WO2016017011A1

WO2016017011A1 - Electrical device, energy management controller, energy management method and program

Info

Publication number: WO2016017011A1
Application number: PCT/JP2014/070259
Authority: WO
Inventors: 香佐藤; 一郎丸山; 聡司峯澤; 裕信矢野; 矢部　正明
Original assignee: 三菱電機株式会社
Priority date: 2014-07-31
Filing date: 2014-07-31
Publication date: 2016-02-04
Also published as: JPWO2016017011A1; JP6173600B2

Abstract

An operation schedule data (540), in which at least a scheduled operation start time is indicated, is stored in a data storage unit (54) provided to an IHCH (5). A consumable power query unit (550) provided to the IHCH (5) sends a query on consumable power to an energy management controller at a pre-determined time before the scheduled operation start time indicated in the operation schedule data (540) and conserves, in the data storage unit (54) etc., data indicating the consumable power notified from the energy management controller in response to the query. An operation control unit (551) provided to the IHCH (5) controls a main operation unit (53) within the range of the notified consumable power.

Description

Electrical equipment, energy management controller, energy management method and program

The present invention relates to an electric device, an energy management controller, an energy management method, and a program.

In order to prevent the electric power supply from the commercial power source from being cut off by the current limiter installed in the home of a general household, the electric power connected via the network is monitored by the system that monitors the power consumed in this household. Technologies for reducing power consumption of devices are known (for example, Patent Documents 1 and 2).

In Patent Document 1, when an operation to increase power consumption is performed by a user, power information available to the power control system is inquired. When power information available from the power control system is received, power consumption is determined according to the power information. An induction heating cooker that determines the upper limit of is disclosed.

Further, in Patent Document 2, each electric device is activated with a common small amount of power, communicates with the power control device, notifies the operation mode selected by the user, and responds to the operation permission from the power control device. Is obtained, a system for starting operation in the operation mode is disclosed.

JP 2014-078324 A JP 2011-078223 A

In the above-described conventional technology, it takes time until the operation corresponding to the operation is performed after the operation by the user, which may cause inconvenience to the user.

The present invention has been made to solve the above-described problem, and an object of the present invention is to provide an electric device or the like that does not impair the convenience of the user while reliably preventing the interruption of the electric supply by the current limiter. And

In order to achieve the above object, an electrical device according to the present invention is:
A user interface unit that accepts user operations;
A communication unit communicating with the energy management controller;
An operation schedule storage unit for storing an operation schedule indicating at least the time at which the operation is scheduled to start;
An operation unit that operates based on an operation received from a user;
When a predetermined time before the time indicated in the operation schedule is reached, the energy management controller is inquired about consumable power, and the consumable power notified from the energy management controller in response to the inquiry A consumable power inquiry unit that stores data indicating
An operation control unit that controls the operation unit within the notified range of consumable power.

According to the present invention, it is possible to reliably prevent the electric power supply from being interrupted by the current limiter and maintain the convenience of the user.

It is a figure which shows the whole structure of the energy management system which concerns on Embodiment 1 of this invention. 2 is a block diagram illustrating a configuration of an IHCH according to Embodiment 1. FIG. It is a figure which shows a driving schedule. It is a block diagram which shows the structure of the energy management controller of Embodiment 1. It is a figure which shows the function structure of the control part with which the energy management controller of Embodiment 1 is provided. 3 is a flowchart illustrating a procedure of pre-operation processing that is executed by the IHCH according to the first embodiment. In Embodiment 1, it is a figure which shows the communication sequence between IHCH and an energy management controller. It is a figure which shows the function structure of the control part with which the energy management controller which concerns on Embodiment 2 of this invention is provided. 6 is a flowchart illustrating a procedure of power securing processing executed by the energy management controller according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing an overall configuration of an energy management system 1 according to Embodiment 1 of the present invention. The energy management system 1 is a so-called HEMS (Home Energy Management System) that manages electric power used in a general household. The energy management system 1 includes an energy management controller 2, an operation terminal 3, a power meter 4, an IHCH 5, and a plurality of devices 6 (

devices

6a, 6b,...).

The energy management controller 2 is installed at an appropriate location in the house H, monitors the power consumed in this home (demand area), displays the power consumption status via the operation terminal 3, and displays the IHCH 5 and The operation of each device 6 is controlled. Details of the energy management controller 2 will be described later.

The operation terminal 3 includes an input device such as a touch panel and a touch pad, a display device such as a liquid crystal display, and a communication interface. The operation terminal 3 performs data communication with the energy management controller 2 in accordance with a well-known wireless LAN standard such as Wi-Fi (registered trademark). The operation terminal 3 functions as an interface (user interface) between the energy management system 1 and a user who is a resident of the house H.

IHCH5 (electric equipment, specific equipment) is an electromagnetic cooker called a so-called IH (Induction Heating) cooking heater. The IHCH 5 is supplied with power from the commercial power source 7 and the like via the power line D1, the distribution board 8, and the power line D2. Details of IHCH5 will be described later.

The device 6 (

devices

6a, 6b,...) Is a controlled device other than the IHCH 5, and is, for example, an illuminator, an air conditioner, a refrigerator, a rice cooker, a microwave oven, a floor heating system, and the like, and is connected to the power line D2. . Each device 6 includes a wireless communication interface, and is communicably connected to the energy management controller 2 via a wireless network (not shown) constructed in the house H. This wireless network is, for example, a network conforming to ECHONET Lite. Each device 6 may be of a specification that is connected to this wireless network via an external communication adapter (not shown).

The power meter 4 measures the power (total power consumption) consumed in this home (demand area). The power meter 4 is connected to a CT (Current Transformer) connected to the power line D2 via a communication line. CT is a sensor that measures alternating current. The power meter 4 measures the total power consumption based on the CT measurement result. The power meter 4 includes a wireless communication interface, and is communicably connected to the energy management controller 2 via the wireless network (not shown). The power meter 4 may be of a specification that is connected to this wireless network via an external communication adapter (not shown).

In response to the request from the energy management controller 2, the power meter 4 generates measurement data that stores the measured total power consumption value and transmits the measurement data to the energy management controller 2.

As shown in FIG. 2, the IHCH 5 includes a user interface unit 50, a communication unit 51, an internal communication unit 52, a main operation unit 53, a data storage unit 54, and a control unit 55. The user interface unit 50, the communication unit 51, the internal communication unit 52, the data storage unit 54, and the control unit 55 are connected to each other via a bus 56.

The user interface unit 50 includes, for example, a display device such as a liquid crystal display or an organic EL (Electro-Luminescence) display, and an input device such as a touch panel and a touch pad. The user interface unit 50 receives an operation input by the user, and displays various screens according to the operation input.

The communication unit 51 includes a communication interface such as a wireless LAN card, for example, is connected to the above-described wireless network, and performs wireless data communication with the energy management controller 2 under the control of the control unit 55. The internal communication unit 52 is an interface for communication with the main operation unit 53. The main operation unit 53 is a component for realizing an original function (for example, a heating function) of the IHCH 5.

The data storage unit 54 includes, for example, a readable / writable nonvolatile semiconductor memory such as a flash memory. The data storage unit 54 stores operation schedule data 540. In addition, the data storage unit 54 stores programs and data for data communication with the energy management controller 2, programs and data for controlling the main operation unit 53, and the like.

The operation schedule data 540 is data indicating the operation schedule of the IHCH5. More specifically, the driving schedule data 540 is data indicating a driving start schedule (see FIG. 3) of IHCH 5 in one day. The operation schedule of the IHCH 5 is constructed by the energy management controller 2 and transmitted to the IHCH 5.

The control unit 55 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. (all not shown), and controls the IHCH 5 in an integrated manner. Functionally, the control unit 55 includes a consumable power inquiry unit 550 and an operation control unit 551.

The consumable power inquiry unit 550 acquires the scheduled operation start time from the operation schedule data 540, and when it is a predetermined time (for example, 3 minutes) before the acquired scheduled time, the energy management controller 2 Inquire about the power consumption. Here, the consumable power is power indicating an allowable value of power consumed by the IHCH 5 and is determined by the energy management controller 2.

When the consumable power is notified from the energy management controller 2 in response to the above inquiry, the consumable power inquiry unit 550 sends the data indicating the notified consumable power to the RAM or the data storage unit 54 or the like. save. The operation control unit 551 operates the main operation unit 53 within the notified consumable power range when an operation such as an increase in heating power (heating amount) is performed by the user.

Subsequently, details of the energy management controller 2 will be described. As shown in FIG. 4, the energy management controller 2 includes a power communication device 4, an IHCH 5, a device communication unit 20 for communicating with each device 6, a terminal communication unit 21 for communicating with the operation terminal 3, a program, The data storage part 22 for hold | maintaining data and the control part 23 which controls these are provided. These components are connected to each other via a bus 24.

The device communication unit 20 includes a communication interface such as a wireless LAN card, for example, is connected to the above-described wireless network, and performs wireless data communication with the power meter 4, IHCH 5, and each device 6 under the control of the control unit 23. .

The terminal communication unit 21 is provided with a predetermined short-range wireless communication interface. The terminal communication unit 21 conforms to the operation terminal 3 and a well-known wireless LAN standard such as Wi-Fi (registered trademark) under the control of the control unit 23. Perform data communication.

The data storage unit 22 is composed of, for example, a readable / writable nonvolatile semiconductor memory such as a flash memory. The data storage unit 22 stores an operation history table 220 and operation schedule data 221. Although not shown, the data storage unit 22 is a program for monitoring power consumed in the home, a program for controlling the operation of the IHCH 5 and each device 6, and execution of these programs. Stores data that is sometimes used.

The operation history table 220 is a data table in which IHCH5 operation information history is stored. The driving information of the IHCH5 is information indicating the date and time (year / month / day) when the driving of the IHCH5 was started by a user operation.

The operation schedule data 221 is data indicating a daily operation schedule of the IHCH5. More specifically, the driving schedule data 221 is data indicating a driving start schedule for IHCH5 in one day.

The control unit 23 is configured to include a CPU, a ROM, a RAM, and the like (all not shown), and comprehensively controls the energy management controller 2. As shown in FIG. 5, the control unit 23 functionally includes a user interface processing unit 230, an operation information acquisition unit 231, an operation schedule learning unit 232, a power monitoring unit 233, a device control unit 234, Is provided. The functions of these components are realized by a CPU or the like executing a program stored in the data storage unit 22.

The user interface processing unit 230 performs user interface processing via the operation terminal 3. That is, the user interface processing unit 230 performs a process of receiving an operation from the user via the operation terminal 3 and the terminal communication unit 21. In addition, the user interface processing unit 230 performs processing for transmitting information to be presented to the user to the operation terminal 3 via the terminal communication unit 21 and displaying the information on the operation terminal 3.

The driving information acquisition unit 231 acquires the above-described driving information from the IHCH 5 through communication with the IHCH 5. The driving information acquisition unit 231 stores the acquired driving information in the driving history table 220.

The driving schedule learning unit 232 learns the driving schedule for IHCH5 for one day from the driving history table 220 stored in the data storage unit 22, and the learning result is driving schedule data stored in the data storage unit 22. 221 is reflected. The driving schedule learning unit 232 executes the processing related to this learning at a predetermined time every day (for example, midnight), and transmits the same data as the driving schedule data 221 reflecting the learning result to the IHCH 5.

The power monitoring unit 233 monitors the power consumed in this home. More specifically, the power monitoring unit 233 requests the power meter 4 to transmit the measurement data described above at regular time intervals, and acquires the total power consumption measured by the power meter 4. Then, the power monitoring unit 233 compares the acquired total power consumption with a predetermined upper limit power, and determines whether or not the total power consumption is below the upper limit power.

The upper limit power is determined based on contract limit power. The contract limit power indicates a limit on the total power consumption in the contract between the user and the power company, and is specifically determined based on a so-called contract amperage value. The value of the upper limit power is determined to be a value smaller than the contract limit power value. How small it is is an arbitrary design matter. For example, a value of about 90% of the contract limit power may be set as the upper limit power value. In addition, the upper limit determined as above when a DR (Demand Response) request is received from a power system or a higher-level system such as CEMS (Cluster / Community Energy Management System) or when the electricity rate is high You may adjust in the direction which makes the value of electric power still smaller.

When the total power consumption exceeds the upper limit power, the power monitoring unit 233 notifies the device control unit 234 to that effect. Alternatively, the power monitoring unit 233 notifies the user via the operation terminal 3 so as to reduce power consumption.

Further, when there is an inquiry about consumable power from the IHCH 5, the power monitoring unit 233 calculates the consumable power from the current total power consumption and the upper limit power, and notifies the calculated consumable power to the IHCH 5.

The device control unit 234 controls the operation of the IHCH 5 and each device 6 based on the monitoring result by the power monitoring unit 233. Specifically, upon receiving notification from the power monitoring unit 233 that the total power consumption exceeds the upper limit power, the device control unit 234 performs peak cut control. Note that the peak cut control here means that the electric power supply from the commercial power source 7 is not cut off by a current limiter (not shown) installed in the distribution board 8 (also referred to as an ampere breaker). This refers to control that suppresses or reduces the power consumption of the devices to be managed at home (that is, the IHCH 5 and each device 6).

FIG. 6 is a flowchart showing a flow of pre-operation processing executed by the control unit 55 of the IHCH 5. When the control unit 55 receives the same data as the operation schedule data 221 transmitted from the energy management controller 2 via the communication unit 51, the control unit 55 overwrites the operation schedule data 540 stored in the data storage unit 54 with the data. To do. The consumable power inquiry unit 550 of the control unit 55 acquires the scheduled operation start time from the operation schedule data 540 updated in this way. Then, the consumable power inquiry unit 550 executes a pre-operation process described below when a predetermined time (for example, 3 minutes) before the acquired scheduled start time of the operation.

The consumable power inquiry unit 550 makes an inquiry about consumable power to the energy management controller 2 (step S101). When the consumable power is notified from the energy management controller 2 in response to the inquiry (step S102; YES), the consumable power inquiry unit 550 notifies the RAM or the data storage unit 54 or the like of the consumable power that has been notified. Is stored (step S103). Thus, the pre-operation process is completed.

FIG. 7 shows a communication sequence between the IHCH 5 and the energy management controller 2.

As described above, according to the energy management system 1 of the present embodiment, the IHCH 5 acquires consumable power from the energy management controller 2 and holds it before use by the user. Thereby, the IHCH 5 does not need to make an inquiry about the power consumption after the user performs an operation on the IHCH 5. Therefore, the IHCH 5 can immediately perform an operation according to the user's operation content. Accordingly, it is possible to reliably prevent interruption of the electric supply by the current limiter without impairing the convenience for the user.

In the above-described pre-operation processing, there may be a situation in which it is impossible to communicate with the energy management controller 2 for some reason and the consumable power cannot be acquired. In this case, the consumable power inquiry unit 550 displays a warning message on the liquid crystal screen or the like of the user interface unit 50 indicating that communication with the energy management controller 2 is not possible and a call for attention to exceeding the total power consumption. . By displaying such a warning message, the user can perform an operation paying attention to the excess of the total power consumption, and as a result, the electric power supply can be prevented from being interrupted by the current limiter.

(Modification 1)
In the present embodiment, the IHCH 5 operation schedule is constructed by the energy management controller 2, but the IHCH 5 may construct the operation schedule by learning from its own operation history. In this case, the IHCH 5 does not necessarily need to transmit the constructed operation schedule to the energy management controller 2.

(Modification 2)
The energy management controller 2 voluntarily notifies the IHCH 5 of consumable power at a timing based on the scheduled operation start time acquired from the operation schedule data 221 (for example, 3 minutes before the scheduled operation start time). May be. In this case, the above-described pre-operation processing in the IHCH 5 is not necessary, and the IHCH 5 only needs to hold the consumable power notified from the energy management controller 2.

(Embodiment 2)
Subsequently, Embodiment 2 of the present invention will be described. In the following description, components and the like that are common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the energy management system 1 of the present embodiment, unlike the data storage unit 54 of the IHCH 5 of the first embodiment, the operation schedule data 540 is not stored in the data storage unit 54 of the IHCH 5. Moreover, IHCH5 of this embodiment performs the operation | movement according to a user's operation content immediately, without performing a driving | operation pretreatment like Embodiment 1. FIG.

In order to realize the operation of the IHCH 5 as described above, the energy management controller 2 of the present embodiment performs a control to reduce the power consumption of all or some of the devices 6 before the operation of the IHCH 5 is started. By reducing the power consumption, a process for securing power corresponding to the maximum power consumption of the IHCH 5 (power securing process) is performed.

As shown in FIG. 8, a process activation unit 235 is added to the control unit 23 provided in the energy management controller 2 of the present embodiment. The process activation unit 235 activates the power securing process. Specifically, when the operation schedule data 221 is updated by the learning process by the operation schedule learning unit 232, the process activation unit 235 acquires the scheduled operation start time from the updated operation schedule data 221. Then, the process activation unit 235 activates the power securing process when a predetermined time (for example, 5 minutes) before the acquired scheduled operation start time.

FIG. 9 is a flowchart showing the flow of the power securing process executed by the control unit 23 of the energy management controller 2. First, the power monitoring unit 233 determines whether or not the power is insufficient when the IHCH 5 operates at the maximum power consumption (step S201). Specifically, when the value obtained by subtracting the current total power consumption and the maximum power consumption of IHCH5 from the upper limit power is negative, the power monitoring unit 233 determines that the power is insufficient, If it is positive, it is determined that there is no shortage of power.

As a result of the above determination, when it is determined that there is no power shortage (step S201; NO), the power securing process ends. In this case, even if the IHCH 5 operates at the maximum power consumption, the total power consumption falls below the upper limit power, so the energy management controller 2 does not perform control for reducing the total power consumption.

On the other hand, when it is determined that the power is insufficient (step S201; YES), the power monitoring unit 233 notifies the device control unit 234 that the power is insufficient and the value of the insufficient power. Upon receiving such notification, the device control unit 234 selects the device 6 that suppresses power consumption (step S202). Here, the device control unit 234 may select all the devices 6 as suppression targets, or may select the devices 6 that satisfy a predetermined selection condition as suppression targets. For example, the device control unit 234 may select the device 6 to be suppressed based on the value of the insufficient power and the priority order previously assigned to each device 6.

The device control unit 234 reduces power consumption of the selected device 6 by controlling the selected device 6 to reduce the current driving ability (step S203).

As described above, according to the energy management system 1 of the present embodiment, the same effects as those of the energy management system 1 of the first embodiment can be obtained. In other words, the IHCH 5 does not need to make an inquiry about the power consumption after an operation on the IHCH 5 is performed by the user, so that it is possible to immediately perform an operation according to the operation content of the user.

In the present embodiment, the IHCH 5 can reduce the frequency of data communication with the energy management system 2, so that a power saving effect can be expected. Furthermore, since the IHCH 5 does not perform any special processing, it can be easily realized by a general-purpose IH cooking heater having a communication function.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, the electric device in the present invention is not limited to the IH cooking heater. The present invention can be applied to various devices such as an electronic microwave oven in which power consumption is rapidly increased by a user operation.

In each of the above embodiments, the program executed by the energy management controller 2 is a CD-ROM (Compact Disc Read Only Memory), DVD (Digital Versatile Disc), MO (Magneto-Optical Disk), USB memory, memory card. It is also possible to store and distribute in a computer-readable recording medium such as the above. Then, by installing such a program on a specific or general-purpose computer, the computer can function as the energy management controller 2 in each of the above embodiments.

Further, the above program may be stored in a disk device or the like included in a server device on a communication network such as the Internet, and may be downloaded onto a computer, for example, superimposed on a carrier wave. The above-described processing can also be achieved by starting and executing a program while transferring it via a communication network. Furthermore, the above-described processing can also be achieved by executing all or part of the program on the server device and executing the program while the computer transmits and receives information regarding the processing via the communication network.

Note that when the above functions are realized by sharing an OS (Operating System) or when the functions are realized by cooperation between the OS and an application, only the part other than the OS is stored in the recording medium and distributed. It may also be downloaded to a computer.

The present invention can be variously modified and modified without departing from the spirit and scope of the broad sense. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

The present invention can be suitably employed in a system that manages electric power used in the home.

1 energy management system, 2 energy management controller, 3 operation terminal, 4 power meter, 5 IHCH, 6a, 6b device, 7 commercial power supply, 8 distribution board, 20 device communication unit, 21 terminal communication unit, 22, 54 data Storage unit, 23, 55 control unit, 24, 56 bus, 50 user interface unit, 51 communication unit, 52 internal communication unit, 53 main operation unit, 220 operation history table, 221 operation schedule data, 230 user interface processing unit, 231 Operation information acquisition unit, 232 operation schedule learning unit, 233 power monitoring unit, 234 device control unit, 235 process start-up unit, 540 operation schedule data, 550 consumable power inquiry unit, 551 operation control unit, D1, D2 power line

Claims

A user interface unit that accepts user operations;
A communication unit communicating with the energy management controller;
An operation schedule storage unit for storing an operation schedule indicating at least the time at which the operation is scheduled to start;
An operation unit that operates based on an operation received from a user;
When a predetermined time before the time indicated in the operation schedule is reached, the energy management controller is inquired about consumable power, and the consumable power notified from the energy management controller in response to the inquiry A consumable power inquiry unit that stores data indicating
And an operation control unit that controls the operation unit within the notified range of consumable power.
The consumable power inquiry unit presents a message with a predetermined content via the user interface unit when an operation by a user is performed when communication with the energy management controller is not possible. Electrical equipment as described in.
A power meter that measures power consumed in a demand area, a communication unit that communicates with a plurality of controlled devices installed in the demand area,
With respect to one specific device among the plurality of controlled devices, an operation schedule storage unit that stores an operation schedule showing at least a time at which operation is scheduled to start, and
When the specific device operates at the maximum power consumption based on the power measured by the power meter and a predetermined upper limit power when the predetermined time before the time indicated in the operation schedule is reached A power monitoring unit for determining whether the power is insufficient,
When it is determined by the power monitoring unit that power is insufficient, a device control unit that controls the operation of all or part of the plurality of controlled devices excluding the specific device so that power consumption is reduced, and Energy management controller.
A power meter that measures the power consumed in the demand area, and a communication unit that communicates with the electrical equipment installed in the demand area,
Regarding the electrical equipment, an operation schedule storage unit that stores an operation schedule in which at least the time at which operation is scheduled to start is stored;
When a predetermined time before the time indicated in the operation schedule is reached, an allowable value of the power consumed by the electrical device is determined based on the power measured by the power meter and a predetermined upper limit power. An energy management controller comprising: a power monitoring unit that calculates consumable power to be displayed and notifies the electrical device of the calculated consumable power.
Acquiring a time at which the operation of the specific device is scheduled to start from an operation schedule related to one specific device among a plurality of controlled devices stored in the storage unit;
When the predetermined time before the acquired time, based on the power measured by the power meter and the predetermined upper limit power, is the power shortage when the specific device operates at the maximum power consumption? Determine whether or not
An energy management method for controlling the operation of all or a part of the plurality of controlled devices excluding the specific device so that power consumption is reduced when it is determined that power is insufficient.
Obtain the time when the operation of the electric device is scheduled to start from the operation schedule of the electric device stored in the storage unit,
When a predetermined time before the acquired time is reached, a consumable power indicating an allowable value of the power consumed by the electrical device is calculated based on the power measured by the power meter and a predetermined upper limit power. And
An energy management method of notifying the electric device of the calculated consumable power.
Computer
The time when the start of the operation of the specific device is scheduled is acquired from the operation schedule related to one specific device among the plurality of controlled devices stored in the storage unit, and a predetermined time before the acquired time Then, based on the power measured by the power meter and a predetermined upper limit power, a power monitoring unit that determines whether or not power is insufficient when the specific device operates at maximum power consumption,
When the power monitoring unit determines that power is insufficient, a program that functions as a device control unit that controls all or part of operations of the plurality of controlled devices except the specific device so that power consumption is reduced. .
Computer
The time when the start of the operation of the electric device is scheduled is acquired from the operation schedule of the electric device stored in the storage unit, and the power measured by the power measuring instrument is a predetermined time before the acquired time. And a program for causing the power device to function as a power monitoring unit that calculates consumable power indicating an allowable value of power consumed by the electrical device based on a predetermined upper limit power and notifies the electrical device of the calculated consumable power .