JP2018014795A - Power distribution control system and power distribution control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power distribution control system capable of suppressing a reduction in power conversion efficiency even when the power generation amount of a photovoltaic power generation device increases or decreases.SOLUTION: The power distribution control system includes: a power generation amount acquisition unit that acquires a power generation amount generated by a photovoltaic power generation device; and a power control unit that compares the obtained power generation amount with a reference value, and, when the power generation amount is less than the reference value, determines that the generated power is to be supplied to a DC load side, and, when the power generation amount is equal to or higher than the reference value, determines that the electric power is converted into an alternating current by the electric power conversion device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power distribution control system and a power distribution control method.

  Houses equipped with photovoltaic (Photovoltaic) and storage batteries are increasing. The DC power generated by PV is converted to AC power, which is used in-house or flows backward to the grid via a distribution board.

  In such power conversion between direct current and alternating current, a converter or a power conditioner is used. The following Patent Document 1 describes a power distribution system that suppresses power conversion loss or performs maximum power point tracking control by not performing power conversion twice or more when using a converter or power conditioner. ing. Patent Document 2 below describes a storage battery control device that determines a charging / discharging schedule for a storage battery in consideration of the efficiency of power conversion and the price of power in an inverter of the storage battery.

Japanese Patent No. 5756903 Japanese Patent Laid-Open No. 2006-63629

  However, since PV generates power using sunlight as an energy source, the amount of power generation depends greatly on the solar radiation situation. The power conditioner is installed according to the maximum power generation of PV. Therefore, when the power generation amount is not sufficient, the conversion efficiency of the power conditioner may be reduced.

On the other hand, in a house provided with a solar power generation device and a storage battery, the total amount of power generated per day may exceed the capacity of the storage battery, particularly in periods of low demand such as air conditioning. In recent years, an integrated power conditioner that is used for both PV and storage batteries with a single power conditioner has come out. In this product, the power generated by PV is sent to the storage battery as DC and charged, so the conversion efficiency is greatly improved compared to the existing product that charges by converting from DC to AC and from AC to DC again. .
However, even when such an integrated power conditioner is used, when the PV generated power exceeds the input power of the storage battery and overflows from the direct current to the alternating current, or after the storage battery is fully charged If the power generation amount is insufficient, the conversion efficiency when converting from direct current to alternating current is reduced.

  The present invention has been made in view of such circumstances, and the object thereof is to suppress power loss due to reduction in power conversion efficiency even when the amount of power generated by a solar power generation device increases or decreases. A power distribution control system and a power distribution control method are provided.

  In order to solve the above-described problem, the present invention compares a power generation amount acquisition unit that acquires a power generation amount generated by a solar power generation device, the acquired power generation amount and a reference value, and the power generation amount is When it is less than the reference value, it is determined that the generated power is supplied to the DC load side, and when the power generation amount is not less than the reference value, the power is converted into AC by a power conversion unit. It has an electric power control part which judges with a reverse power flow.

  Further, in the power distribution control system according to the present invention, when the power generation amount is equal to or greater than the reference value, the power control unit generates at least a part of the generated power exceeding the reference value. It determines with supplying to the DC load side, and determines with converting the remaining generated electric power into alternating current.

  Further, the present invention provides the above power distribution control system, further comprising a power storage device, wherein the power control unit is a case where the power generation amount is less than the reference value, and an AC load to be supplied is configured to reduce the power generation amount. When exceeding, it determines with supplying the electric power discharged from the said electrical storage apparatus and the electric power according to the said electric power generation amount to the said alternating current load.

  Further, the present invention provides a power storage device, a required power prediction unit that obtains a required power amount that is required for storing power in the power storage device, and power generation generated by the solar power generation device in the power distribution control system described above. A power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the amount, and the power control unit, based on the required power amount and the predicted power generation amount when the power generation amount exceeds the reference value Then, the power storage device is charged so as to reach the target charge amount by a predetermined time.

  Further, the present invention provides a power storage device, a required power prediction unit that obtains a required power amount that is required for storing power in the power storage device, and power generation generated by the solar power generation device in the power distribution control system described above. A power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the amount, and the power control unit, based on the required power amount and the predicted power generation amount when the power generation amount exceeds the reference value Then, a part of the power generation amount is stored in the power storage device to perform peak cut of the reverse flow power amount.

  Further, according to the present invention, in the power distribution control system described above, when the power control unit is not connected to a power distribution network, the power control unit supplies the generated DC power to the DC load regardless of the power generation amount.

  In the power distribution control system according to the present invention, the reference value is a conversion efficiency reference value indicating a reference of power conversion efficiency of the power conversion unit, and the power control unit is configured to calculate the acquired power generation amount. The power conversion efficiency of the corresponding power conditioner is compared with the conversion efficiency reference value.

  Further, according to the present invention, in the power distribution control system described above, the reference value is a plurality of reference values that differ depending on a charge / discharge state of the power storage device, and the power control unit performs charge / discharge of the power storage device. Based on the past history, a reference value corresponding to the charge / discharge state corresponding to the past history is compared with the power generation amount.

  Further, according to the present invention, in the power distribution control system described above, the reference value is a plurality of reference values that differ depending on a deterioration state of the power storage device, and the power control unit detects a deterioration state of the power storage device. Based on the detection result, a reference value corresponding to the deterioration state indicated by the detection result is compared with the power generation amount.

  Further, the present invention includes a power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device in the above distribution control system, and the reference value is a prediction A plurality of reference values that differ depending on the generated power generation amount, and the power control unit, based on the predicted power generation amount obtained by the power generation amount prediction unit, the predicted power generation amount according to the predicted power generation amount Is compared with the power generation amount.

  Moreover, in the above-described power distribution control system, the present invention includes a power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device, and the reference value is the A plurality of different reference values are set according to the difference between the power generation amount generated by the solar power generation device and the predicted power generation amount, and the power control unit includes the power generation amount generated by the solar power generation device and the power generation amount A difference between the predicted power generation amount obtained by the power generation amount prediction unit is calculated, and the reference value corresponding to the calculated difference is compared with the power generation amount.

  Further, according to the present invention, in the power distribution control system described above, the first reference value that is a reference value according to the power conversion efficiency of the power conversion unit, the charge / discharge state of the power storage device, the deterioration state of the power storage device, solar power generation Reference value storage that stores a second reference value group that is a plurality of reference values that differ depending on the state of the second item, which is one of the reference value items of the predicted value of the amount of power generated by the device. The power control unit acquires the first reference value and determines whether there is a second reference value corresponding to an acquisition result corresponding to a second item in the second reference value group When there is the second reference value, the second reference value is compared with the power generation amount, and when there is no second reference value, the first reference value is compared with the power generation amount. To do.

  In the present invention, the power generation amount acquisition unit acquires the power generation amount generated by the solar power generation device, the power control unit compares the acquired power generation amount with a reference value, and the power generation amount is When it is less than the reference value, it is determined that the generated power is supplied to the DC load side. When the power generation amount is equal to or greater than the reference value, it is determined that the power is converted into AC by a power converter. This is a power distribution control method.

  As described above, according to the present invention, it is possible to reduce power conversion loss even when the power generation amount of the solar power generation apparatus increases or decreases.

It is a schematic block diagram which shows the structure of the power distribution control system in 1st Embodiment of this invention. It is a figure which shows an example of the power conversion efficiency data memorize | stored in the memory | storage part. 4 is a flowchart for explaining the operation of the power distribution control system 1. It is a figure explaining the power conversion in the power distribution control system 1 in 2nd Embodiment. It is a figure explaining the power conversion in the power distribution control system 1 in 4th Embodiment. It is a figure explaining the power conversion in the power distribution control system 1 in 5th Embodiment. It is a figure explaining the electric power generation amount in 6th Embodiment, and the electric energy converted into alternating current electric power. It is a figure explaining the electric power generation amount in 6th Embodiment, and the electric energy converted into alternating current electric power. It is a figure explaining the charge plan drawn up according to the weather which the weather forecast information on the day for prediction shows. It is a figure explaining the case where it charges by the green mode, and the case where it charges by the power distribution control system.

Hereinafter, a power distribution control system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic block diagram showing a configuration of a power distribution control system according to the first embodiment of the present invention.
The power distribution control system 1 includes a solar power generation device 10, a power conditioner (PCS) 11, a power storage device 12, a prediction unit 13, a storage unit 14, a power control unit 15, and a distribution board 16.
The solar power generation device 10 receives sunlight to generate power.
The PCS 11 has a function of supplying DC power generated by the solar power generation device 10 to a DC load (for example, the power storage device 12), and converts DC power generated by the solar power generation device 10 into AC power. It has a function of supplying to the switchboard 16 and a function of converting DC power supplied from the power storage device 12 into AC power and supplying it to the distribution board 16. The PCS 11 executes these power supply functions based on an instruction from the power control unit 15. An integrated power conditioner can be used as the PCS 11.

  The power storage device 12 charges the power supplied from the PCS 11 during power storage, and discharges the charged power to the PCS 11 during discharge. The power storage device 12 only needs to be able to store electric power. For example, a storage battery, an electric double layer capacitor, a flywheel battery, or the like can be used.

The prediction unit 13 includes a necessary power prediction function for obtaining a required power amount that is the amount of power that needs to be stored in the power storage device 12, and power generation for obtaining a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device 10. A quantity prediction function.
The storage unit 14 stores a reference value. This reference value is a value indicating the reference of the power generated by the solar power generation device 10. Further, as this reference value, a conversion efficiency reference value representing a reference of power conversion efficiency of the power conditioner 11 can be used. In addition, the storage unit 14 stores power conversion efficiency data representing the relationship between the power conversion efficiency of the PCS 11 and the generated power of the solar power generation device 10.
FIG. 2 is a diagram illustrating an example of power conversion efficiency data stored in the storage unit 14. The horizontal axis is the generated power of the photovoltaic power generation apparatus 10, and the vertical axis is the power conversion efficiency indicating the conversion efficiency when converting the DC power of the PCS 11 to the AC power. Here, the power conversion efficiency of the PCS 11 tends to increase from 0 until the generated power reaches a (W), but the power conversion efficiency is lower than that when the generated power is a (W) or more. When power is converted from direct current to alternating current, power loss is large. On the other hand, when the generated power is a (W) or more, the power conversion efficiency of the PCS 11 is η1 or more, and the increase / decrease is moderate compared to the case where the generated power is less than a (W). Thus, when the generated power of the solar power generation device 10 is a (W) or more, in a state of a predetermined power conversion efficiency (η1) or more, DC power can be converted to AC power, It is possible to perform power conversion in a state where power loss is reduced as compared with the case where the generated power is less than a (W). On the other hand, when the generated power is less than a (W), the power is stored in the power storage device 12 as the direct current power without converting the direct current power to the alternating current power. Therefore, the memory | storage part 14 memorize | stores the generated electric power (for example, a (W)) which reaches more than predetermined power conversion efficiency. Moreover, you may make it memorize | store power conversion efficiency (for example, (eta) 1).

  Returning to FIG. 1, the power control unit 15 uses the measurement result obtained by measuring the DC power input from the solar power generation device 10 to the PCS 11 in the PCS 11 as the power generation amount generated by the solar power generation device 10. Get from. In addition, the power control unit 15 compares the acquired power generation amount with the reference value stored in the storage unit 14, and when the power generation amount is less than the reference value, the generated power is transferred from the PCS 11 to a DC load (for example, If the power generation amount is greater than or equal to the reference value, it is determined that the power is converted into AC by the PCS 11, and the determination result is given to the PCS 11. The power conversion is performed accordingly.

  In response to an instruction from the power control unit 15, the distribution board 16 causes power to flow backward through the system or supplies power to the indoor load.

FIG. 3 is a flowchart for explaining the operation of the power distribution control system 1.
The power control unit 15 acquires the power generation amount of the solar power generation apparatus 10 from the PCS 11 (step S101), and compares the obtained power generation amount with a reference value indicating a reference of power stored in the storage unit 14 (step S101). S102). When the power generation amount is equal to or greater than the reference value (step S103—YES), the power control unit 15 outputs an instruction to the PCS 11 to convert the generated power into AC power. In accordance with this instruction, the PCS 11 converts the DC power supplied from the solar power generation device 10 into AC power and supplies the AC power to the distribution board 16 (step S104).
On the other hand, when the generated power is less than the reference value (step S103—NO), the power control unit 15 outputs an instruction for causing the power storage device 12 to output the generated power to the PCS 11. In accordance with this instruction, the PCS 11 supplies DC power supplied from the solar power generation device 10 to the power storage device 12 (step S105). For example, in the PCS 11, the voltage level of the DC power output from the solar power generation device 10 is a voltage level at which the power storage device 12 can be charged, and the DC power output from the solar power generation device 10 is stored as it is. The power storage device 12 is charged by being supplied to the device 12.

The power control unit 15 waits for a certain period of time (step S106) to determine whether a predetermined time has elapsed (step S107). If the predetermined time has not elapsed (step S107-YES), The process proceeds to S106.
On the other hand, when the predetermined time has elapsed (NO in step S107), the power control unit 15 determines whether or not to end the power control (step S108), and when not ending the power control (step S108). -NO), the process proceeds to step S101, the amount of power generation is acquired, and if the power control is to be ended (step S108-YES), this processing flow is ended.

  As described above, the power control unit 15 determines whether to acquire the amount of power every predetermined time and compare it with the reference value to convert to AC power or to supply it to the power storage device 12. Even if the weather in the vicinity of the power generation device 10 changes, it can be determined whether to supply to the power storage device 12 or convert to AC power according to the amount of power that changes with the change in the weather. As a result, even if the power generation amount changes due to a change in weather, if the power loss due to power conversion becomes larger than a predetermined amount according to the power generation amount, the power storage device 12 is not converted into AC power. When the battery is charged and the power loss accompanying power conversion is less than or equal to a predetermined value, it can be converted into AC power and supplied to the distribution board 16 side. As described above, when the power generation amount is small and the power loss due to power conversion is large, it is not converted to AC power, and it is more effective to store power in the power storage device 12 even with a small power generation amount. Can be used.

Next, another embodiment in the above-described power distribution control system 1 will be described. The configuration of another embodiment of the power distribution control system 1 to be described below is basically the same as the configuration shown in FIG. 1, but the control method is partially different, so the difference will be described.
(Second Embodiment)
In the first embodiment, the PCS 11 supplies and charges the direct current power obtained from the solar power generation device 10 to the power storage device 12 as it is. However, in the second embodiment, the PCS 11 is obtained from the solar power generation device 10. The direct current voltage level is converted into a predetermined voltage level, and the direct current power is supplied to the power storage device 12 for storage. When the voltage level of the electric power output from the solar power generation device 10 has not reached the voltage level that can be stored in the power storage device 12, it functions as a DC / DC converter in this way, thereby the power storage device 12 Can be charged. When performing this DC / DC power conversion, it is preferable to use a circuit configuration that reduces the loss of the power conversion.
FIG. 4 is a diagram illustrating power conversion in the power distribution control system 1 according to the second embodiment. The vertical axis is the amount of power generation, and the horizontal axis is time. When the power generation amount is equal to or greater than the reference value, the power control unit 15 causes the DCS obtained from the solar power generation device 10 to be DC / AC converted by the PCS 11 and output as AC power, thereby generating the power generation amount. Is less than the reference value, DC / DC conversion is performed on the DC power obtained from the solar power generation device 10 by the PCS 11 to output the DC power as the DC power, and the power storage device 12 is charged.

(Third embodiment)
In 1st Embodiment, although the electric power control part 15 demonstrated the case where the electric power generation amount of the solar power generation device 10 and a reference value were compared, in 3rd Embodiment, power conversion efficiency is used as a reference value. A reference value (for example, η 1 shown in FIG. 2) is stored in the storage unit 14. Then, when the measurement value of the power generation amount is obtained, the power control unit 15 reads the power conversion efficiency corresponding to the measured generated power based on the relationship between the power conversion efficiency and the generated power shown in FIG. . And the power control part 15 compares the power conversion efficiency according to electric power generation amount with a reference value, and when the power conversion efficiency according to electric power generation amount is more than a reference value, it is output from the solar power generation device 10. When the DC power is converted into AC power by the PCS 11 and the power conversion efficiency corresponding to the amount of power generation is less than the reference value, the DC power output from the solar power generation device 10 is supplied to the power storage device 12. To store electricity.

(Fourth embodiment)
In the first embodiment, the power control unit 15 supplies all the generated power from the solar power generation device 10 to the power storage device 12 as DC power, or supplies it to the distribution board 16 as AC power and reverses it. I tried to control the tide. In the fourth embodiment, when the power generation amount is equal to or greater than the reference value, the power control unit 15 performs at least a part of the power generation amount that exceeds the reference value when the power generation amount is equal to or greater than the reference value. It is determined that the generated power is supplied to the DC load side, and it is determined that the remaining generated power is converted to AC. FIG. 5 is a diagram illustrating power conversion in the power distribution control system 1 according to the fourth embodiment. The vertical axis is the amount of power generation, and the horizontal axis is time. For example, when the power generation amount is equal to or greater than a reference value, the power control unit 15 supplies the power exceeding the reference value to the DC load, and the power less than the reference value is converted from the DC power to the AC power by the PCS 11. Control to convert to electric power. Further, the power control unit 15 may supply all of the power exceeding the reference value to the DC load, or may control to supply a part of the power exceeding the reference value to the DC load. . Further, the power control unit 15 switches between supplying all of the power exceeding the reference value to the DC load or supplying a part of the power exceeding the reference value to the DC load according to time. It may be. For example, during the daytime hours when reverse power flow is likely to occur, all the power exceeding the reference value is supplied to the DC load, and in other times, part of the power exceeding the reference value is supplied. Is supplied to the DC load. Thereby, even if a reverse power flow occurs in a plurality of consumers, it is possible to reduce the peak of the reverse power flow.

(Fifth embodiment)
In 5th Embodiment, the electric power control part 15 is a case where the electric power generation amount of the solar power generation device 10 is less than a reference value, Comprising: In the customer's AC load (for example, the consumer connected to the distribution board 16) If the amount of power that needs to be supplied to the AC load) exceeds the amount of power generation, the power discharged from the power storage device 12, the power generated from the solar power generation device 10, and the AC power generated by the PCS 11 are used. To be supplied to an AC load. FIG. 6 is a diagram illustrating power conversion in the power distribution control system 1 according to the fifth embodiment. The vertical axis is the amount of power generation, and the horizontal axis is time. When the amount of electric power generated at a certain time does not exceed the reference value but the electric power obtained from the solar power generation device 10 needs to be supplied to the AC load, the power control unit 15 The electric power is discharged from 12 and supplied to the PCS 11 so that at least the sum of the discharged electric power and the amount of power generation is equal to or greater than the reference value, and the necessary electric power for the AC load to be supplied is reached. Electric power is discharged from the power storage device 12. Here, even if the amount of power supplied from the solar power generation device 10 is less than the reference value, the power storage device 12 is discharged, and by combining these to obtain the amount of power equal to or greater than the reference value, Loss when converting from electric power to AC power can be reduced as compared with the case where only the electric power supplied from the solar power generation device 10 is converted. As described above, in the fifth embodiment, even when the amount of power from the solar power generation device 10 is below the reference value, when the AC load is large, the power storage device 12 discharges at least until the reference value is exceeded. And DC / AC conversion is performed together with the generated power.

(Sixth embodiment)
In the sixth embodiment, the power control unit 15 accumulates all the power from the solar power generation device 10 in the power storage device 12 in the time zone when the morning and evening sunshine is weak. In a time zone in which the altitude of the sun is high and the power generation amount exceeds the reference value, the power control unit 15 uses the PCS 11 to exchange AC power for the power amount corresponding to at least the reference value of the power from the solar power generation device 10. The power is converted into electric power, and the remaining electric power is charged in the power storage device 12. Here, the amount of power for DC / AC conversion may be any amount of power as long as it is equal to or greater than a reference value.
7 and 8 are diagrams for explaining the power generation amount and the amount of power to be converted into AC power in the sixth embodiment. 7A and 8A, the vertical axis represents the power generation amount, and the horizontal axis represents time. In FIG. 7B and FIG. 8B, the vertical axis represents power generation, and the horizontal axis represents time. 7 (a) and 8 (a), the power generation amount increases from 0 or near zero in the morning time zone, and the power generation amount becomes the highest in the day time zone, and then the power generation amount in the evening time zone. The amount decreases to 0 or near zero. Here, in the case shown in FIG. 7, regarding the time zone exceeding the reference value of the power generation amount (for example, the day time zone), as shown in FIG. 7B, of the electric power obtained from the solar power generation device 10. For certain power, DC power is converted to AC power. When such control is performed by the power control unit 15, the power generation amount does not reach the reference value in the morning time zone and the evening time zone, as shown in FIG. Is charged in the power storage device 12. When the power generation amount exceeds the reference value in the daytime period, the charged power once becomes 0 or almost 0, but as the power generation amount increases, the charged power (converted into power generation amount and AC power). The difference in the amount of electric power) also increases, approaches 0 in the evening time zone, and when the power generation amount becomes less than the reference value, conversion to AC power is not performed. Is stored in the power storage device 12.
In the example illustrated in FIG. 8B, an example of changing the amount of conversion from DC power to AC power among the power obtained from the solar power generation device 10 according to the passage of time is illustrated. Here, the case where the conversion amount increases as time elapses is illustrated. For this reason, as shown in FIG. 8A, when the amount of power generation exceeds the reference value in the daytime period, the amount of stored electricity increases from 0 or near 0, but the amount converted to AC power also increases. . For this reason, in FIG. 8A, the time when the peak of the storage amount in the daytime time arrives is earlier than in the case of FIG.

(Seventh embodiment)
In this embodiment, the power control unit 15 uses the necessary power prediction function and the predicted power generation amount prediction function of the prediction unit 13 to generate a power storage plan, and makes a power use plan from the solar power generation device 10. In this embodiment, for example, in the time zone when the morning and evening sunshine is weak, all the electric power obtained from the solar power generation device 10 is charged, the solar altitude is high, and the power generation amount exceeds the reference value (for example, In the daytime), measure and predict the amount of electricity stored at that time and the amount of charge that should be charged that day, generate a charge plan for when to charge from the predicted value of the amount of solar radiation for that day, and follow the charge plan Charge the battery. The predicted value of the amount of solar radiation can be acquired from, for example, an external server connected via the Internet, and the power control unit 15 can determine the amount of solar radiation on the prediction target day, for example, on the day before the target date of prediction. Receive predicted values from an external server. When predicting the required power, for example, the prediction unit 13 refers to a database in which a power usage history of about several months to several years in the past is stored, and the weather, temperature, room temperature, etc. of the prediction target day are referred to from the weather forecast server. In addition to these weather, temperature, and room temperature, it is predicted by selecting a power usage history in which power was used on the most similar day including the season and day of the week. Further, when predicting the predicted power generation amount, for example, the prediction unit 13 refers to a database in which the power generation history of the past several months to several years is stored, and predicts the weather, temperature, room temperature, etc. of the prediction target day. The prediction is made by selecting the power generation history generated from the server and generated on the most similar day in the weather, memory, and room temperature.

  FIG. 9 is a diagram for explaining a charging plan designed according to the weather indicated by the weather forecast information for the prediction target day. In FIG. 9A, the vertical axis represents the amount of power generation, and the horizontal axis represents time. The vertical axis in FIG. 9B is the AC conversion amount, and the horizontal axis is time. FIG. 9B illustrates a case where the charging plan is set so that the amount to be converted into alternating current reaches a peak at a predetermined time in the daytime period. Here, it is a time zone in which the generated power is predicted to exceed the reference value, and at least the amount of power corresponding to the reference value of the generated power is converted into AC power, and the remaining power is stored in the power storage device 12. The charging plan is generated so that the amount of power stored in the power storage device 12 becomes a predetermined value (for example, the target value of the remaining amount) by a predetermined time (for example, evening time) of the day. The In FIG. 9B, the amount of AC power to be converted is planned such that a predetermined time in the daytime period peaks. For this reason, as shown in FIG. 9A, when the amount of power generation exceeds the reference value in the daytime period, the amount of stored electricity increases from 0 or near 0, which is the same as FIG. 7A. However, since the amount converted into AC power is controlled to increase at a predetermined time, in FIG. 9A, the peak value of the charge amount in the daytime period is shown in FIG. The charge amount is lower than the peak value in the daytime period.

  FIG.9 (c) is a figure explaining the case where power distribution control is performed along the charging plan on the day when it becomes cloudy from the afternoon. In this case, it is predicted that the amount of power generation will be cloudy in the afternoon and the power generation amount will decrease, so the conversion of the power generation amount to the reference value is not started immediately when the power generation amount reaches the reference value. After exceeding, the battery is charged for a certain time, and thereafter, conversion to AC power is started. Thus, when conversion to AC power is performed when the power generation amount reaches the reference value, the cloudy weather is such that the power storage device 12 does not reach the target charge amount by a predetermined time of the day. In addition, even if the power generation amount exceeds the reference value, charging is continued to some extent, so that the power storage device 12 can be charged to the target charge amount by a predetermined time of the day.

  FIG. 9D is a diagram for explaining a case where the peak of the reverse power flow is cut so that the peak of the reverse power flow does not occur during the daytime. In FIG. 9D, the vertical axis represents the power generation amount, and the horizontal axis represents time. In the period when the power generation amount exceeds the reference value, the power control unit 15 obtains a prediction result such that the power generation amount during the day reaches a peak based on the prediction result by the prediction unit 13. Instead of converting all the power into AC power and performing reverse power flow, in at least a part of the period exceeding the reference value, a part of the power generation amount exceeding the reference value is assigned to charge the power storage device 12 and charged. . Thereby, since the electric power which flows backward can be reduced, the peak cut of the electric power which flows backward to the system side can be performed. Such a plan is executed not only by the power distribution control system 1 in one consumer, but also by each power distribution control system 1 in a plurality of consumers in a predetermined area, so that the entire predetermined area The peak of reverse power flow can be reduced.

  FIG. 10 is a diagram illustrating a case where charging is performed in the green mode and a case where charging is performed by the power distribution control system 1. In FIG. 10A, the vertical axis represents the charge amount and the horizontal axis represents time. In FIG. 10B, the vertical axis represents SOC (State Of Charge) and the horizontal axis represents time. In a general green mode, all the generated power is charged into the storage battery, and when the battery is fully charged, all power is controlled to flow backward. For this reason, as shown in FIG. 10A, the amount of charge sharply increases from the start of charging (reference a2). On the other hand, in the above-described power distribution control system 1, the amount of power received can be appropriately controlled in consideration of the amount of power generation that varies depending on the weather, so the amount of charge gradually increases from the start of charging (reference a1). As a result, as shown in FIG. 10B, the SOC is charged in the morning time zone in the green mode, and the SOC reaches almost 100% in the day time zone (reference number a1). In the daytime, all reverse currents occur. On the other hand, in the power distribution control system 1, since charging is performed slowly during the daytime and is charged so that the SOC becomes approximately 100% in the evening (reference a2), power generation is performed during the daytime. Since not all of the quantity is reversely flowed, but part of it is reversely flowed, the peak of reverse flow can be suppressed.

(Eighth embodiment)
In this embodiment, the memory | storage part 14 memorize | stores the some reference value which changes according to the charging / discharging state of the electrical storage apparatus 12 as a reference value. As the plurality of reference values that differ depending on the charge / discharge state of the power storage device 12, for example, a plurality of reference values that differ depending on the remaining amount of the power storage device 12 can be used. In addition, for example, a plurality of different reference values can be used depending on the past history of charge / discharge. The past charge / discharge history includes various charging / discharging such as charging W1 (kwh) from a certain time T1 to time T2 and discharging W2 (kwh) from time T3 to time T4. It is also possible to store different reference values for each of these histories. In addition, for example, a period in which days with less solar radiation continue for a certain period, such as the rainy season, etc., and the charge / discharge cycle etc. has different reference values for different periods (spring, summer, autumn, winter). You may make it memorize | store, You may make it memorize | store a different reference value according to a long-term deterioration state (capacity change) of a battery.

When using a plurality of different reference values depending on the remaining amount of the power storage device 12, the power control unit 15 acquires the measurement result of the remaining amount of the power storage device 12 measured by the remaining amount measuring unit provided in the power storage device 12. Then, a reference value corresponding to the acquired remaining amount is read from the storage unit 14, and this reference value is compared with the power generation amount.
When using a plurality of different reference values according to past histories of charge / discharge, the power distribution control system 1 includes a charge / discharge history storage unit that stores a history of charge / discharge in the power storage device 12, When power storage device 12 is charged or discharged, control unit 15 stores the amount of electric power (charge amount or discharge amount) charged or discharged and the time of charge or discharge in association with each other. And the electric power control part 15 compares using the reference value corresponding to the electric energy in which charge or discharge was performed in a predetermined period.

  When using different reference values for different periods of charge / discharge cycles, such as periods of rainy season, etc., where days with less solar radiation continue for a certain period or longer, etc., other periods (spring, summer, autumn, winter) Based on a certain period (for example, several weeks or one month) as a period for referring to the charge / discharge history, the control unit 15 performs comparison using a reference value corresponding to the period. For example, in the northern hemisphere, the amount of power generation is small in winter due to short sunshine hours and low sun angles. For this reason, a reference value having a lower value than that in other seasons is used. As a result, a certain amount of charge can be secured even when the sunshine time is short. On the other hand, since summer hours are long in summer, a reference value having a higher reference value than in other seasons is used. As a result, reverse power flow can be performed while keeping the amount of charge constant. In this case, the reference value in spring and autumn is higher than the reference value in winter and lower than the reference value in summer. Here, as the winter reference value, it is desirable that the power conversion efficiency of the PCS 11 is equal to or greater than the generated power value corresponding to η1. Thereby, it can be set as the charge amount according to the sunshine time etc. for every season, or the amount of a reverse power flow, suppressing the loss of the electric power which arises in the case of the power conversion of PCS11 within a fixed value.

  When a different reference value is used according to the long-term deterioration state (capacity change) of the battery, the power control unit 15 monitors the deterioration state of the power storage device 12 in a predetermined period, and the reference value according to the monitoring result Use to compare.

(Ninth embodiment)
In this embodiment, the memory | storage part 14 memorize | stores the some reference value which changes according to the deterioration state of the electrical storage apparatus 12 as a reference value. For example, a plurality of levels indicating the degree of SOC (State Of Charge) are set, and different reference values are stored in the respective levels. As the reference value, a plurality of reference values that are set to lower reference values as the deterioration state progresses in the deterioration state of the battery of the power storage device 12 are used. Then, power control unit 15 measures the SOC of power storage device 12, identifies a level according to the measurement result, and compares the level using a reference value corresponding to the identified level. As a result, even if the generated power is low to some extent, it can be controlled to facilitate reverse flow, and when the storage battery of the power storage device 12 deteriorates and the chargeable amount decreases, The amount of charge can be narrowed down to be within the range of the chargeable amount. As a result, it is possible to reduce a loss at the time of charging that charging is performed even in a situation where charging is difficult. Here, it is desirable that the lower reference value among the plurality of reference values is such that the power conversion efficiency of the PCS 11 is equal to or greater than the generated power value corresponding to η1. Thereby, the loss at the time of charge can be reduced in consideration of the deterioration state of the battery of the power storage device 12 while suppressing the loss of power generated during the power conversion of the PCS 11 within a certain range.

(Tenth embodiment)
In this embodiment, the power distribution control system 1 includes a power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device 10. The storage unit 14 stores a plurality of reference values that differ according to the predicted power generation amount as reference values. Here, different reference values are stored in association with different power generation amounts.
The power control unit 15 specifies the predicted power generation amount corresponding to the predicted power generation amount based on the predicted power generation amount obtained by the power generation amount prediction unit, and the reference value and the power generation amount corresponding to the specified power generation amount And compare.

(Eleventh embodiment)
In this embodiment, the power distribution control system 1 includes a power generation amount prediction unit that obtains a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device 10. The storage unit 14 sets and stores a plurality of different reference values according to the difference between the power generation amount generated by the photovoltaic power generation apparatus 10 and the predicted power generation amount as a reference value. As the reference value, a plurality of reference values that are set to be smaller as the actual power generation amount is larger than the predicted power generation amount in the difference between the power generation amount and the predicted power generation amount are used. Further, as the reference value, a plurality of reference values that are set to be larger as the actual power generation amount is smaller than the predicted power generation amount in the difference between the power generation amount and the predicted power generation amount are used. Then, the power control unit 15 calculates a difference between the power generation amount generated by the solar power generation device 10 and the predicted power generation amount obtained by the power generation amount prediction unit, and stores a reference value corresponding to the calculated difference. 14 is read, and this reference value is compared with the power generation amount. As a result, as the power generation amount greatly exceeds the predicted power generation amount, a smaller value is used as the reference value. Therefore, control can be performed so that reverse power flow is facilitated. In addition, since the power generation amount is less than the predicted power generation amount and the difference is larger, a larger value is used as the reference value. Therefore, in a scene where the power generation amount is small and power loss is likely to occur during power conversion, power conversion It is possible to suppress power loss by performing control so that charging is performed without performing as much as possible. Here, it is desirable that the lower reference value among the plurality of reference values is such that the power conversion efficiency of the PCS 11 is equal to or greater than the generated power value corresponding to η1.

(Twelfth embodiment)
In this embodiment, the memory | storage part 14 is the 1st reference value which is a reference value according to the power conversion efficiency of a power converter, the charging / discharging state of the electrical storage apparatus 12, the deterioration state of the electrical storage apparatus 12, and the solar power generation device 10. The second reference value group that is a plurality of reference values that differ depending on the state of the second item, which is one of the reference value items of the predicted value of the power generation amount generated by. And the electric power control part 15 reads 1st reference value from the memory | storage part 14, determines whether there exists 2nd reference value according to the acquisition result corresponding to 2nd item among 2nd reference value groups, When there is the second reference value, the second reference value is compared with the power generation amount, and when there is no second reference value, the first reference value is compared with the power generation amount. Here, which item of the second items is used is determined in advance, for example, and the power control unit 15 obtains an acquisition result such as a measured value or a predicted value corresponding to the item. And it is determined whether there exists a 2nd reference value corresponding to an acquisition result from the acquisition result and the 2nd reference value group in a predetermined item. For example, when the degradation level of the power storage device 12 has a first level and a second level, and the current degradation level of the power storage device 12 corresponds to the first level or the second level, the level corresponds to the level. A second reference value is used. On the other hand, when the current degradation level of the power storage device 12 is the 0th level, the third level, or the like, there is no corresponding degradation level, so the power control unit 15 uses the first reference value as the reference value.

  In the embodiment described above, the power control unit 15 charges the power storage device with the generated power regardless of the amount of generated power when not connected to the grid (distribution network). Also good.

  Although the first to seventh embodiments have been described above, the power distribution control system 1 may be configured by appropriately combining at least two embodiments.

According to the embodiment described above, by performing reverse power flow only when the amount of power generation is sufficient, power conversion can be performed when the conversion efficiency in the PCS is high, and loss of generated power can be reduced. it can.
Moreover, each of the power distribution control systems 1 not only for one consumer but also for a customer in a predetermined area performs charging as described above to perform power generation amount prediction, By concentrating and charging each of the consumers, it is possible to eliminate the case where the reverse power flow of the generated power from the solar power generation device is concentrated from each demand. In particular, in summer, the amount of power generated during the day increases throughout the region, but even in such a case, the peak of reverse power flow can be suppressed.

  You may make it implement | achieve the electric power control part 15 in embodiment mentioned above with a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. Further, the program may be a program for realizing a part of the above-described functions, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. You may implement | achieve using programmable logic devices, such as FPGA (Field Programmable Gate Array).

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Power distribution control system 10 Solar power generation device 11 Power conditioner 12 Power storage device 13 Prediction part 14 Storage part 15 Power control part 16 Distribution board

Claims (13)

A power generation amount acquisition unit for acquiring a power generation amount generated by the solar power generation device;
The acquired power generation amount is compared with a reference value, and when the power generation amount is less than the reference value, it is determined that the generated power is supplied to a DC load side, and the power generation amount is equal to or greater than the reference value. A power control unit that determines that the power is converted into alternating current by the power conversion unit and reverse power flow. The power control unit
When the power generation amount is equal to or greater than the reference value, it is determined that at least a part of the generated power exceeding the reference value is supplied to the DC load side, and the remaining power generation is determined to be converted to AC. The power distribution control system according to claim 1. Having a power storage device,
The power control unit
When the power generation amount is less than the reference value, and the AC load to be supplied exceeds the power generation amount, the power discharged from the power storage device and the power corresponding to the power generation amount are supplied to the AC load. The power distribution control system according to claim 1, wherein the power distribution control system is determined to be supplied to the power supply. A power storage device;
A required power prediction unit for obtaining a required power amount that is an amount of power required to store power in the power storage device;
A power generation amount prediction unit for obtaining a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device,
The power control unit
When the power generation amount exceeds the reference value, the power storage device is charged based on the necessary power amount and the predicted power generation amount so as to reach a target charge amount by a predetermined time. 2. The power distribution control system according to 2. A power storage device;
A required power prediction unit for obtaining a required power amount that is an amount of power required to store power in the power storage device;
A power generation amount prediction unit for obtaining a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device,
The power control unit
When the power generation amount exceeds the reference value, a peak cut of reverse power flow is performed by storing a part of the power generation amount in the power storage device based on the required power amount and the predicted power generation amount. The power distribution control system according to claim 1 or claim 2. The power control unit
The power distribution control system according to any one of claims 1 to 5, wherein, when not connected to a power distribution network, the generated power is supplied to the DC load regardless of the power generation amount. The reference value is a conversion efficiency reference value representing a reference of power conversion efficiency of the power conversion unit,
The power control unit
The power distribution efficiency of the power conditioner corresponding to the acquired power generation amount is compared with the conversion efficiency reference value. The power distribution control system according to any one of claims 1 to 6. The reference value is a plurality of reference values that differ depending on the charge / discharge state of the power storage device,
The power control unit
The power generation amount is compared with a reference value corresponding to a charge / discharge state corresponding to the past history based on a past history of charging / discharging the power storage device. The power distribution control system according to any one of 5. The reference value is a plurality of reference values that differ depending on the deterioration state of the power storage device,
The power control unit
The power generation amount is compared with a reference value corresponding to the deterioration state indicated by the detection result based on the detection result of detecting the deterioration state of the power storage device. The power distribution control system according to claim 1. A power generation amount prediction unit for obtaining a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device,
The reference value is a plurality of reference values that differ depending on the predicted power generation amount,
The power control unit
The power generation amount is compared with a reference value corresponding to the predicted power generation amount according to the predicted power generation amount based on the predicted power generation amount obtained by the power generation amount prediction unit. The power distribution control system according to any one of claims 1 to 3. A power generation amount prediction unit for obtaining a predicted power generation amount that is a predicted value of the power generation amount generated by the solar power generation device,
The reference value is set with a plurality of different reference values according to the difference between the power generation amount generated by the solar power generation device and the predicted power generation amount,
The power control unit calculates a difference between a power generation amount generated by the photovoltaic power generation apparatus and a predicted power generation amount obtained by the power generation amount prediction unit, and the reference value according to the calculated difference and the power generation The power distribution control system according to any one of claims 1 to 3, wherein the amounts are compared. A reference of a first reference value that is a reference value according to the power conversion efficiency of the power conversion unit, a charge / discharge state of the power storage device, a deterioration state of the power storage device, and a predicted value of the amount of power generated by the solar power generation device A reference value storage unit that stores a second reference value group that is a plurality of reference values that differ depending on the state of the second item, which is one of the value items, and the power control unit includes 1 reference value is acquired, it is determined whether there is a second reference value corresponding to the acquisition result corresponding to the second item in the second reference value group, and if there is the second reference value, 3. The second reference value and the power generation amount are compared, and if there is no second reference value, the first reference value and the power generation amount are compared. The power distribution control system described in 1. The power generation amount acquisition unit acquires the power generation amount generated by the solar power generation device,
The power control unit compares the acquired power generation amount with a reference value, and determines that the generated power is supplied to a DC load side when the power generation amount is less than the reference value, and the power generation amount A power distribution control method that determines that the power is converted into alternating current by a power converter when the power is greater than or equal to the reference value.

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