JP6419495B2 - Demand control system and demand control method - Google Patents

Description

  The present invention relates to a demand control system and a demand control method.

  About 50% of the total amount of power in a general office building or the like is occupied by the amount of power used by the air conditioner. Therefore, the reduction of the power consumption of the air conditioner can greatly contribute to the peak cut of the power consumption of the entire building.

  By the way, in the case of a building having rooms on a plurality of floors such as an office building, so-called multi-air conditioners are often employed because a large number of indoor units need to be installed. A multi air conditioner is a type of air conditioner in which a plurality of indoor units are connected to one outdoor unit, and a plurality of indoor units can be operated by one outdoor unit. Many of the multi air conditioners used in office buildings are known to consume more power in the outdoor unit than in the indoor unit because the power consumption of the compressor built in the outdoor unit is large.

  As a method for performing peak cut of the electric energy of the entire building where the multi air conditioner is installed, for example, the following method can be cited. That is, the demand control method (demand control method) that turns on and off indoor units in sequence according to the power consumption value at the power receiving point that measures the energy of the entire building, and the time period during which you want to cut the peak In addition, an intermittent operation control system that repeatedly turns on and off the indoor unit at regular time intervals, and capacity restriction control that limits the maximum power used by the indoor unit and outdoor unit depending on the power consumption value of the power metering point of the entire building The method is known.

  As a background art in this technical field, there is JP-A-2006-29693 (Patent Document 1). This gazette includes “a prediction calculation means 6 for calculating a predicted power amount used for each demand calculation time, and whether or not the predicted power amount calculated by the prediction calculation means exceeds a demand value. When the amount exceeds the demand value, the intermittent cutoff time calculating means 8 that calculates the intermittent cutoff time according to the amount of power exceeding the demand value, and the multi air conditioner into a plurality of groups based on the intermittent cutoff time calculated by the intermittent cutoff time calculating means Operation control means 9 for performing intermittent / rotation operation switching control according to a predetermined priority order for the plurality of divided systems, and each system so that the amount of power used within the demand calculation time is within the range of the demand value The operation switching control of the multi air conditioner is performed every time ”(refer to the summary).

JP 2006-29693 A

  Patent Document 1 describes that when the predicted power amount exceeds the demand value, the intermittent cut-off time of the multi-air conditioner is calculated according to the excess power amount. Specifically, the multi air conditioner is divided into a plurality of groups, a predetermined priority is assigned to the plurality of groups, and intermittent interruption switching control by intermittent / rotation operation is performed based on the priority and the calculated intermittent interruption time. Is what you do.

  However, in such multi-air conditioner operation switching control, when intermittent / rotation operation is on, all indoor units belonging to each group are in operation, while intermittent / rotation operation is off. All the indoor units belonging to each system are stopped.

  However, in the case where the capacity restriction that limits the maximum power used by the outdoor unit is performed, if the operation state of the indoor unit as in Patent Document 1 is adopted, all the indoor units belonging to the group are operated. Then, the power of the outdoor unit whose capacity is limited is distributed and all the indoor units are operated, so the air conditioning operation capability of each indoor unit is lower than normal. Generally, an indoor unit is more efficient in operation and consumes less power when it is operated in a degenerate manner such as a breeze after approaching a target value such as a preset set temperature. However, if the difference between the target value of the set temperature and the measured value is large as a result of the air conditioning capability of each indoor unit weakening due to the capacity limitation of the outdoor unit, the measured value of the set temperature cannot approach the target value, There was a problem that the operation continued without degenerate operation on a regular basis, and the operation efficiency was poor and the power saving effect was not achieved.

Therefore, the present invention enables the peak power consumption of the entire building to be reduced without reducing the operation efficiency of the indoor unit when demand control is performed in a control system for a multi-air conditioner.

In a building demand control system equipped with a multi-air conditioner that operates multiple indoor units in an outdoor unit, a power consumption value acquisition unit that acquires a power consumption value of the building, and a predicted power amount that is predicted based on the power consumption value Determines whether or not the power consumption exceeds a preset power consumption target value. If the predicted power consumption exceeds the power consumption target value, the power supplied to the outdoor unit according to the power consumption exceeding the power consumption target value. An air conditioner operation control unit that outputs a power control command value that limits the amount to the outdoor unit, and sets the number of indoor units that operate among the plurality of indoor units according to the power control command value; have a air conditioner operation control unit, among the indoor units, the accumulated operation uptime long indoor unit preferentially intermittent operation, preferentially operated intermittently release the accumulated operation switching time is long indoor unit, the indoor The machine changed from running to running When calculating the cumulative operation operating time based on the first time and the second time changed from operation on to operation off, the first time is set to the actual time (actually in the operation off state). The actual operation cut-off time—the set operation cut-off time that has been set) ÷ (the set operation cut-off ratio ÷ 100) is added .

When demand control is performed in a control system for a multi-air conditioner, the peak power consumption of the entire building can be reduced without lowering the operation efficiency of the indoor unit.

It is a block diagram of the air-conditioning equipment of the building in the Example of this invention. It is a hardware block diagram of the control instruction | command part 142 in the air conditioner operation control apparatus 14 in the Example of this invention. The 1-minute meter value difference table 46 in the Example of this invention is shown. The power management table 47 in the Example of this invention is shown. It is the demand monitoring table 48 in the Example of this invention. It is the demand control table 49 in the Example of this invention. It is the indoor unit intermittent mode table 50 in the Example of this invention. It is the outdoor unit information table 51 in the Example of this invention. It is the indoor unit information table 52 in the Example of this invention. It is a flowchart which shows the outline | summary of the demand control program in the Example of this invention. It is a figure explaining the intermittent operation of a multi air conditioner in the case where the indoor unit demand type in the present embodiment in the embodiment of the present invention is “intermittent” and the indoor unit operation-off set number (units) is determined. . It is a figure explaining the intermittent operation of a multi air conditioner in the case where the indoor unit demand type in the present embodiment is “comfortable eco-operation” and the set number of indoor unit operation-off (units) is determined. It is a flowchart explaining the determination process of an operation indoor unit when the demand level in a present Example changes.

  Hereinafter, examples will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a building air conditioner according to an embodiment of the present invention.

The building of the example is a three-story office building, and the first floor room area 1, the second floor room area 2, the third floor room area 3, the first floor room area 1, and the second floor room area 2 4, It has the hierarchical structure of the interstitial part 5 of the 2nd floor living room area 2 and the 3rd floor living room area 3, the 3rd floor living room area 3, and the interstitial part 6 of the roof. Air conditioning equipment is provided on each floor and the roof, and the outdoor unit 15 and the indoor units (16, 17, 18) that are operated by the power of the outdoor unit 15 are provided on the roof. The outdoor unit for personal use 15 sends compressed air through the pipe 23 to the indoor units 16 to 18.
Further, the outdoor unit 15 is connected to the air conditioner operation control device 14 via the switching hub 34. The air conditioner operation control device 14 includes a power consumption value acquisition unit 141 and a control command unit 142. The control command unit 142 is connected to the switching hub 34, and the power consumption value acquisition unit 141 is connected to the power receiving measurement point 13 of the entire building. It has been. The general-purpose personal computer 35 is connected via a switching hub 34 via a LAN (Local Area Network).

In addition, in the inter-floor portion 4 on the first floor and the second floor, a first floor air inlet 10, a pipe 28 that connects the first floor air inlet and the first floor outdoor air processing indoor unit 20, and a first floor outdoor air processing indoor unit 20 When having a tether piping 31 and 1 Kaigaiki inlet 25. An indoor exhaust port 7 is also provided in the first-floor room area 1. Since the second and third floors have the same configuration, the description is omitted here. The outdoor air processing outdoor unit 19 installed on the roof sends air through the pipe 24 to the indoor units 20 to 22.

  FIG. 2 is a hardware configuration diagram of the control command unit 142 in the air conditioner operation control device 14 according to the embodiment of the present invention.

Control instruction unit 142, communication unit 37, a central processing unit 38, a time processing unit 39, the storage unit 40, and a database unit 41. These units are configured to be communicable via the communication unit 37. Note that the communication unit 37 is configured to be able to communicate with the control command unit 142, the switching hub 34, and the power consumption value acquisition unit 141.

  When the air conditioner operation control device 14 is activated when the power is turned on, the multitask operation system 42 of the storage unit 40 is activated first, and then the activation execution program 43 is executed in the central processing unit 38. Here, the multitask operation system 42 is a system capable of switching and executing a plurality of tasks. When the startup execution program 43 is executed, the demand monitoring program 44 and the demand control program 45 are started as a plurality of tasks with reference to the demand monitoring table 48 and the demand control table 50 of the database unit 41. The demand monitoring program 44 is a program for changing the demand level by monitoring the magnitude of the demand value for the contract power. The demand control program 45 is a program that controls the outdoor unit and the indoor unit according to the demand level obtained by the demand monitoring program 44. These programs are executed in the central processing unit 38. The demand control program 45 is executed based on information in the database unit 41 described below. The processing flow will be described later with reference to FIG.

  The database unit 41 of the air conditioner operation control device 14 includes a 1-minute meter value difference table 46, a power management table 47, a demand monitoring table 48, a demand control table 49, an indoor unit intermittent mode table 50, an outdoor unit information table 51, an indoor unit A machine information table 52 is stored. The database unit 41 has an interface (not shown) that can be rewritten by the general-purpose personal computer 35 via the LAN, and stored data is registered as shown in FIGS. 3 to 9 described below.

  FIG. 3 shows a 1-minute meter value difference table 46.

  In the table 46, the power consumption value (hW) per minute is stored. Here, the meter value difference (hW) is stored as the power consumption value.

  FIG. 4 shows the power management table 47.

The power management table 47 has contracted power value (kW) of the building, meter value (hW) which is the current power consumption, demand level, and demand monitoring execution data.
Here, the demand level is a combination of a demand alarm start power value rate (%) indicating the ratio to the contract power for starting the alarm and a demand alarm cancel power value ratio (%) indicating the ratio to the contract power for canceling the alarm. The level is determined based on the above, and here, four levels of level 0 to level 3 are taken. Details will be described later with reference to FIG.

  FIG. 5 shows the demand monitoring table 48.

The demand monitoring table 48 has data on demand alarm start power value rate (%) and demand alarm release power value rate (%) for each demand level. For example, when the current power consumption (hW) is 0, the demand level is 0, and then the power consumption increases, resulting in a power consumption of 66% or more and less than 80% of the contracted power value (kW) of the building. The demand level increases and changes from 0 to 1. After that, when the amount of power consumption decreases and becomes less than 60% of the contracted power value (kW), the demand level changes from 1 to 0. Thus, the demand level increases or decreases depending on how much the power consumption is relative to the contract power value (kW).
Here, as the numerical value of the demand level is larger, there is no difference from the contract power value (kW), so it is necessary to perform demand control under more severe conditions.

  FIG. 6 shows the demand control table 49.

  For each outdoor unit ID assigned to each outdoor unit, the demand control table 49 indicates the maximum capacity limit value rate of the outdoor unit determined by the size of the demand level of the building, and the operation among the indoor units connected to the outdoor unit. An intermittent mode ID indicating the number of units to be cut and the type of operation mode of the indoor unit is stored in association with each other. Note that No is a numbering that gives a combination of these data for convenience.

  FIG. 7 shows the indoor unit intermittent mode table 50.

  The indoor unit intermittent mode table 50 has data of an indoor unit intermittent mode name, a set operation cut-in time ratio (%), and a set operation cut-off time (second) for each indoor unit intermittent mode ID. Here, the set operation cut-off ratio is a value obtained by multiplying 100 by a value obtained by dividing the operation cut-off time of the indoor unit by the operation turn-on time of the indoor unit when the indoor unit is intermittently operated. That is, the larger the set operation cut-in ratio (%), the higher the ratio of the operation cut-off time to the indoor unit control time. This example shows that the longer the indoor unit intermittent mode ID, the longer the operation cut-off time due to intermittent operation.

  FIG. 8 shows the outdoor unit information table 51.

  The outdoor unit information table 51 stores information on outdoor unit IDs, and stores outdoor unit names, outdoor unit IP addresses, presence / absence of demand execution, and types of indoor unit demands connected to the indoor unit. . Here, the indoor unit demand type indicates whether the demand control of the indoor unit is intermittent or limited. When the indoor unit demand type is “intermittent”, specifically, the indoor unit intermittent mode ID in FIG. On the other hand, when the indoor unit demand type is “capacity restriction”, intermittent operation is not performed. Specifically, for example, the demand control in which the indoor unit intermittent mode ID in FIG. 7 is 1 is performed.

  FIG. 9 shows the indoor unit information table 52.

The indoor unit information table 52 stores information related to the indoor unit ID. The indoor unit name, the indoor unit IP address, the outdoor unit ID of the outdoor unit connected to the indoor unit by piping, and the current indoor unit start / stop state And intermittent management time data. The start / stop mentioned here indicates whether the air conditioner operation control device 14 issues a command to turn on or off the operation to each indoor unit. In addition, the intermittent management time is the time when the start / stop is changed from the on-operation to the off-operation when the operation is off. On the other hand, when the start / stop is in operation, it is a time obtained by adding a weight to the time when the operation is changed from operation to operation. Here, the weight has an arbitrary unit of hours, minutes, and seconds. For example, (actual operation cut-off time that was actually in operation-set set operation cut-off time) / (set operation) (Cutting ratio / 100). When (actual operation cut-off time−set operation cut-off time) is 20 minutes and the set operation cut-off ratio is 10%, 20 minutes / 10% * 100% = 2 minutes.
By performing this weighting, when the actual operation cut-off time that was actually in the operation cut-off time is longer than the set operation cut-off time, the operation is turned on at a future time from the actual operation start time. Therefore, when determining the order of the intermittent operation targets of the indoor units described later, it is possible to lower the priority of the next operation cut-off.

  FIG. 10 is a flowchart showing an outline of the demand control program.

  This program acquires data from the database unit 41 and is executed in the central processing unit 38.

  When there is an outdoor unit ID that performs demand control, the outdoor unit IP address, demand execution information, and indoor unit demand type assigned to the outdoor unit ID are acquired from the outdoor unit information table 51 (step 1001). For example, if the outdoor unit ID for demand control is 1, the outdoor unit name “personal outdoor unit”, the indoor unit IP address “192.168.2.101”, demand “Execute” is executed, and the indoor unit demand type “intermittent” is acquired.

Next, from demand execution information, the presence or absence of demand execution in the outdoor unit IP is acquired (step 1002).
If the demand execution is “YES”, the process proceeds to step 1003 to execute the demand process (YES in step 1002). On the other hand, if there is no demand execution, the process proceeds to step 1010 described later (NO in step 1002).

  When the demand execution is “YES”, the current demand level is acquired from the power management table 47 (step 1003). In the example of the power management table 47 illustrated in FIG. 4, the demand level is “2”.

  Based on the outdoor unit IP address obtained in step 1001 and the demand level obtained in step 1003, the demand control table 49 is referred to. Then, the maximum capacity limit value rate (%), the indoor unit operation-off set number (units), and the intermittent mode ID determined in the outdoor unit ID and the demand level are acquired (step 1004). In the example of the demand control table 49 shown in FIG. 6, when the indoor unit IP address is “192.168.2.101” and the demand level is “2”, the maximum capacity limit value rate (%) is “60%”. It can be acquired that the indoor unit operation-off set number (units) is “1” and the intermittent mode ID is “4”.

  Next, specific operating conditions of the intermittent mode ID obtained in step 1004 are acquired with reference to the indoor unit intermittent mode table 50. Specifically, the set operation cut-off ratio (%) and the set operation cut-off time (seconds) are acquired (step 1005). In the example of the indoor unit intermittent mode table 50 shown in FIG. 7, when the intermittent mode ID is “4”, the intermittent strong operation is performed, the set operation cut-in ratio (%) is “30%”, and the set operation cut-off time. (Seconds) is “300 seconds”.

  Next, the maximum capacity limit value rate (%) obtained in step 1004 is transmitted to the outdoor unit IP address 15 via the communication unit 37 (step 1006). In the above example, the maximum capacity limit value rate (%) is “60%”, and this value is transmitted to the outdoor unit IP address “192.168.2.101”.

  Next, it is determined whether the indoor unit demand type acquired in step 1001 is “intermittent” (step 1007). In the case of “intermittent” (YES in step 1007), the control proceeds to step 1008 in order to perform control to turn off the indoor unit operation-off set number (units) obtained in step 1004. If this is the case (NO in step 1007), the process proceeds to step 1009 in order to perform intermittent driving or comfortable eco driving.

  Step 1008 is a process of controlling the indoor units so that the number of indoor unit operation cut-off set number (units) is reached. Details will be described with reference to FIG.

  Step 1009 is a process for controlling the indoor unit in an intermittent operation or a comfortable eco-operation. The operation status of the indoor unit in this step will be described with reference to FIG.

  When the processing of step 1008 or step 1009 ends, the current time is acquired by the time processing unit 39 in step 1010 (step 1010).

  In step 1011, it is determined whether 1 minute has passed since the last acquired time (step 1011). If one minute has passed (YES in step 1011), the process proceeds to step 1001. On the other hand, if one minute has not elapsed (NO in step 1011), the process proceeds to step 1010 to acquire the current time again.

  FIG. 11 is a diagram for explaining the intermittent operation of the multi-air conditioner when the indoor unit demand type in this embodiment is “intermittent” and the set number of indoor unit operation cut-off units (units) is determined.

  Here, in the demand control table 49 of FIG. The example of the condition 3 is described, the capacity limit value rate (%) of the outdoor unit is “60%”, the indoor unit operation-off set number (units) is “1”, and the intermittent mode ID is “4”. This is an operation state in the case of “intermittent strong operation” and the set operation cut-off time (seconds) is “300 seconds”.

  The horizontal axis represents time, and shows the intermittent operation status of the indoor units ID 1 to 3 connected to the outdoor unit ID 1. The white band indicates that the operation is on, and the black band indicates that the operation is off. As can be seen from this figure, the number of indoor unit running out at each time is one. As described above, in the demand control table 49, when the number of indoor unit operation-off set number (units) is one or more and the indoor unit intermittent mode ID is intermittent operation (when the outdoor unit ID is 1, In No. 3) in FIG. 6, as shown in FIG. 6, at each time, the indoor unit operates so that the number of indoor units whose operation is stopped among the plurality of indoor units connected to the outdoor unit is maintained. By adopting such a configuration, it is possible to prevent the air-conditioning operation capability of each indoor unit from being lowered than usual even when the capacity limitation of the outdoor unit is implemented. Furthermore, when the difference between the target value of the set temperature and the measured value is large, the measured value of the set temperature cannot approach the target value, and it continues to operate without degenerate operation on a regular basis. The problem that the power saving effect does not appear badly can also be avoided.

  FIG. 12 is a diagram for explaining intermittent operation of a multi air conditioner when the indoor unit demand type in this embodiment is “comfortable eco-operation” and the set number of indoor unit operation cut-off (units) is determined. .

  Here, in the demand control table 49 of FIG. The example of the condition 2 is described, the capacity limit value rate (%) of the outdoor unit is “80%”, the indoor unit operation-off set number (units) is “2”, and the intermittent mode ID is “2”. This is a driving situation in the case of “comfortable eco-driving” and the set driving time limit (seconds) is “100 seconds”.

  In this example, since the indoor unit demand type is comfortable eco-operation, the number of indoor units is controlled as necessary. Here, the number is not necessarily two, and one may be cut off. However, in this case, there is a time zone in which the capacity control value rate (%) of the outdoor unit is “80%” and the number of operating units is three. Driving ability may be reduced.

  Next, a description will be given of a method for determining which indoor unit is preferentially operated when the number of indoor unit operating units varies with a change in demand level.

  FIG. 13 is a flowchart for explaining the operation indoor unit determination process when the demand level changes.

  First, steps 1301 to 1307 are the same processes as steps 1001 to 1007 in FIG. In step 1303, the acquired demand level is recorded in a memory (not shown) or the like.

  In step 1308, it is determined whether it is different from the demand level in the previous loop or not (step 1308).

  If the demand level has not changed (NO in step 1308), the process proceeds to step 1310. Since step 1310 is the same processing as step 1008 in FIG. 10, the description thereof is omitted here.

  On the other hand, if the demand level has changed (YES in step 1308), the process proceeds to step 1309.

  In step 1309, based on the start / stop and intermittent management time stored in the indoor unit information table 52, the cumulative operation off time and the cumulative operation on time of each indoor unit are acquired. In addition, you may acquire the cumulative operation cut-off time and the cumulative operation on-time of each indoor unit by other methods.

  The acquired indoor unit with a long accumulated operation time is preferentially subject to the next intermittent release. That is, since the area where the indoor unit with a long operation time is provided is not likely to reach the set temperature, it is preferentially operated as an intermittent release target. On the other hand, an area with indoor units with a long operation time is likely to reach the set temperature, and other areas are unlikely to reach the set temperature. Turn off.

  After determining the order of the indoor units to be intermittently operated in this way, the process proceeds to step 1310. Since step 1310 is the same processing as step 1009 in FIG. 10, the description thereof is omitted here.

When the process of step 1310 or step 1311 ends, the process proceeds to step 1312 to acquire the current time (step 1312). Next, it is determined whether one minute has passed or not compared with the current time acquired in the previous loop (step 1313). Steps 1312 and 1313 are the same processes as steps 1010 and 1011 in FIG.

1 1st floor living room area 2 2nd floor living room area 3 3rd floor living room area 4 1st floor and 2nd floor floor 5 2nd floor and 3rd floor floor 6 3rd floor and rooftop floor 7 1st floor outlet 8 2nd floor exhaust port 9 3rd floor exhaust port 10 1st floor air intake port 11 2nd floor air intake port 12 3rd floor air intake port 13 Power receiving metering point 14 of entire building Air conditioner operation control device 15 Outdoor unit 16 for personal use Indoor unit 17 for first floor personal use Second floor indoor unit 18 Third floor indoor unit 19 Outdoor air processing outdoor unit 20 First floor outdoor air processing indoor unit 21 Second floor outdoor air processing indoor unit 22 Third floor outdoor air processing indoor unit 23 Personal outdoor unit and 1 Piping connecting the indoor unit for the floor, the indoor unit for the second floor, and the indoor unit for the third floor 24 for the outdoor air processing outdoor unit, the first floor outdoor air processing indoor unit, the second floor outdoor air processing indoor unit, and the third floor outdoor air processing Piping 25 connecting indoor units 1st floor outside air inlet 26 2nd floor outside air inlet 27 3rd floor outside air inlet 28 1st floor inlet and 1 Piping 29 connecting the second-floor air intake indoor unit to the second-floor outdoor air processing indoor unit 30 Piping 30 connecting the second-floor air intake indoor unit to the second-floor outdoor air processing indoor unit Piping 31 connecting the third-floor intake port and the third-floor outdoor air processing indoor unit Pipe 32 connecting the first floor outside air inlet 32 Pipe connecting the second floor outside air processing indoor unit and the second floor outside air inlet 33 Pipe 34 connecting the third floor outside air processing unit and the third floor outside air inlet 34 Switching hub 35 General-purpose personal computer 37 Communication unit 38 of the air conditioner operation control device Central processing unit 39 of the air conditioner operation control device Time processing unit 40 Storage unit 41 Database unit 42 Multitask operation system 43 Start-up execution program 44 Demand monitoring program 45 Demand control Program 46 1-minute meter value difference table 47 Power management table 48 Demand monitoring table 49 Demand control table Bull 50 indoor unit intermittent mode table 51 outdoor unit information table 52 indoor unit information table

Claims (3)

In a demand control system for a building equipped with a multi air conditioner that operates a plurality of indoor units in an outdoor unit,
A power consumption value acquisition unit for acquiring a power consumption value of the building;
It is determined whether or not the predicted power amount predicted based on the power consumption value exceeds a preset power consumption target value. If the predicted power amount exceeds the power consumption target value, the predicted power amount exceeds the power consumption target value. A power control command value that restricts the amount of power supplied to the outdoor unit according to the amount of power is output to the outdoor unit, and the plurality of indoor units according to the power control command value It has a, and the air conditioner operation control unit for setting the number of indoor units to operate among the
The air conditioner operation control unit
Among the indoor units, the indoor unit with a long cumulative operation time is preferentially intermittently operated, and the indoor unit with a long cumulative operation time is preferentially intermittently released,
When calculating the cumulative operation operating time based on a first time when the indoor unit has changed from running-off to running-on and a second time when changing from running-on to running-off, the first time is: Demand control characterized by adding a value obtained by adding (actual operation cut-off time that was actually in operation-set set operation cut-off time) ÷ (set operation cut-in ratio ÷ 100) to the actual time system. The demand control system according to claim 1,
When the outdoor unit is operating based on the power control command value, each indoor unit is intermittently / rotated so that the set number of indoor units operates at each time. Control system. In a demand control method for a building equipped with a multi-air conditioner for operating a plurality of indoor units in an outdoor unit,
Get the power consumption value of the building,
It is determined whether or not the predicted power amount predicted based on the power consumption value exceeds a preset power consumption target value. If the predicted power amount exceeds the power consumption target value, the predicted power amount exceeds the power consumption target value. A power control command value that restricts the amount of power supplied to the outdoor unit according to the amount of power is output to the outdoor unit, and the plurality of indoor units according to the power control command value Set the number of indoor units in operation,
Among the indoor units, the indoor unit with a long cumulative operation time is preferentially intermittently operated, and the indoor unit with a long cumulative operation time is preferentially intermittently released,
When calculating the cumulative operation operating time based on a first time when the indoor unit has changed from running-off to running-on and a second time when changing from running-on to running-off, the first time is: Demand control characterized by adding a value obtained by adding (actual operation cut-off time that was actually in operation-set set operation cut-off time) ÷ (set operation cut-in ratio ÷ 100) to the actual time Method.