Patent Application
20150229128
The present invention relates to an art for managing power supply to users in a certain group for example, and more particularly to a method of managing electric power, a power management device and a program, which allows grid power supplied to a group to be flattened in a certain time range by totally managing electric power within the group.
In recent years, it is proposed that, regarding power supply to residences and buildings among other things, supply control of power is performed using IT (information technology) technology and that power storage system in addition to the grid power from a power plant is used. For example, Patent Document 1 discloses disposing photovoltaic power generator and power storage system in a residence, outputting power from the photovoltaic power generator to an external power system, and using the power for charging the power storage system.
Although Patent Document 1 discloses managing individual electric power for each residence, it does not focus on total electric power management in an area. Meanwhile, to reduce load of a power plant which administers the region, it is desirable to totally manage electric power in the whole region and control grid power required in the region, power from the power storage system, or the like, instead of individually managing power for each house or each building. Particularly, even when the much grid power is consumed intensively in a region, it is preferable that the grid power can be flattened in a certain time range, so that load on power plant can be reduced.
To address the problem, an object of the present invention is to provide a method of managing electric power, a power management device and a program, which allows grid power supplied to a group to be flattened in a certain time range by totally managing electric power within the group.
To achieve the above-described object, a method of managing electric power according to one aspect of the present invention is as follows:
obtaining a power consumed by the users (referred to as “load power”) and a peak cut power in the group;
deciding a power to be discharged from the power storage system in each time segment by using at least the load power and the peak cut power; and
deciding an index indicating how much grid power has been previously consumed within the group (referred to as a “grid power consumption index”),
wherein in step of determining a power to be discharged from the power storage system, the power to be discharged from the power storage system is decided by using all of the grid power consumption index, the load power, and the peak cut power.
As the “users”, residences, buildings, commercial facilities, industrial facilities, medical facilities or the like are included.
As to “time segments”, length of one time segment can be arbitrarily configured, and, for example, the length of one time segment may be several minutes to several tens of minutes, an hour or the like. Moreover, each time segment is not needed to be constant.
According to the present invention, it is possible to provide a method of managing electric power, a power management device and a program, which allows grid power supplied to a group to be flattened in a certain time range by totally managing electric power within the group.
Embodiments of the present invention are described with reference to the drawings. It is noted that configurations, functions, operations and the like described below are according to an embodiment of the present invention and are not intended to limit the present invention.
As shown in
It is noted that while only the building and the residences are shown in
The building 21 includes a power storage system 13 and a photovoltaic power generator 15. While in the present embodiment, the photovoltaic power generator 15 is illustrated as an example of a power generator, it is also possible to use other types of power generator such as a fuel cell.
A power management device, not shown, for measuring and managing information such as a power demand in the building 21 is also provided. The following managements for power and information are performed in the building 21:
In the house 22, a power storage system 13 and a photovoltaic power generator 15 are provided, as with the building 21. A power management device, not shown, for measuring and managing information of power demand, or the like, is also provided. The following managements of power and information are performed in the house 22:
In the house 23, an power storage system 13, a photovoltaic power generator 15 and the like are not provided, but only a power monitor 19 is provided. The following managements of power and information are performed in the house 23:
It is noted that, concerning the above-described (e), it is also possible that power management device, not shown, or power monitor 19 itself transmit information by using network connection function provided therein. Alternatively, the information may be transmitted to outside for example via a server disposed within the building or the house.
As shown in
Concerning (a), for example, the power management device 30 may obtain the power demand by receiving information transmitted from each user and adding these information. Concerning (b), peak cut power may be determined by user inputting the information to the power management device 30 or by automatic input where information relating peak cut power being automatically input from another device connected to the power management device 30.
The power management device 30 may also have a function of determining a power usage situation within the group A or performing a demand response control (control for changing a power consumption pattern), a function of starting/stopping power supply from the power storage system, or the like.
As shown in
The program, by way of example, may be stored in the storage unit of the computer in advance, may be supplied via a network such as an internet, or may be supplied to via a predetermined storage medium storing data of the program.
One example of a method of managing electric power in the system of the present embodiment will be described next.
It should be noted that in the following description, “Peak cut power” is a reference electric power value at which power supply from the power storage system is started in order to cut peak of the electric power, and is herein set to be “1.00”. “Grid power consumption change value” is an index indicating an amount of grid power which has been consumed within the group before the time segment, and is initially set at “0.00”. “Discharge power of power storage system” represents electric power amount discharged from the power storage system in the group A, and its maximum output is set to be “2.00”.
Description will be given below according to the flowchart.
First of all, in step S1, it is determined whether a value obtained by subtracting the “PV generated power” from the “load power” is equal to or greater than the “peak cut power”. In this time segment, since (load power, PV generated power, peak cut power)=(1.04, 0.50, 1.00), and the load power-the PV generated power, 1.04−0.50=0.54, being not equal to or greater than the peak cut power of 1.0, the determination in step S1 is “No”.
The flow then proceeds to step S6, it is determined whether the load power is greater than the PV generated power. In this time segment, since the load power of 1.04 is greater than the PV generated power of 0.50, the determination in step S6 is “Yes”.
As a result, as shown in
Finally, in step S4, a difference between the peak cut power value and the grid power consumption value is calculated to determine a grid power consumption change value in this time segment. Specifically, a value of −0.46, obtained by adding a difference of −0.46 between the peak cut power value of 1.00 and the grid power consumption value of 0.54 to the previous value (initial value of 0.00), is updated as the grid power consumption change value at this time point.
Returning to step S1 again, in the time segment “2”, since (load power, PV generated power, peak cut power)=(3.00, 0.50, 1.00), and the load power—the PV generated power, 3.00−0.50=2.50, being greater than the peak cut power of 1.0, the determination in step S1 is “Yes”.
The flow then proceeds to step S2, it is determined whether a value obtained by subtracting the PV generated power and the peak cut power from the load power and by adding the grid power consumption change value to the resultant is equal to or greater than the maximum discharge power of the power storage system. The grid power consumption change value has been calculated at −0.46 in the previous time segment (see step S4). Therefore, the result of calculation is 3.0−0.5−1.0−0.46=1.04, being not equal to or greater than 2.0 which is the maximum discharge power of the power storage system, thus, the determination in step S2 is “No”.
The flow then proceeds to step S5, power to be discharged from the power storage system is calculated. Specifically, a value obtained by subtracting the PV generated power and the peak cut power from the load power, and by adding the grid power consumption change value to the resultant is set as a power to be discharged. In this time segment, discharging is performed at 3.00−0.50−1.00−0.46=1.04.
As a result, as shown in
Finally, in step S4, a difference of 0.46 between the peak cut value of 1.00 and the grid power consumption value of 1.46 is added to the previous value of −0.46, and then the resultant of 0.00 is updated as the grid power consumption change value in this time segment.
time segment “3”
In this time segment, discharging of the power storage system is performed at maximum output. In the time segment “3”, since (load power, PV generated power, peak cut power)=(4.00, 0.50, 1.00), and the load power—the PV generated power, 4.00−0.50=3.50, being greater than the peak cut power of 1.00, the determination in step S1 is “Yes”.
The flow then proceeds to step S2. The grid power consumption change value has been determined at 0.00 in the previous time segment (see step S4). Since the result of the calculation is 4.00−0.50−1.00−0.00=2.50, being greater than 2.00 which is the maximum discharge power of the power storage system, the determination in step S2 is “Yes”.
As a result, as shown in
Finally, in step S4, a difference of 0.50 between the peak cut power value of 1.00 and the grid power consumption value of 1.50 is added to the previous value of 0.00, and the grid power consumption change value is updated with the resultant of 0.50 in this time segment.
Also in the time segments “4” to “7”, power management can be performed according to the same steps as described above.
In this time segment, since (load power, PV generated power, peak cut power)=(2.10, 0.50, 1.00), and the load power—the PV generated power, 2.10−0.50=1.60, being greater than the peak cut power of 1.00, the determination in step S1 is “Yes”.
The flow then proceeds to step S2. The grid power consumption change value has been determined at 0.80 in the previous time segment (see step S4). Since the result of the calculation is 2.10−0.50−1.00+0.80=1.40, being not equal to or greater than 2.00 which is the maximum discharge amount of the power storage system, the determination in step S2 is “No”.
The flow then proceeds to step S5, discharging is performed at 2.10−0.50−1.00+0.80=1.40.
The steps after step S4 are the same as those described above.
time segment “9”
The time segment “9” in which power supply from the power storage system is stopped will be described.
First of all, in step S1, since (load power, PV generated power, peak cut power)=(1.30, 0.50. 1.00), and the load power—the PV generated power, 1.30−0.50=0.80, being not equal to or greater than the peak cut power of 1.00, the determination in step S1 is “No”.
The flow then proceeds to step S6. Since in the time segment “9”, the load power of 1.30 is greater than the PV generated power of 0.50, the determination in step S6 is “Yes”.
As a result, as shown in
The steps after step S4 are the same as those described above.
Also in the time segments “10”, “11”, “14” and “15”, power management can be performed according to the same steps as those in the time segment “9”.
In these time segments, the power storage system is charged. Taking an example of the time segment “12”, since (load power, PV generated power, peak cut power)=(0.30, 0.50, 1.00), and the load power—the PV generated power, 0.30−0.50=−0.20, being not equal to or greater than the peak cut power of 1.00, the determination in step S1 is “No”.
The flow then proceeds to step S6. Since the load power of 0.30 is not greater than the PV generated power of 0.50, the determination in step S6 is “No”.
The flow then proceeds to step S7, since the load power—the PV generated power, 0.30−0.50=−0.20, discharging is performed at this value (the calculated value being below zero means that the power storage system is charged).
The steps after step S4 are the same as described above.
In this time segment, since (load power, PV generated power, peak cut power)=(1.80, 0.50, 1.00), and the load power—the PV generated power, 1.80−0.50=1.30, being greater than the peak cut power of 1.00, the determination in step S1 is “Yes”.
The flow then proceeds to step S2. The grid power consumption change value has been determined at −4.60 in the previous time segment. As a result of the calculation, since 1.80−0.50−1.00−4.60=−4.30, being not equal to or greater than 2.00 which is the maximum discharge power of the power storage system, the determination in step S2 is “No”.
The flow then proceeds to step S5, discharging is performed at 1.80−0.50−1.00−4.60=−4.30 (that is, the power storage system is charged). As a result, the load power of 1.8 is provided by the PV generated power of 0.5 and the grid power of 1.3.
According to the power management in accordance with the flowchart as described above, in the group A, it is possible to manage electric power for each time segment as shown in
In the case of the conventional power management in
In contrast to this, in the case of the present embodiment, power within the group is totally managed, and power of the power storage system within the group A is determined also taking into account the “grid power consumption index”. It is therefore possible to reduce the grid power in the time segments “6”, “7” and “8”, resulting in reducing load on the power plant. Since the load on the power plant is reduced, it is not necessary to provide a large-scale power storage system at the power plant, and it is possible to realize efficient power consumption in the entire group.
While one aspect of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be modified in various ways. For example:
The present specification also discloses the following inventions:
obtaining a power consumed by the users (referred to as “load power”) and a peak cut power in the group;
deciding a power to be discharged from the power storage system in each time segment by using at least the load power and the peak cut power (S2, S3 and S5); and
deciding an index indicating how much grid power has been previously consumed within the group (referred to as a “grid power consumption index”) (S4),
wherein in the step of determining a power to be discharged from the power storage system (S2, S3 and S5), a power to be discharged from the power storage system is decided by using all of the grid power consumption index, the load power, and the peak cut power.
According to the above-described method, since the index indicating how much grid power was previously consumed within the group (“grid power consumption index”) is used to decide power to be discharged from the power storage system within the group, it is possible to flatten grid power within the group within a certain time range.
It should be noted that the present specification also discloses inventions in which the inventions of the above-described method 1 and the method described in the embodiment are replaced with inventions of an apparatus and a program.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-200415 | Sep 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/074731 | 9/12/2013 | WO | 00 |
