to the photovoltaic power generation output estimating device 100.

[0021] As described above, among the consumers 200-1 to 200-n, the consumers 200-1 and 200-3 can obtain measurement data of the power generation output of the photovoltaic power generation facility 202 by the smart meter 204 or the measuring instrument 206. Since the smart meter 204 can be considered as a part of the measuring instrument, both the consumers 200-1 and 200-3 are consumers from which the measurement data of the power generation output of the photovoltaic power generation facility 202 can be obtained. On the other hand, among the consumers 200-1 to 200-n, the consumers not provided with either the smart meter 204 or the measuring instrument 206 have their residual demand added to their power consumption measured, but the power generation output of the photovoltaic power generation facility 202 is not directly measured, making it difficult to accurately obtain the power generation output. In this embodiment, a method will be described in which the photovoltaic power generation output estimation device 100 accurately estimates the power generation output of a consumer not provided with either the smart meter 204 or the measuring instrument 206 by using at least one of the consumers 200-1 and 200-3. Hereinafter, the photovoltaic power generation facilities of the customers 200-1 and 200-3 used as a reference in estimating the power generation output are also referred to as the first photovoltaic power generation facilities, and the photovoltaic power generation facilities that are the subject of the estimation of the power generation output are also referred to as the second photovoltaic power generation facilities. In addition, the customers (customers 200-1 and 200-3, etc.) where the first photovoltaic power generation facilities are installed are also referred to as the first customers, and the customers (customer 200-2, etc.) where the second photovoltaic power generation facilities are installed are also referred to as the second customers.

[0022] The photovoltaic power generation output estimation device 100 estimates a second photovoltaic power generation output, which is the photovoltaic power generation output of the second photovoltaic power generation facility at a predetermined time point (hereinafter referred to as the "estimation time point"), by using a first photovoltaic power generation output, which is the power generation output of the first photovoltaic power generation facility. The estimation time point includes not only the present time point but also a past or future time point. The photovoltaic power generation output estimation device 100 may be realized by a general-purpose computer system such as a personal computer executing a program, or may be realized by a dedicated computer system. A detailed configuration of the photovoltaic power generation output estimation device 100 will be described later. The distance between the first photovoltaic power generation facility and the second photovoltaic power generation facility is equal to or less than a predetermined value. The predetermined value is, for example, several kilometers, but is not limited to this.

[0023] Next, the function of the photovoltaic power generation output estimation device 100 will be described. The photovoltaic power generation output estimation device 100 estimates a second photovoltaic power generation output, which is the power generation output of the photovoltaic power generation facility 202 of the consumer to be estimated, by using a first photovoltaic power generation output as a reference and a residual demand of the consumer to be estimated. The first photovoltaic power generation output is the power generation output of the first photovoltaic power generation facility provided at the first consumer, and the second photovoltaic power generation output is the power generation output of the second photovoltaic power generation facility provided at the second consumer. Note that the power generation output of the photovoltaic power generation facility 202 and the power consumption of the load 201 include active power and reactive power. However, since general photovoltaic power generation facilities, particularly photovoltaic power generation facilities for home use, are operated with a constant power factor, it is possible to easily estimate the reactive power by estimating the active power. For this reason, the power generation output of the photovoltaic power generation facility 202 and the power consumption of the load 201 described below refer to active power.

[0024] Here, an outline of a method for estimating the power generation output of the photovoltaic power generation facility 202 in the photovoltaic power generation output estimation device 100 will be described. Here, the photovoltaic power generation facility 202 of the consumer 200-2 will be described as an example of a power generation output to be estimated, and the power generation output of the photovoltaic power generation facility 202 of the consumer 200-1 will be described as a photovoltaic power generation output used as a reference in the estimation. That is, in this example, the first photovoltaic power generation output is the power generation output of the photovoltaic power generation facility 202 of the consumer 200-1, and the second photovoltaic power generation output to be estimated is the power generation output of the photovoltaic power generation facility 202 of the consumer 200-2. Note that even when the estimation target is the power generation output of the photovoltaic power generation facility 202 of each of the consumers 200-4 to 200-n, that is, when the second photovoltaic power generation output is the power generation output of the photovoltaic power generation facility 202 of each of the consumers 200-4 to 200-n, the power generation output of the photovoltaic power generation facility 202 can be similarly estimated by using a value corresponding to each consumer as the residual demand. In addition, the second solar power generation output can also be estimated in a similar manner when the power generation output of solar power generation equipment 202 of consumer 200-3, i.e., the power generation output measured by measuring instrument 206, is used instead of the power generation output of solar power generation equipment 202 of consumer 200-1 as the first solar power generation output, which is used as a standard.

[0025] The residual demand of the second consumer, consumer 200-2, is P 2 (t), the power consumption of the load 201 of the consumer 200-2 is P L2 (t), the power generation output of the photovoltaic power generation facility 202 of the consumer 200-2, which is the second photovoltaic power generation output, is P PV2 The power generation output of the photovoltaic power generation facility 202 of the first consumer 200-1, i.e., the first photovoltaic power generation output, is denoted as P PV1 (t). In this case, P 2 The equation for (t) holds, and furthermore, as shown in equation (2), P PV2 We can assume an equation for (t).

[0026]

number

[0027]

number

[0028] Here, α is the coefficient for converting the first solar power generation output to the second solar power generation output, and τ s is the delay time, i.e., the time it takes for the solar radiation fluctuation to propagate between the installation points of the first and second solar power generation facilities, ε 12 (t) is the time disturbance.

[0029] And P L2 (t) and ε 12 The fluctuations of (t) are, respectively, P PV1 Assuming that there is no correlation with the fluctuations in (t) and that time stationarity holds in the above equations (1) and (2), the following equation (3) can be derived from the above equations (1) and (2).

[0030]

number

[0031] Here, Cov t [] denotes the operator that calculates the covariance of two quantities, and Cov in the above formula (3) t [P PV1 (t),P PV1 (t+τ+τ s )] is τ = -τ s Therefore, the covariance function Cov of the time series data of the first solar power generation output and the second consumer's residual demand is t [P PV1 (t),P 2 The delay time τ is calculated by multiplying the time lag τ when (t+τ)] is at its minimum (the sign is "-" and the absolute value is maximum). s It is.

[0032] Moreover, by substituting τ=0 into the above equation (3), the following equation (4) is obtained.

[0033]

number

[0034] Then, by transforming the above equation (4) into the following equation (5), an estimate of the coefficient α can be obtained.

[0035]

number

[0036] Cov t [P PV1 (t),P 2 (t)] is the first solar power generation output P PV1 (t) and residual demand P 2 (t), and this covariance is called the first covariance. Cov t [P PV1 (t),P PV1 (t+τ s )] is the delay time τ s The two offset primary solar power generation outputs, P PV1 (t) and P PV1 (t+τ s ) and this autocovariance is called the second covariance. And α is the first covariance Cov t [P PV1 (t),P 2 (t)] is the second covariance Cov t [P PV1 (t),P PV1 (t+τ s )] and multiplying by -1.

[0037] Also, ε 12 Assuming that (t+τ) is small and can be ignored, the following equation (6), which is an approximation equation for the second photovoltaic power generation output, can be obtained from the above equation (2).

[0038]

number

[0039] The photovoltaic power generation output estimating device 100 of this embodiment estimates the second photovoltaic power generation output using the estimation method described above. That is, the photovoltaic power generation output estimating device 100 calculates the above-mentioned first covariance and second covariance, and calculates an estimate of the coefficient α by equation (5) using the calculated first covariance and second covariance. The process of calculating the coefficient α only needs to be performed before the estimation time point, which is the time to be estimated for the second photovoltaic power generation output. However, if the estimation time point is in the past, the process may be performed from the estimation time point, which is in the future of the estimation time point, to the present. As described above, the calculation of the coefficient α uses time-series data of each measurement data, so that measurement data for a certain period of time is required. This period is set to a range before the estimation time point and not too far away in time from the estimation time point. For example, this period is an arbitrary period between the estimation time point at which the second photovoltaic power generation output is estimated and a period going back about one or two weeks. Then, the photovoltaic power generation output estimating device 100 calculates the estimated value of the coefficient α by applying a delay time τ from the estimation time point t to the estimation time point t. s The first solar power generation output P at the time of deviation PV1 (t+τ s ) to obtain the second solar power generation output P PV2 The estimated value of (t) can be calculated. PV2 When calculating the estimate of (t), the delay time τ s is assumed to be 0, and the estimated value of coefficient α is the first photovoltaic power generation output P PV1 An estimate may be made by multiplying by (t).

[0040] By using the first estimation method (hereinafter referred to as the first estimation method), which is the estimation method described above, the power generation output of the photovoltaic power generation facility 202 that is the subject of the surplus purchase contract can be estimated with high accuracy. On the other hand, the photovoltaic power generation facilities 202 may include overloaded photovoltaic power generation facilities. Overloaded photovoltaic power generation facilities have the following problems. In general, when connecting the photovoltaic power generation facility 202, the installer of the photovoltaic power generation facility 202 often only needs to apply to a system operator such as an electric power company for either the solar panel capacity or the rated capacity of the PCS. Therefore, the system operator such as an electric power company cannot manage whether each photovoltaic power generation facility 202 is overloaded or not. In the overloaded photovoltaic power generation facility 202, when the solar radiation intensity is strong (large), the solar power generation output is saturated at the rated capacity of the PCS, so the solar power generation output is not proportional to the solar radiation intensity. The above-mentioned estimation method is premised on the premise that the photovoltaic power generation output is proportional to the solar radiation intensity and assumes the formula (2). Therefore, if the photovoltaic power generation output of an overloaded photovoltaic power generation facility 202 is estimated directly using the above-mentioned estimation method, the estimation accuracy will decrease when the solar radiation intensity is strong.

[0041] The estimation result by the photovoltaic power generation output estimating device 100 of this embodiment can be used for asset management such as facility formation planning of power distribution facilities, for example, by calculating the actual load using the estimation result. At this time, if the photovoltaic power generation output cannot be estimated accurately, the estimation accuracy of the actual load also decreases, and accurate power flow prediction cannot be performed, making it difficult to formulate an appropriate facility formation plan. For this reason, it is first desirable to identify an overloaded photovoltaic power generation facility 202, and further desirable to accurately estimate the power generation output of the overloaded photovoltaic power generation facility 202.

[0042] As described above, during a time period when saturation occurs in the overloaded photovoltaic power generation facility 202, the correlation between the solar radiation intensity and the power generation output of the photovoltaic power generation facility 202 becomes low. For this reason, if the photovoltaic power generation facility 202 of the second consumer is overloaded, the correlation between the first photovoltaic power generation output and the second photovoltaic power generation output becomes low, and it is assumed that the correlation between the first photovoltaic power generation output, which is the power generation output of the photovoltaic power generation facility 202 of the first consumer, and the residual demand of the second consumer also becomes low. In this embodiment, by utilizing this, the photovoltaic power generation output estimation device 100 determines that the photovoltaic power generation facility 202 of the second consumer is overloaded when there is a time when the overload determination coefficient indicating the correlation between the first photovoltaic power generation output, which is the power generation output of the photovoltaic power generation facility 202 of the first consumer, and the residual demand of the second consumer falls below a threshold value. The overload determination coefficient is, for example, a correlation coefficient between the first photovoltaic power generation output and the residual demand of the second consumer. In the following, an example will be described in which the overload determination coefficient is a correlation coefficient between the first solar power generation output and the residual demand of the second consumer, but the overload determination coefficient is not limited to this, and for example, the value obtained by dividing the covariance between the first solar power generation output and the residual demand of the second consumer by the autocovariance (i.e., variance) of the first solar power generation output, or the covariance between the first solar power generation output and the residual demand of the second consumer itself may be used.

[0043] Furthermore, when the photovoltaic power generation output estimation device 100 of the present embodiment determines that the photovoltaic power generation facility 202 of the second consumer is overloaded, it estimates the power generation output of the photovoltaic power generation facility 202 of the second consumer by a second estimation method (hereinafter referred to as the second estimation method). Specifically, the photovoltaic power generation output estimation device 100 estimates the coefficient α by the above formula (5) using the first photovoltaic power generation output and the residual demand of the second consumer in the time period when the overload determination coefficient is equal to or greater than the threshold value. Then, the photovoltaic power generation output estimation device 100 estimates the saturation value of the photovoltaic power generation facility 202 of the second consumer by using the first photovoltaic power generation output and the coefficient α in the time period when the overload determination coefficient is equal to or greater than the threshold value. A method of calculating the saturation value will be described later. The photovoltaic power generation output estimation device 100 determines the smaller of the saturation value and the value calculated by the above formula (6) for each estimation time point as the estimated value of the second photovoltaic power generation output. In this embodiment, the saturation value of the second solar power generation output determined to be overloaded is estimated, and the estimated saturation value is used together with the value calculated by the above equation (6), so that the power generation output of the solar power generation equipment 202 of the overloaded second consumer can be estimated with high accuracy.

[0044] The method for determining an overloaded photovoltaic power generation facility 202 according to the present embodiment is not limited to the case where photovoltaic power generation output is estimated by the above-mentioned photovoltaic power generation output estimation method, and can be applied to other applications. For example, even when estimating photovoltaic power generation output using an estimated value of solar radiation intensity, the estimation accuracy is improved by determining an overloaded photovoltaic power generation facility 202 and performing estimation procedures separately for the overloaded photovoltaic power generation facility 202 and the photovoltaic power generation facility 202 that is not overloaded. Therefore, the method for determining an overloaded photovoltaic power generation facility 202 according to the present embodiment may be applied when estimating photovoltaic power generation output by another method. In addition, it is considered that a system operator or the like may wish to grasp the number of overloaded photovoltaic power generation facilities 202 in each region, or the geographical distribution of the overloaded photovoltaic power generation facilities 202, and the method for determining an overloaded photovoltaic power generation facility 202 according to the present embodiment may be used for such applications. The photovoltaic power generation output estimation device 100 of this embodiment can identify overloaded photovoltaic power generation facilities 202, and therefore can display the number of overloaded photovoltaic power generation facilities 202 per region, the geographical distribution of the overloaded photovoltaic power generation facilities 202, and the like.

[0045] Next, a functional configuration example of the photovoltaic power generation output estimation device 100 will be described. Fig. 2 is a block diagram showing a functional configuration example of the photovoltaic power generation output estimation device 100 of this embodiment. The photovoltaic power generation output estimation device 100 is a device that estimates a second photovoltaic power generation output, which is a power generation output at the time of estimation of the photovoltaic power generation facility 202. As shown in Fig. 2, the photovoltaic power generation output estimation device 100 includes a data acquisition unit 110, a first covariance calculation unit 120, a second covariance calculation unit 130, a power generation output estimation unit 140, an overload estimation unit 150, a display unit 160, an input reception unit 170, and a storage unit 180.

[0046] The data acquisition unit 110 receives measurement data from the smart meters 203 to 205 and the measuring instrument 206 via the communication network 25 and the communication network 50, and stores the received measurement data in the storage unit 180. In detail, the measurement data received from the smart meter 204 and the measuring instrument 206 is stored in the storage unit 180 as photovoltaic power generation output data 182, and the measurement data received from the smart meter 205 is stored in the storage unit 180 as residual demand data 183. These measurement data are associated with a time for each measurement value. The time intervals of the measurement values ​​of these measurement data stored in the storage unit 180 are, for example, 1 second, 10 seconds, 1 minute, 30 minutes, or 1 hour, but are not particularly limited to these, and an appropriate value is determined by the user. In addition, these measurement data are stored together with the identification information of the consumers 200-1 to 200-n or the identification information of the photovoltaic power generation facility 202. In addition, when the data acquisition unit 110 receives measurement data from the smart meter 203 and the smart meter 204 of the consumer 200-1, it calculates the residual demand of the consumer 200-1 using these measurement data and stores the residual demand data 183 in the memory unit 180.

[0047] Here, an example is shown in which the photovoltaic power output estimation device 100 acquires measurement data from the smart meters 203-205 and the measuring instrument 206 via the communication network 25 and the communication network 50, but the measurement data of the smart meters 203-205 may be collected by a so-called aggregation device or a head-end system, and transmitted from the collecting device to the photovoltaic power output estimation device 100. That is, a device that collects measurement data may be present in the communication network 25 and the communication network 50, and the photovoltaic power output estimation device 100 may acquire the measurement data from the device. Furthermore, the communication route between the photovoltaic power output estimation device 100 and the smart meters 203-205 and the measuring instrument 206 is not limited to the example shown in FIG. 1 and FIG. 2, and the communication route through which the photovoltaic power output estimation device 100 receives the measuring instrument 206 may be different from the communication route through which the photovoltaic power output estimation device 100 receives the measurement data of the smart meters 203-205. Furthermore, the communication network between the photovoltaic power generation output estimating apparatus 100 and the smart meters 203-205 and the measuring instrument 206 does not need to be separated into the communication network 25 and the communication network 50. Furthermore, the photovoltaic power generation output estimating apparatus 100 may receive measurement data of the smart meters 203-205 via a plurality of communication routes.

[0048] The storage unit 180 stores the above-mentioned photovoltaic power generation output data 182 and residual demand data 183, and also stores various data calculated in the photovoltaic power generation output estimation device 100 as calculation data 185. The storage unit 180 also stores, for example, location information data 181 input by a user via the input reception unit 170. The location information data 181 may be transmitted from another device instead of being input via the input reception unit 170, acquired by the data acquisition unit 110, and stored in the storage unit 180. The location information data 181 is data of location information such as addresses or latitude and longitude of the consumers 200-1 to 200-n that own the photovoltaic power generation facilities 202. The storage unit 180 also stores overload estimation data 184 that is data related to the overloaded photovoltaic power generation facilities 202. The overload estimation data 184 includes identification information of the photovoltaic power generation facilities 202 that are determined to be overloaded. The overload estimation data 184 may include an estimate of the saturation value of the photovoltaic power generation equipment 202 that is determined to be overloaded.

[0049] The first covariance calculation unit 120 refers to the location information data 181 of the storage unit 180 and selects a first consumer whose distance from the second consumer, which is a consumer to be estimated for power generation output, is within a predetermined distance and has a photovoltaic power generation facility 202 that serves as a reference for estimation. As described above, the first consumer is the consumer 200-1 having the photovoltaic power generation facility 202 that is the subject of a full purchase contract, or the consumer 200-3 whose power generation output of the photovoltaic power generation facility 202 is measured by a measuring instrument 206. The first covariance calculation unit 120 calculates a first covariance that is the covariance between the first photovoltaic power generation output, which is the power generation output of the photovoltaic power generation facility 202 of the first consumer, and the residual demand of the second consumer, and stores the calculated first covariance in the storage unit 180 as calculation data 185. The consumer to be estimated for power generation output is, for example, the consumer 200-2 as described above, but may be the consumers 200-4 to 200-n. All of consumers 200-2, 200-4 to 200-n may be subject to estimation in sequence, and estimation may be performed for each of consumers 200-2, 200-4 to 200-n, or if a total value is required, the total value may be estimated all at once.

[0050] Specifically, the first covariance calculation unit 120 extracts and reads out the first photovoltaic power generation output in at least one first period from the photovoltaic power generation output data 182 in the storage unit 180, and extracts and reads out the residual demand of the second consumer from the residual demand data 183 in the storage unit 180. The first period is, for example, a period of about 6 to 10 hours, preferably 8 hours, within a period going back about 1 or 2 weeks from the estimation time point. The first period is selected within a period from sunrise to sunset. In addition, the first period is preferably a period during which the solar radiation intensity is strong and the fluctuation of the solar radiation intensity is large. The first period may be one or more. The first covariance calculation unit 120 determines whether to process data at all times in the first period or data at some times in the first period according to the determination result notified from the overload estimation unit 150. The determination result and the some times notified from the overload estimation unit 150 will be described later.

[0051] The first covariance calculation unit 120 calculates a first covariance, which is the covariance between the first photovoltaic power generation output and the residual demand of the second consumer in the first period, using the read data of the first photovoltaic power generation output and the residual demand of the second consumer at the time determined to be the processing target, and stores the calculated data in the storage unit 180 as calculated data 185. Furthermore, the first covariance calculation unit 120 calculates a delay time τ s is calculated and stored in storage unit 180 as calculated data 185. Note that the delay time may be approximated to 0 without being calculated.

[0052] The second covariance calculation unit 130 calculates the delay time τ s is extracted and read from the calculation data 185 in the storage unit 180, and the first photovoltaic power generation output in the first period and the delay time τ sThe second covariance calculation unit 130 extracts and reads out the first photovoltaic power generation output during the shifted second period from the photovoltaic power generation output data 182 in the storage unit 180. The second covariance calculation unit 130 determines whether to process data at all times during the first period or data at some times during the first period, depending on the determination result notified from the overload estimation unit 150. Note that at this time, the time determined as the processing target is the same as the time at which the first covariance calculation unit 120 calculated the first covariance. The second covariance calculation unit 130 then calculates the delay time τ s The second covariance calculation unit 130 calculates a second covariance, which is an autocovariance of the two shifted first photovoltaic power generation outputs, and stores the calculated second covariance in the storage unit 180 as calculated data 185. In detail, the second covariance calculation unit 130 calculates the time series data of the first photovoltaic power generation output in the first period and the delay time τ s The second covariance calculation unit 130 then reads out the time series data of the first photovoltaic power generation output in the first period and the time series data of the first photovoltaic power generation output in the second period. The second covariance calculation unit 130 then calculates a second covariance, which is the autocovariance of the time series data of the first photovoltaic power generation output in the first period and the time series data of the first photovoltaic power generation output in the second period, and stores the calculated second covariance in the storage unit 180 as calculated data 185. Note that the delay time τ s is approximated to 0, the second covariance calculation section 130 calculates the variance of the time-series data of the first photovoltaic power generation output in the first period as the second covariance.

[0053] The power generation output estimation unit 140 estimates the second photovoltaic power generation output by the first estimation method or the second estimation method according to the determination result notified from the overload estimation unit 150. Specifically, when the determination result notified from the overload estimation unit 150 indicates that the photovoltaic power generation facility 202 of the second consumer is not overloaded, the power generation output estimation unit 140 estimates the second photovoltaic power generation output by the first estimation method, and when the determination result notified from the overload estimation unit 150 indicates that the photovoltaic power generation facility 202 of the second consumer is overloaded, the power generation output estimation unit 140 estimates the second photovoltaic power generation output by the second estimation method.

[0054] In detail, when estimating by the first estimation method, the power generation output estimation unit 140 calculates (estimates) a coefficient α (which can also be said to be a ratio between the first and second photovoltaic power generation outputs) that is a coefficient for converting the first photovoltaic power generation output to the second photovoltaic power generation output using the first covariance and second covariance stored in the storage unit 180 as the calculation data 185, and estimates the second photovoltaic power generation output by multiplying the first photovoltaic power generation output with a delay time from the estimation time point by the coefficient α. When estimating by the second estimation method, the power generation output estimation unit 140 calculates (estimates) a coefficient α that is a ratio between the first and second photovoltaic power generation output using the first covariance and second covariance stored in the storage unit 180 as the calculation data 185, and calculates a value by multiplying the first photovoltaic power generation output with a delay time from that time by the coefficient α for each time before and after the time period when the overload determination coefficient is equal to or greater than the threshold, and sets the larger of the calculated values ​​as the saturation value. Then, for each estimation time point, the power generation output estimating unit 140 estimates the second photovoltaic power generation output to be the smaller of the saturation value and a value obtained by multiplying the first photovoltaic power generation output by the delay time from the estimation time point.

[0055] Although the coefficient α is unlikely to change in a short period such as one or two weeks, it is unlikely to change over a long period such as the delay time τ s is likely to change in a short period of time due to changes in wind direction or speed. Therefore, the delay time τ s It is preferable that the value is changed in real time taking into account weather data, etc. Alternatively, it may be approximated to 0.

[0056] The display unit 160 displays various data stored in the storage unit 180. The input receiving unit 170 receives input from the user.

[0057] Here, a hardware configuration of the photovoltaic power generation output estimation device 100 will be described. In the photovoltaic power generation output estimation device 100 of this embodiment, a photovoltaic power generation output estimation program, which is a program describing the processing in the photovoltaic power generation output estimation device 100, is executed on a computer system, so that the computer system functions as the photovoltaic power generation output estimation device 100. FIG. 3 is a diagram showing an example of the configuration of a computer system that realizes the photovoltaic power generation output estimation device 100 of this embodiment. As shown in FIG. 3, this computer system includes a control unit 101, an input unit 102, a storage unit 103, a display unit 104, a communication unit 105, and an output unit 106, which are connected via a system bus 107.

[0058] In FIG. 3, the control unit 101 is a processor such as a CPU (Central Processing Unit) and executes a photovoltaic power generation output estimation program in which the processing in the photovoltaic power generation output estimation device 100 of the present embodiment is described. The input unit 102 is composed of, for example, a keyboard, a mouse, and the like, and is used by a user of the computer system to input various information. The storage unit 103 includes various memories such as a RAM (Random Access Memory) and a ROM (Read Only Memory) and a storage device such as a hard disk, and stores the program to be executed by the control unit 101, necessary data obtained in the process of processing, and the like. The storage unit 103 is also used as a temporary storage area for the program. The display unit 104 is composed of a display, an LCD (Liquid Crystal Display Panel), and the like, and displays various screens to the user of the computer system. The communication unit 105 is a receiver and a transmitter that perform communication processing. The output unit 106 is a printer, etc. Note that FIG. 3 is an example, and the configuration of the computer system is not limited to the example of FIG. 3.

[0059] Here, an example of the operation of the computer system until the photovoltaic power generation output estimation program of this embodiment is in an executable state will be described. In the computer system having the above-mentioned configuration, for example, the photovoltaic power generation output estimation program is installed in the storage unit 103 from a CD-ROM or DVD-ROM set in a CD (Compact Disc)-ROM drive or DVD (Digital Versatile Disc)-ROM drive (not shown). Then, when the photovoltaic power generation output estimation program is executed, the photovoltaic power generation output estimation program read from the storage unit 103 is stored in the storage unit 103. In this state, the control unit 101 executes the process as the photovoltaic power generation output estimation device 100 of this embodiment according to the program stored in the storage unit 103.

[0060] In the above description, a program describing the processing in the photovoltaic power generation output estimation device 100 is provided on a CD-ROM or DVD-ROM as a recording medium. However, this is not limited to this, and depending on the configuration of the computer system and the capacity of the program to be provided, for example, a program provided over a transmission medium such as the Internet via the communication unit 105 may be used.

[0061] The first covariance calculation unit 120, the second covariance calculation unit 130, the power generation output estimation unit 140, and the overload estimation unit 150 shown in Fig. 2 are realized by executing the photovoltaic power generation output estimation program stored in the storage unit 103 shown in Fig. 3 by the control unit 101 shown in Fig. 3. The storage unit 180 shown in Fig. 2 is a part of the storage unit 103 shown in Fig. 3. The data acquisition unit 110 shown in Fig. 2 is realized by the communication unit 105 and the control unit 101 shown in Fig. 3. The display unit 160 shown in Fig. 2 is realized by the display unit 104 shown in Fig. 3, and the input reception unit 170 shown in Fig. 2 is realized by the input unit 102 shown in Fig. 3. The photovoltaic power generation output estimation device 100 may be realized by a plurality of computer systems.

[0062] Next, the operation of the photovoltaic power generation output estimating device 100 of this embodiment will be described in detail. Fig. 4 is a flowchart showing an example of a processing procedure for estimating the second photovoltaic power generation output by the photovoltaic power generation output estimating device 100 of this embodiment. Below, the processing for estimating the second photovoltaic power generation output by the photovoltaic power generation output estimating device 100 will be described along the flow of Fig. 4. First, the first covariance calculating unit 120 selects the first photovoltaic power generation facility (step S1).

[0063] Specifically, in step S1, the first covariance calculation unit 120 refers to the location information data 181 in the storage unit 180 and selects, as the first photovoltaic power generation facility, the photovoltaic power generation facility 202 of the first consumer, which is a consumer whose power generation output is to be estimated, and which has a photovoltaic power generation facility 202 serving as a reference for estimation and is within a predetermined distance from the second consumer. Note that this step S1 may be performed by the power generation output estimation unit 140, and the result may be notified to the first covariance calculation unit 120.

[0064] FIG. 5 is a diagram showing a schematic diagram of the geographical location of the photovoltaic power generation facility 202 of each customer indicated by the location information data 181 of the present embodiment. In FIG. 5, it is assumed that the geographical location of the photovoltaic power generation facility 202 of each customer coincides with the geographical location of the customer. In FIG. 5, the photovoltaic power generation facility 202 of the customer 200-i (i=1, 2, ..., 8) is shown as PVi. For example, PV1 is the photovoltaic power generation facility 202 of the customer 200-1, and PV2 is the photovoltaic power generation facility 202 of the customer 200-2. PV1 and PV3 shown in solid line frames are the photovoltaic power generation facilities 202 of the customers 200-1 and 200-3, respectively, and the power generation output is measured. PV2 and the like shown in dashed line frames are the photovoltaic power generation facilities 202 of the customer 200-2 and the like, whose power generation output is not measured.

[0065] The range 301 in FIG. 5 is a circle with a radius of the predetermined distance centered on PV1, which is the photovoltaic power generation facility 202 of the consumer 200-1, and the power generation output of PV1 can be used to estimate the power generation output of the photovoltaic power generation facility 202 of the consumer within the range 301. Similarly, the range 302 in FIG. 5 is a circle with a radius of the predetermined distance centered on PV3, which is the photovoltaic power generation facility 202 of the consumer 200-3, and the power generation output of PV3 can be used to estimate the power generation output of the photovoltaic power generation facility 202 of the consumer within the range 302. Therefore, for example, when PV2, which is the photovoltaic power generation facility 202 of the consumer 200-2, is set as a power generation output estimation target, since PV2 is within the range 301 and the range 302, both the consumer 200-1 corresponding to PV1 and the consumer 200-3 corresponding to PV3 are candidates for the first consumer. In this way, when there are multiple candidates for the first consumer, the consumer 200-2, which is the consumer closer to the estimation target PV2, is selected as the first consumer. Alternatively, measurement data of a plurality of candidates for the first consumer may be combined and used, in which case a plurality of consumers are selected as the first consumer.

[0066] Fig. 6 is a diagram showing the correspondence between the photovoltaic power generation facility 202 to be estimated and the photovoltaic power generation facility 202 to be used for the estimation in this embodiment. The first covariance calculation unit 120 may perform step S1 every time the power generation output is estimated, but as shown in Fig. 6, the correspondence between the photovoltaic power generation facility 202 selected in step S1 and each of the photovoltaic power generation facilities 202 to be estimated may be stored in the calculation data 185 as facility correspondence data, and when the photovoltaic power generation facility 202 recorded in the facility correspondence data is used as the estimation target, the processing of step S1 may be omitted by reading the facility correspondence data of the calculation data 185. In this case, the first covariance calculation unit 120 may update the facility correspondence data in the calculation data 185 by performing step S1, for example, when a certain period of time has elapsed.

[0067] Return to the description of FIG. 4. After step S1, the first covariance calculation unit 120 acquires the first photovoltaic power generation output and the residual demand of the second consumer in the first period (step S2). In detail, the first covariance calculation unit 120 refers to the time series data of the first photovoltaic power generation output, which is the power generation output of the photovoltaic power generation facility 202 of the first consumer, in the photovoltaic power generation output data 182 stored in the storage unit 180, and searches for a period in which the solar radiation intensity is strong. For example, the first covariance calculation unit 120 searches for a period of about 6 to 10 hours in which the first photovoltaic power generation output is large on the day before the day on which the second photovoltaic power generation output is estimated. Then, the first covariance calculation unit 120 sets the searched period as the first period. Note that the first covariance calculation unit 120 may search for the above period itself and then search for the first period from the period, rather than searching for the first period from the above period (for example, the day before the day on which the second photovoltaic power generation output is estimated). As described above, the first period may be set by any method without searching for a period of about 6 to 10 hours in which the first photovoltaic power generation output is large. The first covariance calculation unit 120 holds the acquired first photovoltaic power generation output and the residual demand of the second consumer in the first period, and outputs them to the overload estimation unit 150.

[0068] Next, the overload estimation unit 150 calculates N A An overload determination coefficient is calculated using the first photovoltaic power generation output and the residual demand of the second consumer at the time of the point (step S3). A is an integer equal to or greater than 2, for example 3. A The value of is not limited to 3 and can be set by the user. Next, the overload estimation unit 150 judges whether or not the calculation of the overload determination coefficient for all time periods in the first period has been completed (step S4). If the calculation of the overload determination coefficient for all time periods in the first period has not been completed (step S4 No), the overload estimation unit 150 changes the position of the moving window (step S5) and repeats the process from step S3.

[0069] Fig. 7 is a diagram showing an example of a moving window according to the present embodiment. In Fig. 7, the horizontal axis indicates time and the vertical axis indicates active power. In the example shown in Fig. 7, the points indicated by circles in the data 401 correspond to the first photovoltaic power generation output P PV1 The triangle points in the data 402 represent the residual demand P 2 In the example shown in FIG. 7, the first solar power generation output P PV1 (t) and the residual demand of the second consumer P 2 (t) is data for every 30 minutes, and within the moving window 403, which is a time window, the first solar power generation output P PV1 (t) and the residual demand of the second consumer P 2 Each of the data includes three points of data (t) from the first photovoltaic power generation output P PV1 (t) and the second consumer's residual demand P 2 In the second step S3, as shown in moving window 404, the position of the moving window is moved by one point, and the overload determination coefficient is calculated using data of three points within moving window 404.

[0070] In this way, the overload estimation unit 150 calculates the overload determination coefficient for each time by sequentially moving the time window including the time in the first period. The time corresponding to the overload determination coefficient is, for example, the center time of the corresponding time window.

[0071] Returning to the description of FIG. 4, when the calculation of the overload determination coefficient for all time periods in the first period is completed (step S4 Yes), the overload estimation unit 150 judges whether or not there is a time when the overload determination coefficient falls below the threshold value (step S6). In the example shown in FIG. 7, the overload estimation unit 150 repeatedly calculates the overload determination coefficient by moving the position of the moving window by one point at a time, and when the calculation of the overload determination coefficient using the data of three points at each time in the moving window 405 is completed, the overload estimation unit 150 judges Yes in step S4. When there is a time when the overload determination coefficient falls below the threshold value (step S6 Yes), the second photovoltaic power generation output is estimated by the second estimation method, and when there is no time when the overload determination coefficient falls below the threshold value (step S6 No), the second photovoltaic power generation output is estimated by the first estimation method. The estimation process of the second photovoltaic power generation output by the first estimation method is the process of steps S11 to S12, and the estimation process of the second photovoltaic power generation output by the second estimation method is the process of steps S7 to S10. In this way, the overload estimation unit 150 of the present embodiment determines whether the second photovoltaic power generation equipment is overloaded or not based on whether there is a time when the overload determination coefficient falls below the threshold value. If it is determined that the second photovoltaic power generation equipment is not overloaded, the second photovoltaic power generation output is estimated by the first estimation method, and if it is determined that the second photovoltaic power generation equipment is overloaded, the second photovoltaic power generation output is estimated by the second estimation method.

[0072] 8 is a diagram showing an example of a calculation result of the overload determination coefficient in this embodiment. In the example shown in FIG. 8, the overload estimation unit 150 calculates the first photovoltaic power generation output P PV1 (t) and the second consumer's residual demand P 2 8, the horizontal axis indicates time and the vertical axis indicates the correlation coefficient. Each diamond-shaped point in the calculation result 406 corresponds to the first photovoltaic power generation output P PV1 (t) and the second consumer's residual demand P 2(t) is shown. The threshold value 407 shown in FIG. 8 is a threshold value used in step S6, and is a threshold value used to determine whether or not the photovoltaic power generation facility 202, the power generation output of which is to be estimated, is overloaded. Here, the threshold value is set to 0.9, but the threshold value is not limited to 0.9 as long as it is set to a value that indicates a high correlation. In the example shown in FIG. 8, the correlation coefficient is below the threshold value during the period from 8:30 to 13:30. In this way, when the correlation coefficient is below the threshold value, the overload estimation unit 150 determines that the photovoltaic power generation facility 202 of the second consumer is overloaded, and starts the estimation process of the second photovoltaic power generation output by the second estimation method. Note that in step S6 shown in FIG. 4, when the correlation coefficient is N B If the correlation coefficient falls below the threshold consecutively, the result is Yes. If the correlation coefficient falls below the threshold consecutively, the result is N. B If the number of times that the correlation coefficient falls below the threshold value is less than N times, the result of step S6 may be determined as No. Also, if the number of times that the correlation coefficient falls below the threshold value is N times or more in the first period, the result of step S6 may be determined as No. B If the number of times is more than N, the determination is Yes in step S6. B If the number of times is less than the number of times, the determination in step S6 may be No. B is an integer equal to or greater than 1 and can be set by the user.

[0073] Returning to the description of FIG. 4, if the answer to step S6 is Yes, the overload estimation unit 150 calculates the time t immediately before the overload determination coefficient falls below the threshold for the first time. 1 and the time t immediately after the threshold was last exceeded 2 (Step S7). 1 is the time immediately before the time period in which the correlation coefficient falls below the threshold, and is the second time t 2 is the time immediately after the time period in which the correlation coefficient falls below the threshold. The overload estimation unit 150 temporarily stores the time t 1 and time t 2 Alternatively, the time t may be recorded as the overload estimation data 184 in the storage unit 180 together with the identification information of the photovoltaic power generation facility 202 whose power output is to be estimated. 1 and time t 2In the former case, the overload estimation unit 150 records the identification information of the photovoltaic power generation facility 202 of the second consumer, the power generation output of which is to be estimated, as the overload estimation data 184 in the storage unit 180. The overload estimation unit 150 records the identification information of the photovoltaic power generation facility 202 of the second consumer, the power generation output of which is to be estimated, as the overload estimation data 184 in the storage unit 180. 1 and time t 2 , the overload estimation unit 150 notifies the first covariance calculation unit 120 of the determination result indicating that the photovoltaic power generation facility 202 of the second customer is overloaded. In detail, the overload estimation unit 150 notifies the first covariance calculation unit 120, the second covariance calculation unit 130, and the power generation output estimation unit 140 of the determination result indicating that the photovoltaic power generation facility 202 of the second customer is overloaded.

[0074] In addition, when the solar radiation intensity in the first period is not so strong, even if it is determined as No in step S6, the solar power generation equipment 202 of the second consumer may actually be overloaded. For example, in winter, even if the solar power generation equipment 202 of the second consumer is overloaded, the second solar power generation output may not be saturated. In such a case, even if the solar power generation equipment 202 of the second consumer is overloaded, the estimation accuracy does not decrease even if the second solar power generation output is estimated by the first estimation method. In other words, the determination of whether or not the solar power generation equipment 202 is overloaded in this embodiment does not indicate a determination of whether or not it is actually overloaded, but indicates a determination of whether or not to treat the solar power generation equipment 202 as an overloaded solar power generation output and estimate it. In addition, if a period in which the solar radiation intensity is sufficiently strong is selected as the first period, it is possible to determine whether or not the solar power generation equipment 202 of the second consumer is actually overloaded.

[0075] For example, in the example shown in FIG. 8, the saturation time zone 408, which is a time zone below the threshold value 407, is a time zone in which the photovoltaic power generation facility 202 of the second customer, whose power output is to be estimated, is estimated to be saturated. In the example shown in FIG. 8, in step S7, 1 and the immediately following time t 2 The following is recorded.

[0076] Returning to the description of FIG. 4, after step S7, the photovoltaic power generation output estimating device 100 performs the process of determining whether t≦t 1, and t ≥ t 2 In detail, when the first covariance calculation unit 120 receives a notification of the determination result indicating that the photovoltaic power generation facility 202 of the second consumer is overloaded, the first covariance calculation unit 120 estimates the coefficient α by using the first photovoltaic power generation output and the residual demand of the second consumer during the time period t 1 and time t 2 Read out t≦t 1 , and t ≥ t 2 The second covariance calculation unit 130 calculates a first covariance and a delay time using the first photovoltaic power generation output and the residual demand of the second consumer in the time period t and records them in the calculated data 185 of the storage unit 180. When the second covariance calculation unit 130 is notified of a determination result indicating that the photovoltaic power generation facility 202 of the second consumer is not overloaded, the second covariance calculation unit 130 reads out the delay time from the calculated data 185 of the storage unit 180, and extracts and reads out the first photovoltaic power generation output for the first period and the second period shifted from the first period by the delay time from the photovoltaic power generation output data 182 of the storage unit 180. Then, the second covariance calculation unit 130 calculates a first covariance and a delay time using the first photovoltaic power generation output and the residual demand of the second consumer in the time period t≦t 1 , and t ≥ t 2 The power generation output estimation unit 140 then calculates the second covariance using data corresponding to the time period, and records the second covariance in the calculation data 185 in the storage unit 180. The power generation output estimation unit 140 then reads out the first covariance and the second covariance from the calculation data 185, estimates the coefficient α by the above-mentioned equation (5) using the read out first covariance and second covariance, and notifies the overload estimation unit 150 of the coefficient α.

[0077] Next, the overload estimation unit 150 sets a saturation value (step S9). In detail, the overload estimation unit 150 sets a saturation value based on the coefficient α notified by the power generation output estimation unit 140, the first photovoltaic power generation output acquired in step S2, and the time t 1 and time t 2 Using and, at time t 1 The value obtained by multiplying the first photovoltaic power generation output by the coefficient α is α·P PV1 (t 1 ) and time t 2 The value obtained by multiplying the first photovoltaic power generation output by the coefficient α is α·PPV1 (t 2 ) is calculated. Then, the saturation value P of the second photovoltaic power generation output is calculated using the following formula (7). PV2 max Estimate.

[0078]

number

[0079] That is, the overload estimation unit 150 calculates α·P PV1 (t 1 ) and α P PV1 (t 2 ) is set as the estimated value of the saturation value of the second photovoltaic power generation output. For example, the overload estimation unit 150 sets the saturation value of the photovoltaic power generation facility 202 of the second consumer by recording the estimated value as the saturation value in the overload estimation data 184 of the storage unit 180. Note that, although the overload estimation unit 150 estimates and sets the saturation value here, this process may be performed by the power generation output estimation unit 140.

[0080] 9 is a diagram showing an example of the estimation result of the saturation value according to the present embodiment. Each circle in the data 409 shown in FIG. 9 represents α·P PV1 (t) is used to calculate the coefficient α. In other words, it corresponds to the second photovoltaic power generation output estimated by the first estimation method using the first photovoltaic power generation output. 1 , and t ≥ t 2 This method differs from the first estimation method in that it uses data from the time period t≦t 1 , and t ≥ t 2 During this time period, α·P PV1 (t) corresponds to the second solar power generation output estimated by the first estimation method. As shown in FIG. 9, α·P PV1 (t) is estimated to be saturated during the saturation time period 408. For this reason, in this embodiment, 1 Data 410 at time t 2The larger of the two values ​​is used as the estimated saturation value. 2 Since the data 411 at time t is larger, 2 The value of data 411 in α·P PV1 (t 2 ) is the saturation value P PV2 max is set to.

[0081] FIG. 10 is a diagram showing an example of the overload estimation data 184 according to the present embodiment. In the example shown in FIG. 10, the overload estimation data 184 includes identification information of the photovoltaic power generation facility 202 of the second customer determined to be overloaded (in FIG. 10, it is indicated as an overloaded PV), and a saturation value. As described above, the overload estimation data 184 includes information on the saturation value at time t 1 and time t 2 Note that the saturation value does not change in a short period of time once it is determined for one photovoltaic power generation facility 202. 1 and time t 2 Since is temporary data that changes depending on the date selected as the first period, it may be temporarily recorded in the calculation data 185 without being included in the overload estimation data 184 as described above.

[0082] Returning to the description of FIG. 4, after step S9, the power generation output estimating unit 140 estimates the power generation output of the second consumer using the saturation value, the coefficient α, and the first photovoltaic power generation output (step S10), and the estimation process of the second photovoltaic power generation output is completed. Specifically, in step S10, the power generation output estimating unit 140 extracts and reads out the first photovoltaic power generation output shifted by a delay time from the estimation time point from the photovoltaic power generation output data 182 in the storage unit 180, and reads out the saturation value from the overload estimation data 184 in the storage unit 180. The power generation output estimating unit 140 estimates the second photovoltaic power generation output by the following formula (8) using the first photovoltaic power generation output shifted by a delay time from the read estimation time point and the saturation value, and the coefficient α estimated in step S8. That is, for each estimation time point, α·P PV1 (t+τ s The smaller of the delay time τ smay be approximated to 0.

[0083]

number

[0084] On the other hand, if there is no time when the overload determination coefficient falls below the threshold value (No in step S6), the photovoltaic power generation output estimating device 100 estimates the second photovoltaic power generation output in steps S11 and S12, and the process of estimating the second photovoltaic power generation output ends.

[0085] In step S11, the photovoltaic power generation output estimating device 100 estimates the coefficient α by using the first photovoltaic power generation output in all time periods and the residual demand of the second consumer. In detail, when the first covariance calculating unit 120 receives a notification of a determination result indicating that the photovoltaic power generation facility 202 of the second consumer is not overloaded, the first covariance calculating unit 120 calculates a first covariance and a delay time by using the first photovoltaic power generation output in all time periods and the residual demand of the second consumer among the first photovoltaic power generation output and the residual demand of the second consumer in the first period acquired in step S2, and records the first covariance and the delay time in the calculation data 185 of the storage unit 180. When the second covariance calculation unit 130 receives a notification of the determination result indicating that the photovoltaic power generation facility 202 of the second consumer is not overloaded, the second covariance calculation unit 130 reads the delay time from the calculation data 185 in the storage unit 180, reads the first photovoltaic power generation output for the first period and the second period shifted from the first period by the delay time from the photovoltaic power generation output data 182 in the storage unit 180, calculates the second covariance using the read data, and records it in the calculation data 185 in the storage unit 180. Then, the power generation output estimation unit 140 reads the first covariance and the second covariance from the calculation data 185, and estimates the coefficient α by the above-mentioned formula (5) using the read first covariance and second covariance.

[0086] In step S12, the second photovoltaic power generation output of the second consumer is estimated using the coefficient α and the first photovoltaic power generation output. In detail, the power generation output estimation unit 140 extracts and reads out the first photovoltaic power generation output shifted by a delay time from the estimation time point from the photovoltaic power generation output data 182 in the storage unit 180, and estimates the second photovoltaic power generation output of the second consumer by the above-mentioned formula (6) using the read-out first photovoltaic power generation output and the coefficient α estimated in step S11.

[0087] In the example shown in Fig. 4, the coefficient α is estimated each time the second photovoltaic power generation output is estimated, but the timing of the estimation process of the coefficient α (including the setting of the saturation value) and the estimation process of the second photovoltaic power generation output using the coefficient α may be set separately. For example, the process of steps S1 to S9 or the process of steps S1 to S11, which is the estimation process of the coefficient α, may be performed once a week, and the estimation process of the second photovoltaic power generation output may be performed every other day. In addition, when real-time data of the first photovoltaic power generation output is available, for example, the estimation of the coefficient α may be performed using past data up to the previous day, and the estimation process of the second photovoltaic power generation output may be performed using the first photovoltaic power generation output obtained in real time.

[0088] Next, the operations of the first covariance calculation unit 120, the second covariance calculation unit 130, and the power generation output estimation unit 140 will be described. FIG. 11 is a flowchart showing an example of a first covariance calculation process procedure in the first covariance calculation unit 120. As shown in FIG. 11, first, the first covariance calculation unit 120 acquires the first photovoltaic power generation output and the residual demand of the second consumer in the first period (step S21). Specifically, the first covariance calculation unit 120 acquires the first photovoltaic power generation output in the first period by reading out the time series data of the first photovoltaic power generation output in the first period from the photovoltaic power generation output data 182 in the storage unit 180, and acquires the residual demand of the second consumer in the first period by reading out the time series data of the residual demand of the second consumer in the first period from the residual demand data 183 in the storage unit 180.

[0089] Next, the first covariance calculation unit 120 judges whether the photovoltaic power generation facility 202 of the second consumer is overloaded (step S22). Specifically, when the judgment result notified by the overload estimation unit 150 indicates that the photovoltaic power generation facility 202 of the second consumer, whose power output is to be estimated, is overloaded, the first covariance calculation unit 120 judges that the photovoltaic power generation facility 202 of the second consumer is overloaded.

[0090] If the photovoltaic power generation facility 202 of the second customer is not overloaded (step S22: No), the first covariance calculation unit 120 proceeds to step S24 described later. If the photovoltaic power generation facility 202 of the second customer is overloaded (step S22: Yes), the first covariance calculation unit 120 determines whether t≦t 1 , and t ≥ t 2 In detail, the first covariance calculation unit 120 extracts data for the time period t≦t from the time series data of the first photovoltaic power generation output and the time series data of the residual demand of the second consumer in the first period acquired in step S21. 1 , and t ≥ t 2 Extract data for the time period.

[0091] Next, the first covariance calculation unit 120 calculates the first covariance (step S24). In detail, the first covariance calculation unit 120 calculates the covariance between the time series data of the first photovoltaic power generation output and the time series data of the residual demand of the second consumer as the first covariance, and writes it to the calculation data 185 of the storage unit 180. In step S24, if step S23 has been passed, the first covariance calculation unit 120 calculates the first covariance using the time series data of the first photovoltaic power generation output and the time series data of the residual demand of the second consumer extracted in step S23, and if step S23 has not been passed, the first covariance calculation unit 120 calculates the first covariance using all the time series data of the first photovoltaic power generation output and the time series data of the residual demand of the second consumer during the first period. In this way, when it is determined that the second photovoltaic power generation facility is overloaded, the first covariance calculation unit 120 calculates the first covariance from the time t 1 The previous time and time t in the first period 2The first covariance is calculated using the time series data of the first photovoltaic power generation output and the time series data of the second consumer's residual demand at the subsequent times. The first covariance calculated when it is determined that the second photovoltaic power generation facility is overloaded is also referred to as the third covariance.

[0092] After step S24, the first covariance calculation unit 120 acquires the delay time (step S25), stores it in the storage unit 180 as calculated data 185, and ends the calculation process of the first covariance. In step S25, if step S23 has been passed, the first covariance calculation unit 120 calculates the delay time using the time series data of the first photovoltaic power generation output and the time series data of the residual demand of the second consumer extracted in step S23, and if step S23 has not been passed, calculates the delay time using all the time series data of the first photovoltaic power generation output in the first period and the time series data of the residual demand of the second consumer.

[0093] In step S25, in detail, for example, a delay time between the installation point of the second photovoltaic power generation facility, which is the subject of power generation output estimation, and the installation point of the first photovoltaic power generation facility is calculated, and stored in the storage unit 180 as calculated data 185. As described above, this delay time is the time it takes for solar radiation fluctuations to propagate between the installation points of the first photovoltaic power generation facility and the installation points of the second photovoltaic power generation facility. The first covariance calculation unit 120 calculates, for example, a covariance function Cov t [P PV1 (t),P 2 The time lag τ when (t+τ)] is at its minimum (the sign is "-" and the absolute value is maximum) is multiplied by -1 to get the delay time τ s Calculate.

[0094] Next, the calculation process of the second covariance will be described below. Fig. 12 is a flowchart showing an example of the procedure of the calculation process of the second covariance by the second covariance calculation section 130 of this embodiment.

[0095] The second covariance calculation unit 130 calculates the delay time τ s The delay time τs (Step S31). Next, the second covariance calculation unit 130 obtains the delay time τ s The second covariance calculation unit 130 obtains two pieces of time series data of the first photovoltaic power generation output that are shifted from each other (step S32). That is, the second covariance calculation unit 130 obtains the time series data of the first photovoltaic power generation output in the first period and the time series data of the first photovoltaic power generation output with a delay time τ s The time series data of the first photovoltaic power generation output during the shifted second period is extracted, read, and acquired from the photovoltaic power generation output data 182 in the storage unit 180. s If is 0, the delay time τ s Since the two shifted first photovoltaic power generation outputs are the same, the second covariance calculation section 130 only needs to read out the first photovoltaic power generation output for the first period from the photovoltaic power generation output data 182 in the storage section 180.

[0096] Next, the second covariance calculation unit 130 judges whether the photovoltaic power generation facility 202 of the second consumer is overloaded (step S33). Specifically, when the judgment result notified by the overload estimation unit 150 indicates that the photovoltaic power generation facility 202 of the second consumer, whose power output is to be estimated, is overloaded, the second covariance calculation unit 130 judges that the photovoltaic power generation facility 202 of the second consumer is overloaded.

[0097] If the photovoltaic power generation facility 202 of the second customer is not overloaded (step S33: No), the second covariance calculation unit 130 proceeds to step S35 described later. If the photovoltaic power generation facility 202 of the second customer is overloaded (step S33: Yes), the second covariance calculation unit 130 calculates the covariance t≦t 1 , and t ≥ t 2 In detail, the second covariance calculation unit 130 extracts data for the time period t≦t from the time series data of the first photovoltaic power generation output in the first period acquired in step S32. 1 , and t ≥ t 2 The data for the time period t≦t is extracted from the time series data of the first photovoltaic power generation output for the second period acquired in step S32. 1 +τ s、 and t ≥ t 2 +τ sExtract data for the time period.

[0098] Next, the second covariance calculation unit 130 calculates the second covariance (step S35), writes the calculated second covariance to the calculation data 185, and ends the calculation process of the second covariance. s The second covariance is calculated as the autocovariance of the time series data of the two shifted first photovoltaic power generation outputs. Specifically, if step S34 has been passed, the second covariance calculation unit 130 calculates the autocovariance of the time series data of the two extracted first photovoltaic power generation outputs as the second covariance, and if step S34 has not been passed, the second covariance calculation unit 130 calculates the autocovariance of the time series data of the first photovoltaic power generation output in the first period and the time series data of the first photovoltaic power generation output in the second period acquired in step S32 as the second covariance. In this way, when it is determined that the second photovoltaic power generation equipment is overloaded, the second covariance calculation unit 130 calculates the autocovariance of the time series data of the first photovoltaic power generation output in the first period and the time series data of the first photovoltaic power generation output in the second period acquired in step S32 as the second covariance. 1 The previous time and time t in the first period 2 A second covariance is calculated using the time series data of the first photovoltaic power generation output at a later time and the time series data of the first photovoltaic power generation output shifted by a delay time from the time series data of the first photovoltaic power generation output. The second covariance calculated when it is determined that the second photovoltaic power generation equipment is overloaded is also referred to as a fourth covariance.

[0099] Next, the operation of the power generation output estimating unit 140 will be described. Fig. 13 is a flowchart showing an example of a processing procedure in the power generation output estimating unit 140 of this embodiment. The power generation output estimating unit 140 first calculates the coefficient α using the first covariance and the second covariance (step S41). In detail, the power generation output estimating unit 140 reads out the first covariance and the second covariance from the calculation data 185 in the storage unit 180, and calculates the coefficient α according to the above-mentioned formula (5) using the read out first covariance and second covariance.

[0100] Next, the power output estimating unit 140 calculates the delay time (step S42). In detail, the power output estimating unit 140 calculates the delay time between the installation point of the first solar power generation facility and the installation point of the second solar power generation facility at the estimation time. The power output estimating unit 140 may use the delay time stored in the storage unit 180 as the calculation data 185 as the delay time at the estimation time, or may update the delay time by reflecting weather data at the estimation time. For example, the power output estimating unit 140 may calculate the time it takes for clouds to pass from wind direction and wind speed data included in the weather data and update the delay time using the calculated value, or may update the delay time using satellite images or the like, or may update the delay time using weather data by other methods. The delay time may also be approximated to zero.

[0101] Next, the power generation output estimation unit 140 acquires the first photovoltaic power generation output at the time to be estimated, i.e., the time shifted by the delay time from the estimation time point (step S43). In detail, the power generation output estimation unit 140 acquires data at the time shifted by the delay time from the estimation time point among data corresponding to the first photovoltaic power generation facility in the photovoltaic power generation output data 182 in the storage unit 180.

[0102] Next, the power generation output estimation unit 140 judges whether the photovoltaic power generation facility 202 of the second consumer is overloaded (step S44). Specifically, when the judgment result notified by the overload estimation unit 150 indicates that the photovoltaic power generation facility 202 of the second consumer, whose power generation output is to be estimated, is overloaded, the power generation output estimation unit 140 judges that the photovoltaic power generation facility 202 of the second consumer is overloaded.

[0103] If the photovoltaic power generation facility 202 of the second consumer is overloaded (Yes in step S44), the power generation output estimation unit 140 estimates the power generation output of the photovoltaic power generation facility 202 to be estimated by taking the smaller of the saturation value and the value obtained by multiplying the first photovoltaic power generation output at a time shifted by the delay time from the estimation time point for each time (step S45), and ends the process. In step S45, in detail, the power generation output estimation unit 140 reads out the corresponding saturation value from the overload estimation data 184 in the storage unit 180, and estimates the second photovoltaic power generation output by the above-mentioned formula (8) using the read out saturation value, the first photovoltaic power generation output at a time shifted by the delay time from the estimation time point acquired in step S43, and the coefficient α calculated in step S41.

[0104] If the photovoltaic power generation facility 202 of the second consumer is not overloaded (No in step S44), the power generation output estimation unit 140 estimates the power generation output of the photovoltaic power generation facility 202 to be estimated by multiplying the first photovoltaic power generation output by the coefficient α (step S46), and ends the process. In detail, the power generation output estimation unit 140 estimates the second photovoltaic power generation output by the above-mentioned formula (6) using the first photovoltaic power generation output at a time shifted by the delay time from the estimation time point acquired in step S43 and the coefficient α calculated in step S41.

[0105] By the above-described processing, the photovoltaic power generation output estimation device 100 of this embodiment is capable of identifying an overloaded photovoltaic power generation facility 202, and further capable of accurately estimating the power generation output of the overloaded photovoltaic power generation facility 202.

[0106] Next, an example of a display screen displayed by the display unit 160 of the present embodiment will be described. The display unit 160 of the present embodiment can display the estimation result of the second photovoltaic power generation output, data used in the estimation of the second photovoltaic power generation output, information on the overloaded photovoltaic power generation facility 202, and the like. For example, the display unit 160 displays at least one of the estimation result of the second photovoltaic power generation output, the determination result by the overload estimation unit 150, and the overload determination coefficient.

[0107] FIG. 14 is a diagram showing an example of an estimation result of the second photovoltaic power generation output displayed by the display unit 160 of the present embodiment. FIG. 14 shows a display screen of the estimation result of the second photovoltaic power generation output of the overloaded photovoltaic power generation facility 202 as an example of a display screen displayed by the display unit 160. In FIG. 14, the horizontal axis represents time, and the vertical axis represents active power. In the example shown in FIG. 14, the saturation value is 1.83 kW, and the estimation result of the second photovoltaic power generation output is the saturation value from 9:30 to 13:00. As shown in FIG. 14, for example, the estimation result of the second photovoltaic power generation output is displayed together with the identification information of the consumer 200 to be estimated, such as consumer #2.

[0108] Fig. 15 is a diagram showing an example of an estimation result of the second photovoltaic power generation output displayed by the display unit 160 of the present embodiment. In Fig. 15, the horizontal axis represents time, and the vertical axis represents active power or correlation coefficient. In the example shown in Fig. 15, the display unit 160 displays the first photovoltaic power generation output (reference photovoltaic power generation output) and the residual demand of the second consumer (residual demand of the consumer to be estimated) used as input data in estimating the coefficient α, as well as the correlation coefficient therebetween. In addition, in the example shown in Fig. 15, identification information of the consumer 200 to be estimated and identification information of the consumer 200 used as the reference are displayed.

[0109] Furthermore, the display unit 160 may display the result of multiplying the first photovoltaic power output used for estimating the coefficient α by the coefficient α, as shown in FIG. 9. At this time, as shown in FIG. 1 and time t 2 The value in may be highlighted by encircling it so that it can be distinguished. The highlighting method may be a different color or a different mark, and is not limited to a circle.

[0110] FIG. 16 is a diagram showing an example of a screen for selecting an area for displaying the judgment result of the overloaded photovoltaic power generation facility 202 according to the present embodiment. In order to display the judgment result of the overloaded photovoltaic power generation facility 202, the display unit 160 displays, for example, the selection screen exemplified in FIG. 16, and accepts input from the user using input fields 501 to 503. The input field 501 is a selection button that is pressed when performing full area display, and the input field 502 is an input field in the form of a pull-down menu that is used when selecting a prefecture. The input field 503 is an input field in which an address is input by the user. The user presses the input field 501, or selects a prefecture in the form of a pull-down menu in the input field 502, or inputs an address in the input field 503 and presses an enter key or the like, thereby selecting a geographical area to be displayed. The full area may be the entire country, such as Japan, or the entire area under the jurisdiction of a grid operator. In addition, when a prefecture is selected in the input field 502 using a pull-down menu, an input field in the form of a pull-down menu for selecting a city, ward, town, or village is displayed thereafter, so that it may be possible to select whether to display the entire prefecture or display each city, ward, town, or village. Note that the input acceptance unit 170 accepts the inputs in the input fields 501 to 503.

[0111] FIG. 17 is a diagram showing an example of a display screen of the determination result of the overloaded photovoltaic power generation facility 202 in this embodiment. In the example shown in FIG. 17, an example of a display screen when A prefecture is selected as the geographical area is shown. In the example shown in FIG. 17, the display unit 160 shows the geographical positions of the photovoltaic power generation facilities 202 other than overloaded (described as PV (other than overloaded) in FIG. 17) with circles, and shows the geographical positions of the overloaded photovoltaic power generation facilities 202 (described as overloaded PV in FIG. 17) with diamonds. By using the location information data 181 and the overload estimation data 184 of the storage unit 180, the display unit 160 can display each photovoltaic power generation facility 202 by distinguishing between overloaded and other, as shown in FIG. 17. In addition, as shown in the area 504 in FIG. 17, the display unit 160 may enlarge and display the inside of the area 504 by accepting the selection of the area from the user. The selection of the area 504 is accepted by the input acceptance unit 170.

[0112] FIG. 18 is a diagram showing an example of a display screen in which the judgment result of the overloaded photovoltaic power generation facility 202 of the present embodiment is enlarged. FIG. 18 shows a screen in which a part of the area shown in FIG. 17 is enlarged and the judgment result is superimposed on map information showing roads and the like. In this way, the display unit 160 can display the position of the photovoltaic power generation facility 202 judged to be overloaded and the position of the photovoltaic power generation facility 202 not judged to be overloaded on the map using different figures. Also, in FIG. 17 and FIG. 18, information showing the address of the area displayed at the top, the total PV number, and the overloaded PV number are shown. The total PV number is the total number of photovoltaic power generation facilities 202 in the selected area, and the overloaded PV number is the number of photovoltaic power generation facilities 202 judged to be overloaded among the photovoltaic power generation facilities 202 in the selected area. In this way, the display unit 160 can display the number of photovoltaic power generation facilities 202 judged to be overloaded for each selected area. As shown in Figures 17 and 18, by displaying the judgment results of overloaded solar power generation equipment 202, the grid operator can understand which solar power generation equipment 202 is overloaded and how many solar power generation equipment 202 are overloaded.

[0113] In the examples shown in Figs. 17 and 18, the determination result is displayed on a map, but the display unit 160 may display the number of overloaded PV for each region in text. Fig. 19 is a diagram showing an example of a display screen displaying the determination result of the overloaded photovoltaic power generation facility 202 in this embodiment in text. As shown in Fig. 19, the total number of PV and the number of overloaded PV for each region may be displayed in text. Although not shown in the figures, the display unit 160 may display the total number of PV and the number of overloaded PV for each region in a graph.

[0114] Note that the display screens shown in Figures 14 to 19 are just examples, and the display position of each display item on the display screen, the shape of the mark indicating PV (other than overload) and overload PV, the items to be displayed, the method of accepting input, etc. are not limited to the examples shown in Figures 14 to 19.

[0115] In the above, an example has been described in which the power generation output of the second photovoltaic power generation equipment of one second consumer is estimated using the power generation output of the first photovoltaic power generation equipment of one first consumer. Although the power generation output of the overloaded second photovoltaic power generation equipment is estimated individually, the total amount (combined value) of the power generation output of multiple second photovoltaic power generation equipment that is not overloaded may be estimated using the power generation output of the first photovoltaic power generation equipment of one first consumer. In addition, the total amount (combined value) of the power generation output of multiple second photovoltaic power generation equipment that is not overloaded or the power generation output of one second photovoltaic power generation equipment may be estimated using the total amount (combined value) of the power generation output of the first photovoltaic power generation equipment of multiple first consumers. For example, when it is necessary to estimate the total amount of the power generation output of the photovoltaic power generation equipment 202 of multiple consumers, such as by distribution section unit such as by pole-mounted transformer unit, by distribution line unit, by transmission line unit, etc., the total amount of the power generation output of consumers whose power generation output has not been measured can be estimated in the same manner.

[0116] FIG. 20 is a diagram showing an example of the coefficient α in the case where the photovoltaic power generation facilities 202 of the multiple consumers 200 are the estimation targets in this embodiment. In the case where the second photovoltaic power generation facility estimates the power generation output of the multiple second photovoltaic power generation facilities using the power generation output of the first photovoltaic power generation facilities of the multiple first consumers, the coefficient α is calculated for each combination of the multiple photovoltaic power generation facilities as shown in FIG. 20. In this case, the delay time is the time it takes for the solar radiation fluctuation to propagate between the centroid position of the installation point of the first photovoltaic power generation facility and the centroid position of the installation point of the second photovoltaic power generation facility. The delay time may be set to 0. FIG. 20 shows an example in which the coefficient α is determined for each distribution section and the power generation output is estimated for each distribution section, but the unit for integrating the consumers 200 is not limited to this.

[0117] As described above, the first photovoltaic power generation output may be a measurement value such as a measurement value of a smart meter of the photovoltaic power generation facility 202 that is the subject of the full-amount purchase contract, a measurement value by a PCS or a HEMS, etc. The first photovoltaic power generation output is not limited to this, and after estimating the second photovoltaic power generation output using the first photovoltaic power generation output that is measurement data, the estimated second photovoltaic power generation output may be used as the first photovoltaic power generation output to estimate the power generation output of another photovoltaic power generation facility. By repeating this, for example, even if there is no photovoltaic power generation facility 202 whose power generation output is measured within a predetermined distance from the photovoltaic power generation facility 202 to be estimated, the power generation output of the photovoltaic power generation facility 202 to be estimated can be estimated. That is, the first photovoltaic power generation output may be a measurement value or an estimate value.

[0118] Alternatively, an actual or estimated value of the solar radiation intensity may be used instead of the first solar power generation output. In this case, the actual or estimated value of the solar radiation intensity is the first 2 The solar power generation output is within a predetermined distance from the solar power generation facility. In other words, the first solar power generation output is an example of solar radiation intensity information indicating solar radiation intensity. When using a solar radiation intensity estimate using a satellite image, the solar radiation intensity estimate is often estimated in mesh units of X [km] × Y ​​[km], which depends on the resolution of the satellite image. For this reason, when using a solar radiation intensity estimate using a satellite image, If The solar radiation intensity estimate for the mesh that includes the second solar power generation facility to be estimated is used.

[0119] As described above, in this embodiment, the power generation output estimation unit 140 estimates the power generation output of the photovoltaic power generation facility 202 using solar radiation intensity information indicating solar radiation intensity, and the overload estimation unit 150 calculates an overload judgment coefficient indicating a correlation between the solar radiation intensity information and a residual demand that is the apparent power consumption of the consumer in which the second photovoltaic power generation facility is installed, and judges whether or not the photovoltaic power generation facility is overloaded using the overload judgment coefficient. In addition, the photovoltaic power generation output estimation program of this embodiment causes a computer to execute a step of estimating the power generation output of the photovoltaic power generation facility 202 using solar radiation intensity information indicating the solar radiation intensity within a predetermined distance from the photovoltaic power generation facility 202, and a step of calculating an overload judgment coefficient indicating a correlation between the solar radiation intensity information and a residual demand that is the apparent power consumption of the consumer in which the photovoltaic power generation facility 202 is installed, and judging whether or not the photovoltaic power generation facility 202 is overloaded using the overload judgment coefficient.

[0120] It is possible that the first photovoltaic power generation facility subject to the full purchase contract or the first photovoltaic power generation facility whose power generation output is measured by the measuring instrument 206 is overloaded, and in this case, it can be determined whether or not the measurement value of the first photovoltaic power generation output is saturated. The saturation value can also be estimated based on the measurement value. The overloaded photovoltaic power generation facility 202 may not be used as the first photovoltaic power generation facility, or only the first photovoltaic power generation output during the time period when it is not saturated may be used to estimate the second photovoltaic power generation output.

[0121] Furthermore, the photovoltaic power generation output estimating device 100 may calculate a representative value (e.g., a statistical value such as a median or an average value) of the coefficient α estimated for each of the past several days, and use the representative value to perform the processes of steps S9, S10, and S12. By using the representative value, the estimation accuracy of the coefficient α is improved, and thus the estimation accuracy of the second photovoltaic power generation output is improved.

[0122] In addition, in winter, even on clear days, there are days when the solar radiation intensity is not very strong, and on such days, the second solar power generation output may not be saturated even if the second solar power generation facility is overloaded. On days when the second solar power generation output is not saturated, the overload judgment coefficient does not fall below the threshold. On the other hand, since the coefficient α is a ratio between the solar power generation outputs, it does not fluctuate significantly throughout the year. By utilizing this, the coefficient α may be estimated and stored using the first solar power generation output and the residual demand of the second consumer on a day when the overload judgment coefficient does not fall below the threshold, and the saturation value of the second solar power generation facility may be set using the stored coefficient α and the first solar power generation output and the residual demand of the second consumer on a day when the solar radiation intensity is strong. In other words, when performing the process shown in FIG. 4 using the first photovoltaic power generation output and the residual demand of the second consumer on a day with strong solar radiation intensity, the photovoltaic power generation output estimation device 100 may perform steps S9 and S10 using the above-mentioned stored coefficient α (coefficient α estimated using data for a day on which the overload determination coefficient is not less than the threshold value) without performing step S8.

[0123] Through the above processing, the photovoltaic power generation output estimating device 100 of this embodiment can estimate whether the photovoltaic power generation facility 202, the power generation output of which is to be estimated, is overloaded or not, and can accurately estimate the power generation output of the overloaded photovoltaic power generation facility 202. As a result, the photovoltaic power generation output of the photovoltaic power generation facility 202 including the overloaded photovoltaic power generation facility 202 can be estimated with high accuracy.

[0124] Embodiment 2 Next, a photovoltaic power generation output estimating apparatus 100 according to a second embodiment will be described. The functional configuration and hardware configuration of the photovoltaic power generation output estimating apparatus 100 of this embodiment are similar to those of the photovoltaic power generation output estimating apparatus 100 of the first embodiment. However, the operation of the first covariance calculating unit 120 is partially different from that of the first embodiment. Components having the same functions as those of the first embodiment will be described with the same reference numerals as those of the first embodiment, and descriptions that overlap with those of the first embodiment will be omitted. Below, differences from the first embodiment will be mainly described.

[0125] 21 is a flowchart showing an example of a processing procedure for estimating the second photovoltaic power output by the photovoltaic power output estimating apparatus 100 of the present embodiment. The photovoltaic power output estimating apparatus 100 selects the first photovoltaic power generation facility (step S51), similarly to step S1 in the first embodiment.

[0126] Next, the photovoltaic power generation output estimation device 100 judges whether or not a saturation value of the photovoltaic power generation facility to be estimated has been set (step S52). In detail, the first covariance calculation unit 120 refers to the overload estimation data 184 in the storage unit 180 and judges whether or not a saturation value of the photovoltaic power generation facility 202 to be estimated has been stored in the overload estimation data 184. That is, the first covariance calculation unit 120 judges whether or not a saturation value of the photovoltaic power generation facility 202 to be estimated has been set.

[0127] If the saturation value of the photovoltaic power generation facility 202 to be estimated has not been set (No in step S52), the photovoltaic power generation output estimating device 100 performs estimation processing including overload determination (step S56). The estimation processing including overload determination is the processing of steps S2 to S12 shown in FIG. 4 of the first embodiment.

[0128] If the saturation value of the photovoltaic power generation facility 202 to be estimated has already been set (step S52 Yes), the first covariance calculation unit 120 selects a first period in which saturation does not occur, and acquires the first photovoltaic power generation output and the residual demand of the second consumer in the first period (step S53). In detail, the first covariance calculation unit 120 sets, for example, a period in which the maximum value of the first photovoltaic power generation output is equal to or greater than the first threshold value and equal to or less than the second threshold value as the first period, thereby setting the first period as a period in which the second photovoltaic power generation output is not saturated. Note that the second threshold value is greater than the first threshold value. The first threshold value is determined so as to exclude days with low solar radiation intensity, such as rainy days, from the first period, and the second threshold value is determined so as not to exceed the saturation value of the photovoltaic power generation facility 202 of the second consumer, for example, based on the value of the coefficient α calculated in the past. Alternatively, a period in which the maximum value of the solar radiation intensity is equal to or greater than the third threshold value and equal to or less than the fourth threshold value may be set as the first period. Alternatively, the first covariance calculation unit 120 selects the first period in the same manner as in the first embodiment, and the first covariance calculation unit 120 and the overload estimation unit 150 perform steps S2 to S6 of the first embodiment. If it is determined in step S6 that there is a time when the overload determination coefficient falls below the threshold, the first period is reset to a period with lower solar radiation intensity than the previous time, and steps S2 to S6 are performed. Then, by repeating the change of the first period and steps S2 to S6 until the overload determination coefficient falls below the threshold in step S6, a first period in which saturation does not occur may be selected. Alternatively, only the times when the overload determination coefficient falls below the threshold may be excluded from the first period.

[0129] After step S53, step S54 is carried out in the same manner as step S11 in the first embodiment. That is, in step S54, the coefficient α is estimated using data for all time periods in the first period. Then, step S55 is carried out in the same manner as step S10 in the first embodiment. That is, the power generation output estimating unit 140 extracts and reads out the first photovoltaic power generation output shifted by the delay time from the estimation time point from the photovoltaic power generation output data 182 in the storage unit 180, and reads out the saturation value from the overload estimation data 184 in the storage unit 180. Then, the power generation output estimating unit 140 calculates α·P PV1 (t+τ s The smaller of the delay time τ s may be approximated to 0.

[0130] In this manner, in the present embodiment, the first period is set to a period in which the second photovoltaic power generation output is not saturated, and the coefficient α is estimated using data from all time periods in the first period. The operation of the present embodiment other than that described above is the same as that of the first embodiment. In the present embodiment, as in the first embodiment, it is possible to estimate whether the photovoltaic power generation facility 202, the power generation output of which is to be estimated, is overloaded or not.

[0131] In addition, the fact that the photovoltaic power generation facility is overloaded and its saturation value may be managed by the electric power company based on an application from a consumer. Even in this case, although it is not necessary to estimate the saturation value, as described in the first or second embodiment, the estimation accuracy of the second photovoltaic power generation output can be improved by finding a time period in which the overload determination coefficient is not below a threshold value or a day in which the overload determination coefficient is not below a threshold value, and estimating the coefficient α using the first photovoltaic power generation output only in the found time period or only on the found day and the residual demand of the second consumer. Then, the second photovoltaic power generation output estimated using the coefficient α is compared with the saturation value based on the application, and the smaller one is set as the final second photovoltaic power generation output, thereby improving the estimation accuracy.

[0132] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0133] 10 Photovoltaic power generation output estimation system, 100 Photovoltaic power generation output estimation device, 110 Data acquisition unit, 120 First covariance calculation unit, 130 Second covariance calculation unit, 140 Power generation output estimation unit, 150 Overload estimation unit, 160 Display unit, 170 Input reception unit, 180 Memory unit, 200-1 to 200-4, 200-m, 200-n Consumers, 201 Load, 202 Photovoltaic power generation equipment, 203 to 205 Smart meters, 206 Measuring instrument.

Claims

1. a power generation output estimation unit that estimates a power generation output of the photovoltaic power generation facility using solar radiation intensity information indicating solar radiation intensity within a predetermined distance from the photovoltaic power generation facility; an overload estimation unit that calculates an overload determination coefficient indicating a correlation between the solar irradiance information and a residual demand, which is an apparent power consumption of a consumer in which the solar power generation facility is installed, and determines whether the solar power generation facility is overloaded using the overload determination coefficient; A photovoltaic power generation output estimating device comprising:

2. 2. The photovoltaic power generation output estimation device according to claim 1, characterized in that the solar radiation intensity information is a first photovoltaic power generation output that is the power generation output of a first photovoltaic power generation facility, the photovoltaic power generation facility is a second photovoltaic power generation facility installed within the predetermined distance from the first photovoltaic power generation facility, and the power generation output to be estimated is a second photovoltaic power generation output that is the power generation output of the second photovoltaic power generation facility.

3. a first covariance calculation unit that calculates a first covariance, which is a covariance between time series data of the first photovoltaic power generation output and time series data of residual demand of a consumer in which the second photovoltaic power generation facility is installed, in at least one first period prior to a time point in which the second photovoltaic power generation output is estimated, when it is determined that the second photovoltaic power generation facility is not overloaded; a second covariance calculation unit that calculates a second covariance that is an autocovariance between time series data of the first photovoltaic power generation output in the first period and time series data of the first photovoltaic power generation output in a second period shifted from the first period by a delay time when it is determined that the second photovoltaic power generation facility is not overloaded; Equipped with The photovoltaic power generation output estimation device according to claim 2, characterized in that, when it is determined that the second photovoltaic power generation equipment is not overloaded, the power generation output estimation unit calculates a coefficient that is a ratio between the first photovoltaic power generation output and the second photovoltaic power generation output using the first covariance and the second covariance, and estimates the second photovoltaic power generation output by multiplying the first photovoltaic power generation output with a delay time from the estimation time point by the coefficient.

4. 4. The photovoltaic power generation output estimating device according to claim 3, wherein the coefficient is a value obtained by dividing the first covariance by the second covariance and multiplying the result by −1.

5. the overload determination coefficient is a correlation coefficient between the time series data of the first photovoltaic power generation output and the time series data of the residual demand within a time window of a determined length in the first period, The photovoltaic power generation output estimation device according to claim 3 or 4, characterized in that the overload estimation unit calculates the correlation coefficient for each time within the first period by sequentially moving the time window including the time, and determines whether the photovoltaic power generation equipment is overloaded based on whether there is a time period in which the correlation coefficient is below a threshold value.

6. The overload estimation unit obtains a first time that is a time immediately before a time period in which the correlation coefficient is below a threshold value and a second time that is a time immediately after a time period in which the correlation coefficient is above the threshold value, the first covariance calculation unit, when it is determined that the second photovoltaic power generation equipment is overloaded, calculates a third covariance which is a covariance between the time series data of the first photovoltaic power generation output and the time series data of the residual demand, using the time series data of the first photovoltaic power generation output at a time before the first time in the first period and at a time after the second time in the first period; the second covariance calculation unit, when it is determined that the second photovoltaic power generation equipment is overloaded, calculates a fourth covariance which is an autocovariance of the two time series data of the first photovoltaic power generation output shifted by the delay time from the time series data of the first photovoltaic power generation output, using the time series data of the first photovoltaic power generation output at a time before the first time in the first period and at a time after the second time in the first period, and the time series data of the first photovoltaic power generation output shifted by the delay time from the time series data of the first photovoltaic power generation output; the power generation output estimating unit calculates the coefficient by using the third covariance and the fourth covariance when it is determined that the second photovoltaic power generation facility is overloaded; the overload estimation unit sets a larger value of the first photovoltaic power generation output, which is shifted by a delay time from the first time, multiplied by the coefficient and the first photovoltaic power generation output, which is shifted by a delay time from the second time, multiplied by the coefficient as a saturation value of the second photovoltaic power generation equipment; The photovoltaic power generation output estimation device according to claim 5, characterized in that the power generation output estimation unit estimates the second photovoltaic power generation output as the smaller of a value obtained by multiplying the first photovoltaic power generation output, which is shifted by a delay time from the estimation time point, by the coefficient for each time point and the saturation value.

7. 7. The photovoltaic power generation output estimating device according to claim 6, wherein the coefficient is a value obtained by dividing the third covariance by the fourth covariance and multiplying the result by −1.

8. the first covariance calculation unit, when the saturation value of the second photovoltaic power generation facility has been set, sets the first period to a period in which the second photovoltaic power generation output is not saturated, and calculates the first covariance using time series data of the first photovoltaic power generation output and time series data of the residual demand at all times during the first period; a second covariance calculation unit, when the saturation value of the second photovoltaic power generation facility has been set, calculates the second covariance using time series data of the first photovoltaic power generation output at all times in the first period set to a period in which the second photovoltaic power generation output is not saturated and time series data of the first photovoltaic power generation output in the second period shifted from the first period by the delay time; 8. The photovoltaic power generation output estimation device according to claim 6 or 7, wherein, when the saturation value of the second photovoltaic power generation facility has been set, the power generation output estimation unit calculates the coefficient using the first covariance and the second covariance, and sets the estimated value of the second photovoltaic power generation output to the smaller of the value obtained by multiplying the coefficient by the first photovoltaic power generation output shifted by a delay time from the estimation time point for each time and the saturation value.

9. a display unit that displays at least one of the estimation result of the power generation output of the photovoltaic power generation facility, the determination result by the overload estimation unit, and the overload determination coefficient; The photovoltaic power generation output estimating device according to any one of claims 1 to 8, further comprising:

10. The photovoltaic power generation output estimating device according to claim 9 , wherein the display unit displays the number of the photovoltaic power generation facilities determined to be overloaded for each selected region.

11. The photovoltaic power generation output estimation device according to claim 9 or 10, characterized in that the display unit displays the location of the photovoltaic power generation equipment determined to be overloaded and the location of the photovoltaic power generation equipment not determined to be overloaded on a map using different graphics.

12. a photovoltaic power generation output estimation device estimating a power generation output of the photovoltaic power generation facility using solar radiation intensity information indicating solar radiation intensity within a predetermined distance from the photovoltaic power generation facility; A photovoltaic power generation output estimation method, characterized in that a photovoltaic power generation output estimation device calculates an overload determination coefficient indicating a correlation between the solar irradiance information and residual demand, which is the apparent power consumption of a consumer in which the photovoltaic power generation equipment is installed, and determines whether the photovoltaic power generation equipment is overloaded using the overload determination coefficient.

13. estimating a power output of the photovoltaic power generation facility using solar radiation intensity information indicating solar radiation intensity within a predetermined distance from the photovoltaic power generation facility; calculating an overload determination coefficient indicating a correlation between the solar irradiance information and a residual demand, which is an apparent power consumption of a consumer in which the solar power generation facility is installed, and determining whether or not the solar power generation facility is overloaded using the overload determination coefficient; A photovoltaic power generation output estimation program characterized by causing a computer to execute the above.

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