DEVICE FOR CONTROLLING ELECTRICAL POWER

Abstract

An object of the present invention is to provide a technology that can precisely control the transmitted power according to a predetermined plan when power generated by a power generation system consisting of a solar cell and a storage battery is transmitted between locations via a power transmission network. A device for controlling electrical power according to the present invention calculates the power to be absorbed and delivered by the storage battery based on the difference between the planned power to be transmitted via the power transmission network and the actual resulting power that was actually transmitted, and calculates the power that the solar cell must generate.

Description

Technical area

[0001] The present invention relates to a technology for controlling transmitted power when power generated by a power generation system consisting of a solar cell and a storage battery is transmitted between sites via a power transmission network. Technical background

[0002] Self-delivery uses a power transmission network owned by a power company. When self-delivery is performed, a power transmission plan must be submitted to an operating organization (e.g., the Organization for Cross-Regional Coordination of Transmission Operators: OCCTO) before the start of a delivery (e.g., the day before). Furthermore, while self-delivery is performed, power must be transmitted as planned at predetermined time intervals (e.g., every 30 minutes). If the actual transmitted power deviates from a predetermined plan (imbalance), a penalty is generally imposed.

[0003] The following Patent Document 1, with the object of "providing a power monitoring control device that can self-supply surplus power according to a scheduled value," describes a technology wherein "a power monitoring control device (10) includes an actual resultant value determining unit (14) that determines whether or not an actual resultant delivery value in a predetermined delivery period has reached an upper limit threshold of an actual resultant value, and a control unit (16) that performs delivery prohibition control of a target device when the actual resultant delivery value in the delivery period has reached the upper limit threshold of an actual resultant value (see abstract).

[0004] The following Patent Document 2 describes, with the objective of "providing a rational evaluation method for the minimum capacity of an installed storage battery and the optimal charging and discharging logic for a small-capacity storage battery, taking into account the occurrence of prediction errors inherent in solar radiation amount prediction technology and storage battery management technology," a technology wherein "a storage facility management device 1 includes a charging / discharging schedule creation unit 2 that sets a delivery time zone in which a predicted surplus power value will occur based on a power demand estimate predicted by referring to a predetermined database 5 and a predicted value of renewable energy generation power, when the delivery time zone extends over a plurality of time units greater than or equal to a predetermined value,divides the delivery time zone into several time segments, each consisting of one or more of the time units, prepares a charging / discharging plan for the energy storage device such that the delivery energy is constant for each time segment, and stores the prepared charging / discharging plan in a predetermined storage unit 4" (see summary).

[0005] Although Japanese Patent Application No. 2020-127908 is not related to self-supply, it describes a method for estimating the amount of solar radiation for a solar cell by converting the operating characteristics of the solar cell into values ​​under a standard amount of solar radiation and a standard temperature. Citation listPatent literature Patent Literature 1: Japanese Unexamined Published Patent Application No. 2021-141769 Patent Literature 2: Japanese Unexamined Published Patent Application No. 2020-058141 Summary of the inventionTechnical problem

[0006] Consider a case where a power generation system that generates power to be transmitted through self-supply consists of, for example, a solar cell and a storage battery. In order to transmit power while performing self-supply while fulfilling a predetermined schedule, it is necessary to suppress the amount of generated power so that it is less than the maximum power point when the solar cell generates power in excess of the scheduled power to be delivered, and to allocate the excess power generation amount to charging the storage battery. That is, when the amount of power generated by the power generation system exceeds the scheduled power to be delivered that has been scheduled in advance, the power generation system instructs the solar cell to suppress the amount of generated power from the maximum power point and instructs the storage battery to perform a charging operation.

[0007] At this point, it is necessary to balance the power generated by the solar cell while maintaining below the maximum power point and the charging power charged to the storage battery. However, since the IV characteristics (the relationship between the output voltage and output current) of the solar cell vary depending on various factors, it is not always easy to accurately determine the amount of suppression from the maximum power point. If the amount of power suppression is unknown, it is also difficult to accurately command the charging power to be allocated to charging the storage battery. This can make it difficult to adhere to the specified schedule.

[0008] The present invention was conceived in view of the problems described above. An object of the present invention is to provide a technology that can accurately control the transmitted power according to a predetermined schedule when power generated by a power generation system consisting of a solar cell and a storage battery is transmitted between locations via a power transmission network. Solution to the problem

[0009] An electric power control device according to the present invention calculates the power to be input and output by the storage battery based on the difference between the planned power that was planned to be transmitted by means of the power transmission network and the actual resulting power that was actually transmitted, and calculates the power that the solar cell needs to generate. Advantageous effects of the invention

[0010] According to the electric power control device of the present invention, when the power generated by the power generation system consisting of the solar cell and the storage battery is transmitted between sites via the power generation grid, it is possible to precisely control the transmitted power according to the predetermined schedule. Problems, configurations, effects, and the like other than those described above will become apparent from the following description of embodiments. Brief description of the drawings Fig. Figure 1A is an example of a configuration of a power generation system provided by an entrepreneur implementing self-supply. Fig. Figure 1B is an example of a configuration of a power generation system provided by an entrepreneur implementing self-supply. Fig. Figure 2 is a schematic diagram illustrating the manner in which self-delivery between sites is performed. Fig. 3 is a diagram describing an imbalance of the transmitted power. Fig. Figure 4A is a schematic diagram describing a method for estimating the amount of solar radiation (the expected amount of solar radiation) radiated to a solar cell. Fig. Figure 4B is a schematic diagram showing a procedure for predicting the amount of power generated by a solar cell using learning results from Fig. 4A describes. Fig. Figure 5 illustrates an example of converting IV properties during normal operation into values ​​under a standard solar radiation amount and a standard temperature. Fig. 6 illustrates an example in which an operating point at which the power generation amount is suppressed below the maximum power point is converted into a value below a standard solar radiation amount and a standard temperature. Fig. Figure 7 is a flowchart describing a procedure of estimating a variable j and the expected amount of solar radiation. Fig. 8 is a flowchart describing a procedure by which an electric power control device 1 suppresses a power transmission imbalance during implementation of self-supply. Fig. Figure 9 is a flowchart describing a procedure of determining a probability c. Fig. 10A is an example of a user interface provided by the electrical power control device 1. Fig. 10B is an example of the user interface provided by the electrical power control device 1. Fig. 10C is an example of the user interface provided by the electrical power control device 1. Description of the embodimentsFirst embodiment

[0011] Fig. 1A and Fig. 1B are each an example of a configuration of a power generation system provided by an entrepreneur implementing self-supply. A power generation system is composed of a solar cell (PV) and a storage battery (a battery). The solar cell is connected to a power transmission grid via a DC / DC converter and a DC / AC converter. The same applies to the storage battery. An electric power control device 1 transmits operation instructions to a drive device of the solar cell and a drive device of the storage battery (each constituted by the converter described above), thereby controlling the respective operations of the solar cell and the storage battery. This is a case where both the plurality of solar cells and the plurality of storage batteries are arranged.

[0012] Fig. Figure 2 is a schematic diagram illustrating the manner in which self-delivery between sites is carried out. Site A contains the power generation system, which is Fig. 1(a) and Fig. 1(b). Power generated at site A is transmitted to site B via a high-voltage grid. The electric power control device 1 controls the transmitted power based on demand forecast data, measurement data of each facility, etc., according to a procedure to be described later. The electric power control device 1 includes a calculation unit 11 and a storage unit 12. These will be described later.

[0013] Fig. Figure 3 is a diagram describing an imbalance in transmitted power. Before performing self-delivery (e.g., the day before), the entrepreneur submits a delivery plan to an energy management organization, which describes the planned power to be delivered in units of, for example, 30 minutes. The planned power to be delivered is determined, for example, by subtracting a demand forecast from a power generation quantity forecast by the power generation system and multiplying the result by a coefficient (≤ 1.0). This coefficient is a coefficient for enabling the power generation system to have an operating capacity. In the present embodiment, it is referred to as a probability.By instructing the solar cell to produce power based on the result of multiplying the probability, the solar cell operates at an operating point to output less power than the maximum power point.

[0014] If the actual generated power exceeds the planned power to be delivered, the excess is compensated by suppressing the solar cell output below the maximum power point and charging the storage battery. If the actual generated power falls short of the planned power to be delivered, the shortfall is compensated by discharging the storage battery.

[0015] In order to grasp how much the output of the solar cell has been inhibited from the maximum power point (that is, how much power can be charged into the storage battery), it is necessary to obtain the maximum power point of the solar cell. The maximum power point of the solar cell is an operating point at which the product of voltage and current in the IV characteristics of the solar cell becomes maximum. However, since the IV characteristics vary depending on various factors, it is not always easy to grasp them accurately. Therefore, it is not always easy to accurately determine the maximum power point and the amount of suppression from the maximum power point. Furthermore, it is correspondingly difficult to judge whether the probability c is set approximately or not. This is because the probability c is set using the maximum power point as a reference.

[0016] In view of the above-described problems in the conventional self-supply system, the present invention aims to provide a technology that can accurately control the transmitted power during self-supply, thereby suppressing penalties associated with power transmission imbalance. First, a method for predicting the power generation amount of the power generation system (solar cell) will be described, followed by a method for controlling the power to be supplied using the power generation amount prediction.

[0017] Fig. 4A is a schematic diagram describing a method for estimating the amount of solar radiation (the expected amount of solar radiation) radiated to a solar cell. The electric power control device 1 acquires the results of measuring the output voltage and output current of the solar cell, for example, from an electric power conversion device (a DC-DC converter driving the solar cell, or the like). The electric power control device 1 uses the measurement results to estimate the expected amount of solar radiation to the solar cell. A method for estimating the expected amount of solar radiation will be described later.

[0018] Apart from that, the electric power control device 1 acquires a solar radiation amount forecast (or measurement results) from a weather information provider or the like. The electric power control device 1 learns a correspondence relationship between the solar radiation amount forecast and the expected solar radiation amount through machine learning or the like and stores the result thereof. Here, an example is shown in which the two have a correspondence relationship expressed by a linear function similar to that shown in Fig. 4A. In this case, the electrical power conversion device learns a coefficient every month, for example.

[0019] The solar radiation amount forecast provided by the weather information provider is the result of predicting (measuring) the amount of solar radiation in a specific area. On the other hand, it is conceivable that only a portion of the solar radiation amount is radiated to the solar cell. However, it is conceivable that the amount of solar radiation in an area and the amount of solar radiation to the solar cell have a correspondence relationship. By learning this relationship, the electric power control device 1 can estimate the expected amount of solar radiation applied to the solar cell from the solar radiation amount forecast. Fig. Figure 4A illustrates this.

[0020] Fig. Figure 4B is a schematic diagram showing a procedure for predicting the amount of power generated by a solar cell using learning results from Fig. 4A. The electric power control device 1 obtains the expected solar radiation amount by applying the solar radiation amount forecast obtained from the weather information provider to the learning result. The electric power conversion device substitutes the expected solar radiation amount into the following formula to calculate the power generation amount forecast E of the solar cell. E[kW]=K×PAS×IT,G÷GS K=K'⋅KPT⋅ed K': constant (arrangement loss 0.97) e d : Wear coefficient KPT=1+αPMAX⋅(TPA−25) / 100 α PMAX % / °C T PA : Battery temperature P AS : Nominal value I T,G : inclined solar radiation amount (expected solar radiation amount) G S : Standard solar radiation

[0021] Next, a description is given of the method for estimating the expected solar radiation amount. The expected solar radiation amount can be estimated using the same physical model and method as in Japanese Patent Application No. 2020-127908. This method is used to obtain the expected solar radiation amount by converting the operating characteristics of the solar cell into values ​​under the standard solar radiation amount and standard temperature. However, since the same method is used in the same application in the context of detecting partial wire breaks and partial shadows, the estimation method is described again in the present application.

[0022] Fig. Figure 5 illustrates an example of converting IV characteristics during normal operation into values ​​under a standard solar radiation level and a standard temperature. It is assumed that the solar cell operates at an operating voltage V PEand an operating current I PE works ( Fig. 5(a)). During normal operation, when the temperature of the solar cell is calculated by a procedure to be described later, the calculated temperature agrees well with the actual temperature of the solar cell ( Fig. 5(b)). Furthermore, if the operating voltage V PE and the operating current I PE into values ​​(V P0 , I P0 ) under the standard solar radiation quantity and the standard temperature (referred to as standard condition: STC) by the procedure to be described later, the converted values ​​are well with a standard operating current I 0P_ST and a standard operating voltage V 0P_ST , which are defined as product specification values ​​at standard solar radiation and standard temperature ( Fig. 5(c)).

[0023] Fig. Figure 6 illustrates an example in which an operating point at which the power generation amount is suppressed below the maximum power point is converted to a value under a standard solar radiation amount and a standard temperature. It is assumed that the solar cell operates at an operating voltage V PE and an operating current I PE works ( Fig. 6(a)). This operating point is suppressed more than the maximum power point. When the temperature of the solar cell is calculated by the procedure described later, the calculated temperature is lower than the actual temperature of the solar cell ( Fig. 6(b)). In this case, when the operating voltage V PE and the operating current I PE into values ​​(V P0 , I P0 ) under the standard solar radiation quantity and the standard temperature, the current conversion values ​​are less than a standard operating current I 0P_ST, which is defined as a product specification value for the standard solar radiation quantity and the standard temperature ( Fig. 6C).

[0024] It is conceivable that the difference between the maximum power point and the current operating point in the current IV characteristics can be determined by converting the maximum power point and the current operating point in the current IV characteristics into values ​​in the IV characteristics under the standard solar radiation amount and standard temperature (this conversion is called STC conversion) and identifying the difference between them. Specifically, a variable j is sought for which the operating point after STC conversion reaches the standard maximum power point while changing the ratio of an operating current to a short-circuit current (the variable j to be described later). By determining how much j has changed from the initial value, the difference between the current operating point and the maximum power point in the current IV characteristics can be expressed by the specified variable j.Furthermore, as described later, the expected amount of solar radiation can be determined in this process. These specific calculation procedures are described below.

[0025] Fig. Figure 7 is a flow chart describing a procedure for estimating a variable j and the expected amount of solar radiation. Each step in Fig. 7 is described below. The process of deriving a calculation formula in each step will be described later. Fig. 7 uses the following formula 1 as a basis. At a voltage V, a solar cell type, which is denoted by the number of cells as N cellconfigured can be expressed by the following formula 1. I: Output current of a solar battery cell [A], Is: Saturation reverse current of the diode [A], V: Output voltage of the solar battery cell [V], Isc: Short-circuit current [A], T: Absolute temperature of the solar battery cell [K], k: Boltzmann constant, q: Charge amount of an electron [C], nf: Junction constant and p: Amount of solar radiation [kW / m 2 ]. I=Isc⋅p−ls⋅{exp((q⋅(V / Ncell)) / (nf⋅k⋅T))} (Fig. 7: Step S701)

[0026] The electrical power control device 1 acquires measurement data that determine the operating voltage V PE and the operating current I PEof the solar cell. The solar cell referred to here is a battery, which is the subject of the diagnosis. The electric power control device 1 further acquires specification data describing specification values ​​of the solar cell. The specification data describes the following specification values. (a) Short-circuit current: I SC_ST , (b) Open circuit voltage: V OC_ST , (c) optimal operating current: I OP_ST , (d) optimal operating voltage: V 0P_STand (e) coefficients in a calculation formula described later: α and β. Here, α is the temperature characteristic of the short-circuit current [% / °C], and β is the temperature characteristic of the operating voltage [mV / °C]. The specification data can be obtained, for example, from the power conditioner or can be stored in advance in a storage device included in the electric power control device 1. They can also be acquired by other suitable means. (Fig. 7: Step S7O2)

[0027] The electrical power control device 1 initializes the short-circuit current I SC based on the specification value I SC_ST . (Fig. 7: Step S703)

[0028] Fig. Figure 7 assumes that a sensor that detects the amount of solar radiation on the solar cell and a sensor that detects the temperature of the solar cell are not used. Therefore, the electric power control device 1 calculates the expected amount of solar radiation p for the solar cell. The expected amount of solar radiation p can be expressed as the ratio of the short-circuit current during the current amount of solar radiation to the short-circuit current I SC_ST , during the standard solar radiation amount. Since the current operating current at the current solar radiation amount I PE the short-circuit current at the current solar radiation level can be calculated as I PE / j. Therefore, the expected solar radiation amount p is defined by (the short-circuit current at the current solar radiation amount) / I SC_ST, that is, the following formula 2. The use of this formula is useful when circumstances exist that make it impossible to identify the operating point at maximum power at the current amount of solar radiation. (Fig. 7: Step S7O3: Calculation formula) P=(IPE / j) / ISC_ST j = (operating current at the current operating point at the current solar radiation level) / (short-circuit current at the current solar radiation level) (Fig. 7: Step S704)

[0029] The electrical power control device 1 uses kT / q = 0.026 at 298 K in formula 1 to obtain an operating voltage V P at the expected solar radiation amount p and battery temperature T = 298 K according to the following formula. (Fig. 7: Step S7O4: Calculation formula) VP=nf⋅0.026⋅Ncell⋅ln(p)+Vop_ST (Fig. 7: Step S705)

[0030] The electric power control device 1 calculates the expected temperature T of the solar cell according to the following formula 7. β is generally a temperature characteristic of silicon and is about -2mV / K. (Fig. 7: Step S705: Calculation formula) T=298+(VPE−VP) / (Ncell⋅β) (Fig. 7: Step S706)

[0031] If the electric power control device 1 has repeated S703 to S705 a predetermined number of times or more (e.g., three times), it jumps to step S708. If the electric power control device 1 has not repeated them, it returns to step S703 after executing S707. (Fig. 7: Step S707)

[0032] The electrical power control device 1 updates the short-circuit current I SC according to the following formula and returns to step S703. (Fig. 7: Step S707: Calculation formula) ISC=ISC_ST⋅{1+(a⋅(T−298)) / 100} (Fig. 7: Step S708)

[0033] The device 1 for controlling electrical power sets the operating voltage V PE and the operating current I PE according to the following formulas into values ​​(V P0 , I P0 ) below the standard solar radiation level or the standard temperature. (Fig. 7: Step S708: Calculation formulas) VP0=(VPE−(Ncell⋅nf⋅0.026 / 298⋅T⋅ln(p)))−Ncell⋅β⋅(298−T) IP0={(IPE / j) / p⋅(1+α⋅(298−T) / 100)}⋅j (Fig. 7: Step S709)

[0034] The electrical power control device 1 determines whether I P0 , which was calculated in S708, is greater than the standard operating current I OP_ST is or not. If I OP_ST is greater than that, the electric power control device 1 decreases j and returns to S703. If not (ie, when I P0 and I OP_SThave reached a point where they are substantially consistent), this schedule will be terminated. (Fig. 7: Steps S703 and S709: Supplement)

[0035] The initial value of j in S703 is taken as a value assuming that the maximum power point in the current IV characteristics (the second white circle from the bottom in Fig. 6C). Decreasing j corresponds to moving closer to the current operating point from the maximum power point in the current IV properties and corresponds to moving closer to the standard maximum power point in the IV properties after an STC implementation. <Erste Ausführungsform: Herleitungsprozess der Berechnungsformel in S704>

[0036] In Formula 1, if I SC = I SC_ST , kT / q = 0.026 at 298 K and I = I SC_ST · p · j are used, F SC V P can be expressed by the following formula 3. VP=nf⋅0.026⋅ln(((1−j)⋅ISC_ST⋅p) / lS)

[0037] The standard operating voltage V OP_ST at p = 1.0 is expressed by the following formula 4. VOP_ST=nf⋅0.026⋅ln(((1−j)⋅ISC_ST) / IS)

[0038] Subtracting formula 4 from formula 3 to calculate the voltage difference yields the following formula 5. VP−VOP_ST=nf⋅0.026⋅ln(p)

[0039] Therefore, the following formula 6 can be derived. This formula 6 is used in S704. VP=(VP−VOP_ST)+VOP_ST=nf⋅0.026⋅ln(p)+VOP_ST <Erste Ausführungsform: Herleitungsprozess der Berechnungsformel in S708>

[0040] The STC has a solar radiation amount of 1.0kW / m 2 and a temperature of 298 K. If a saturation reverse current at temperature T is equal to I S_T , formula 3 is converted to obtain formulas 8 and 9, which are described below. PU=nf⋅0.026 / 298⋅T⋅ln(((1−j)⋅Isc⋅p) / IS_T) VP1=nf⋅0.026 / 298⋅T⋅ln(((1−j)⋅ISC) / IS_T)

[0041] Subtracting formula 9 from formula 8 yields the following formula 10. VPE−VP1=nf⋅0.026 / 298⋅T⋅ln(p)

[0042] Therefore, V P1 can be expressed by the following formula 11. VP1=VPE−(VPE−VP1)=VPE−nf⋅0.026 / 298⋅T⋅ln(p)

[0043] If V P1 in V P0 at room temperature, the following formula 12 is obtained. Substituting formula 11 into formula 12 yields the calculation formula in S708. VP0=VP1−β⋅Ncell⋅(298−T)

[0044] After calculating V P0 becomes I P0 determined. I SC at temperature T is expressed by the following formula 13. ISC=(IPE / j) / p

[0045] If I SC to I SCO at room temperature, the following formula 14 is obtained. ISC0=((IPE / j) / p)⋅(1+α⋅(298−T) / 100)

[0046] Therefore, I P0 expressed by the following formula 15. This formula 15 is used in S708. IP0=ISC0⋅j=j⋅((IPE / j) / p)⋅(1+α⋅(298−T) / 100)

[0047] Fig. Figure 8 is a flowchart describing a procedure by which the electric power control device 1 suppresses a power transmission imbalance during the implementation of self-supply. For example, the present flowchart may be executed in the same time interval as S801 during the period in which self-supply is executed. Each step in Fig. 8 is described below. (Fig. 8: Step S801)

[0048] The electric power control device 1 acquires power demand forecast data and power generation forecast data. These data are acquired at each time interval (30 minutes in this example) where it is necessary to describe a delivery schedule. The power demand forecast data can be, for example, from a power transmission destination (a location B in Fig. 2). The power generation forecast data can be collected according to the method described in Fig. 4A and Fig. 4B is described. (Fig. 8: Step S802)

[0049] The electric power control device 1 subtracts the demand forecast from the power generation forecast and multiplies the subtraction result by the probability c to thereby calculate the planned supply power. The planned supply power is calculated at the same time interval as in S801. (Fig. 8: Step S803)

[0050] The electric power control device 1 acquires the solar cell output voltage, solar cell output current, and power demand data. The data acquired in this step are actually measured values ​​at time intervals shorter than those in S801 (1 minute in this example). In other words, the present flowchart is for implementing control using electric power instead of power quantity by implementing the following steps using instantaneous power values ​​every minute. (Fig. 8: Step S804)

[0051] The electric power control device 1 calculates a supply result for each time interval in S803 based on the data acquired in S803. Specifically, the supplied power can be calculated by subtracting the power demand in that time interval from the result of multiplying the output voltage of the solar cell and the output current of the solar cell. (Fig. 8: Step S805)

[0052] The electric power control device 1 detects a SOC (state of charge) and C-rate constraints of the storage battery, e.g., from a battery management unit (BMU). The electric power control device 1 uses these values ​​to determine a threshold for when the storage battery is charged or discharged during the delivery time. For example, the upper and lower limits of the SOC determine constraints (thresholds) of the capacity of the storage battery after charging and discharging, and the upper and lower limits of the C-rate constraints (thresholds) determine the rate at which the storage battery is charged and discharged (i.e., the power input and output to and from the storage battery during charging and discharging operations).For example, in the case where the storage battery fails, if the entire amount of surplus power generated by the solar cell is used to charge the storage battery, the upper limit constraint of the charging rate C-Rate can be used. (Fig. 8: Step S806)

[0053] The electric power control device 1 compares the planned supply power calculated in S802 and the supply result power calculated in S804. If the planned supply power is larger, the electric power control device 1 proceeds to S807; otherwise, it proceeds to S808. (Fig. 8: Step S807: Part 1)

[0054] The electric power control device 1 determines the result of subtracting the delivery result power from the planned delivery power as the electric power to be delivered from the storage battery. Consequently, a deficit in the power actually generated by the solar cell is compensated by discharging the storage battery. However, if the calculated discharge power exceeds the discharge power threshold determined in S805, the discharge power is set to the discharge power threshold. In this case, the power to be delivered from the storage battery is in short supply. The power shortage is determined by subtracting the discharge power threshold from the calculated discharge power. (Fig. 8: Step S807: Part 2)

[0055] The electric power control device 1 further determines the output power of the solar cell. In this step, since the power generated by the solar cell is insufficient compared to the planned output power, it is necessary to increase the output power of the solar cell. Since the remaining part after subtracting the power demand from the solar cell output is planned for delivery, it is necessary to set the result of adding the demand to the planned output power as the solar cell output in order to meet the planned output power. (Fig. 8: Step S808)

[0056] In the present step, the output power is greater than the planned output power, that is, the solar cell has an excess of output power. This corresponds to the solar cell operating at an output power lower than the maximum power point. Therefore, the electric power control device 1 calculates the output power (hereinafter referred to as the possible power) that is assumed to be further outputtable by the solar cell operating at the maximum power point. The possible power can be obtained by obtaining the maximum power point in the process of implementing the schedule of Fig. 7. Therefore, the electric power control device 1 calculates the possible power by implementing the schedule of Fig. 7. A specific calculation procedure will be described later. (Fig. 8: Step S809: Part 1)

[0057] The electric power control device 1 determines the result of subtracting the planned power to be delivered from the delivered power and adding the possible power as the power to be charged to the storage battery. Thus, the surplus power actually generated by the solar cell can be consumed by charging the storage battery. However, if the calculated charging power exceeds the charging power threshold determined in S805, the charging power is set to the charging power threshold. In this case, even if the storage battery is charged, surplus power will still be generated. The surplus power is obtained by subtracting the charging power threshold from the calculated charging power. The surplus power is discarded. (Fig. 8: Step S809: Part 2)

[0058] The electric power control device 1 determines the output power of the solar cell. In this step, since there is a possibility that the solar cell has excess power generation, the output power is determined taking the excess power generation into account. In order to meet the planned power to be supplied, it is necessary to set at least the result of adding the demand to the planned power to be supplied as the output of the solar cell. Furthermore, the result of adding the excess power (the possible power in S808) is set as the solar cell output. (Fig. 8: Step S810)

[0059] The device 1 for controlling electrical power comprises the control device of the solar cell (the device which in the example corresponds to each of Fig. 1A and Fig. 1B consists of the converter) to take the output power determined in S807 or S808 as an instruction value. The electric power control device 1 further instructs the storage battery drive device (the device which, in the example, is each of Fig. 1A and Fig. 1B consists of the converter) to take the charge / discharge power determined in S807 or S808 as a charge / discharge instruction value. (Fig. 8: Steps S811 and S812)

[0060] The electric power control device 1 repeatedly executes S803 to S810 until the time interval of the delivery schedule (in this example, 30 minutes) is reached. When it is reached, the insufficient power supplied by the storage battery (when S807 is performed) or the surplus power remaining after charging the storage battery (when S808 is performed) is recorded. <Erste Ausführungsform: Details von S808)

[0061] The electric power control device 1 determines the operating point (I'p, V'p) after STC implementation when the output of the solar cell is inhibited, according to the following calculation formulas. This operating point is determined by subjecting the lower white circle in Fig. 6(c) to an STC implementation. In the calculation formulas, j is a variable j, which is determined by the schedule in Fig. 7. Here, j0 is the ratio of the operating current at the maximum power point at the standard solar radiation and temperature to the short-circuit current at the standard solar radiation and temperature. Furthermore, r is the ratio between the maximum power and the current operating power when converted to the standard solar radiation and temperature. The potential power can be calculated by multiplying the operating power (IpE × VpE) before STC implementation by this ratio. However, in the present schedule, since the potential power is obtained as the amount inhibited by the maximum power (the difference between the maximum power and the current power), it is multiplied by (r - 1) in this calculation formula. I'p=Isc_st×j V'p=nf⋅0.026⋅Ncell⋅ln((Isc_st⋅(1−j) / (Isc_st⋅(1−j0))+Vop_st j0=Iop_st / Isc_st r=(Iop_st×Vop_st) / (I'p×V'p) possible power=(IpE×VpE)×(r−1) I sc_st : Short-circuit current at standard solar radiation and standard temperature l op_st : Battery current at maximum power point at standard solar radiation and standard temperature V op_st : Battery voltage at maximum power point at standard solar radiation and standard temperature

[0062] Fig. Figure 9 is a flowchart describing a procedure for determining the probability c. The penalty for failing to fulfill the delivery plan is particularly high when the actual transmission power is insufficient compared to the planned power. Therefore, this flowchart seeks the probability c that does not cause such a power shortage. This flowchart may, for example, be executed during a period when the electric power control device 1 is not performing self-delivery. For example, this may be performed every time all the data acquired in S902 and S903 have been accumulated for a predetermined number of days. Each step in Fig. 9 is described below. (Fig. 9: Steps S901 to S903)

[0063] The electric power control device 1 initializes the number of repetitions m (S901). The electric power control device 1 acquires weather forecast data for each delivery period x1 to xN. The electric power control device 1 acquires the expected solar radiation amount (S902) and the power generation forecast (S903) for each delivery period using the method described in Fig. 4A and Fig. 4B is described. (Fig. 9: Step S904)

[0064] The electrical power control device 1 executes the schedule of Fig. 8 for each delivery period. Based on the result of its execution, the electric power control device 1 determines the shortage of power output by the solar cell during the delivery period and adds them together. The electric power control device 1 increases the number of repetitions m. The electric power control device 1 repeatedly increases the probability c (e.g., by 0.01) and returns to S904 until m reaches a predetermined number. (Fig. 9: Step S904: Addition)

[0065] In this step, instead of increasing the probability c or additionally the coefficients (slope a and an intercept b in the example of Fig. 4A), which describe the learning outcomes that are Fig. 4A. This allows the search scope to be further expanded. (Fig. 9: Step S905)

[0066] In the process of repeating S904, the electric power control device 1 sets the probability c when the total value of power shortages goes from a positive value to 0. For example, when c = 0.90, the power shortage is a small positive value, and when c = 0.91, the power shortage reaches 0. The electric power control device 1 uses this c as the probability. As long as there is no power shortage, such a c can be assumed that the amount of power generated by the solar cell is in excess. (Second embodiment>

[0067] The electric power control device 1 described in the first embodiment may include the calculation unit 11 that performs the operations described in Fig. 3 to Fig. 8. The calculation unit 11 may also be configured using hardware such as a circuit device that implements its function, or may also be configured by causing a calculation device such as a CPU (central processing unit) to execute software that implements the function. The electric power control device 1 may further include a storage unit 12 that stores a history of all the data (e.g., power generation amount forecast data, demand data, demand forecast data, etc.) described in the first embodiment.

[0068] Fig. 10A to Fig. 10C are examples of the user interface provided by the electric power control device 1. The user interface can be displayed by the calculation unit 11 on a display device such as a display or the like. The user interface can, for example, display numerical values ​​for the planned power to be delivered and the delivery result for each delivery period ( Fig. 10A), accurate graphs describing their changes over time ( Fig. 10B to Fig. 10C) etc. Furthermore, the performance deficiency and the surplus performance can also be illustrated (performance deficiency in Fig. 10B and discarded power in Fig. 10C). <Abwandlung der vorliegenden Erfindung>

[0069] It should be noted that the present invention is not limited to the above-described embodiment and includes various modification embodiments. For example, the above-described embodiments have been described in detail to simply describe the present invention and do not necessarily include all of the described configurations. In addition, part of the configuration of one embodiment may be replaced with the configurations of other embodiments, and in addition, the configuration of one embodiment may also be supplemented with the configurations of other embodiments. In addition, part of the configuration of each of the embodiments may be subject to addition, deletion, and replacement with respect to other configurations. List of reference symbols 1 device for controlling electrical power 11 Calculation unit 12 storage units QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-127908 [0005, 0021] JP 2021-141769

[0005] JP 2020-058141

[0005]

Claims

[1] An electric power control device that controls the transmitted power when power generated by a power generation system comprising a solar cell and a storage battery is transmitted between locations by means of a power transmission network, the electric power control device comprising: a calculation unit that calculates the transmitted power, where the calculation unit records a planned power representing the power that is planned to be output by the power generation system to the power transmission network during a power transmission period in which the power transmission is carried out, the calculation unit records an actual resulting power, which represents the power output by the power generation system to the power transmission network during the power transmission period, the calculation unit of power to be absorbed or delivered by the storage battery is calculated based on a difference between the planned power and the actual resulting power during the power transfer period, and the calculation unit calculates the power that the solar cell must generate during the power transmission period based on the difference. [2] An electric power control device according to claim 1, wherein the calculation unit records the power demand during the power transmission period, the calculation unit subtracts the power requirement from the result of multiplying an output voltage of the solar cell and an output current of the solar cell to calculate the actual resulting power, and then, if the planned power is greater than the actual resulting power, the calculation unit determines the difference between the planned power and the actual resulting power as the power to be delivered by the storage battery. [3] An electric power control device according to claim 1, wherein the calculation unit records the power demand during the power transmission period, the calculation unit subtracts the power requirement from the result of multiplying an output voltage of the solar cell and an output current of the solar cell to calculate the actual resulting power, and then, if the actual resulting power is greater than or equal to the planned power, the calculation unit power to be absorbed by the storage battery is determined based on the difference between the actual resulting power and the planned power. [4] An electric power control device according to claim 3, wherein the calculation unit calculates a first difference between the actual resulting performance and the planned performance, the calculation unit calculates a second difference between the maximum power that the solar cell can generate and the power actually generated by the solar cell, and the calculation unit adds the second difference to the first difference to determine the power to be absorbed by the storage battery. [5] An electric power control device according to claim 4, wherein the calculation unit performs a convergence calculation while changing an operating current of the solar cell such that the converted maximum power obtained by converting the maximum power into a value assuming that the solar cell operates under a standard solar radiation amount and a standard temperature and the converted actual generated power obtained by converting the actual generated power into a value assuming that the solar cell operates under a standard solar radiation amount and a standard temperature agree with each other, and the calculation unit calculates the second difference using the operating current of the solar cell obtained in the process of convergence calculation. [6] An electric power control device according to claim 5, wherein the calculation unit performs the convergence calculation while changing a first ratio of an operating current of the solar cell to a short-circuit current of the solar cell to determine the first ratio at which the converted maximum power and the converted actual generated power agree, the calculation unit determines a second ratio of an operating current of the solar cell to a short-circuit current of the solar cell when the solar cell operates at the maximum power point at the standard solar radiation amount and the standard temperature, the calculation unit calculates the converted actual generated power using the first ratio obtained by the convergence calculation and the second ratio, the calculation unit calculates a third ratio between the maximum power converted and the actual generated power converted using the first and second ratios, and the calculation unit applies the third ratio to the solar cell output current and the solar cell output voltage to calculate the second difference. [7] An electric power control device according to claim 1, wherein the calculation unit calculates an expected amount of solar radiation for the solar cell using the output voltage of the solar cell and the output current of the solar cell, the calculation unit sets a result of estimating the temperature of the solar cell as an expected temperature and the calculation unit predicts the amount of power generated by the solar cell using the expected amount of solar radiation and the expected temperature to calculate the designed power. [8] An electric power control device according to claim 7, wherein the calculation unit converts the output voltage of the solar cell and the output current of the solar cell into a converted standard current and a converted standard voltage, which were converted into values ​​under the assumption that the solar cell operates under a standard amount of solar radiation and a standard temperature, and the calculation unit repeats the conversion until the difference between a standard current when the solar cell operates under the standard solar radiation amount and the standard temperature and the converted standard current converges to determine the expected solar radiation amount and the expected temperature. [9] An electric power control device according to claim 1, wherein the calculation unit calculates an expected amount of solar radiation for the solar cell using the output voltage of the solar cell and the output current of the solar cell, the calculation unit records a measured value of the amount of solar radiation, the calculation unit learns a correspondence relationship between the expected amount of solar radiation and the measured value, the calculation unit applies the newly acquired measured value to the learned correspondence relationship to set a result of predicting the amount of solar radiation irradiated to the solar cell as a predicted amount of solar radiation, and the calculation unit calculates the planned power by predicting an amount of power generated by the solar cell using the predicted amount of solar radiation. [10] An electric power control device according to claim 1, wherein the calculation unit subtracts the power demand during the power transmission period from the predicted power generation amount of the solar cell during the power transmission period to calculate a candidate value of the planned power, the calculation unit calculates a difference between the planned power and the actual resulting power using a result of multiplying the planned power by a coefficient representing a rate at which the power generation capacity of the solar cell is inhibited, the calculation unit searches for the coefficient that can compensate for the difference between the planned power and the actual resulting power by discharging the storage battery, and the calculation unit calculates the power to be delivered by the storage battery using the desired coefficient. [11] An electric power control device according to claim 10, wherein the calculation unit calculates an expected amount of solar radiation for the solar cell using the output voltage of the solar cell and the output current of the solar cell, the calculation unit records a measured value of the amount of solar radiation, the calculation unit learns a correspondence relationship between the expected amount of solar radiation and the measured value, the calculation unit applies the newly acquired measured value to the learned correspondence relationship to determine a result of predicting the amount of solar radiation irradiated onto the solar cell as a predicted amount of solar radiation, the calculation unit calculates the planned power by predicting an amount of power generated by the solar cell using the predicted amount of solar radiation, and the calculation unit searches for the coefficient while changing the correspondence relationship. [12] The electric power control apparatus according to claim 10, further including a storage unit that stores data describing a history of each of the predicted power generation amount and the power demand, wherein the calculation unit performs the search again each time the data have been accumulated for a predetermined number of days. [13] An electric power control device according to claim 1, wherein the calculation unit outputs a user interface and the user interface is configured to display the following: the planned performance and / or the actual resulting performance and / or the power required by the storage battery to charge or discharge during the power transfer period, and / or the power that the solar cell must generate during the power transfer period.

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