JP7356922B2 - Distributed power systems and distributed power supplies - Google Patents

Description

The present invention relates to a distributed power supply system and a distributed power supply device.

For example, a distributed power supply device such as a fuel cell may be installed in a building such as a house (that is, a consumer) (for example, Patent Document 1).

JP2017-91922A

In recent years, demand response that can contribute to power supply and demand adjustment has been studied not only by power suppliers but also by power consumers. For example, when an aggregator that bundles and manages the distributed power supplies of each customer receives a demand response command from a power company requesting a reduction in power demand, it increases the output of each distributed power supply under its management. and supply surplus power to the power grid. In addition, when an aggregator receives an increased demand response command from an electric power company requesting an increase in electricity demand, the aggregator reduces the output of each distributed power supply device under its management to relatively increase the load and of electricity is consumed by the load.

However, since distributed power supplies have lower output than power plants, their ability to adjust supply and demand is relatively low. Therefore, depending on the operating status and load status of each distributed power supply device, there is a possibility that supply and demand adjustment cannot be adequately addressed.

In view of such problems, an object of the present invention is to provide a distributed power supply system and a distributed power supply device that can improve the ability to adjust supply and demand.

In order to solve the above problems, the distributed power supply device of the present invention includes a distributed power supply unit connected to an electric power system and a load, a storage battery connected to the distributed power supply unit, and a distributed power supply device that requires a reduction in power demand. In response to receiving a lower demand response command, the output of the distributed power supply unit is lowered to a level higher than the output before receiving the demand response command, and the storage battery is discharged to supply power to the power grid. A control unit, the charge/discharge control unit predicts the occurrence of a future lower demand response command based on the reception date and time of the past lower demand response command, and according to the prediction result of the lower demand response command, a predetermined standard SOC is set, and when the demand response corresponding to the reception of the lower demand response command is not performed, charging and discharging of the storage battery is controlled so that the SOC of the storage battery is maintained at the reference SOC.

In order to solve the above problems, the distributed power supply device of the present invention includes a distributed power supply unit connected to a power system and a load, a storage battery connected to the distributed power supply unit, and a distributed power supply device that requires increased power demand. a charging/discharging control unit that increases the output of the distributed power supply unit in response to receiving the demand response command and sets it to less than the output before the reception timing of the demand response command, and charges the storage battery with power from the power grid; The charging/discharging control unit predicts the occurrence of a future increased demand response command based on the reception date and time of the past increased demand response command, and sets a predetermined standard SOC according to the prediction result of the increased demand response command, When demand response response in response to reception of an increased demand response command is not performed, charging and discharging of the storage battery is controlled so that the SOC of the storage battery is maintained at a reference SOC.

According to the present invention, it is possible to improve the ability to adjust supply and demand.

1 is a schematic diagram showing the configuration of a distributed power supply system according to the present embodiment. FIG. 2 is a schematic diagram illustrating details of a distributed power supply device. It is a figure explaining operation of a charge and discharge control part when receiving a demand response command. It is a figure explaining an example of operation of a demand control part. It is a flowchart explaining the flow of operation of a demand control part. It is a flowchart explaining the flow of operation of a charging/discharging control section in a distributed power supply device. It is a flowchart explaining the flow of lower DR handling processing in a charge/discharge control part. It is a flowchart explaining the flow of the raising DR corresponding process in a charge/discharge control part.

Aspects of embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

FIG. 1 is a schematic diagram showing the configuration of a distributed power supply system 1 according to the present embodiment. Distributed power supply system 1 includes a power company 10, a plurality of aggregators 12A, 12B, and a plurality of distributed power supply devices 14A, 14B, 14C. Hereinafter, the plurality of aggregators 12A and 12B may be collectively referred to as the aggregator 12. Further, the plurality of distributed power supply devices 14A, 14B, and 14C may be collectively referred to as a distributed power supply device 14.

The aggregator 12 may be, for example, a for-profit organization such as a company, a non-profit organization, or a local government. The aggregator 12 corresponds to the electric power company 10 that manages the electric power system in the area to which the aggregator 12 belongs. Although FIG. 1 illustrates two aggregators 12A and 12B corresponding to the electric power company 10, the number of aggregators 12 corresponding to the electric power company 10 may be one or three or more.

The aggregator 12 bundles and manages a plurality of distributed power supply devices 14 installed in each building (customer). For example, as shown in FIG. 1, an aggregator 12A manages three distributed power supplies 14A, 14B, and 14C. For convenience of explanation, the number of distributed power supplies 14 managed by the aggregator 12 is set to three, but the number of distributed power supplies 14 managed by the aggregator 12 may be one, two, or four or more. It's okay.

The aggregator 12 is authorized as an aggregator 12, for example, by satisfying a condition that the total output of the distributed power supply devices 14 under management is equal to or higher than a predetermined output.

The distributed power supply device 14 is provided for each building such as a house, for example. Hereinafter, buildings such as houses may be referred to as consumers. Note that the distributed power supply device 14 may be provided across multiple buildings. In this case, the aggregator 12 may manage distributed power supply devices 14 provided across multiple buildings.

Distributed power supply device 14 includes a distributed power supply unit 16 . The distributed power supply unit 16 is, for example, a fuel cell unit, but is not limited to this example. For example, the distributed power supply unit 16 may be a renewable energy power generation facility, such as a solar power generation device, a wind power generation device, a hydroelectric power generator, a geothermal power generator, a solar thermal power generator, or an atmospheric thermal power generator, whose output can be adjusted. Alternatively, it may be an internal combustion power generator or the like.

Aggregator 12 includes a demand control section 20. The demand control unit 20 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM in which programs and the like are stored, and a RAM as a work area.

When the demand of the entire power system increases, the electric power company 10 transmits a lower demand response command to the aggregator 12 requesting the electric power demand to be reduced. When the demand control unit 20 of the aggregator 12 receives the lower demand response command, it transmits the lower demand response command to the distributed power supply device 14 under management. Thereby, the demand control unit 20 increases the output of the distributed power supply device 14 under management, creates surplus power, and outputs it to the power grid.

Further, when the surplus power of the entire power system increases, the power company 10 transmits an increase demand response command to the aggregator 12 requesting the power demand to be increased. When the demand control unit 20 of the aggregator 12 receives the increased demand response command, it transmits the increased demand response command to the distributed power supply device 14 under management. Thereby, the demand control unit 20 reduces the output of the distributed power supply device 14 under management, and consumes surplus power of the power system due to the relatively increased load.

In this way, the aggregator 12 plays a role in responding to supply and demand adjustment requested by the electric power company 10 by adjusting the output of each distributed power supply device 14 under its management. Note that the lower demand response and the higher demand response may be collectively referred to simply as demand response. Further, demand response is sometimes called DR. Demand response is a mechanism that can contribute to power supply and demand adjustment not only on the power supplier side (power company 10 side) but also on the power consumer side (for example, the aggregator 12 side).

By the way, since the distributed power supply device 14 has a lower output than a power plant or the like, its ability to adjust supply and demand is relatively low. Therefore, depending on the operating status and load status of each distributed power supply device 14, there is a possibility that supply and demand adjustment cannot be adequately handled.

Therefore, the distributed power supply device 14 of the distributed power supply system 1 of this embodiment includes a storage battery 18.

The storage battery 18 is a secondary battery that can be charged and discharged. The storage battery 18 is provided in association with the distributed power supply unit 16. That is, in the distributed power supply device 14, the distributed power supply unit 16 and the storage battery 18 are connected in association so that one storage battery 18 corresponds to one distributed power supply unit 16. For example, the storage battery 18 may be built into the distributed power supply device 14 or may be provided outside the casing of the distributed power supply device 14 . Further, the storage battery 18 may be installed in advance in a new distributed power supply device 14, or may be installed in an existing distributed power supply device 14 as a retrofit.

Note that the storage batteries 18 corresponding to the distributed power supply units 16 only need to be connected under the control of the aggregator 12. The mode is not limited to one storage battery 18 provided for one distributed power supply unit 16, for example, a plurality of storage batteries 18 may be provided for one distributed power supply unit 16, or a plurality of distributed power supply units 16 may be provided with one storage battery 18. One storage battery 18 may be provided for the power supply unit 16.

In addition to increasing or decreasing the output of the distributed power supply device 14 in response to the reception of the demand response command, the demand control unit 20 of the present embodiment also causes the distributed power supply device 14 to charge and discharge the storage battery 18 . This point will be explained in detail later.

FIG. 2 is a schematic diagram illustrating details of the distributed power supply device 14. A building 30 to which the distributed power supply system 1 is applied is provided with a distribution board 32, an outlet 34, and a load 36 in addition to the distributed power supply device 14.

The distribution board 32 is connected to a power system 38. The outlet 34 is connected to the distribution board 32. Note that a plurality of outlets 34 may be connected to the distribution board 32. A load 36 is connected to the outlet 34 .

The distributed power supply device 14 is connected to the distribution board 32. Note that the distributed power supply device 14 may be connected to the distribution board 32 through the outlet 34. Further, the outlet 34 is not limited to an indoor outlet placed indoors, but may be an outdoor outlet placed outdoors. Power is supplied to the load 36 from the power system 38 and the distributed power supply device 14 .

The power distribution board 32 is provided with a power consumption detection section 40 . The power consumption detection unit 40 detects the power consumed by the load 36. Note that when a plurality of loads 36 are connected to the distribution board 32, the power consumption detection section 40 may detect the total power consumption of the plurality of loads 36.

Distributed power supply device 14 includes, in addition to distributed power supply unit 16 and storage battery 18, a power conditioner 50, a first DC/DC converter 52, a second DC/DC converter 54, a communication section 56, and a distributed power supply control section 58.

Power conditioner 50 is connected to distribution board 32. Distributed power supply unit 16 is connected to power conditioner 50 through first DC/DC converter 52 . Storage battery 18 is connected to power conditioner 50 through a second DC/DC converter 54.

The power conditioner 50 performs power conversion between AC power on the power grid 38 side and DC power on the distributed power supply unit 16 and storage battery 18 sides. The first DC/DC converter 52 performs voltage conversion between the DC voltage on the power conditioner 50 side and the DC voltage on the distributed power supply unit 16 side. The second DC/DC converter 54 performs voltage conversion between the DC voltage on the power conditioner 50 side and the DC voltage on the storage battery 18 side.

The communication unit 56 can communicate with the outside of the distributed power supply device 14 wirelessly or by wire. The communication unit 56 can communicate with the aggregator 12, for example.

The distributed power supply control unit 58 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM in which programs and the like are stored, and a RAM as a work area.

The distributed power supply control unit 58 can receive a demand response command (lower demand response command or higher demand response command) from the aggregator 12 through the communication unit 56 . When the distributed power supply control unit 58 receives the demand response command, it responds to the demand response requested by the demand response command.

As will be described in detail later, in response to receiving the lower demand response command, the distributed power supply control unit 58 lowers the output of the distributed power supply unit 16 to a level higher than the output before (for example, just before) the timing of receiving the demand response command. At the same time, the storage battery 18 is discharged. In addition, in response to receiving the raised demand response command, the distributed power supply control unit 58 sets the output of the distributed power supply unit 16 to be less than the output before (for example, just before) the timing of receiving the raised demand response command, and The storage battery 18 is charged. Note that the above-mentioned immediately before indicates, for example, the previous output control timing with respect to the current output control timing in the distributed power supply unit 16.

Hereinafter, the time when demand response is supported may be referred to as demand response time. Further, a time when a demand response command is not received and the demand response command is not supported may be called a normal time.

The distributed power supply control unit 58 normally performs load following control in which the output of the distributed power supply unit 16 is changed to follow the load 36 to cover the power of the load 36.

Further, the distributed power supply control unit 58 functions as a charging/discharging control unit 60 by executing a program. The charging/discharging control unit 60 normally controls charging/discharging of the storage battery 18 so that the SOC (State of Charge) of the storage battery 18 is approximately maintained at a predetermined reference SOC.

The charge/discharge control unit 60 can set the reference SOC to an arbitrary value. The reference SOC is set, for example, to the median value (50%). By setting the reference SOC to the median value, the storage battery 18 can be sufficiently discharged when a lower demand response is received, and the storage battery 18 can be sufficiently charged when a higher demand response is received. be able to.

Note that the reference SOC is not limited to the median value. For example, the reference SOC may be set higher than the median value or lower than the median value to the extent that charging or discharging can be performed during demand response.

When the SOC of the storage battery 18 becomes smaller than the reference SOC due to natural discharge or the like, the charge/discharge control unit 60 charges the storage battery 18 by relatively lowering the voltage on the storage battery 18 side of the second DC/DC converter 54, and the storage battery 18 is charged. Raise the SOC above the standard SOC. The SOC of the storage battery 18 is maintained at the standard SOC by repeating natural discharge and charging.

Note that the charging/discharging control unit 60 is not limited to controlling charging/discharging of the storage battery 18 so as to maintain the reference SOC of 1. For example, the charge/discharge control unit 60 may set an upper threshold value and a lower threshold value instead of the reference SOC. The charge/discharge control unit 60 may start charging when the SOC of the storage battery 18 becomes less than the lower threshold due to natural discharge, and may terminate charging when the SOC of the storage battery 18 becomes equal to or higher than the upper threshold.

Further, the charge/discharge control unit 60 may actively discharge the storage battery 18 by controlling the voltage of the second DC/DC converter 54 instead of using natural discharge to maintain the SOC of the storage battery 18 at the reference SOC. .

FIG. 3 is a diagram illustrating the operation of the charge/discharge control section 60 when receiving a demand response command. Here, description will be given assuming that the rated output of the distributed power supply unit 16 is 500W, the rated capacity of the storage battery 18 is 500W, and the power consumption by the load 36 is 200W. Note that power flow indicates the direction of power supply between the power system 38 and the building 30 (consumer), forward power flow indicates that power is supplied from the power system 38 to the building 30, and reverse power flow is It shows that power is supplied from the building 30 to the power system 38.

First, in normal times, since load following control is performed, the output of the distributed power supply unit 16 is 200W, corresponding to the 200W of the load 36. At this time, it is assumed that the reference SOC of the storage battery 18 is maintained, neither charging nor discharging is performed, and the charging/discharging power is 0W. Further, at this time, it is assumed that neither forward current nor reverse current occurs, and the current is 0W.

Furthermore, since the rated output of the distributed power supply unit 16 is 500W and the current output of the distributed power supply unit 16 is 200W, the current surplus capacity of the distributed power supply unit 16 (surplus capacity = rated output - current output ) is 300W.

Here, it is assumed that the charge/discharge control unit 60 receives a lower demand response command from the aggregator 12 through the communication unit 56. The lowering demand response command includes a lowering request value indicating a required value of the amount of reduction in power demand. The charging/discharging control unit 60 that has received the lower demand response command generates surplus power by generating additional power in addition to the power consumed by the load 36, and controls the surplus power to flow backward into the power grid 38.

For example, it is assumed that the charge/discharge control unit 60 receives a lower demand response command (lower demand response command with a lower request value of 200 W) requesting to reduce the power demand by 200 W from the aggregator 12. In this case, the current surplus capacity of the distributed power supply unit 16 is 300W, which is greater than the required reduction value (200W). Therefore, the charge/discharge control unit 60 increases the output of the distributed power supply unit 16 to the output (400 W) obtained by adding the lowered request value (200 W) to the current output (200 W). Then, the power (200 W) obtained by subtracting the power consumption (200 W) of the load from the changed output (400 W) can be supplied to the power system 38 through reverse flow.

On the other hand, assume that, for example, the charge/discharge control unit 60 receives from the aggregator 12 a lower demand response command (lower demand response command with a lower request value of 700 W) requesting to reduce the power demand by 700W. In this case, the current surplus capacity of the distributed power supply unit 16 is only 300W, and the distributed power supply unit 16 alone cannot generate the required power of 700W.

Therefore, the charge/discharge control unit 60 increases the output of the distributed power supply unit 16 to the rated output (500 W), and further discharges the insufficient power from the storage battery 18. At this time, the charge/discharge control unit 60 discharges the power (400 W) obtained by subtracting the surplus capacity (300 W) of the distributed power supply unit 16 from the lowering request value (700 W) from the storage battery 18. Then, the power (700 W) obtained by adding the discharge power (400 W) of the storage battery 18 to the surplus capacity (300 W) of the distributed power supply unit 16 can be supplied to the power system 38 through reverse flow.

In this way, by using the discharge of the storage battery 18 in combination, it is possible to cover the power consumption of the load 36 while supplying power greater than the rated output of the distributed power supply unit 16 to the power system 38. In other words, it is possible to appropriately respond to the lowering demand response command according to the lowering request value.

It is also assumed that the charge/discharge control unit 60 receives an increased demand response command from the aggregator 12 through the communication unit 56. The increase demand response command includes an increase request value indicating a request value for the amount of increase in electric power demand. The charge/discharge control unit 60 that has received the increase demand response command performs control so that the power in the power system 38 flows forward by the amount of the increase request value.

For example, assume that the charge/discharge control unit 60 receives from the aggregator 12 an increase demand response command (an increase demand response command with an increase request value of 200W) requesting to increase the power demand by 200W during normal times. In this case, the current power consumption (200W) in the load 36 is equal to the increase request value (200W). Therefore, the charge/discharge control unit 60 reduces the output of the distributed power supply unit 16 to 0W (stops the distributed power supply unit 16). Then, the power (200 W) obtained by subtracting the changed output (0 W) from the current power consumption (200 W) at the load 36 can be forwarded from the power system 38 and consumed within the building 30.

On the other hand, assume that, for example, the charge/discharge control unit 60 receives from the aggregator 12 an increase demand response command (an increase demand response command with an increase request value of 700W) requesting to increase the power demand by 700W. In this case, the current load 36 is only 200W, and the current load 36 alone cannot consume the power of 700W, which is the requested increase value.

Therefore, the charge/discharge control unit 60 lowers the output of the distributed power supply unit 16 to 0W, and further charges the storage battery 18 to function like the load 36, thereby transferring the excess power to the storage battery 18. Consume it. At this time, the charge/discharge control unit 60 charges the storage battery 18 with power (500 W) obtained by subtracting the power consumption (200 W) at the current load 36 from the increase request value (700 W). Then, the power (700 W) obtained by adding the charging power (500 W) of the storage battery 18 to the current power consumption by the load 36 (200 W) can be consumed within the building 30 by flowing forward.

In this way, by simultaneously charging the storage battery 18, it is possible to consume more power in the power system 38 within the building 30 than the current power consumption in the load 36. In other words, it is possible to appropriately respond to the increase demand response command according to the increase request value.

As described above, upon receiving the demand response command, the charging/discharging control unit 60 starts changing the output of the distributed power supply unit 16 and charging/discharging the storage battery 18 (that is, executing demand response). Then, the charge/discharge control unit 60 continues executing the demand response for a period specified by the demand response command (supply and demand adjustment period), and ends the execution of the demand response when the supply and demand adjustment period has elapsed. When execution of the demand response ends, the distributed power supply control unit 58 returns to the original load following control.

Incidentally, the supply and demand adjustment period from the start to the end of demand response may last, for example, several hours. Therefore, when the storage battery 18 is used in conjunction with demand response as described above, depending on the capacity of the storage battery 18, the supply and demand adjustment period for the lower demand response may be longer than the discharge time until the storage battery 18 is completely discharged. It can be long. Further, the supply and demand adjustment period for the increased demand response may be longer than the charging time until the storage battery 18 is fully charged.

Therefore, the demand control unit 20 of the aggregator 12 exclusively and sequentially shifts the distributed power supply devices 14 corresponding to demand response according to time.

FIG. 4 is a diagram illustrating an example of the operation of the demand control unit 20. In FIG. 4, it is assumed that the supply and demand adjustment period is 1 hour and 30 minutes.

As shown in FIG. 4, the demand control unit 20 causes the distributed power supply device 14A to start adjusting supply and demand, for example, when the demand response start time comes. When 30 minutes have passed since the start of demand response, the demand control unit 20 ends the supply and demand adjustment by the distributed power supply device 14A, and then starts the supply and demand adjustment by the distributed power supply device 14B. When one hour has passed since the start of demand response, the demand control unit 20 ends the supply and demand adjustment by the distributed power supply device 14B, and then starts the supply and demand adjustment by the distributed power supply device 14C. Then, when 1 hour and 30 minutes have passed since the start of the demand response, the demand control unit 20 ends the supply and demand adjustment by the distributed power supply device 14C.

In this way, the demand control unit 20 switches the distributed power supply device 14 that performs supply and demand adjustment every 30 minutes. When the distributed power supply device 14 that performs supply and demand adjustment is switched, the storage battery 18 that performs charging and discharging is substantially switched.

That is, the demand control unit 20 can exclusively sequentially switch the storage batteries 18 to be discharged during the supply and demand adjustment period instructed by the lower demand response command. As a result, for example, even if the storage battery 18 corresponding to the distributed power supply device 14A is completely discharged in 30 minutes, the storage battery 18 corresponding to the distributed power supply device 14B is then switched to the distributed power supply device 14B. It can be discharged. As a result, it becomes possible to continue supply and demand adjustment according to the requested reduction value from the start to the end of the reduction demand response.

Similarly, the demand control unit 20 can exclusively sequentially switch the storage batteries 18 to be charged during the supply and demand adjustment period instructed by the increased demand response command. As a result, for example, even if the storage battery 18 corresponding to the distributed power supply device 14A is fully charged in 30 minutes, the storage battery 18 corresponding to the distributed power supply device 14B is then switched to the distributed power supply device 14B. It can be charged. As a result, it becomes possible to continue adjusting supply and demand according to the requested increase value from the start to the end of the increase demand response.

In addition, in FIG. 4, an example was given in which the distributed power supply device 14 is switched every 30 minutes. However, the switching timing of the distributed power supply device 14 is not limited to 30 minutes, and may be shorter than 30 minutes or longer than 30 minutes. Moreover, in FIG. 4, an example was given in which the distributed power supply devices 14A, 14B, and 14C are switched in this order. However, the order of the distributed power supply devices 14 is not limited to this example, and may be, for example, the order of the distributed power supply devices 14B, 14C, and 14A.

Further, in FIG. 4, an example is given in which the number of distributed power supply devices 14 that are made to correspond to supply and demand adjustment in each of the divided supply and demand adjustment periods is one. However, for example, when the supply and demand adjustment period is short, a plurality of distributed power supply devices 14 may be arranged in parallel to handle supply and demand adjustment. For example, if the supply and demand adjustment period is one hour and there are four distributed power supplies 14, the first 30 minutes will be spent adjusting supply and demand with two distributed power supplies 14, and the last 30 minutes will be spent on the remaining two distributed power supplies. Supply and demand may be adjusted for the type power supply device 14. In this aspect, the amount of discharge (or amount of charge) borne by the storage battery 18 of each distributed power supply device 14 can be suppressed.

FIG. 5 is a flowchart illustrating the flow of operations of the demand control unit 20. Demand control unit 20 waits until it receives a lower demand response command or an increased demand response command from electric power company 10 (NO in S100).

Upon receiving the lower demand response command or the higher demand response command (YES in S100), the demand control unit 20 sets a schedule indicating which distributed power supply device 14 is to perform supply and demand adjustment in which order (S110). For example, the demand control unit 20 sets a schedule for switching the distributed power supply devices 14A, 14B, and 14C in this order every 30 minutes.

Next, the demand control unit 20 transmits a lower demand response command or an increased demand response command to each distributed power supply device 14 according to the set schedule (S120). As a result, each distributed power supply device 14 adjusts supply and demand at a timing according to the set schedule.

FIG. 6 is a flowchart illustrating the operation flow of the charge/discharge control section 60 in the distributed power supply device 14. The charge/discharge control unit 60 repeats the series of processes shown in FIG. 2 at each interrupt timing that occurs in a predetermined control cycle.

First, the charge/discharge control unit 60 determines whether a lower demand response command has been received (S200). If the lower demand response command is received (YES in S200), the charge/discharge control unit 60 performs lower DR corresponding processing, which is a process of adjusting supply and demand according to the lower demand response command (S210). The flow of the lower DR handling process will be described later.

If the lower demand response command has not been received (NO in S200), the charge/discharge control unit 60 determines whether or not the lower demand response command has been received (S220). When the increased demand response command is received (YES in S220), the charge/discharge control unit 60 performs increased DR corresponding processing, which is a process of adjusting supply and demand according to the increased demand response command (S230). The flow of the raised DR handling process will be described later.

If the increased demand response command has not been received (NO in S220), the charging/discharging control unit 60 considers it to be a normal time and sets the reference SOC (S240). For example, the charge/discharge control unit 60 sets the reference SOC to the median value (50%).

Next, the charge/discharge control unit 60 derives the current SOC of the storage battery 18 based on the terminal voltage of the storage battery 18, etc. (S250).

Next, the charge/discharge control unit 60 determines whether the current SOC is equal to or higher than the reference SOC (S260). If the current SOC is equal to or higher than the reference SOC (YES in S260), the charge/discharge control unit 60 ends the series of processing.

If the current SOC is less than the reference SOC (NO in S260), the charge/discharge control unit 60 charges the storage battery 18 (S270), and ends the series of processing. Note that the charge/discharge control unit 60 starts charging if charging has not started, and continues charging if charging has already started. Thereby, the SOC of the storage battery 18 is maintained at the reference SOC.

FIG. 7 is a flowchart illustrating the flow of the lowered DR handling process (S210) in the charge/discharge control unit 60.

First, the charge/discharge control unit 60 acquires the current power consumption of the load 36 from the power consumption detection unit 40 (S300). Next, the charge/discharge control unit 60 derives the current surplus capacity of the distributed power supply unit 16 (S310). Specifically, the charge/discharge control unit 60 subtracts the current output from the rated output of the distributed power supply unit 16 to derive the current surplus capacity (surplus capacity=rated output−current output).

Next, the charge/discharge control unit 60 determines whether the current surplus capacity of the distributed power supply unit 16 is greater than or equal to the lowering request value in the current lowering demand response command (S320).

If the current surplus capacity of the distributed power supply unit 16 is equal to or greater than the lowering request value (YES in S320), the charge/discharge control unit 60 derives a new output in the distributed power supply unit 16 (S330). Specifically, the charge/discharge control unit 60 adds the lowering request value to the current power consumption and sets it as a new output (output=current power consumption of the load 36 + lowering request value). Thereafter, the charge/discharge control unit 60 changes the output of the distributed power supply unit 16 to the derived output (S340), and ends the series of processing.

If the current surplus capacity of the distributed power supply unit 16 is less than the lowering request value (NO in S320), the charge/discharge control unit 60 changes the output of the distributed power supply unit 16 to the rated output (S350). Next, the charge/discharge control unit 60 derives the discharge power of the storage battery 18 (S360). Specifically, the charge/discharge control unit 60 derives the discharge power by subtracting the current surplus capacity derived in step S310 from the required decrease value (discharge power=requested decrease value−current surplus capacity). Thereafter, the charge/discharge control unit 60 causes the storage battery 18 to discharge the derived discharge power (S370), and ends the series of processing. Thereby, it is possible to supply the electric power according to the lowered request value to the electric power system 38.

FIG. 8 is a flowchart illustrating the flow of the raised DR handling process (S230) in the charge/discharge control unit 60.

First, the charge/discharge control unit 60 acquires the current power consumption of the load 36 from the power consumption detection unit 40 (S400).

Next, the charge/discharge control unit 60 determines whether the current power consumption of the distributed power supply unit 16 is greater than or equal to the increase request value in the current increase demand response command (S410).

If the current power consumption of the distributed power supply unit 16 is equal to or greater than the requested increase value (YES in S410), the charge/discharge control unit 60 derives a new output in the distributed power supply unit 16 (S420). Specifically, the charge/discharge control unit 60 subtracts the increase request value from the current power consumption to obtain a new output (output=current power consumption of the load 36−increase request value). Thereafter, the charge/discharge control unit 60 changes the output of the distributed power supply unit 16 to the derived output (S430), and ends the series of processing.

If the current power consumption of the distributed power supply unit 16 is less than the requested increase value (NO in S410), the charge/discharge control unit 60 changes the output of the distributed power supply unit 16 to zero (S440). Next, the charge/discharge control unit 60 derives the charging power of the storage battery 18 (S450). Specifically, the charge/discharge control unit 60 derives the charging power by subtracting the current power consumption from the increase request value (charging power=increase request value−current power consumption of the load 36). Thereafter, the charge/discharge control unit 60 causes the storage battery 18 to be charged by the derived charging power (S460), and ends the series of processing. Thereby, the power of the power system 38 can be consumed according to the increase request value.

As described above, in the distributed power supply system 1 of the present embodiment, in response to reception of the lower demand response command, the output of the distributed power supply unit 16 is set to be higher than the output before the reception timing of the lower demand response command. At the same time, the storage battery 18 is discharged and power is supplied to the power grid 38. Thereby, in the distributed power supply system 1 of this embodiment, it is possible to supply power equal to or higher than the rated output of the distributed power supply unit 16 to the power system 38.

Further, in the distributed power supply system 1 of this embodiment, in response to receiving the raised demand response command, the output of the distributed power supply unit 16 is set to be less than the output before the reception timing of the raised demand response command, and the storage battery 18 is charged, and power from the power grid 38 is consumed. As a result, the distributed power supply system 1 of this embodiment can consume more power from the power system 38 than the current load 36.

Therefore, according to the distributed power supply system 1 of this embodiment, it is possible to improve the ability to adjust supply and demand.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these embodiments. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the claims, and these naturally fall within the technical scope of the present invention. Understood.

For example, the charge/discharge control unit 60 may set the reference SOC as follows. The charge/discharge control unit 60 stores demand response commands received in the past in association with the date and time of reception. The charge/discharge control unit 60 predicts the generation of future demand response commands based on the date and time of reception of past demand response commands. For example, the charge/discharge control unit 60 predicts that the probability of occurrence of a lower demand response command is high one year after the reception date and time of the past lower demand response command. Note that the prediction of future demand response command generation is not limited to the reception date and time, and may be performed taking other information into consideration, such as the weather or temperature at the reception date and time, a weather forecast, and expected temperature.

Then, the charge/discharge control unit 60 determines the reference SOC according to the prediction result of the future demand response command. For example, if it is predicted that the probability of occurrence of a lower demand response command in the near future is high, the charge/discharge control unit 60 may set the reference SOC higher than the median value. Further, the charge/discharge control unit 60 may set the reference SOC lower than the median value when it is predicted that the probability of occurrence of an increased demand response command in the near future is high.

By setting the reference SOC in this way, the SOC of the storage battery 18 can be adjusted in preparation for future demand response, and when a demand response occurs as predicted, the storage battery 18 can be appropriately charged or discharged. can.

INDUSTRIAL APPLICATION This invention can be utilized for a distributed power supply system and a distributed power supply device.

1 Distributed power supply system 14 Distributed power supply device 16 Distributed power supply unit 18 Storage battery 20 Demand control section 36 Load 38 Power system 60 Charge/discharge control section

Claims (2)

a distributed power supply unit connected to the power grid and loads;
a storage battery connected to the distributed power supply unit;
In response to receiving a lower demand response command requesting a reduction in power demand, the output of the distributed power supply unit is set to be higher than the output before the reception timing of the lower demand response command, and the storage battery is discharged. a charge/discharge control unit that supplies power to the power system;
Equipped with
The charge/discharge control section includes:
predicting the occurrence of the future lowering demand response command based on the reception date and time of the past lowering demand response command, and setting a predetermined standard SOC according to the prediction result of the lowering demand response command;
A distributed power supply device that controls charging and discharging of the storage battery so that the SOC of the storage battery is maintained at the reference SOC when a demand response response is not performed in response to reception of the lower demand response command. a distributed power supply unit connected to the power grid and loads;
a storage battery connected to the distributed power supply unit;
In response to receiving an increased demand response command requesting an increase in power demand, the output of the distributed power supply unit is set to less than the output before the reception timing of the increased demand response command, and the power of the power system is increased. a charge/discharge control unit that charges the storage battery;
Equipped with
The charge/discharge control section includes:
predicting the occurrence of the future raised demand response command based on the reception date and time of the past raised demand response command, and set a predetermined standard SOC according to the prediction result of the raised demand response command;
A distributed power supply device that controls charging and discharging of the storage battery so that the SOC of the storage battery is maintained at the reference SOC when a demand response response is not performed in response to reception of the increased demand response command.

Images