CN110945556B

CN110945556B - Power management device

Info

Publication number: CN110945556B
Application number: CN201780093330.1A
Authority: CN
Inventors: 中岛义统; 北上真二; 妻鹿利宏; 川野裕希; 佐藤冬树; 小林直树
Original assignee: Mitsubishi Electric Building Solutions Corp
Current assignee: Mitsubishi Electric Building Solutions Corp
Priority date: 2017-07-25
Filing date: 2017-07-25
Publication date: 2023-10-03
Anticipated expiration: 2037-07-25
Also published as: JP6644953B2; WO2019021372A1; JPWO2019021372A1; CN110945556A

Abstract

The appropriate power consumption can be estimated from the utilization condition of the building, and an update of the contract power corresponding to the power consumption can be provided to the contractor such as the building owner. The power management device (10) has a base load threshold setting unit (54), a demand control execution value setting unit (56), and an increase confirmation unit (60). The base load threshold setting unit (54) sets base load thresholds (BLth_max, BLth_min) on the basis of the unit power of a base load period dBL in which the change in unit power in the operation period of the building is stable. A demand control execution value setting unit (56) sets a demand control execution value DMctrl on the basis of at least one of the base load threshold values BLth_max and BLth_min and the unit power of the base load period dBL. Further, the demand control execution value setting unit (56) sets the demand control execution value DMctrl again when the unit power in the base load period dBL exceeds the base load thresholds BLth_max and BLth_min. When the re-set demand control execution value DMctrl exceeds the contract power value CNT, the increase confirmation unit (60) inquires whether the contract power value CNT can be increased.

Description

Power management device

Technical Field

The present invention relates to a power management device that performs power management by demand control.

Background

A contractor (building owner, etc.) who receives high voltage electricity, such as a building, makes a contract with an electric power company to determine an electricity reception contract of contract electric power [ kW ], which is also called a demand value. The calculation unit of the power consumption is represented by the power consumption per unit time (unit power value). The contract power is determined, for example, from the average power consumption per 30 minutes, which is called demand time limit.

For example, when the unit power value actually consumed by the building exceeds a predetermined contract power, a basic charge for a contract period (for example, within one year) is set based on the exceeding unit power value regardless of the contract power.

Therefore, a power management system (EMS: energy Management System) for suppressing the power consumption of a building to a contract power or less has been conventionally known. The power management system performs power management according to so-called demand control.

For example, the demand control execution value is set to a value lower than the contract power. When the unit power value actually consumed exceeds the demand control execution value, the power consumption of the management target device is reduced. For example, to stop a portion of the operating equipment.

As such demand control, for example, patent documents 1 and 2 disclose that the demand control execution value is appropriately changed. For example, the power consumption tendency in spring and autumn is obtained in which the consumed power is relatively small in1 year, in other words, the possibility that the consumed power exceeds the contract power is low, and the demand control execution value is lowered according to the tendency.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication 2016-127688

Patent document 2: japanese patent laid-open No. 2014-81881

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional demand control, in order to prevent the consumed electric power from exceeding the contract electric power, the demand control execution value is set to a value lower than the contract electric power. However, such setting of the contract power and demand control execution value sometimes does not coincide with the use condition of the building. For example, in the case where a new check-in contract is made for an empty tenant of a building and a large-scale server is imported for the tenant, the server and an air conditioner for the server consume a large amount of power. In this case, when demand control based on contract power at the time of empty tenants is performed, the comfort of the whole building may be reduced, such as frequent stop of air conditioning by other tenants within the building, or the like. Accordingly, an object of the present invention is to provide a power management device as follows: the appropriate power consumption can be estimated from the utilization condition of the building, and an update of the contract power corresponding to the power consumption can be provided to the contractor such as the building owner.

Means for solving the problems

The present invention relates to a power management device. The device comprises a unit power metering unit, a threshold setting unit, a control execution value setting unit, and a confirmation unit. The unit power measurement unit obtains unit power, which is average power consumption of the building per unit time. The threshold setting unit sets a base load threshold value based on the unit power in the base load period in which the change in the unit power in the operation period of the building is stable. The control execution value setting unit sets the demand control execution value according to at least one of the unit power in the base load period and the base load threshold value, and sets the demand control execution value again when the unit power in the base load period exceeds the base load threshold value. When the re-set demand control execution value exceeds the contract power value, the confirmation unit inquires whether the contract power value can be increased.

In the above invention, the power management device may further include a base load period setting unit that sets a stop period of the air conditioner in the operation period as the base load period.

In the above invention, the power management device may further include an operation time period setting unit that sets a time point at which the elevators provided in the building are stopped at all stop floors as an initial time point of the operation time period.

In the above invention, when a stop-skip floor is set for an elevator installed in a building, the operation time period setting unit may set the time point at which the elevator stops at all the stop floors except the stop-skip floor as the initial time point of the operation time period.

In the above invention, the operation time period setting unit may set a termination point of the operation time period when the elevator provided in the building is in the standby state for a predetermined period of time.

In the above invention, the threshold setting unit may determine the base load threshold value from a unit power of a lighting device installed in the building in the operation period.

Effects of the invention

According to the present invention, it is possible to estimate appropriate power consumption according to the utilization condition of a building, and to provide a contractor such as a building owner with an update of the increase in contract power corresponding to the power consumption.

Drawings

Fig. 1 is a diagram illustrating a power system diagram including a power management device according to the present embodiment.

Fig. 2 is a diagram illustrating functional blocks of the power management apparatus.

Fig. 3 is a diagram illustrating an operation period and a base load period.

Fig. 4 is a diagram illustrating a base load power value, a base load upper limit threshold value, a base load lower limit threshold value, and a demand control execution value.

Fig. 5 is a diagram illustrating a demand control execution value change flow (at the time of lifting) according to the present embodiment.

Fig. 6 is a timing chart showing an example of the demand control execution value change flow (at the time of lifting) of the present embodiment.

Fig. 7 is a diagram illustrating a demand control execution value change flow (at the time of lowering) according to the present embodiment.

Fig. 8 is a timing chart showing an example of the demand control execution value change flow (at the time of lowering) of the present embodiment.

Detailed Description

Fig. 1 illustrates a power management system including a power management device 10 according to the present embodiment. The power management system illustrated in fig. 1 is constituted by a monitoring control system BEMS (Building and Energy Management System) of a multi-story building apparatus such as a building.

The power management system has a power management device 10 (B-OWS), sub-controllers 14A-14C (B-BC), digital controllers 16A, 16B (DDC), and a remote station 18 (RS), which are connected to a bus. The digital controllers 16A, 16B and the remote station 18 are connected to respective electrical devices 20A-20D and various sensors 22A-22F.

The electrical devices 20A to 20D are various devices installed in a building, and include, for example, lighting devices, air conditioning devices, elevators, sanitary devices, disaster prevention devices, and theft prevention devices. In the example of fig. 1, the electric device 20A is a lighting device, the electric device 20B is a lighting operation panel, the electric device 20C is an air conditioner, and the electric device 20D is an elevator control panel.

The sensor 22A is an illuminance sensor, the sensor 22B is an illumination power meter, the sensor 22C is an air conditioner sensor, the sensor 22D is an air conditioner power meter, and the sensor 22E is an elevator power meter. The sensor 22F is a power demand meter, and in other words, a meter that measures power demand for the entire building, which is the management target of the power management apparatus 10, from the power company.

In order to facilitate viewing the drawings, fig. 1 illustrates a part of the devices such as the sub-controller 14 connected to the lower side of the power management apparatus 10, and various devices may be connected in addition to the illustrated configuration.

The power management device 10 is configured by, for example, a so-called B-OWS (BACnet Operator Workstation), and has a function as a client PC that is monitored by an operation by a manager or the like, and a function as a server that performs data storage, application processing, and the like. In the power management apparatus 10, for example, screen display and setting operations are performed.

The sub-controller 14 mainly assumes control functions. The sub-controller 14 is constituted by, for example, a so-called B-BC (Building Controller), and communicates with terminal transmission devices such as the digital controller 16 and the remote station 18 to manage point data, scheduling control, and the like. For example, the sub-controller 14 is provided for each of the functional systems (sub-systems) such as an air conditioning system, an illumination system, an elevator system, a sanitary system, and an antitheft system.

The digital controller 16 may also be a so-called DDC (Direct Digital Controller) having a function as a regulator for realizing the decentralized control in the BEMS. For example, the digital controller 16 controls the electric devices 20C and 20D to be connected by program control based on the schedule setting transmitted from the sub-controller 14, feedback control based on the target value transmitted from the sub-controller 14, or the like. The digital controller 16 transmits the measured values of the sensors 22C to 22E, warnings of the electrical devices 20C and 20D, and the like to the above-described system and other digital controllers 16.

The remote station 18, also called a substation or a local station, monitors and controls the sensors 22A and 22B and the electrical devices 20A and 20B of the connection destination. Functionally repeated with the digital controller 16, therefore, either one of the digital controller 16 and the remote station 18 is appropriately selected according to the electrical devices 20A to 20D and the sensors 22A to 22E of the connection destination.

The power management device 10, the sub-controller 14, the digital controller 16, and the remote station 18 are constituted by computers. For example, as representatively shown in the power management apparatus 10, a CPU26, a memory 28, a Hard Disk Drive (HDD) 30, an input section 32, an output section 34, and an input-output interface 36 are provided.

As described later, the CPU26, the memory 28, and the hard disk drive 30 of the power management device 10 constitute functional blocks illustrated in fig. 2. The output unit 34 is, for example, a display, and displays an inquiry screen concerning whether or not the contract power can be increased in a demand control execution value changing flow described later. Further, an answer to the query (whether or not it is possible to increase) is input to the input unit 32.

Further, demand control is performed by the power management apparatus 10. When executing demand control, the power management apparatus 10 appropriately controls the operation of the electric device 20 based on the difference between the sum of consumed electric power per unit time of the electric device 20 under control (management target) and contract electric power. The power consumption per unit time may be, for example, power consumption per time period of demand, or may be an average value of 30 minutes of power consumption.

For example, the power consumption of the electric device 20 is accumulated in 30 minutes, and when the accumulated value is close to the contract power amount obtained by the contract power value×30 minutes, the power management apparatus 10 appropriately controls the operation state of the electric device 20 in operation to the suppression side (for example, reduces the air volume if it is an air conditioner).

As a value for determining whether or not the integrated value of the consumed power is close to the contract power amount, in other words, as a value for triggering execution of the demand control, the demand control execution value DMctrl is set. For example, when the integrated value of the consumed power exceeds the demand control execution power amount obtained by the demand control execution value dmctrl×30 minutes, the demand control is executed.

The demand control execution value DMctrl is set to be smaller than the contract power value (demand value) in the initial state, for example. Further, in the power management device of the present embodiment, the demand control execution value DMctrl is set again appropriately according to the base load power BL described later.

In this embodiment, each time the resetting is performed, the value of the region equal to or smaller than the contract power value is not limited to the value that can be taken as the demand control execution value DMctrl. In practice, if the re-set demand control execution value DMctrl exceeds the contract power value, the contractor is asked whether or not to increase the contract power value.

Fig. 2 illustrates functional blocks of the power management apparatus 10. The power management device 10 includes an operation time period setting unit 40, a base load time period setting unit 42, a unit power metering unit 44, a power comparing unit 46, a number of days counter 48, a number of days count comparing unit 50, a base load setting unit 52, a base load threshold setting unit 54, a demand control execution value setting unit 56, a contract power comparing unit 58, an increase confirming unit 60, a contract power storing unit 62, and a number of days threshold storing unit 64. These functional units are configured by being allocated with resources such as the CPU26, the memory 28, and the hard disk drive 30 of the power management device 10. The functions and actions of these functional units will be described later.

< description of control parameters >

Various parameters used in the demand control execution value setting flow of the present embodiment will be described with reference to fig. 3 and 4. Fig. 3 illustrates a transition of power consumption of a day of a building to be managed by the power management apparatus 10. As units of consumed power, unit power values (30-minute demand values) are shown as vertical axes. That is, the average power consumption value for 30 minutes is shown. Since the step graph is obtained in 30 minutes, it is actually a 30 minute scale, but in fig. 3 and the subsequent graphs, this is represented by a curve for the sake of simplicity.

The power management device 10 of the present embodiment obtains a power consumption tendency when the power consumption of the building is appropriate, and determines whether or not the contract power is appropriately increased based on the tendency. For example, an increase in contract power associated with an increase in users of a building or an increase in electrical devices installed in the building can be proposed to a contractor (building owner).

Each time such proposal is made, in the present embodiment, an operation period and a base load period are set. First, the operation time period setting unit 40 (see fig. 2) obtains the operation time period from the power consumption of the building. The operation period refers to an activity time of a user (tenant, etc.) of the building in the building. The operation period may be, for example, a period of 8 or more times that a user of the building is within the building.

For example, when the office core time of each tenant is known, a period in which the core time of each tenant is repeated may be set as the operation time period.

Further, for example, the operation time period is obtained by monitoring the power consumption transition of the power demand meter 22F. For example, as illustrated in fig. 3, the unit power value gradually increases from early morning and finally reaches a peak value. The boundary between the rise and the peak can be set as the initial point of the operation time zone. For example, a gradient of the unit power value may be obtained, and after a maximum value of the gradient is detected, a point of time at which the maximum value is set may be set as an initial point of the operation time period.

Also, as approaching late night, the unit power value gradually decreases. The time point at which the operation period ends can be captured at the time of the decrease. For example, a gradient of the unit power value may be obtained, and after detecting a minimum value of the gradient, the time point of the minimum value may be set as the end time point of the operation period.

As shown in fig. 3, the unit power value is also reduced in the daytime due to the power saving operation at noon break and the like. In order to prevent the detection of the time point of the end of the operation period, for example, the operation period setting unit 40 may be provided with a clock function, and the detection of the time point of the end of the day may be prohibited.

The power management device 10 may be used to manage the operation state of the electrical equipment 20 every time the initial time and the end time of the operation period are set. The operating condition of the elevator apparatus is obtained from the elevator control panel 20D, for example. For example, when the elevator apparatus is in a standby state, that is, when the elevator car is not moving or the call button of the elevator floor is not pressed for a predetermined time (for example, 3 hours), it can be estimated that there are few users in the building in which the elevator apparatus is installed. That is, it can be estimated to be outside the operation period.

Therefore, the operation time period setting unit 40 may acquire the control signal of the elevator control panel 20D, and when the elevator apparatus (elevator) is in the standby state for a predetermined period, set the counting start point of the predetermined period as the end point of the operation time period.

Similarly, the operation time period setting unit 40 may set the control signal to the initial point of the operation time period when the control signal is acquired from the elevator control panel 20D in a rest time period other than the operation time period. For example, stop floor information of the elevator car may be acquired from the elevator control panel 20D in the stop time zone, and the time point at which the elevator car (elevator) stops at all the stop floors may be set as the initial time point of the operation time zone.

When a predetermined floor of the building is an empty tenant, the elevator control panel 20D may be set to exclude the floor from the stop floors (stop floor jump setting). In this case, the time point at which the elevator car (elevator) stops at all the stop floors except the stop skip floor may be set as the initial time point of the operation time zone.

Next, the base load period dBL and the base load power BL are obtained. The base load period setting section 42 (refer to fig. 2) sets the base load period dBL in the operation period. The base load period refers to a period in which a change in unit power consumption in the operation period is stable, and refers to a period in which a pattern of power consumption is not easily affected by an external environment (air temperature or the like).

As an example of a period (base load period) in which a change in unit power consumption in the operation period is stable, for example, a period in which power saving is sufficiently performed can be cited. That is, when the consumed power in the environment where the power saving is sufficiently performed approaches the contract power and approaches the demand control execution value, it is considered that increasing the update of the contract power is more advantageous than further realizing the power saving, to improve the convenience of the tenant user.

For example, the base load period dBL may correspond to a noon break period in an operating period. This period is typically an out-of-office time, and power saving is strictly performed. For example, the period becomes an air conditioner stop period in which the air conditioner is stopped (turned off). Thereby, the operation of the (unstable) electric appliance whose operation condition varies according to the external environment is stopped.

For example, the base load time period setting unit 42 sets the initial time point of the base load time period dBL when the operation time period and the unit power consumption value obtained from the air-conditioning power meter 22D are equal to or smaller than a predetermined value (not required to be 0). Then, the unit power consumption value obtained from the air-conditioning power meter 22D exceeds a predetermined value, and the expiration time of the basic load period dBL is set.

The total power consumption of the building in the base load period dBL is found as the base load power value BL. Like the contract power (demand value), the base load power value BL may be an average power consumption value [ kW ] of 30 minutes.

In addition, as shown in fig. 1, when the sub-controller 14 is provided for each equipment system, for example, the unit power of the lighting equipment provided in the building may be set as the base load power. For example, the power consumption of all the lighting devices in the building is obtained from the lighting power meter 22B connected to the sub-controller 14A, and is set as the base load power. In this case, the operation period=the base load period.

Instead of obtaining the base load time period, the base load power may be obtained from the change in the unit power. For example, the unit power consumption of the operation period of a certain period (for example, one month) is extracted for each demand time period, and the dispersion is obtained. The unit power consumption at the minimum-dispersed demand time period is set as the base load power BL.

Next, a base load upper limit threshold value blth_max and a base load lower limit threshold value blth_min are obtained from the base load power value BL at a predetermined time. As illustrated in fig. 4, the base load upper limit threshold blth_max is set to a value higher than the base load power value BL by a prescribed magnitude Δw3. The base load lower limit threshold blth_min is set to a value lower than the base load power value BL by a predetermined amplitude Δw4. The magnitudes Δw3 and Δw4 may be set, for example, based on the standard deviation obtained based on the unit consumption power of the operation period of the above-described past fixed period.

As described later, when the base load power value BL exceeds the region surrounded by the temporarily set base load upper limit threshold value blth_max and base load lower limit threshold value blth_min, that is, when the base load power value BL takes a value higher than the base load upper limit threshold value blth_max and a value lower than the base load lower limit threshold value blth_min, the resetting of the demand control execution value DMctrl is performed.

Further, the demand control execution value DMctrl is set according to at least any one of the base load power value BL, the base load upper limit threshold value blth_max, and the base load lower limit threshold value blth_min. The demand control execution value DMctrl is set by a demand control execution value setting unit 56 described later. For example, as shown in fig. 4, the demand control execution value DMctrl is set to a value higher than the base load upper limit threshold blth_max by a predetermined magnitude Δw2.

In the initial state where the base load upper limit threshold blth_max is not set, the demand control execution value DMctrl may be set according to the contract electric power CNT. For example, a value lower than the contract power CNT by a prescribed magnitude Δw1 may be set as (an initial value of) the demand control execution value DMctrl.

After setting the initial value of the demand control execution value DMctrl, the demand control execution value DMctrl may be set (updated) again based on the base load upper limit threshold blth_max without referring to the contract power CNT.

< flow of setting execution value of demand control (at lifting) >)

The demand control execution value setting flow of the power management apparatus 10 according to the present embodiment will be described with reference to fig. 5 and 6. Fig. 5 illustrates a demand control execution value setting flowchart, and fig. 6 illustrates a timing chart of the demand control execution value setting flowchart. The horizontal axis of fig. 6 represents time, and the vertical axis represents a unit power value (30 minutes demand value).

First, as initial conditions, for example, base load upper limit thresholds blth_max1 and blth_minu1 are set according to the base load power BL of day1 of fig. 6. The operation time period setting unit 40 obtains the power consumption of the entire building (the required power from the electric power company) from the required power meter 22F, and determines whether or not the current time is included in the operation time period (S10). Alternatively, the operation time zone setting unit 40 obtains the control signal of the elevator apparatus from the elevator control panel 20D, and determines whether the current time is included in the operation time zone based on whether the elevator car stops at all stop floors (except for the stop skip floor).

If the current time is not included in the operation period, the process returns to step S10 again. When the current time is included in the operation time period, the operation time period setting unit 40 transmits an instruction to the effect that the current time is included in the operation time period to the basic load time period setting unit 42.

When receiving the instruction from the operation period setting section 40, the base load period setting section 42 determines whether or not the current time is included in the base load period dBL (S12). For example, as described above, the unit power consumption value obtained from the air-conditioning power meter 22D is set to be the initial time of the basic load period dBL when the unit power consumption value is equal to or smaller than the predetermined value.

In the case where it is not contained in the basic load period dBL at the present time, the process returns to step S10. On the other hand, when the present time is included in the base load time period dBL, the base load time period setting unit 42 transmits a permission command to permit the unit power metering unit 44 to meter the unit power.

The unit power meter unit 44 that receives the permission command monitors the unit power value DMD (30 minutes demand value), which is the power consumption of the entire building, according to the demand power meter 22F (S14). As described above, the unit power value DMD refers to the average power consumption of the building per unit time. Instead of the power meter 22F, the unit power meter unit 44 may calculate the sum of the unit power consumption values from the various power meters connected to the respective sub-controllers 14, and use the sum as the unit power value DMD.

The counted unit power value DMD is sent to the power comparing unit 46. The power comparing unit 46 determines whether or not the received unit power value DMD exceeds the base load upper limit threshold blth_max (S16). The base load upper limit threshold blth_max is transmitted from the base load threshold setting unit 54.

Day4 to day6 of fig. 6 show examples of DMD > blth_max. On the other hand, day1 to day3 in fig. 6 show an example in which dmd+.ltoreq.blth_max. If DMD is equal to or less than blth_max, the routine returns to step S10, and the monitoring of the unit power value is continued. On the other hand, when DMD > blth_max, the power comparing unit 46 sends an instruction to increase the number of days count kd_u to the number of days counter 48.

The day counter 48 determines (confirms) whether the day count kd_u has increased in the monitor subject day (for example, day 4) (S18). In the case where the addition has been made, no further addition is made, and the flow returns to step S10. When the number of days to be monitored has not yet increased, the number of days counter 48 increases the number of days count kd_u (S20).

The increased number of days kd_u is sent to the number of days count comparing section 50. The day count comparing unit 50 determines whether or not the received day count kd_u is equal to or greater than a count threshold kd_ uth (S22). The count threshold kd_ uth is stored in the day threshold storage unit 64 in advance and is called by the day count comparing unit 50. For example, the count threshold kd_ uth is input from the input unit 32 (see fig. 1) by an administrator or the like in advance. For example, the count threshold kd_ uth =3 (3 days).

In the case where kd_u < kd_ uth, the flow returns to step S10. On the other hand, when kd_u+ kd_ uth, first, the day count comparing unit 50 resets the day count kd_u (returns to 0) to prepare for the next time (S24). Further, the day count comparing unit 50 transmits an update command (reset command) of the base load power BL to the base load setting unit 52.

In addition to the update instruction of the base load power BL to the base load setting portion 52, the unit power value is transmitted from the unit power metering portion 44 to the base load setting portion 52. The base load setting unit 52 transmits the base load power BL (shown as BL2 in fig. 6), which is the most recent unit power value from the time when the update command is received, to the base load threshold setting unit 54. Alternatively, the base power BL may be obtained (for example, an average value) from the unit power of the base load period dBL from the day counter 48 to the date (day 4 to day 6) at which the day count kd_u is increased to the day count threshold kd_ uth. As shown in fig. 6, the updated base load power BL2 is raised as compared with the base load power BL1 before the update (S26).

In the base load threshold setting section 54, the base load upper limit threshold blth_max2 and the lower limit threshold blth_minum2 are set (updated) again based on the received base load power BL. In the examples of fig. 5 and 6, the base load power BL (BL 2) of day4 to day6 is higher than the base load power BL (BL 1) of day1 to day3, and therefore, the base load upper limit threshold blth_max and the base load lower limit threshold blth_min are raised (S28).

The raised base load upper limit threshold value blth_max and the raised base load lower limit threshold value blth_min are sent to the power comparison unit 46. The base load upper limit threshold blth_max is also transmitted to the demand control execution value setting unit 56. The demand control execution value setting section 56 sets (updates) the demand control execution value DMctrl again based on the received base load upper limit threshold blth_max (S30). In the examples of fig. 5 and 6, the base load upper limit threshold blth_max is raised, and therefore, the demand control execution value DMctrl is raised correspondingly thereto.

In addition, the lifting magnitudes of the base load upper limit threshold value blth_max, the lower limit threshold value blth_min, and the demand control execution value DMctrl may be based on, for example, the ratio of DMD > blth_max in step S16. For example, dmctrl2=dmd/blth_max×dmctrl1.

The lifted demand control execution value DMctrl2 is sent to the contract power comparison section 58. The contract power comparison unit 58 determines whether or not the lifted demand control execution value DMctrl2 exceeds the contract power CNT (S32). The value of contract power CNT is obtained from contract power storage 62.

In the case where DMctrl 2+.cnt, demand control is performed in a region smaller than contract power CNT, and therefore, there is no need to perform an increase update of contract power. In this case, the flow returns to step S10.

On the other hand, in the case of DMctrl2> CNT, demand control is performed in an area exceeding the contract power CNT, and therefore, if the demand control execution value DMctrl2 is directly set, the power consumption of the building may be higher than the contract power in a form that the contractor is unaware. In this case, the contract power comparing section 58 outputs an issue instruction asking the increase confirming section 60 for an increase update (S34). The addition confirmation unit 60 causes the output unit 34 (see fig. 1) of the power management device 10 to output a screen on which an addition update is presented.

For example, a message indicating that an increase update of the contract power is necessary under the condition that the power saving is sufficiently performed is output to the output unit 34, and a graph comparing the time series data of the base load power BL with the contract power is output as needed. Further, the magnitude of increase of contract power (for example, 110% of the boosted demand control execution value DMctrl 2) is prompted, and a button for acknowledging the proposal and a button for rejecting the proposal are displayed (S36).

When the proposal for the increase update of the contract power is refused, the increase confirmation unit 60 transmits the refusal reply to the demand control execution value setting unit 56. The demand control execution value setting unit 56 returns the demand control execution value DMctrl1 before lifting (S40), and sends it to the demand control execution unit. The demand control execution unit is provided in the power management apparatus 10, for example.

On the other hand, when the proposal of the contract power increase update is acknowledged, the increase confirmation unit 60 transmits the acceptance answer to the demand control execution value setting unit 56 (S38). The demand control execution value setting unit 56 sends the lifted demand control execution value DMctrl2 to the demand control execution unit.

The demand control is not executed at the stage where the power consumption of the building does not reach the boosted demand control execution value DMctrl2, and as a result, the power consumption is higher than the contract power. Thereby, contract power automatically increases the update.

As described above, according to the power management device of the present embodiment, the appropriate power consumption (base load power BL) is estimated from the utilization condition of the building, and the contract power increase update corresponding to the power consumption can be made to the contractor such as the building owner.

< flow of setting execution value of demand control (at the time of reduction) >

The demand control execution value setting flow of the power management apparatus 10 according to the present embodiment will be described with reference to fig. 7 and 8. In this example, the process of lowering the demand control execution value accompanied by lowering of the base load power is executed.

Fig. 7 illustrates a demand control execution value setting flowchart, and fig. 8 illustrates a timing chart of the demand control execution value setting flowchart. The horizontal axis of fig. 7 represents time, and the vertical axis represents a unit power value (30 minutes demand value).

First, as initial conditions, for example, base load upper limit thresholds blth_max1 and blth_min1 are set according to the base load power BL of day1 of fig. 8. The operation time period setting unit 40 obtains the power consumption of the entire building from the electric power demand meter 22F, and determines whether or not the current time is included in the operation time period (S50). Alternatively, the operation time zone setting unit 40 obtains the control signal of the elevator apparatus from the elevator control panel 20D, and determines whether the current time is included in the operation time zone based on whether the elevator car stops at all stop floors (except for the stop skip floor).

If the current time is not included in the operation period, the process returns to step S50 again. When the current time is included in the operation time period, the operation time period setting unit 40 transmits an instruction to the effect that the current time is included in the operation time period to the basic load time period setting unit 42.

When receiving the instruction from the operation period setting section 40, the base load period setting section 42 determines whether or not the current time is included in the base load period dBL (S52). For example, as described above, the unit power consumption value obtained from the air-conditioning power meter 22D is set to be equal to or smaller than a predetermined value, and is the initial point of the basic load period dBL.

In the case where it is not contained in the basic load period dBL at the present time, the process returns to step S50. On the other hand, when the present time is included in the base load time period dBL, the base load time period setting unit 42 transmits a permission command to permit the unit power metering unit 44 to meter the unit power.

The unit power meter unit 44 that receives the permission command monitors the unit power value DMD (30 minutes demand value), which is the power consumption of the entire building, according to the demand power meter 22F (S54). Alternatively, the sum of the unit power consumption values from the various power meters connected to each sub-controller 14 may be obtained and set as the unit power value DMD.

The counted unit power value DMD is sent to the power comparing unit 46. The power comparing section 46 determines whether or not the received unit power value DMD exceeds (interrupts) the base load lower limit threshold blth_min (at the negative side) (S56). The base load lower threshold blth_min is transmitted from the base load threshold setting unit 54.

For example, day3 to day5 in fig. 8 show an example of DMD < blth_min. Meanwhile, day1 and day2 of fig. 8 show an example of DMD ∈ blth_min, for example. If DMD is equal to or greater than blth_min, the routine returns to step S50, and the monitoring of the unit power value is continued. On the other hand, in the case of DMD < blth_min, the power comparing unit 46 sends an instruction to increase the number of days count kd_d to the number of days counter 48.

The day counter 48 determines (confirms) whether the day count kd_d has increased in the monitor subject day (for example, day 3) (S58). In the case where the addition has been made, no further addition is made, and the flow returns to step S50. When the number of days to be monitored has not yet increased, the number of days counter 48 increases the number of days count kd_d (S60).

The increased number of days kd_d is sent to the number of days count comparing section 50. The day count comparing unit 50 determines whether or not the received day count kd_d is equal to or greater than a count threshold kd_dth (S62). The count threshold kd_dth is stored in the day threshold storage unit 64. For example, the count threshold kd_dth is input from the input unit 32 (see fig. 1) by an administrator or the like in advance. For example, the count threshold kd_dth=3 (3 days) is set.

In the case where kd_d < kd_dth, the flow returns to step S50. On the other hand, when kd_d+ kd_dth, first, the day count comparing unit 50 resets the day count kd_d (returns to 0) (S64) to prepare for the next time. Further, the day count comparing unit 50 transmits an update command (reset command) of the base load power BL to the base load setting unit 52.

In addition to the update instruction of the base load power BL to the base load setting portion 52, the unit power value is transmitted from the unit power metering portion 44 to the base load setting portion 52. The base load setting unit 52 transmits the base load power BL (shown as BL3 in fig. 8), which is the most recent unit power value from the time when the update command is received, to the base load threshold setting unit 54. Alternatively, the basic power BL may be obtained from the unit power of the basic load period dBL from the day counter 48 to the date (day 3 to day 5) from the day count kd_d to the day count threshold kd_dth. As shown in fig. 8, the updated base load power BL3 is lowered as compared with the base load power BL1 before update (S66).

In the base load threshold setting section 54, the base load upper limit threshold blth_max3 and the lower limit threshold blth_minum3 are set (updated) again based on the received base load power BL. In the examples of fig. 7 and 8, the base load power BL (BL 3) of day3 to day5 is lower than the base load power BL (BL 1) of day1 and day2, and therefore, the base load upper limit threshold blth_max and the base load lower limit threshold blth_min are lowered (S68).

The reduced base load upper limit threshold value blth_max3 and the reduced base load lower limit threshold value blth_min3 are transmitted to the power comparing section 46. The base load upper limit threshold blth_max is also transmitted to the demand control execution value setting unit 56. The demand control execution value setting section 56 sets (updates) the demand control execution value DMctrl again based on the received base load upper limit threshold blth_max (S70).

In addition, the magnitude of the decrease in the base load upper limit threshold value blth_max, the lower limit threshold value blth_min, and the demand control execution value DMctrl may be based on, for example, the ratio of DMD < blth_min in step S56. For example, dmctrl3=dmd/blth_min×dmctrl1.

The re-set demand control execution value DMctrl3 is a value lower than the demand control execution value DMctrl1 before setting, and therefore, becomes a value lower than the contract power CNT. Therefore, it is not necessary to compare the contract power with the re-set demand control execution value DMctrl3, and the demand control execution value DMctrl3 is directly transmitted to the demand control execution unit (not shown).

Description of the reference numerals

10: a power management device; 20: an electrical device; 22: a sensor; 40: an operation time period setting unit; 42: a base load time period setting unit; 44: a unit power metering unit; 46: a power comparison unit; 48: a day counter; 50: a day count comparison unit; 52: a base load setting unit; 54: a base load threshold setting unit; 56: a demand control execution value setting unit; 58: a contract power comparison unit; 60: an addition confirmation unit; 62: a contract power storage unit; 64: a day threshold storage unit; BL: a base load power value; blth_max: a base load upper threshold; blth_min: a base load lower threshold; CNT: contract power value; dBL: a base load period; DMctrl: demand control execution value.

Claims

1. A power management apparatus, the power management apparatus comprising:

a unit power measurement unit that obtains unit power that is average power consumption of the building per unit time;

a threshold setting unit that sets a base load threshold value according to the unit electric power in a base load period in which a change in the unit electric power is stable in an operation period of the building;

a control execution value setting unit that sets a demand control execution value that is a value higher than the base load threshold value in a time period, and that, when the unit power in the base load time period exceeds the base load threshold value, allows a value exceeding a contract power value to be a value that can be taken as the demand control execution value every time the re-setting is performed, when the unit power in the base load time period exceeds the base load threshold value, causes demand control that suppresses operation of electrical equipment of the building to be performed; and

and a confirmation unit that inquires whether or not the contract power value can be increased when the re-set demand control execution value exceeds the contract power value.

2. The power management device according to claim 1, wherein,

the power management device has a base load period setting section that sets a stop period of the air conditioning equipment in the operation period as the base load period.

3. The power management device according to claim 1 or 2, wherein,

the power management device includes an operation time period setting unit that sets a point at which elevators provided in the building are stopped at all stop floors as an initial point of the operation time period.

4. The power management device according to claim 3, wherein,

when a stop-skip floor is set for an elevator installed in the building, the operation time period setting unit sets the time point at which the elevator stops at all the stop floors except the stop-skip floor as the initial time point of the operation time period.

5. The power management device according to claim 3, wherein,

the operation time period setting unit sets a termination time point of the operation time period when a lifter provided in the building is in a standby state for a predetermined period of time.

6. The power management device according to claim 1, wherein,

the threshold setting unit obtains the base load threshold from the unit power of the lighting devices provided to the building in the operation period.

7. The power management device of claim 4, wherein,