Power control equipment, power control systems, and programs

Abstract

To provide a power control device, a power control system, and a program that suppress imbalance in self-consignment of power generation using renewable energy and suppress three-phase unbalance.SOLUTION: A power control device controls the self-consigned power of the three-phase power generated on the basis of renewable energy. The power control device controls charging and discharging of a storage battery connected in parallel to a single-phase load to which single-phase power based on three-phase power is supplied.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a power control device, a power control system, and a program. [Background technology]

[0002] Conventionally, self-consignment has been known as a mechanism for transmitting power output from a power generation facility to a demand facility via a power grid managed by a third-party entity. In a system that performs self-consignment, a technique for appropriately grasping the self-consignment power has been proposed (for example, see Patent Document 1).

[0003] Currently, there is a growing interest in using self-dispatch to transmit electricity generated by renewable energy sources such as solar power to other bases of a company via grid lines. When using self-dispatch, it is necessary to forecast the amount of electricity demand and supply in specified time intervals (for example, 30 minutes) and report the planned values ​​(i.e., it is necessary to adhere to the system of simultaneous balancing of planned values). If a discrepancy occurs between the planned value and the actual value, i.e., an imbalance occurs, a penalty (imbalance fee) is imposed according to the imbalance.

[0004] Furthermore, when the power generated by a power generation system is used as three-phase power, variations in the connection phases of single-phase loads can cause uneven voltage drops among the three phases (three-phase imbalance). When three-phase unbalanced power is supplied to a three-phase load, it can cause various malfunctions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-52557 Summary of the Invention [Problem to be solved by the invention]

[0006] In the power generation system described above, it is desirable to suppress imbalance in the self-transmission of power generated by renewable energy. Also, in the power generation system described above, it is desirable to suppress three-phase unbalance.

[0007] An object of the present disclosure is to provide a power control device, a power control system, and a program that suppress imbalance in self-consignment of power generated by renewable energy and suppress three-phase unbalance. [Means for solving the problem]

[0008] The power control device according to one embodiment includes: Controlling the self-transferred power of three-phase power generated based on renewable energy A power control device, The storage battery controlled by the power control device is a power supply connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; 、 The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, The storage battery is charged and discharged so as to suppress the imbalance and the three-phase unbalance of the self-consigning power.

[0009] A power control system according to one embodiment includes: A power control system including a power control device that controls self-transported power among three-phase power generated based on renewable energy, the storage battery controlled by the power control device is connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, The power control device charges and discharges the storage battery so as to suppress imbalance while suppressing three-phase unbalance of the self-consigning power.

[0010] A program according to an embodiment includes: Controlling the self-transferred power of three-phase power generated based on renewable energy Power Control Equipment A program to be executed by the storage battery controlled by the power control device is connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, The power control device is caused to execute a step of charging and discharging the storage battery so as to suppress imbalance while suppressing three-phase unbalance of the self-consigning power. [Effects of the Invention]

[0011] According to one embodiment, it is possible to provide a power control device, a power control system, and a program that suppress imbalance in self-consignment of power generated by renewable energy and suppress three-phase unbalance. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a power control system according to a comparative example of an embodiment. [Figure 2] FIG. 10 is a diagram illustrating self-consignment in a power control system according to a comparative example of an embodiment. [Figure 3] FIG. 10 is a diagram illustrating self-consignment in a power control system according to a comparative example of an embodiment. [Figure 4] 1 is a diagram illustrating a configuration of a power control system according to an embodiment. [Figure 5] FIG. 2 is a diagram illustrating the operation of a power control system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present disclosure, a power control system and / or a power control device may be a system and / or a device that operates using power. Also, a power control system and / or a power control device may include a function for controlling power. The function of the power control system and / or the power control device is not limited to the function for controlling power, and may include other functions.

[0014] Furthermore, in this disclosure, "self-dispatch" may be defined, for example, as defined in the "Guidelines for Self-Dispatch" (enforced on April 1, 2014, revised on November 18, 2021) established by the Agency for Natural Resources and Energy, an external bureau of the Ministry of Economy, Trade and Industry. In other words, self-dispatch may refer to the electricity transmission service provided by a general electric utility when a person who installs private power generation equipment transmits electricity generated using the private power generation equipment to a factory or the like located in a different location of the person who installs the private power generation equipment via a transmission and distribution network maintained and operated by the general electric utility.

[0015] A power control system according to an embodiment will be described below with reference to the drawings. Before describing the power control system according to an embodiment, a power control system according to a comparative example of the embodiment will first be described.

[0016] FIG. 1 is a diagram illustrating an example of the configuration of a power control system according to a comparative example of an embodiment.

[0017] The power control system shown in Fig. 1 transmits power generated in a power plant 100 to a demand location 200 via a system line GL. As shown in Fig. 1, the power plant 100 and the demand location 200 are both connected to the system line GL. Therefore, the power plant 100 and the demand location 200 are connected via the system line GL. In Fig. 1, paths for transmitting and / or receiving power, i.e., paths of power, are mainly indicated by solid lines. Also, in Fig. 1, paths for transmitting and / or receiving information, i.e., paths of electrical signals, are mainly indicated by dashed lines.

[0018] The power plant 100 may include a power control device 10, a meter 11, a switch 12, a three-phase transformer 13, a power conditioner 20, a solar cell 30, and a storage battery 40.

[0019] The power control device 10 controls the power of the power plant 100 by controlling each functional unit in the power plant 100. The power control device 10 may be a controller that controls the operation of each functional unit in the power plant 100. The controller may include at least one processor, such as a central processing unit (CPU) or a digital signal processor (DSP), to provide control and processing capabilities for executing various functions. The controller may be implemented with one processor or multiple processors. The controller may be implemented as a single integrated circuit. The processor may be implemented as multiple integrated circuits and discrete circuits connected to each other in a communicative manner. The controller may be configured as a CPU or a DSP and software such as a program executed by the CPU or DSP. The program executed in the controller and the results of the processing executed in the controller may each be stored in an arbitrary memory unit.

[0020] The power control device 10 may be configured as a hardware resource, may be configured as software, or may be constructed by software and hardware resources working together. Control by the power control device 10 will be described further below.

[0021] The meter 11 measures the power output from the power plant 100 to the grid line GL. The meter 11 may also measure the power supplied to the power plant 100 from the grid line GL. The power from the power plant 100 output from the meter 11 is supplied to the grid line GL. For this reason, the meter 11 and the grid line GL may be connected by, for example, an electric wire. The meter 11 may also be capable of appropriately measuring the power of each of the other components. The measurement results by the meter 11 may be transmitted to the power control device 10. For this reason, the meter 11 and the power control device 10 may be connected by at least one of a wire and a wireless connection. The meter 11 may be any device that measures the power of each component. Since the meter 11 may be any known device that measures the power of each component, a detailed description thereof will be omitted. The meter 11 may also be connected to the switch 12 by, for example, an electric wire.

[0022] The switch 12 switches between connecting (closing) and disconnecting (opening) the power path between the meter 11 and the three-phase transformer 13. The switch 12 may be switched between opening and closing by, for example, the power control device 10. The switch 12 may also be switched between opening and closing by other means or manually. The switch 12 may be any device that switches between connecting and disconnecting the power path between two points. The switch 12 itself is known, so a more detailed description will be omitted. The switch 12 may be connected to the three-phase transformer 13 by, for example, an electric wire.

[0023] The three-phase transformer 13 transforms three-phase power (three-phase AC power). The power generated by the solar cell 30 passes through the power conditioner 20 and is then input to the three-phase transformer 13. The three-phase transformer 13 transforms the input three-phase power and outputs it to the switch 12. For this reason, the three-phase transformer 13 may be connected to the power conditioner 20, for example, by an electric wire. The three-phase transformer 13 may also be connected to the switch 12, for example, by an electric wire. The three-phase transformer 13 may be any device that transforms (steps up and / or steps down) three-phase power. As the three-phase transformer 13 may be any known device that transforms three-phase power, a more detailed description thereof will be omitted.

[0024] The power conditioner 20 controls and / or manages the power generation by the solar cell 30. The power conditioner 20 may have, for example, a function of converting input DC power into AC power. The power conditioner 20 may be any power conditioner (Power Conditioning Subsystem: PCS) that controls the power generated by a power generation device such as the solar cell 30 and output to the outside. Since the power conditioner itself is known, a detailed description thereof will be omitted. The power conditioner 20 may be connected to the solar cell 30 by, for example, an electric wire or the like.

[0025] The solar cell 30 converts light energy into electricity. There are no limitations on the type of solar cell 30 as long as it is capable of photoelectric conversion. The solar cell 30 may be, for example, a silicon-based polycrystalline solar cell, a silicon-based monocrystalline solar cell, or a thin-film solar cell such as CIGS. In one embodiment, the solar cell may be any power source as long as it has the function of generating solar power to supply electricity. Furthermore, the solar cell 30 is shown as an example of a power generation device that generates electricity using renewable energy. Therefore, the solar cell 30 may be replaced with a device that generates electricity using other renewable energy sources, such as wind power generation.

[0026] 1, the power generated by the solar cell 30 may be converted from DC to AC by the power conditioner 20, and may be boosted from, for example, 200 V to, for example, 6600 V by the three-phase transformer 13. The AC power boosted in this way by the three-phase transformer 13 can be sent to the grid line GL as power for self-wheeling.

[0027] In one embodiment, the power control device 10 may control the power generation of the solar cell 30. The power control device 10 may, for example, control the power conditioner 20 that controls the power generation of the solar cell 30. For this reason, the power control device 10 and the power conditioner 20 may be connected by at least one of a wired connection and a wireless connection. In one embodiment, the power control device 10 may control the power generation of the solar cell 30 based on the measurement result by the meter 11.

[0028] The storage battery 40 may be any storage battery capable of charging and discharging power. For example, the storage battery 40 may be a lithium-ion battery, a nickel-metal hydride battery, or the like. The storage battery 40 can supply power by discharging charged power. The storage battery 40 may convert AC power to DC power and charge the converted DC power. The storage battery 40 may discharge charged DC power, convert the discharged DC power back into AC power, and then output the power. As such, a functional unit that converts DC power and AC power is included in the storage battery 40 and is therefore not shown in FIG. 1 . The functional unit that converts DC power and AC power may have the same function as, for example, the power conditioner 20 connected to the solar cell 30 shown in FIG. 1 .

[0029] The storage battery 40 can be charged with at least one of power supplied from the grid line GL, power supplied from the solar cell 30, power supplied from a fuel cell, and power supplied from other power sources. In this case, the storage battery 40 may be connected to each functional unit that exchanges power via, for example, an electric wire. In one embodiment, the storage battery 40 may be any power source that has the function of charging and discharging power. The storage battery 40 may also be, for example, an electric vehicle (EV) or a plug-in hybrid vehicle equipped with an on-board charging device.

[0030] As shown in FIG. 1, the storage battery 40 may be connected between the three-phase transformer 13 and the power conditioner 20 by, for example, an electric wire.

[0031] In one embodiment, the power control device 10 may control at least one of charging and discharging of the storage battery 40. For this reason, the power control device 10 and the storage battery 40 may be connected by at least one of wire and wirelessly. In one embodiment, the power control device 10 may control at least one of charging and discharging of the storage battery 40 based on the measurement result by the meter 11.

[0032] The demand location 200 may be provided with a load that consumes the electricity generated by the power plant 100 and self-consigns it to the demand location 200. The business operator that owns the demand location 200 may be the same as the business operator that owns the power plant 100, or may have a close relationship with the business operator that owns the power plant 100, such as being part of the same group of companies.

[0033] Next, the self-consignment performed in the power control system shown in FIG. 1 will be described.

[0034] The power plant 100 shown in Fig. 1 can utilize the storage battery 40 when performing self-dispatch of the power generated by the solar cell 30. For example, the power plant 100 shown in Fig. 1 may self-dispatch the surplus power generated by the solar cell 30, after subtracting the power consumed in the power plant 100, to the demand location 200. As described above, in the self-dispatch system, it is necessary to output the same amount of power to the grid line GL according to a planned value for every predetermined time period (for example, 30 minutes) (planned value simultaneous balancing amount).

[0035] FIG. 2 is a diagram showing an example of planned values ​​of power output to the grid line GL as self-forwarding every 30 minutes. FIG. 2 is a bar graph showing planned values ​​of power output to the grid line GL as self-forwarding on a certain day, broken down into 30-minute segments. The horizontal axis of the graph shown in FIG. 2 shows 24 hours of a certain day broken up into 30-minute segments. This horizontal axis may represent 24 hours starting at midnight on a certain day and ending at midnight the following day of that day. The vertical axis of the graph shown in FIG. 2 may represent planned values ​​of power output to the grid line GL as self-forwarding. This vertical axis may represent a relative amount, with the minimum planned value of power output to the grid line GL as self-forwarding being zero and the maximum planned value being one.

[0036] For example, during the time period from midnight to 5:30 AM (frames 1 to 11), solar cell 30 does not generate power, and therefore the planned value of self-consignment power is zero. During the time period from 5:30 AM to 11:30 AM (frames 12 to 23), solar cell 30 power generation gradually increases, and the planned value of self-consignment power also tends to gradually increase overall. During the time period from 11:30 AM to 1:00 PM (frames 24 to 26), solar cell 30 is at or near its maximum, and the planned value of self-consignment power reaches its peak. During the time period from 1:00 PM to 6:00 PM (frames 27 to 36), solar cell 30 power generation gradually decreases, and the planned value of self-consignment power also tends to gradually decrease overall. During the time period from 6:00 PM to midnight the next day (frame 37 to frame 48), solar cell 30 does not generate power, and therefore the planned value of self-consignment power is also zero.

[0037] 2, for example, in the case of photovoltaic power generation by solar cell 30, the planned value of power to be self-consigned may be estimated based on the amount of power generated the next day, for example, based on a weather forecast for the previous day. At this time, the planned value of power to be self-consigned may also be estimated taking into consideration a forecast of power to be consumed in power plant 100 the next day. Power control device 10 may acquire the above-mentioned weather forecast and the forecast of power to be consumed in power plant 100 from, for example, any functional unit in power plant 100 or an external server.

[0038] However, the actual value of solar power generation by solar cell 30 depends on the weather at the installation location of solar cell 30 on the day. For this reason, the actual value of the power actually sent by the solar cell 30 may have an error from the planned value, i.e., an imbalance may occur. The power control device 10 may acquire the actual value of solar power generation by solar cell 30 from any functional unit (e.g., power conditioner 20) in the power plant 100.

[0039] In order to suppress such an imbalance, when the actual value of power generation by the solar cell 30 is likely to exceed the planned value, the power control device 10 may, for example, limit the power output by the solar cell 30 by controlling the power conditioner 20. By limiting the power in this way, it is possible to deal with, for example, a case where the weather suddenly changes from cloudy to sunny contrary to prediction. However, even with such a limit, it is not possible to deal with, for example, a case where the weather suddenly worsens contrary to prediction.

[0040] Therefore, as in the power control system shown in Fig. 1, the imbalance may be reduced by utilizing a storage battery 40 connected in parallel to a power generation facility such as a solar cell 30. That is, when the actual value of the amount of power transmitted (reverse flow) of self-dispatch exceeds the planned value, the power control device 10 may control the storage battery 40 so that the excess amount is charged to the storage battery 40. This amount of power transmitted (reverse flow) of self-dispatch may be measured by a meter 11. On the other hand, when the actual value of the amount of power transmitted (reverse flow) of self-dispatch falls short of the planned value, the power control device 10 may control the storage battery 40 so that the shortfall is discharged from the storage battery 40.

[0041] FIG. 3 is a diagram illustrating an example of an operation for avoiding imbalance in the power control system shown in FIG.

[0042] Fig. 3 shows that in the time slot from 7:00 AM to 8:00 AM (frames 15 to 16), the actual value of self-consignment power increases above the planned value shown in Fig. 2, and if this continues, the surplus imbalance shown in Fig. 3 is expected to occur. In this case, power control device 10 may control storage battery 40 so that the power that is expected to cause the surplus imbalance is charged to storage battery 40.

[0043] Furthermore, Fig. 3 shows that in the time period from 11:00 AM to 12:00 PM (frames 23 to 24), the actual value of self-consignment power is lower than the planned value shown in Fig. 2, and if this continues, a shortage imbalance is expected to occur as shown in Fig. 3. In this case, power control device 10 may control storage battery 40 so that the power that is expected to cause a shortage imbalance is discharged from storage battery 40.

[0044] On the other hand, in other time periods (frame 1 to frame 14, frame 17 to frame 22, and frame 25 to frame 48), no difference occurs between the planned value and the actual value. Therefore, in these time periods, the power control device 10 does not need to control the storage battery 40 to avoid or suppress the imbalance.

[0045] Through the above-described control, power control device 10 can bring the actual value of self-consignment power, which was likely to be as expected as shown in Fig. 3, closer to the planned value shown in Fig. 2. Therefore, the power control system shown in Fig. 1 can avoid or suppress imbalance when performing self-consignment.

[0046] However, in the power plant 100 shown in Figure 1, if three-phase power generated by the solar cell 30 is supplied to a three-phase load and one of the three-phase power is then supplied as single-phase power to the single-phase load, a three-phase unbalance may occur. This three-phase unbalance occurs because the voltage drops among the three phases are uneven due to variations in the phase to which the single-phase load is connected. When this three-phase unbalanced power is supplied to a three-phase induction motor, inverter, or the like, it may cause various problems, such as vibration, temperature, and / or harmonics.

[0047] Therefore, a power control system that suppresses imbalance in self-wheeling and suppresses three-phase unbalance will be described below.

[0048] Figure 4 is a diagram showing a power control system according to one embodiment. In Figure 4, the same functional units as those shown in Figure 1 are designated by the same reference numerals. Hereinafter, the description of the same functional units as those shown in Figure 1 will be simplified or omitted as appropriate.

[0049] The power control system according to one embodiment shown in Fig. 4 further includes a single-phase transformer 14, a reverse power relay 15, and a three-phase transformer 16 in addition to the components of the power control system shown in Fig. 1. The power control system shown in Fig. 4 also includes a single-phase load 50 and a three-phase load 60 in addition to the components of the power control system shown in Fig. 1. Meanwhile, Fig. 4 does not show the power plant 100, which is the self-dispatch source of power, and the demand site 200, which is the self-dispatch destination, shown in Fig. 1. As shown in Fig. 4, the equipment including the power control device 10, the meter 11, the switchgear 12, the three-phase transformer 13, the single-phase transformer 14, the reverse power relay 15, and the three-phase transformer 16 may be referred to as power receiving and substation equipment 1.

[0050] The single-phase transformer 14 transforms single-phase power (single-phase AC power). As shown in FIG. 4 , the single-phase transformer 14 may be connected between the switch 12 and the three-phase transformer 13, for example, by an electric wire. That is, the single-phase transformer 14 may be connected in parallel with the three-phase transformer 13. The single-phase transformer 14 may transform (step down) the voltage of the power generated by the solar cell 30, which is converted to AC by the power conditioner 20 and then boosted by the three-phase transformer 13. The single-phase transformer 14 may use one phase of the three-phase power as single-phase power and transform the voltage of the single-phase power. Here, the single-phase power may be, for example, one of the R phase, S phase, and T phase. The single-phase transformer 14 may output the transformed power to the reverse power relay 15. For this purpose, the single-phase transformer 14 may be connected to the reverse power relay 15 by, for example, an electric wire.

[0051] Any device that transforms (steps up and / or steps down) single-phase power may be employed as the single-phase transformer 14. Since any known device that transforms single-phase power may be employed as the single-phase transformer 14, a more detailed description thereof will be omitted.

[0052] The reverse power relay 15 may be a reverse power relay (RPR) that is installed to prevent the occurrence of reverse power flow. When the reverse power relay 15 detects reverse power, it can prevent reverse power flow by opening a circuit breaker or the like. The reverse power relay 15 operates when reverse power flow occurs, thereby stopping the flow of power and preventing reverse power flow. A known RPR may be used as the reverse power relay 15, and therefore a detailed description thereof will be omitted. The reverse power relay 15 may be connected to the single-phase load 50 by, for example, an electric wire or the like.

[0053] The single-phase load 50 may be any of various devices that consume general single-phase power of 100V or 200V (so-called lighting load). The single-phase load 50 may be any load that consumes single-phase power and is connected to the power receiving and transforming equipment 1.

[0054] In the power control system shown in FIG. 1 , the storage battery 40 is connected between the three-phase transformer 13 and the power conditioner 20. On the other hand, in a power control system according to an embodiment shown in FIG. 4 , the storage battery 40 is connected between the reverse power relay 15 and the single-phase load 50. That is, in the power control system shown in FIG. 4 , the storage battery 40 may be connected in parallel with the single-phase load 50. In the power control system according to this embodiment shown in FIG. 4 , charging and / or discharging of the storage battery 40 may be controlled by the power control device 10. Therefore, the power control device 10 and the storage battery 40 may be connected by at least one of a wired connection and a wireless connection. In one embodiment, the power control device 10 may control at least one of charging and discharging of the storage battery 40 based on a measurement result by the meter 11.

[0055] Similar to three-phase transformer 13, three-phase transformer 16 transforms three-phase power (three-phase AC power). As shown in Fig. 4, three-phase transformer 16 may be connected between switch 12 and three-phase transformer 13 together with single-phase transformer 14 by, for example, electric wires. That is, three-phase transformer 16 may be connected in parallel with three-phase transformer 13 and single-phase transformer 14.

[0056] Three-phase transformer 16 may transform (e.g., step down) the voltage of the power generated by solar cell 30, which is converted into AC by power conditioner 20 and then boosted by three-phase transformer 13. Three-phase transformer 16 may output the transformed power to three-phase load 60. For this reason, three-phase transformer 16 may be connected to three-phase load 60 by, for example, an electric wire or the like.

[0057] Similar to the three-phase transformer 13, the three-phase transformer 16 may be any device that transforms (steps up and / or steps down) three-phase power. Similar to the three-phase transformer 13, the three-phase transformer 16 may be any known device that transforms three-phase power, and therefore a more detailed description thereof will be omitted.

[0058] The three-phase load 60 may be, for example, various devices that consume three-phase power of 200 V (so-called power loads). The three-phase load 60 may be a load that is connected to the power receiving and transforming equipment 1 and consumes three-phase power.

[0059] As described above, the power control system according to one embodiment shown in Fig. 4 may be configured such that the storage battery 40 is connected in parallel to the single-phase load 50 in a power control system that performs self-dispatch of power generated by the solar cell 30 in a three-phase system. The power control system according to one embodiment shown in Fig. 4 can suppress imbalance and also suppress three-phase unbalance in the self-dispatch of power generated by the solar cell 30.

[0060] Next, the operation of the power control system shown in FIG. 4 will be described.

[0061] The power receiving and transforming equipment 1 shown in Fig. 4 can utilize the storage battery 40 when performing self-wheeling of power generated by the solar cell 30. For example, the power receiving and transforming equipment 1 shown in Fig. 4 may output, to the grid line GL, surplus power generated by the solar cell 30 minus power consumed by the single-phase load 50 and the three-phase load 60 connected to the power receiving and transforming equipment 1 as self-wheeling. As described above, in the self-wheeling system, it is necessary to output the same amount of power to the grid line GL at the same time according to a planned value for every predetermined time period (for example, 30 minutes) (planned value simultaneous balancing amount).

[0062] 4, power control device 10 may control charging and / or discharging of storage battery 40 in conjunction with a self-wheeling plan. By such control, power receiving and transforming equipment 1 can charge and discharge storage battery 40 within the range of power consumed by single-phase load 50, thereby suppressing imbalance.

[0063] Power control device 10 may perform control so that the power stored in storage battery 40 is discharged during times when self-dispatch power transmission is not performed (for example, at night). Such control can improve three-phase imbalance caused by single-phase load 50. Furthermore, as a basic control performed by power control device 10, control may be performed so that storage battery 40 is charged when self-dispatch power transmission (reverse power flow) is performed in power receiving and transforming equipment 1. In this way, by charging surplus power generated by solar cell 30 to storage battery 40 and discharging the power charged in storage battery 40 during times when self-dispatch power transmission is not performed, it is possible to suppress an increase in peak power of single-phase load 50.

[0064] In the power control system shown in FIG. 4, only one single-phase load 50 is shown. However, the power control system according to one embodiment may include a plurality of single-phase loads 50. Here, the plurality of single-phase loads 50 may be a plurality of loads of the same phase, or may be a plurality of loads of different phases. The power control system according to one embodiment may control the balance of the plurality of single-phase loads in different phases.

[0065] The power control system shown in Fig. 4 can suppress the imbalance by charging and discharging the storage battery 40. However, depending on the degree of imbalance, it is conceivable that the power control system shown in Fig. 4 may not be able to fully suppress the imbalance by simply charging and discharging the storage battery 40. In such a case, that is, when the imbalance cannot be fully suppressed by simply charging and discharging the storage battery 40, the power control device 10 may suppress power generation by the solar cell 30, for example, by controlling the power conditioner 20.

[0066] 4 does not necessarily have to be a stationary storage battery. The storage battery 40 may be, for example, an electric vehicle (EV) or a plug-in hybrid vehicle equipped with an on-board charging device.

[0067] Furthermore, in one embodiment, as an operation in the event of a power outage, for example, power control device 10 may open switch 12 to perform stand-alone operation using solar cell 30. In this way, power control device 10 performs stand-alone operation using solar cell 30, thereby enabling stable operation of the power control system shown in Fig. 4.

[0068] Next, the operation of the power control system according to one embodiment will be described in more detail.

[0069] FIG. 5 is a diagram illustrating the operation of a power control system according to one embodiment. Similar to FIG. 3, FIG. 5 shows that the actual value of self-dispatched power during the time period from 7:00 AM to 8:00 AM (frames 15 to 16) is greater than the planned value shown in FIG. 2, and if this continues, an instantaneous surplus imbalance as shown in FIG. 5 is expected to occur. Also, in FIG. 5, the instantaneous value of the self-dispatched power transmission (reverse flow) energy is shown by a line graph. This instantaneous value of the self-dispatched power transmission (reverse flow) energy may be measured by meter 11. In FIG. 5, the difference between the instantaneous value of the self-dispatched power transmission (reverse flow) energy and the planned value is shown as the instantaneous value of the surplus imbalance.

[0070] First, in a power control system according to one embodiment, the power control device 10 resets the integrated value of the amount of power when a target time period (frame 15) arrives. Next, the power control device 10 compares the amount of power (real-time integrated value) of self-dispatched power transmission (reverse flow) with the planned value, as shown in FIG. 5. Here, the amount of power (reverse flow) of self-dispatched power exceeds the planned value. Therefore, the power control device 10 controls the amount of power that exceeds the planned value (i.e., the amount of surplus imbalance) to be charged to the storage battery 40. This offsets the difference in the surplus imbalance. Through this control, the storage battery 40 will charge power that exceeds the planned value.

[0071] In the next time period (frame 16), power control device 10 may estimate the amount of power to be self-consign within a predetermined time period (here, 30 minutes), and repeat the above-described operation.

[0072] For example, when a shortage imbalance is expected to occur in the amount of self-dispatched power transmission (reverse flow) power, such as during the time period from 11:00 AM to 12:00 PM (frames 23 to 24) shown in Fig. 3, power control device 10 performs the following operation. That is, in this case, power control device 10 controls the amount of power that is insufficient (i.e., the amount of shortage imbalance) to be discharged from storage battery 40 to single-phase load 50.

[0073] As described above, the power control system according to one embodiment can suppress imbalances that occur when surplus power generated by renewable energy sources such as solar power generation is self-consignment. Furthermore, the power control system according to one embodiment can suppress three-phase imbalances because single-phase power discharged from the storage battery 40 is supplied to the single-phase load 50. Therefore, the power control system and power control device 10 according to one embodiment can suppress imbalances that occur when surplus power generated by renewable energy sources is self-consignment, and can also suppress three-phase imbalances.

[0074] Although the above-described embodiments have been described as typical examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited by the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the claims. For example, multiple building blocks shown in the block diagrams of the embodiments can be combined into one, or one building block can be divided.

[0075] For example, the power control system shown in FIG. 4 may further include a storage battery 40 capable of charging and discharging the power generated by the solar cell 30, as shown in FIG.

[0076] Furthermore, for example, the power control system shown in Fig. 4 is not limited to a system that performs self-consignment of power generated by solar cell 30. For example, the power control system shown in Fig. 4 may also perform self-consignment of three-phase power generated based on other renewable energy sources, such as wind power generation.

[0077] The above-described embodiments are not limited to implementation as a system such as the power control system shown in Fig. 4. For example, the above-described embodiments may be implemented as a device (such as the power control device 10) that constitutes at least a part of a system such as the power control system shown in Fig. 4.

[0078] The above-described embodiments may also be implemented as, for example, a control method for the above-described system or device. The above-described embodiments may also be implemented as, for example, a program executed on a computer of the above-described system or device. Furthermore, the above-described embodiments may also be implemented as, for example, a recording medium on which a program executed on a computer of the above-described system or device is recorded, i.e., a computer-readable recording medium. [Explanation of symbols]

[0079] 1. Power receiving and transforming equipment 10 Power control equipment 11 Instruments 12 Switches 13 Three-phase transformer 14 Single-phase transformer 15 Reverse power relay 16 Three-phase transformer 20 Power Conditioner 30 Solar Cells 40 Storage battery 50 Single-phase load 60 three phase load 100 Power Plants 200 Demand location

Claims

1. A power control device that controls self-transported power among three-phase power generated based on renewable energy, the storage battery controlled by the power control device is connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, A power control device that charges and discharges the storage battery so as to suppress a three-phase imbalance of the self-consigning power while suppressing an imbalance.

2. The power control device according to claim 1, wherein charging and discharging of the storage battery are controlled according to a plan for self-transported power among the three-phase power generated based on the renewable energy.

3. The power control device according to claim 1 , wherein the power control device controls the storage battery to discharge at least a portion of the power consumed by the single-phase load.

4. The power control device according to claim 1, wherein the power control device performs control so that a surplus of three-phase power generated based on renewable energy, obtained by subtracting power consumed by the single-phase load and the three-phase load, is self-wheeled.

5. 5. The power control device according to claim 1, wherein, when an actual value of three-phase power generated based on renewable energy exceeds a planned value, control is performed so that surplus imbalance power is charged to the storage battery.

6. The power control device according to claim 1 , wherein the power control device controls the storage battery to charge power during a time when self-consignment is not performed.

7. 5. The power control device according to claim 1, wherein, when an actual value of three-phase power generated based on renewable energy is less than a planned value, control is performed so that power equivalent to a deficiency imbalance is discharged from the storage battery.

8. The power control device according to claim 1 , wherein control is performed so that power is discharged from the storage battery during a time when self-consignment is performed.

9. The power control device according to claim 1 , which controls charging and discharging of a stationary storage battery as the storage battery.

10. The power control device according to claim 1 , which controls charging and discharging of a storage battery provided in an electric vehicle as the storage battery.

11. A power control system including a power control device that controls self-consignment power among three-phase power generated based on renewable energy, the storage battery controlled by the power control device is connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, The power control device charges and discharges the storage battery so as to suppress a three-phase imbalance of the self-consigning power while suppressing an imbalance.

12. A program to be executed by a power control device that controls self-consignment power among three-phase power generated based on renewable energy, the storage battery controlled by the power control device is connected in parallel to a single-phase load to which single-phase power based on the three-phase power is supplied; The storage battery and the single-phase load are provided in a power plant that generates electricity based on renewable energy or in the vicinity of the power plant, A program that causes the power control device to execute a step of charging and discharging the storage battery so as to suppress imbalance while suppressing three-phase unbalance of the self-consigning power.

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