JP6016730B2 - Demand control apparatus and demand control method - Google Patents

Description

  The present invention relates to a demand control device and a demand control method for controlling a plurality of power loads such that demand power in a demand time limit of the plurality of power loads is equal to or less than a target power.

  In the conventional demand control device, the power used by the power load is received and the predicted power R at the end of the demand time period is calculated. Then, it has been proposed that the adjusted power U is obtained by comparing the predicted power R and the target power Q, and the power load is cut off when the adjusted power U is positive (see, for example, Patent Document 1).

JP 60-5738 A (2nd page, upper left column)

  In the demand control device described in Patent Document 1, the predicted power R in the demand time period T (demand time period) is calculated by the equation (1).

That is, the demand power ΔP (kW) increased from the time point t before the current time t to the current time t is linearly extrapolated for the remaining time (T−t) to the current time t at the current time t. A value obtained by adding the demand power P is defined as a predicted power R (kW) (see FIG. 16).
The demand power P (demand) is an average value obtained by dividing the amount of power (kWh) used within the demand time period T (minutes) by the demand time period T / 60 (hr), and the unit is kW.

  Moreover, the adjustment electric power U is calculated by Formula (2). The adjusted power U (kW) is power that should be adjusted between the current time t and the end of the demand time period T in order to make the demand power P coincide with the target power Q at the end of the demand time period. When the adjusted power U is positive, the predicted power R exceeds the target power Q, and if it remains as it is, the demand will exceed, so it is necessary to reduce the power consumption of the power load.

  As can be seen from equation (2), even if the excess amount of the predicted power R with respect to the target power Q is the same, the shorter the remaining time (T−t), the larger the adjusted power U becomes. Conversely, if the remaining time (T−t) is long, the adjustment power U becomes small. Therefore, it is necessary to reduce the power consumption of the power load more strongly as the remaining time (Tt) is shorter, and the suppression of the power consumption of the power load may be more gradual as the remaining time (Tt) is longer. .

  In the technique of the above-mentioned Patent Document 1, whether the calculated adjustment power U is positive or negative is determined, and when U> 0 (R> Q), an alarm is issued or the power load is cut off to reduce the power consumption. Reduced and avoided over demand. When an alarm is issued, the power load is interrupted by a person or another system using the alarm as a trigger. This series of operations will be referred to as demand control.

  Here, as the power load to be cut off, an air conditioner, a refrigerator or the like (hereinafter collectively referred to as “refrigeration cycle apparatus”) is often selected. The main reason is that the power consumption is relatively large compared to other devices. Shutting down (stopping) the refrigeration cycle system has the disadvantage that the temperature of the space to be cooled increases or the temperature of the space to be heated decreases. However, if the demand is exceeded, a penalty will be incurred and the contracted power for the next period Since the (basic charge) is raised, the refrigeration cycle apparatus is shut off in a trade-off with the above demerits.

In recent years, in the refrigeration cycle apparatus, an inverter drive type (hereinafter referred to as an inverter machine) refrigeration cycle apparatus in which the operation frequency of the compressor is variable has become mainstream.
However, in the demand control device of Patent Document 1, when the predicted power R exceeds the target power Q, the power load is cut off. That is, the operation is also stopped (blocked) for the refrigeration cycle apparatus of the inverter machine.
As a result, when the refrigeration cycle apparatus is an air conditioner, the temperature of the space to be cooled increases and the temperature of the space to be heated decreases, so that it is difficult to maintain the room temperature at the target value (set temperature). There was a problem. Further, when the refrigeration cycle apparatus is a refrigerator, there is a problem that the quality of a load such as food in the warehouse is lowered, and the comfort of workers in the warehouse is lowered.

  The present invention has been made to solve the above-described problems, and controls a plurality of power loads so that the demand power in the demand time limit is equal to or lower than the target power, and the operation of the refrigeration cycle apparatus that is the power load. The demand control device and the demand control method can be obtained.

  A demand control device according to the present invention is a demand control device for controlling a plurality of power loads such that a demand power in a demand time limit is equal to or less than a target power of a plurality of power loads including at least a refrigeration cycle device, Used power amount acquisition means for acquiring the used power amount of a plurality of power loads, the demand time limit, a timing adjustment means for synchronizing the timing timing of a time timer in the demand control device, and the used power amount acquisition means Power amount storage means for storing the used power amount acquired by the power consumption amount acquired by the power consumption amount acquisition means, the past power consumption amount held by the power amount storage means, At the end of the demand period based on the demand period and the remaining time that is the difference between the demand period and the elapsed time from the timing start time of the demand period to the present. Based on predicted power calculation means for obtaining predicted power, the predicted power, the target power, the demand time limit, and the remaining time, the demand power at the end of the demand time limit is made equal to or less than the target power. Adjusted power calculating means for obtaining the adjusted power of the power supply, and demand limiting means for controlling the operation of one or more of the power loads including at least the refrigeration cycle apparatus based on the adjusted power, the demand limiting means Determining the total power consumption that is the sum of the current power consumption of the power load to be controlled, and when the ratio of the adjusted power to the total power consumption exceeds a threshold, stop the operation of the power load to be controlled. When the ratio of the adjusted power to the total power consumption is less than or equal to a threshold value, the power load of the power load to be controlled is reduced to operate. To.

  The present invention can control a plurality of power loads so that the demand power in the demand time period is equal to or less than the target power, and can continue the operation of the refrigeration cycle apparatus that is the power load.

1 is an overall configuration diagram of a cooling system including a demand control device 1 according to Embodiment 1 of the present invention. FIG. 2 is a refrigerant circuit diagram of a refrigeration apparatus group in the cooling system of FIG. 1. It is a detailed block diagram of the cooling system of FIG. It is a block diagram which shows the structure of the demand control apparatus 1 which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the compressor frequency ratio and COP ratio in a refrigerator. It is the figure which showed the operation | movement flow of the measurement controller 33 which concerns on Embodiment 1 of this invention. It is the figure which showed the operation | movement flow of the demand control apparatus 1 which concerns on Embodiment 1 of this invention. It is a whole cooling system block diagram containing the demand control apparatus 1 which concerns on Embodiment 2 of this invention. It is a detailed block diagram of the cooling system of FIG. It is a block diagram which shows the structure of the demand control apparatus 1 which concerns on Embodiment 2 of this invention. It is a figure which shows the relationship between the prediction electric power R [X] and the demand time limit T in the present time t of the demand control apparatus 1 which concerns on Embodiment 2 of this invention. It is the figure which showed the operation | movement flow of the demand control apparatus 1 which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the demand control apparatus 1 which concerns on Embodiment 3 of this invention. It is a figure which shows the relationship between target electric power, a cutoff point, and a charging point. It is the figure which showed the operation | movement flow of the demand control apparatus 1 which concerns on Embodiment 3 of this invention. It is a conceptual diagram which shows the relationship between the demand time limit and demand power in demand control.

  In the following embodiment, the case where the power load for the demand control device to adjust the power consumption is a refrigerator will be described, but the present invention is not limited to this. In the present invention, the power load includes not only a refrigerator but also a refrigeration cycle apparatus such as an air conditioner and a dehumidifier.

  In addition, 30 minutes is normally employ | adopted for the demand time limit T which is a time interval which an electric power company measures demand power. That is, the measurement interval of demand power is from 0:00 to 0:30, from 0:30 to 1:00. Accordingly, the following description will be made assuming that the demand time period T is 30 minutes, but the present invention is not limited to this, and can be similarly applied to other demand time periods (for example, 15 minutes).

The demand control device can be classified into the following two types according to the demand time limit.
(1) The predicted power is calculated and demand control is performed in synchronization with the demand period of the power company (see FIG. 16). That is, the demand control is performed so that the power demand does not exceed the target power at the end of the demand time limit. However, in this case, a time adjustment operation with a device for adjusting the demand time limit and the time in the demand control device is necessary.
(2) Generate 10 predicted powers, for example, from 3 minutes ahead to 30 minutes ahead for every control period (for example, 1/10 of the demand time period) without synchronizing with the demand time period, and based on these predicted values, Implement demand control. In other words, since the end point of the demand period measured by the power company is unknown in this method, the target can be seen in any 30 minutes (equivalent to the demand period) in increments of 3 minutes (1/10 of the demand period). This is a method that prevents power from being exceeded.
Hereinafter, the method (1) is shown in the first embodiment, and the method (2) is shown in the second and third embodiments.

Embodiment 1 FIG.
[overall structure]
FIG. 1 is an overall configuration diagram of a cooling system including a demand control device 1 according to Embodiment 1 of the present invention.
The cooling system shown in FIG. 1 includes a plurality of refrigerators 22 (22-1, 22-2, 22-3), a plurality of coolers 23 (23-1, 23-2, 23-3), and a plurality of refrigerators. A plurality of unit controllers 24 (24-1, 24-2, 24-3) for controlling the operation and stop of the machine 22 and the plurality of coolers 23 are provided, and a refrigeration apparatus group is configured. The plurality of coolers 23 are arranged in one freezer warehouse 11 and cool the air in the freezer warehouse 11.

FIG. 2 is a refrigerant circuit diagram of a refrigeration apparatus group in the cooling system of FIG.
As shown in FIG. 2, the refrigerator 22 includes a compressor 51, a condenser 52, and a blower 53 that supplies air to the condenser 52. The cooler 23 includes an expansion valve 54 (expansion means), an evaporator 55 (cooler), and a blower 56 that supplies air to the evaporator 55. The compressor 51, the condenser 52, the expansion valve 54, and the evaporator 55 are annularly connected by a refrigerant pipe to form a refrigerant circuit.

The compressor 51 is a compressor whose operating capacity can be varied, and is composed of, for example, a positive displacement compressor driven by a motor controlled by an inverter.
The condenser 52 and the evaporator 55 are comprised by the fin & tube type heat exchanger comprised by the heat exchanger tube and many fins, for example.
The expansion valve 54 is composed of, for example, an electronic expansion valve, and adjusts the flow rate of the refrigerant by setting the opening, and expands the refrigerant by decompressing it.
The blower 53 and the blower 56 are driven by a fan motor or the like, and can adjust the air volume by changing the motor rotation speed, thereby adjusting the air volume.

In the refrigeration apparatus group, the refrigerant circulates in the refrigerant circuit, so that the refrigerant in the evaporator 55 and the air in the refrigeration warehouse 11 exchange heat to cool the inside of the refrigerator.
That is, in the cooling operation, the high-temperature and high-pressure refrigerant discharged from the compressor 51 flows into the condenser 52, exchanges heat with the outside air in the condenser 52, condenses and liquefies, and becomes a high-pressure and low-temperature refrigerant. The high-pressure and low-temperature refrigerant that has flowed out of the condenser 52 is reduced in pressure by the expansion valve 54 to become a gas-liquid two-phase refrigerant, and is exchanged with the air in the freezer warehouse 11 by the evaporator 55 to evaporate and cool.
Note that, for example, a four-way valve or the like may be provided so that the cooling operation and the heating operation can be switched. In this case, in the heating operation, the refrigerant circulation direction is opposite to the cooling operation.

  Refer to FIG. 1 again. The cooling system further includes a centralized controller 21 for centrally managing the refrigeration apparatus group, and is connected to the refrigerator 22 and the unit controller 24 via a communication line 27.

  The refrigerator 22 has a communication function and can exchange data with the centralized controller 21 and the unit controller 24 by communication. An operation or stop command is transmitted from the unit controller 24 to the refrigerator 22 by communication. The refrigerator 22 starts and stops according to the received command. Moreover, the refrigerator 22 transmits information, such as an operation state, the temperature and pressure of each part of the refrigerator, the current operating frequency, the current power consumption, and the rated power consumption, to the centralized controller 21 by communication.

  The unit controller 24 includes temperature sensors 26 (26-1, 26-2, 26-3), and detects the air temperature in the freezer warehouse 11. Further, the unit controller 24 is connected to the remote control 25 (25-1, 25-2) and the remote control line 28 (28-1, 28-2). The unit controller 24 transmits the air temperature and control state in the freezer warehouse 11 to the remote controller 25 to display information. Further, the unit controller 24 receives values of various settings (for example, set temperature) set and changed by the user with the remote controller 25 and stores them in the memory of the unit controller 24.

  Further, the unit controller 24 compares the set temperature set by the user with the centralized controller 21 or the remote controller 25 and the temperature detected by the temperature sensor 26, and determines whether the refrigeration apparatus group is operated or stopped. When the temperature detected by the temperature sensor 26 is higher than the thermo return temperature slightly higher than the set temperature, the unit controller 24 operates the refrigerator 22 and the cooler 23. On the other hand, when the temperature detected by the temperature sensor 26 is lower than the thermo stop temperature slightly lower than the set temperature, the unit controller 24 stops the refrigerator 22 and the cooler 23.

  When the refrigerator 22 receives the operation command from the unit controller 24, the refrigerator 22 starts to start and enters the steady operation after the start-up is completed. In the steady operation, the refrigerator 22 feedback-controls the frequency of the compressor 51 so that the saturation temperature (evaporation temperature) corresponding to the refrigerant pressure sucked into the compressor 51 matches the target evaporation temperature. The unit controller 24 calculates an optimum target evaporation temperature as needed from the set temperature and the current detected temperature, transmits this to the refrigerator 22 by communication, and sets it as a target value for frequency control of the compressor 51 in the refrigerator 22. To do.

  As described above, the internal temperature of the freezer warehouse 11 is maintained near the set temperature, and the load (the object to be cooled) such as food in the internal storage can be cooled and stored.

  The centralized controller 21 has the function of the demand control device 1 that executes demand control. Details of the demand control device 1 will be described later.

Further, the centralized controller 21 is provided with a time adjustment device 41, which is configured to be able to perform demand control in synchronization with a demand time period defined by the electric power company. In this case, in order to adjust the demand time limit, it is necessary to adjust the starting point of timekeeping, and the user presses the time setting button (not shown) of the time setting device 41 in accordance with the time display of the power transaction meter. Set time. After the time adjustment, the time adjustment device 41 keeps time synchronized with the demand time by using the power frequency. Then, the centralized controller 21 performs demand control using the time of the clock possessed by the time setting device 41.
Note that some electric power companies can also output a time pulse for time adjustment of demand together with the power pulse. In that case, time adjustment may be performed by the time pulse, and manual time adjustment is not necessary. .

FIG. 3 is a detailed configuration diagram of the cooling system of FIG.
As shown in FIG. 3, on the communication line 27, in addition to the above-described refrigerator 22 and the like, a transmission line power supply device 32 that supplies power necessary for communication using the communication line 27, used electric energy, and A measuring controller 33 that measures the amount of gas and water used, a general-purpose interface 34 (contact input / output) with a local system, and a measuring controller 35 that measures manufacturing process temperature and analog signals are connected.
The centralized controller 21 is a device that collectively manages and controls all of these devices, and is connected to the PC 31-1 as a man-machine interface.

  In the PC 31-1, various temperatures and pressures of the refrigerator 22, the control state, and the temperature in the detection chamber and the control state of the unit controller 24 can be monitored. In addition, setting temperature setting change, forced operation or stop operation of the refrigerator 22 and the unit controller 24, operation state of the refrigeration apparatus group, measurement and measurement data (power consumption, water usage, gas usage, etc.), It is possible to create forms for various data. The PC 31-1 is connected to the public line network 38 via the communication device 37-1. Furthermore, the PC 31-2, which is a remote monitoring terminal connected to the public line network 38 through the communication device 37-2, can perform operations equivalent to those of the PC 31-1 from a remote location.

[Configuration of Demand Control Device 1]
FIG. 4 is a block diagram showing the configuration of the demand control apparatus 1 according to Embodiment 1 of the present invention.
The centralized controller 21 has the function of the demand control device 1 that executes demand control.
As shown in FIG. 4, the demand control device 1 includes a used power amount acquisition unit 2, a predicted power calculation unit 3, an adjusted power calculation unit 4, a demand limit unit 5, a priority order storage unit 6, and a power amount storage unit 7. Prepare.
The power consumption acquisition means 2 acquires the power consumption of the entire refrigeration system including the refrigeration warehouse 11 (power consumption of a plurality of power loads) by the watt hour meter 36 via the metering controller 33.
The electric energy storage means 7 sequentially stores information on the electric energy used acquired by the electric energy acquisition means 2.
The predicted power calculation means 3 and the adjusted power calculation means 4 time the elapsed time from the start of the demand time period T to the present time (hereinafter referred to as “current time t”) in synchronization with the time of the time setting device 41.
The predicted power calculating means 3 includes the used power amount acquired by the used power amount acquiring means 2, the past used power amount held by the power amount storage means 7, the demand time limit T, the demand time limit T, and the demand time limit T. The predicted power R at the end of the demand time period T is obtained based on the remaining time that is the difference from the elapsed time from the time measurement start to the present time.
The adjusted power calculation means 4 adjusts the adjusted power U for making the demand power P at the end of the demand time period T less than or equal to the target power Q based on the predicted power R, the target power Q, the demand time period T, and the remaining time. Ask for.
The demand limiting unit 5 transmits a demand command to the unit controller 24 or the refrigerator 22 based on the adjusted power U and the priority order condition acquired from the priority order storage unit 6, and operates the refrigerator group (power load). Control.

  In the first embodiment, the case where the centralized controller 21 has the function of the demand control device 1 will be described. However, the present invention is not limited to this, and the demand control device 1 may be provided separately. Each configuration of the demand control device 1 can be realized by hardware such as a circuit device that realizes these functions, or can be realized as software executed on an arithmetic device such as a microcomputer or a CPU. .

[Demand control]
Details of demand control in the first embodiment will be described below.
In the first embodiment of the present invention, a method that synchronizes with the demand time period is adopted as a method for calculating the predicted power. Since this method needs to be synchronized with the demand time limit, a device for time adjustment (time adjustment device 41) is required, and a time adjustment operation is required.
Here, when the integrated power amount p is used instead of the current demand power P in the equation (1), the equation (3) is transformed. Δp (kWh) in the expression (3) is an increase amount of the integrated power amount p increased from the time point Δt before the current time point to the current time point t.

  The first term on the right side of Equation (1) corresponds to the first term on the right side of Equation (3), the second term on the right side of Equation (1), and the second term on the right side of Equation (3). Multiplying the right side of Equation (3) by 60 / T is a process for converting the integrated power amount (kWh) to demand power (kW).

  When the demand time limit T is 30 minutes in the equation (3), the predicted power R is expressed by the equation (4). If the control cycle of demand control is defined as 1/10 of the demand time limit T, the control cycle is 3 minutes, and Δt = 3 (minutes) in the equation (4).

The unit of each amount in the curly brackets of the formula (4) is kWh. Further, since the predicted power R is an average value (kW) obtained by dividing the amount of power used within the demand time period by the demand time period, in the calculation of the predicted power R, the power obtained within the curly brackets of the equation (4) It is necessary to divide the quantity (kWh) by the demand time limit of 30 minutes, that is, 0.5 hours, which is the meaning of x2 on the right side of Equation (4).
On the other hand, the calculation formula of the adjusted power U is expressed by the formula (5) when 30 minutes is adopted as the demand time limit T in the formula (2).

In order to calculate Equation (4) and Equation (5), it is necessary to know the amount of electric power used by the area where the demand control target (electric power load) is installed or the entire office including the area.
The used power amount acquisition means 2 measures the used power amount (integrated power amount p) with the watt-hour meter 36 and the metering controller 33. The watt hour meter 36 is connected to an electric wire to be measured, and is further connected to the metering controller 33 by an a contact or a c contact. The watt-hour meter 36 converts the amount of power used into a pulse and transmits it to the metering controller 33 by opening and closing the contact. The metering controller 33 counts the number of output pulses of the watt hour meter 36 and multiplies the multiplication factor (kWh / pulse) to convert it into an electric energy (kWh). The multiplication factor needs to be set according to the pulse unit setting (kWh / pulse) of the watt-hour meter 36 to be used, and the user sets the weighing controller 33 by operating the PC 31-1 or PC 31-2. . The metering controller 33 holds the measured power amount (kWh) as an accumulated value, and if there is a response request (communication) of the used power amount from the centralized controller 21, the cumulative value at that time is sent to the centralized controller 21. Respond with communication.
Here, the watt-hour meter 36 is described as a pulse output of the measured electric energy, but the output form of the electric energy is not only the pulse but also an analog output of DC0-5V or DC4-20mA, or a digital value by communication. Any method may be used.

  Thus, the predicted power R and the adjusted power U can be calculated. For each control period (3 minutes), the predicted power R and the adjusted power U are calculated, and the execution / cancellation of demand restriction is determined based on the value of the adjusted power U.

  Specifically, the demand control device 1 calculates the predicted power R in Expression (4) and the adjusted power U in Expression (5) at the timing when the control cycle arrives, and if the adjusted power U is a positive value, Demand restriction is implemented to reduce the power consumption of the refrigerator group (refrigeration cycle device) that is the power load.

When the adjusted power U is large with respect to the power load, “stop” is adopted as the demand limit, and the power consumption of the power load is greatly reduced.
Conversely, when the adjusted power U is small with respect to the power load, “compressor frequency down” is adopted as a demand limit, and the power consumption of the power load is gradually reduced.
Details of the determination when the adjusted power U is large or small with respect to the power load will be described later.

  In addition, as the demand restriction when the adjusted power U is relatively small with respect to the power load, “target evaporation temperature up” or “set temperature up” may be used in addition to “compressor frequency down”. In “target evaporation temperature up”, the target value of the evaporation temperature is temporarily increased. As a result, the frequency of the compressor 51 is reduced, and as a result, the power consumption of the refrigerator 22 is reduced. The set temperature is a set air temperature (target air conditioning target) that can be set by the unit controller 24, the PC 31-1, or the PC 31-2. In “set temperature increase”, the set temperature is temporarily increased. As a result, the frequency of the compressor 51 is decreased or the compressor 51 is stopped, so that the power consumption of the refrigerator 22 is reduced.

Further, if the adjusted power U is a positive value even in the next control cycle, a demand limit is further output to reduce the power consumption of the refrigerator 22 as a power load.
On the other hand, when the adjustment power U becomes a negative value at the timing when the control cycle arrives, the refrigerator 22 that has applied the demand restriction is returned (demand restriction is released). If the adjustment power U is a negative value even in the next control cycle, another refrigerator 22 is returned.

Selection of the target refrigerator (power load to be controlled) at the time of the demand restriction is performed according to the following priority condition. This priority order condition is stored in the priority order storage means 6.
The demand limiting means 5 first determines (Condition 1), determines (Condition 2) when (Condition 1) is plural, and determines (Condition 3) when (Condition 2) is plural. When (Condition 3) is plural, the target refrigerator 22 is selected according to (Condition 4).

(Condition 1) Low demand prohibition order (1, 2, ... 9, 10, no setting) (Condition 2) Non-defrosting (Condition 3) Smallest internal temperature margin (Condition 4) Most One with a large address

(Condition 1) is a priority set by the user, with 1 being the highest priority and no setting being the lowest.
(Condition 2) is a condition for excluding the refrigerator 22 during the cooler defrosting. If the refrigerator 22 or the unit controller 24 is stopped during the defrosting, the defrosting is completed incompletely, and the frost attached to the cooler 23 further grows to form an ice block, which causes a failure such as crushing of the cooler piping. It is.
(Condition 3) is a condition for shutting off the refrigerator 22 having a small internal temperature margin. The internal temperature margin is defined as “internal temperature−thermo stop temperature” when the refrigerator 22 (or air conditioner) is cooled. When the power load is an air conditioner, it is defined as “thermo stop temperature−internal temperature” during heating. That is, in the case of the refrigerator 22, the shutoff priority of the refrigerator 22 introduced into the chamber in which the internal air is sufficiently cooled compared to the thermo stop temperature is increased. This is to minimize the influence of the rise in the internal temperature accompanying the shutoff of the refrigerator 22 (which affects the quality of the load).
(Condition 4) is a condition for setting a priority order based on an address assigned to each device on the communication line 27 in order to execute communication using the communication line 27. Since the same address is not set redundantly for a plurality of devices, one refrigerator 22 is reliably determined according to the condition (Condition 4).
When priorities are assigned to all the refrigerators 22 shown in FIG. 1 by the procedure of (Condition 1) to (Condition 4), Table 1 is obtained.

On the other hand, the selection of the target refrigerator 22 when the demand restriction is released is performed according to the following priority condition.
The demand limiting means 5 first determines (Condition 5), determines (Condition 6) when (Condition 5) is plural, and (Condition 6) indicates that the target A refrigerator 22 is selected.
(Condition 5) High demand prohibition order (1, 2, ... 9, 10, no setting) (Condition 6) Largest room temperature margin (Condition 7) Smallest address (Condition 5)- When priorities are assigned to all the refrigerators 22 shown in FIG. 1 according to the procedure of (Condition 7), Table 2 is obtained.

Next, the above-described determination of “adjusted power U is large or small with respect to the power load” will be described.
The current power consumption of each refrigerator 22 is defined as Pi. When the demand restriction is performed, the refrigerator 22 (control target power load) subject to demand restriction is selected in advance from the top to the bottom of Table 1. At this time, the one whose absolute value of the internal temperature margin is less than the desired value is selected. The desired value is a setting value that can be set by the user with the PC 31-1, PC 31-2. If the temperature margin is equal to or less than the desired value, the value that can be considered that the internal air temperature substantially matches the set temperature. It is.
Assuming that n units have been selected as demand-restricted refrigerators, the value of equation (6) obtained by dividing the adjusted power U by the sum of the n units of current power consumption Pi (Σ ⁿ Pi) Thus, “adjusted power U is large or small with respect to the power load” is determined.

  Specifically, the determination is made by the following equations (7) to (11). In addition, although the case where three types of “target evaporation temperature up”, “compressor frequency down”, and “stop” are used as an example of the demand limiting operation is exemplified here, the present invention is limited to this. is not.

  When satisfying the relationship of Expression (7), the demand limiting unit 5 maintains the current state (does nothing for the power load).

  When satisfying the relationship of Expression (8), the demand limiting unit 5 can be considered that the excess amount of the predicted power R with respect to the target power Q is small, and therefore selects “target evaporation temperature up” as the demand limiting operation. . The increase amount (° C.) of the target evaporation temperature can be set by the user on the PC 31-1 and PC 31-2. Here, it is set to 3 ° C., for example.

  When satisfying the relationship of Expression (9), the demand limiting unit 5 selects “compressor frequency down” as the demand limiting operation because it can be considered that the excess amount of the predicted power R with respect to the target power Q is not small. The reduction amount (%) of the frequency of the compressor 51 can be set by the user at the PC 31-1 and PC 31-2. Here, for example, 10%.

  When satisfying the relationship of Expression (10), the demand limiting unit 5 selects “stop” as the demand limiting operation because it can be considered that the excess amount of the predicted power R with respect to the target power Q is large.

When satisfying the relationship of Expression (11), the demand limiting unit 5 selects “stop” as the demand limiting operation because it can be considered that the excess amount of the predicted power R with respect to the target power Q is remarkably large. However, since the above n units are insufficient as the amount of power consumption of the power load, an additional target refrigerator (control target power load) is further selected from Table 1. Assuming that the total number of the n units and the added target refrigerators is m units, a minimum m unit satisfying U ≦ Σ ^m Pi is obtained, and a demand command for “stopping” operation is output to the m units. To do.

Assuming that the number of all the refrigerators 22 (electric load) is N, if U> Σ ^N Pi, the demand limiting means 5 issues a demand command to “stop” the operation of all the refrigerators 22. Output. Further, when U> Σ ^N Pi, there is a high possibility that demand will be exceeded, so the demand control device 1 issues an alarm by the PC 31-1 or PC 31-2 and reduces the power consumption to the user. You may make it perform the operation | movement prompting.

Note that the threshold value of 0.10 described in the above equations (8) and (9) is an example, and other values may be used. Here, an approximate upper limit value that is theoretically conceivable is used, which is the ratio of refrigerator power consumption that can be reduced by temporarily increasing the target evaporation temperature of the refrigerator 22.
Moreover, the threshold value of 0.40 described in the above formulas (9) and (10) is also an example, and other values may be used. Here, it was determined based on the frequency ratio at which the coefficient of performance (COP) of the refrigerator 22 starts to decrease significantly as the frequency of the compressor 51 decreases. As shown in FIG. 5, since the COP starts to greatly decrease when the frequency of the compressor 51 falls below about 60% of the maximum frequency, the refrigerator 22 is inefficient if the frequency is further decreased. It becomes an operation state and is not preferable.

  Based on the above description, a series of control operations of the demand control apparatus 1 according to the first embodiment will be described in detail with reference to FIGS.

FIG. 6 is a diagram showing an operation flow of the weighing controller 33 according to Embodiment 1 of the present invention.
The metering controller 33 constantly counts the pulses output from the watt-hour meter 36, multiplies the number of pulses by a multiplier (kWh / pulse), converts it to an electric energy, and measures it as a cumulative value. The latest integrated power amount is stored in a storage device (not shown) in the weighing controller 33.
That is, in step S11, the metering controller 33 starts measuring the integrated power amount.
Next, in step S12, the output pulses of the watt hour meter 36 are counted.
In step S <b> 13, the number of pulses measured in step S <b> 12 is multiplied by a multiplication factor to be converted into electric energy (increment).
In step S14, the increment of the electric energy obtained in step S13 is added to the current integrated electric energy to update the integrated electric energy to the latest value.
In step S15, the latest integrated electric energy is stored in the storage device.

FIG. 7 is a diagram showing an operation flow of the demand control apparatus 1 according to Embodiment 1 of the present invention.
Next, the operation of the demand control device 1 (centralized controller 21) will be described with reference to FIG.
First, in step S21, the demand limiting unit 5 starts counting of a control cycle timer for demand control (counting start after timer reset). Here, the control period is defined as 1 / 10th of the demand time limit, which is 3 minutes.

  In step S <b> 22, the used power amount acquisition unit 2 measures the used power amount (integrated power amount) of the power load. The used power amount acquisition means 2 requests the metering controller 33 for the power amount in order to obtain the current integrated power amount. Upon receiving the request, the weighing controller 33 responds to the centralized controller 21 (used power amount acquisition means 2) by communication with the latest value of the integrated power amount (kWh). The electric energy storage means 7 sequentially stores information on the integrated electric energy acquired by the used electric energy acquisition means 2.

In step S23, the predicted power calculation means 3 calculates the predicted power R using equation (4).
In step S24, the adjusted power calculation means 4 calculates the adjusted power U using the equation (5).

  In step S25, the demand limiting unit 5 determines whether or not the adjusted power U is 0 or more. If the adjusted power U is 0 or more, the process proceeds to step S29.

  In step S29, the demand limiting unit 5 selects the demand limiting operation according to the above-described demand limiting operation selection method (equation (7) to equation (11)).

  In step S31, the demand restricting means 5 selects the demand-restricted refrigerators according to the above-mentioned priority conditions at the time of demand restriction (selects from the top to the bottom of Table 1). At this time, the one having an absolute value of the internal temperature margin below the desired value is selected.

  In step S32, the demand limiting unit 5 applies the demand according to the demand limiting operation determined in step S29 to the target chiller selected in step S31 (power load to be controlled) or the unit controller 24 of the target chiller. The command is transmitted and the process proceeds to step S28. Here, when the demand command is “stop”, the demand limiting unit 5 transmits the demand command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand command transmits the stop command to the target refrigerator. It becomes a procedure. The target refrigerator that has received the demand command “stops” the operation based on the demand command, or reduces the power consumption as described above by “compressor frequency down”, “target evaporation temperature up” or “set temperature up”. ”Is performed.

In step S25, the demand limiting means 5 proceeds to step S26 when the adjusted power U is not 0 or more.
In step S26, the demand restriction unit 5 determines whether or not demand restriction is being implemented at the current time t. If there is one or more refrigerators 22 whose demand is limited, the process proceeds to step S33.

  In step S33, the demand restricting means 5 selects the target refrigerator for which the demand restriction is released according to the priority order when the demand restriction is released (from the top to the bottom of Table 2). At this time, the one whose absolute value of the internal temperature margin exceeds the desired value is selected.

  In step S34, the demand restriction unit 5 cancels the demand restriction of the target refrigerator selected in step S33, and proceeds to step S28. Here, when the demand restriction to be released is “stop”, the demand restriction unit 5 transmits a demand restriction release command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand release command receives the target freezing. This is the procedure for sending a return (restart) command to the machine.

  If there is no demand-limited refrigerator 22 in step S26, the process proceeds to step S27, in which the demand restriction unit 5 does not perform the demand restriction execution or release operation, and does not execute the current demand restriction state (demand No limit).

  In step S28, the demand limiting means 5 compares the current value of the control cycle timer that started timing in step S21 with the control cycle. If the value of the control cycle timer is less than the control cycle, the process returns to step S27 to maintain the current state. Conversely, if the value of the control cycle timer is equal to or greater than the control cycle, the process returns to step S21 and the main flow is completed.

  By repeating the above, the demand limit is executed or canceled for each control cycle, or the output of the current status is maintained, so that the demand power P does not exceed the target power Q.

As described above, in the first embodiment, the demand limiting operation is changed in accordance with the magnitude relationship of the adjusted power U with respect to the power load, and control that stops the refrigerator group (refrigeration cycle apparatus) that is the power load as much as possible is performed. Do.
For this reason, it becomes possible to suppress the rise (at the time of cooling) or the fall (at the time of heating) of the internal temperature (room temperature), and it is possible to maintain the quality of the cargo and the working environment.

  The target power Q may be matched with the contract power or may be set to a value less than the contract power. In addition, if the power consumption of power loads (for example, production lines, elevators, etc.) other than the refrigerator group (refrigeration cycle device) is relatively large, or the operating rate of these power loads changes suddenly In such a case, setting the target power Q to a value less than the contract power is less likely to exceed demand.

Embodiment 2. FIG.
FIG. 8 is an overall configuration diagram of a cooling system including the demand control device 1 according to Embodiment 2 of the present invention.
FIG. 9 is a detailed configuration diagram of the cooling system of FIG.
8 and 9, the cooling system including the demand control device 1 according to the second embodiment is obtained by removing the time setting device 41 from the refrigeration system according to the first embodiment. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same configurations.

[Configuration of Demand Control Device 1]
FIG. 10 is a block diagram showing a configuration of the demand control apparatus 1 according to Embodiment 2 of the present invention.
In FIG. 10, the predicted power calculation means 3 virtually regards the remaining time as the remaining time regardless of the timekeeping, sets a plurality of assumed remaining times within a range larger than 0 and shorter than the demand time limit T, and there is no plural. For each remaining time, based on the used electric energy acquired by the used electric energy acquisition means 2, the past used electric energy held by the electric energy storage means 7, the demand time limit T, and the assumed remaining time. Then, a plurality of predicted powers R [X] are obtained.
The adjusted power calculation means 4 uses the predicted power R [X], the target power Q, the demand time limit T, and the assumed remaining time X as the target power Q when the remaining time has elapsed since the current time. A plurality of adjustment powers U [X] for obtaining the following are obtained.
The demand limiting unit 5 transmits a demand command to the unit controller 24 or the refrigerator 22 based on the maximum adjustment power U [X] among the plurality of adjustment powers U [X] obtained for each control cycle, and the refrigerator Controls group (power load) operation.
Other configurations are the same as those of the first embodiment.

[Demand control]
Details of demand control in the second embodiment will be described below.
In Embodiment 2 of the present invention, a method that does not synchronize with the demand time limit T of the electric power company is adopted as a method for calculating the predicted power R. Since this method does not need to be synchronized with the demand time limit T, a device for time adjustment (time adjustment device 41) is unnecessary, and a time adjustment operation is not required and it is simple.

On the other hand, since it is not synchronized with the demand time period T, the current time t in the time interval from the start of time measurement to the end of time measurement of the demand time period T is unknown, and the expression (4) cannot be calculated (in the demand time period). Remaining time (Tt) is unknown).
Therefore, in the demand control device 1 according to the second embodiment, the predicted power is calculated for each control cycle shorter than the demand time limit T. For example, assuming that 1/10 of the demand time limit T (30 minutes) is the control period (3 minutes), 10 predicted electric powers are calculated at time intervals of 1/10 of the demand time period T for each control period.

  Here, in the above equation (3), the predicted power (kW) after X minutes from the current time t is set as R [X], and the time from the time before the current time t by the control cycle Δt to the current time t The amount of increase in the integrated power amount p that has been increased to Δp (Δp = current integrated power amount−integrated power amount before Δt minutes) is defined as Δp. Assuming that the virtual remaining time from the current time t to the demand time limit T (hereinafter referred to as “deemed remaining time”) matches X, R [X] is expressed by the following equation (12). The

In Expression (12), when 30 minutes is adopted as the demand time limit T and the control cycle is set to 1/10 of the demand time period, the predicted power R [X] calculated by the predicted power calculation means 3 is expressed by Expression (13). As shown in FIG. 5, every 3 minutes, which is the control cycle, the number is 10 in 3 minute increments (X = 3, 6, 9,...).
In addition, each formula of Formula (13) is the same form as what was put with t = 0, 3, 6, ..., 24, 27 in Formula (4).

Here, Δp = the current integrated power amount—the integrated power amount three minutes before.
Further, the equation (13) calculates R [X] on the assumption that the assumed remaining time X matches the remaining time (30-t) in the demand time limit.

  In this Embodiment 2, since it is not synchronizing with the demand time limit T, the actual remaining time is unknown. For this reason, 10 R [X] are calculated by X every 3 minutes for every control cycle. That is, by executing the demand control using R [X] in Expression (13), the demand power P does not exceed the target power Q in any 30 minutes that move every 3 minutes.

FIG. 11 is a diagram showing a relationship between the predicted power R [X] and the demand time limit T at the current time t in the demand control device 1 according to Embodiment 2 of the present invention.
As shown in FIG. 11, in the demand control device 1 according to the second embodiment, the coordinates of the current time t and the predicted power R [X] in the demand time period T are asynchronous with the demand time period T measured by the power company. It is not fixed. That is, the end time of the demand time limit T (“time A” shown in FIG. 11) is unknown, and the above equation (4) cannot be calculated.
Therefore, it is assumed that the time point when the assumed remaining time X has elapsed from the current time t is the arrival time point of the demand time limit T (“time A” shown in FIG. 11), and the time A is unknown. = Calculate the predicted power R [X] for 10 of 3, 6, ... 30 and try to adjust the power consumption of the power load so that all the R [X] are below the target power Q To do.
Accordingly, the demand power P does not exceed the target power Q in any of the 30 minutes (equivalent to the demand time limit T) shown in FIG.

  Since a plurality of predicted powers R [X] are calculated for each control cycle, the adjusted power calculation means 4 needs to calculate a plurality of adjusted powers U for each control cycle. When the adjustment power corresponding to Equation (13) is U [X], U [X] is represented by Equation (14). Each expression of the expression (14) is the same as that of the expression (5) where t = 0, 3, 6,..., 24, 27.

  The demand restriction unit 5 determines whether to perform demand restriction or release using the maximum value of the ten U [X].

FIG. 12 is a diagram showing an operation flow of the demand control apparatus 1 according to Embodiment 2 of the present invention.
Next, the operation of the demand control device 1 (centralized controller 21) will be described with reference to FIG.
In FIG. 12, the same processes as those in the operation flow of the first embodiment (FIG. 7) are denoted by the same reference numerals, and the description thereof will be omitted or will be simplified.
The operation flow of the weighing controller 33 is the same as the content described in the description of the operation flow (FIG. 6) of the first embodiment, and the description thereof is omitted.

  First, in step S21, the demand limiting unit 5 starts counting of a control cycle timer for demand control (counting start after timer reset). Here, as in the first embodiment, the control cycle is defined as 1 / 10th of the demand time limit, that is, 3 minutes.

In step S <b> 22, the used power amount acquisition unit 2 measures the used power amount (integrated power amount) of the power load.
In step S41, the predicted power calculation means 3 calculates 10 predicted powers R [X] using equation (13).
In step S42, the adjusted power calculation means 4 calculates 10 adjusted powers U [X] using equation (14).
In step S43, the demand limiting means 5 compares the ten adjustment powers U [X] to obtain the maximum value.

  In step S44, the demand limiting unit 5 determines whether or not the maximum value of the adjusted power U [X] obtained in step S43 is 0 or more. When the maximum value of the adjustment power U [X] is 0 or more, the process proceeds to step S45.

  In step S45, the demand limit operation is selected according to the demand limit operation selection method (equation (7) to equation (11)) similar to that of the first embodiment, using the maximum value of adjustment power U [X]. To do.

  In step S31, the demand limiting unit 5 selects the demand-restricted refrigerators according to the priority order when the demand limitation is performed as described in the first embodiment (selects from the top to the bottom of Table 1). At this time, the one having an absolute value of the internal temperature margin below the desired value is selected.

  In step S32, the demand limiting unit 5 applies the demand limiting operation determined in step S45 to the target refrigerator (controlled power load) or the unit controller 24 selected in step S31, and proceeds to step S28. . Here, when the demand command is “stop”, the demand limiting unit 5 transmits the demand command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand command transmits the stop command to the target refrigerator. It becomes a procedure. The target refrigerator that has received the demand command “stops” the operation based on the demand command, or reduces the power consumption as described above by “compressor frequency down”, “target evaporation temperature up” or “set temperature up”. ”Is performed.

In step S44, when the maximum value of the adjustment power U [X] is not 0 or more, the demand limiting unit 5 proceeds to step S26.
In step S <b> 26, the demand limiting unit 5 determines whether the demand limitation is being performed at the current time. If there is one or more refrigerators 22 whose demand is limited, the process proceeds to step S46.

  In step S46, the demand restriction unit 5 selects the target refrigerator for which the demand restriction is released according to the priority order at the time of releasing the demand restriction described in the first embodiment (selects from the top to the bottom of Table 2). . At this time, the one whose absolute value of the internal temperature margin exceeds the desired value is selected.

  In step S34, the demand restriction unit 5 releases the demand restriction of the target refrigerator selected in step S46, and the process proceeds to step S28. Here, when the demand restriction to be released is “stop”, the demand restriction unit 5 transmits a demand restriction release command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand release command receives the target freezing. This is the procedure for sending a return (restart) command to the machine.

In step S26, if there is no demand-restricted refrigerator 22, the process proceeds to step S27, and the demand restriction unit 5 maintains the current demand restriction state (no demand restriction).
The process in step S28 is the same as the process in the first embodiment.

  By repeating the above, the demand limit is executed or canceled for each control cycle, or the output of the current status is maintained, so that the demand power P does not exceed the target power Q.

As described above, in the second embodiment, the demand limiting operation is changed according to the magnitude relationship of the adjusted power U [X] with respect to the power load, and the refrigerator group (refrigeration cycle apparatus) that is the power load is stopped as much as possible. Do not control.
For this reason, it becomes possible to suppress the rise (at the time of cooling) or the fall (at the time of heating) of the internal temperature (room temperature), and it is possible to maintain the quality of the cargo and the working environment.

In particular, in the second embodiment, the time adjustment device 41 is not necessary, so that the initial cost when the demand control device 1 is introduced can be reduced. In addition, since the time adjustment operation is unnecessary, the operation can be performed more easily.
In the second embodiment, the target power Q may be contract power or may be set to a value less than the contract power as in the first embodiment.

Embodiment 3 FIG.
In the first embodiment and the second embodiment, the demand limiting operation is changed according to the magnitude relationship (formula (7) to formula (11)) of the adjusted power U with respect to the power load.
In other words, the demand limit operation is changed depending on the length of the remaining time Tt (the assumed remaining time X in the second embodiment) until the end of the demand time. That is, when the remaining time T-t (or the assumed remaining time X) is short (when the adjustment power is large), there is no time margin until the demand is exceeded, so “stop” is adopted as a demand limit to reduce the power consumption of the power load. It was greatly reduced.
On the contrary, when the remaining time Tt (or the assumed remaining time X) is long, there is a relatively long time until the demand is exceeded, so that the demand limit operation is “compressor frequency down” or “target evaporation temperature up”. The power consumption of the power load was gradually reduced.

  In the third embodiment, a method that is simpler than that of the second embodiment will be described. Specifically, it is determined whether or not to perform demand restriction based only on the predicted power R [X], and when performing demand restriction, the operation of demand restriction is determined based on the remaining time X. is there.

  The configuration of the refrigeration system in the third embodiment is the same as that of the refrigeration system in the second embodiment (FIGS. 8 and 9), and the same reference numerals are given to the same configurations.

[Configuration of Demand Control Device 1]
FIG. 13 is a block diagram showing the configuration of the demand control apparatus 1 according to Embodiment 3 of the present invention.
In FIG. 13, the demand control device 1 according to the third embodiment does not include the adjusted power calculation unit 4.
The demand limiting means 5 is configured such that at least one of a plurality of predicted powers R [X] obtained for each control cycle exceeds a preset cutoff point (limit value), and only the predicted power R and the remaining time X is If it is short (less than the second threshold), the operation of the power load to be controlled is stopped. Further, when at least one of a plurality of predicted powers R [X] obtained for each control cycle exceeds a preset cutoff point (limit value), and only the predicted power R is not present and the remaining time X is long (first) 2 or more), the power load of the power load to be controlled is reduced to operate.

Other configurations are the same as those in the second embodiment.
That is, in the third embodiment, as in the second embodiment, a method that does not synchronize with the demand time limit is adopted as a method for calculating the predicted power R. Therefore, when the demand time limit T is set to 30 minutes, 10 predicted powers R [X] every 3 minutes are calculated every 3 minutes which is the control cycle. The arithmetic expression is Expression (13).

[Demand control]
Details of demand control in the third embodiment will be described below.
FIG. 14 is a diagram illustrating the relationship between the target power, the cutoff point, and the input point.
As shown in FIG. 14, the demand limiting means 5 is a timing at which the control cycle has arrived, and a plurality of predicted power R [X] calculated by the equation (13) and a 95% value (cut-off) of the target power Q. If any one of the 10 R [X] is equal to or higher than the cut-off point, demand restriction is performed on the refrigerator 22.
At this time, when there are a plurality of predicted powers R [X] that are equal to or higher than the cutoff point, the one with the smallest remaining time X is adopted as the representative value R ′ [X] of the predicted power R [X]. .

The target refrigerator at the time of demand restriction implementation is selected from Table 1 as in the first embodiment, but the number selected is 10% of the total number of refrigerators (at least one).
Here, the demand-restricted refrigerators are selected at the same rate regardless of the demand limit operation, but the rate may be changed by the demand limit operation. For example, when the demand limit is “stop”, the total number of refrigerators is 10%. When the demand limit operation is “compressor frequency down”, the total number of refrigerators is 30%.

When only the predicted power R [X] or the representative value R ′ [X] is not present and the remaining time X is short, it is assumed here that there is no time margin until the demand is exceeded when X = 3, 6, 9, 12 minutes. Then, “stop” is selected as the demand limit. That is, when the predicted power R [X] or the representative value R ′ [X] is not present and the remaining time X is less than 15 minutes (second threshold), “stop” is selected as the demand limit.
On the other hand, if the assumed remaining time X is long, here, if X = 15, 18, 21, 24, 27, 30 minutes, it is assumed that there is a time margin until the demand is exceeded, Select “Compressor frequency down”. That is, when only the representative value R ′ [X] is left and the remaining time X is 15 minutes (second threshold) or more, an operation for reducing power consumption is selected as a demand limit.
In addition, the reduction rate of the frequency of the compressor 51 is 10% here. As the demand limiting operation, “target evaporation temperature up” or “set temperature up” may be used in addition to “compressor frequency down”.

If one or more of the predicted power R [X] is equal to or greater than the cutoff point even in the next control cycle, a demand limit is further output.
On the other hand, at the timing when the control cycle arrives, the predicted power R [X] is compared with 90% of the target power (input point), and if all of the predicted power R [X] falls below the input point, the refrigerator 22 is turned on. Return (cancel demand limit).

The refrigerating machine 22 to be restored is selected from Table 2 as in the first embodiment, but the number to be selected is 10% (minimum of 1 or more) of the total number of refrigerators.
Here, the demand release target refrigerators 22 are selected at the same rate regardless of the demand limiting operation, but the rate may be changed by the demand limiting operation. If all of the predicted power R [X] is less than the input point even in the next control cycle, the demand restriction is released for the refrigerators corresponding to 10% of the total number of refrigerators.

  Note that the coefficients of the cutoff point and the input point shown in FIG. 14 are examples, and the present invention is not limited to this. The coefficient of the cut-off point and the input point, the second threshold value for judging the length of the assumed remaining time X, the reduction rate of the frequency of the compressor 51, the ratio of the number of demand restriction target, and the ratio of the number of demand restriction release target are all determined by the user. The setting can be arbitrarily changed and can be adjusted by the PC 31-1 or the PC 31-2.

FIG. 15 is a diagram showing an operation flow of the demand control device 1 according to the third embodiment of the present invention.
Next, the operation of the demand control device 1 (centralized controller 21) will be described with reference to FIG.
In FIG. 15, the same processes as those in the operation flow of the second embodiment (FIG. 12) are denoted by the same reference numerals, and the description thereof will be omitted or will be simplified.
The operation flow of the weighing controller 33 is the same as the content described in the description of the operation flow (FIG. 6) of the first embodiment, and the description thereof is omitted.

  First, in step S21, the demand limiting unit 5 starts counting of a control cycle timer for demand control (counting start after timer reset). Again, the demand time period is 30 minutes, and the control period is 3 minutes, which is 1/10 of the demand time period.

In step S <b> 22, the used power amount acquisition unit 2 measures the used power amount (integrated power amount) of the power load.
In step S41, the predicted power calculation means 3 calculates 10 predicted powers R [X] using equation (13).

  In step S51, the demand limiting unit 5 compares each of the ten predicted powers R [X] with a cutoff point, and determines whether the predicted power R [X] is equal to or higher than the cutoff point. If one or more of the predicted power R [X] is greater than or equal to the cutoff point, the process proceeds to step S53.

In step S53, the demand limiting means 5 selects the demand limiting operation according to the selection method of the demand limiting operation according to the above-described none and remaining time X length.
In step S54, the demand restricting means 5 selects a target refrigerator for demand restriction in accordance with the priority order when the demand restriction is performed.

  In step S55, the demand limiting unit 5 applies the demand limiting operation determined in step S53 to the target refrigerator selected in step S54 or the unit controller 24 of the target refrigerator, and proceeds to step S28. Here, when the demand command is “stop”, the demand limiting unit 5 transmits the demand command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand command transmits the stop command to the target refrigerator. It becomes a procedure. The target refrigerator that has received the demand command “stops” the operation based on the demand command, or reduces the power consumption as described above by “compressor frequency down”, “target evaporation temperature up” or “set temperature up”. ”Is performed.

In step S51, the demand limiting unit 5 proceeds to step S52 if all of the predicted power R [X] is less than the cutoff point.
In step S52, the demand limiting unit 5 compares each predicted power R [X] with the input point, and determines whether the predicted power R [X] is equal to or higher than the input point. If any of the ten predicted powers R [X] is greater than or equal to the input point, the process proceeds to step S27.
In step S27, an operation such as execution or cancellation of demand restriction is not particularly performed, and the current demand restriction state (during restriction or no restriction) is maintained.

In step S52, the demand limiting means 5 proceeds to step S26 if all 10 predicted powers R [X] are less than the input point.
In step S <b> 26, the demand limiting unit 5 determines whether the demand limitation is being performed at the current time. If there is one or more refrigerators for which demand is limited, the process proceeds to step S56.

In step S56, the demand restriction unit 5 selects the refrigerator 22 that is the target for releasing the demand restriction in accordance with the priority order when the demand restriction is released.
In step S34, the demand restriction unit 5 cancels the demand restriction of the target refrigerator selected in step S56, and proceeds to step S28. Here, when the demand restriction to be released is “stop”, the demand restriction unit 5 transmits a demand restriction release command to the unit controller 24 of the target refrigerator, and the unit controller 24 that has received the demand release command receives the target freezing. This is the procedure for sending a return (restart) command to the machine.

In step S26, if there is no demand-restricted refrigerator 22, the process proceeds to step S27, and the demand restriction unit 5 maintains the current demand restriction state (no demand restriction).
The process in step S28 is the same as the process in the first embodiment.

  By repeating the above, the demand limit is applied or canceled or the current status is output for each control cycle so that the demand power does not exceed the target power.

As described above, in the third embodiment, only the predicted power R [X] or the representative value R ′ [X] is present, and the demand limit operation is changed according to the length of the remaining time X, and the refrigerator that is a power load Control is performed so as not to stop the group (refrigeration cycle apparatus) as much as possible.
For this reason, it becomes possible to suppress the rise or fall of the internal temperature (indoor temperature), and the quality and work environment of the cargo can be maintained.

  Particularly, in the third embodiment, the time adjustment device 41 and the time adjustment operation are unnecessary, and the same effect as the effect of the second embodiment can be obtained. In addition, since it is not necessary to calculate the adjustment power U [X], the configuration (software) of the demand control device 1 (centralized controller 21) can be simplified, and the processing time for demand control can be reduced. In addition, since software can be simplified, software development costs can be reduced.

  In the above description, the cutoff point is a value obtained by multiplying the target power by the cutoff coefficient, but the present invention is not limited to this. For example, if the cutoff point is set to 1.00, the target power Q matches the contract power.

  DESCRIPTION OF SYMBOLS 1 Demand control apparatus, 2 Used electric energy acquisition means, 3 Predicted electric power calculation means, 4 Adjustment electric power calculation means, 5 Demand restriction means, 6 Priority order storage means, 7 Electric energy storage means, 11 Refrigerated warehouse, 21 Centralized controller, 22 Refrigerator, 23 cooler, 24 unit controller, 25 remote controller, 26 temperature sensor, 27 communication line, 28 remote control line, 31 PC, 32 transmission line feeding device, 33 weighing controller, 34 general-purpose interface, 35 measurement controller, 36 watt hour meter 37 communication equipment, 38 public line network, 41 timing device, 51 compressor, 52 condenser, 53 blower, 54 expansion valve, 55 evaporator, 56 blower.

Claims (11)

A demand control device that controls the plurality of power loads such that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition means for acquiring power consumption of the plurality of power loads;
The time limit means for synchronizing the demand time period and the time measurement timing of the time timer in the demand control device;
Electric energy storage means for storing the electric energy used acquired by the electric energy consumption means;
From the used electric energy acquired by the used electric energy acquisition means, the past used electric energy held by the electric energy storage means, the demand time period, the demand time period, and the timing start time of the demand time period Based on the remaining time which is the difference from the elapsed time up to the present time, a predicted power calculation means for obtaining a predicted power at the end of the demand time period;
Based on the predicted power, the target power, the demand time limit, and the remaining time, adjusted power calculation means for obtaining an adjusted power for making the demand power at the end of the demand time period equal to or less than the target power; ,
Demand limiting means for controlling the operation of one or more of the power loads including at least the refrigeration cycle apparatus based on the adjusted power;
With
The demand limiting means includes
Obtain the total power consumption that is the sum of the current power consumption of the power load to be controlled,
When the ratio of the adjusted power to the total power consumption exceeds a threshold, the operation of the power load to be controlled is stopped,
When the ratio of the adjusted power to the total power consumption is equal to or less than a threshold value, the demand control device operates by reducing power consumption of the power load to be controlled. A demand control device that controls the plurality of power loads such that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition means for acquiring power consumption of the plurality of power loads;
Electric energy storage means for storing the electric energy used acquired by the electric energy consumption means;
The remaining time is assumed as the remaining time regardless of the timing, and a plurality of the remaining time is set within a range larger than 0 and shorter than the demand time period, and for each of the plurality of remaining remaining times, Prediction for obtaining predicted power based on the used power amount acquired by the used power amount acquiring unit, the past used power amount held by the power amount storage unit, the demand time limit, and the remaining time remaining Power calculation means;
Based on the predicted power, the target power, the demand time limit, and the assumed remaining time, an adjusted power for setting the demand power at the time when the considered remaining time has elapsed from the current time to be equal to or less than the target power. An adjustment power calculation means to be obtained;
Demand limiting means for controlling the operation of one or more of the power loads including at least the refrigeration cycle device based on the maximum adjusted power among a plurality of the adjusted powers obtained.
With
The demand limiting means includes
Obtain the total power consumption that is the sum of the current power consumption of the power load to be controlled,
When the ratio of the adjusted power to the total power consumption exceeds a threshold, the operation of the power load to be controlled is stopped,
When the ratio of the adjusted power to the total power consumption is equal to or less than a threshold value, the demand control device operates by reducing power consumption of the power load to be controlled. Priority order storage means for storing information related to priority orders of the plurality of power loads,
The demand limiting means includes
If the adjusted power is greater than 0, one or more of the power loads is selected as the power load to be controlled according to the information on the priority order;
The demand control apparatus according to claim 1, wherein the total power consumption of the selected power load to be controlled is reduced by the adjustment power or more. The demand limiting means includes
When the adjusted power is less than 0, according to the information on the priority order, select one or a plurality of control target power loads for canceling a power limit among the control target power loads,
The demand control apparatus according to claim 3, wherein the power restriction of the selected electric power load to be controlled is released. A demand control device that controls the plurality of power loads such that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition means for acquiring power consumption of the plurality of power loads;
Electric energy storage means for storing the electric energy used acquired by the electric energy consumption means;
The remaining time is assumed as the remaining time regardless of the timing, and a plurality of the remaining time is set within a range larger than 0 and shorter than the demand time period, and for each of the plurality of remaining remaining times, Prediction for obtaining predicted power based on the used power amount acquired by the used power amount acquiring unit, the past used power amount held by the power amount storage unit, the demand time limit, and the remaining time remaining Power calculation means;
Demand limiting means for controlling operation of one or more of the power loads including at least the refrigeration cycle apparatus;
With
The demand limiting means includes
At least one of the plurality of predicted powers obtained exceeds a preset limit value, and the smallest remaining time of the estimated power exceeding the limit value is less than a second threshold value. The operation of the power load to be controlled is stopped,
At least one of the predicted powers obtained in a plurality exceeds a preset limit value, and the smallest remaining time of the estimated power exceeding the limit value is greater than or equal to a second threshold value. In this case, the demand control device operates by reducing power consumption of the power load to be controlled. Priority order storage means for storing information related to priority orders of the plurality of power loads,
The demand limiting means includes
When at least one of the predicted powers obtained in a plurality exceeds the limit value, one or more power loads are selected as the power load to be controlled according to the information on the priority order,
The demand control apparatus according to claim 5, wherein power consumption of the selected power load to be controlled is limited. The demand limiting means includes
One or a plurality of control targets for releasing the power restriction among the power loads to be controlled according to the information on the priority order when all of the plurality of predicted powers obtained are lower than a preset input value Select the power load of
The demand control apparatus according to claim 6, wherein the power restriction of the selected electric power load to be controlled is canceled. The refrigeration cycle apparatus has a refrigerant circuit in which a compressor, a condenser, an expansion means, and an evaporator are connected by a refrigerant pipe and the refrigerant circulates,
The demand limiting means includes
When reducing the power consumption of the refrigeration cycle device,
8. The method according to claim 1, wherein at least one of a reduction in a driving frequency of the compressor, an increase in a target value of an evaporation temperature of the refrigerant circuit, and a change in a target temperature of air to be air-conditioned are performed. The demand control apparatus according to claim 1. A demand control method for controlling the plurality of power loads so that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition step of acquiring power consumption of the plurality of power loads;
A power storage step for storing the power consumption acquired in the power consumption acquisition step;
From the used electric energy acquired in the used electric energy acquisition step, the past used electric energy stored in the electric energy storage step, the demand time period, the demand time period, and the timing start time of the demand time period A predicted power calculation step for obtaining a predicted power at the end of the demand time period based on a remaining time that is a difference from an elapsed time up to the present time;
An adjustment power calculation step for obtaining an adjustment power for making the demand power equal to or less than the target power at the end of the demand time period based on the predicted power, the target power, the demand time limit, and the remaining time; ,
A demand limiting step of controlling the operation of one or more of the power loads including at least the refrigeration cycle device based on the regulated power;
With
The demand limiting step includes
Obtain the total power consumption that is the sum of the current power consumption of the power load to be controlled,
When the ratio of the adjusted power to the total power consumption exceeds a threshold, the operation of the power load to be controlled is stopped,
When the ratio of the adjusted power to the total power consumption is equal to or less than a threshold value, the demand control method is characterized in that the power load of the power load to be controlled is reduced to operate. A demand control method for controlling the plurality of power loads so that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition step of acquiring power consumption of the plurality of power loads;
A power storage step for storing the power consumption acquired in the power consumption acquisition step;
The remaining time is assumed as the remaining time regardless of the timing, and a plurality of the remaining time is set within a range larger than 0 and shorter than the demand time period, and for each of the plurality of remaining remaining times, Predicted power for obtaining predicted power based on the used power amount acquired in the used power amount acquisition step, the past used power amount stored in the power amount storage step, the demand time limit, and the remaining time remaining A calculation step;
Based on the predicted power, the target power, the demand time limit, and the assumed remaining time, an adjusted power for setting the demand power at the time when the considered remaining time has elapsed from the current time to be equal to or less than the target power. An adjustment power calculation step to be obtained;
A demand limiting step of controlling the operation of one or more of the power loads including at least the refrigeration cycle device based on the maximum adjusted power among the plurality of adjusted powers obtained;
With
The demand limiting step includes
Obtain the total power consumption that is the sum of the current power consumption of the power load to be controlled,
When the ratio of the adjusted power to the total power consumption exceeds a threshold, the operation of the power load to be controlled is stopped,
When the ratio of the adjusted power to the total power consumption is equal to or less than a threshold value, the demand control method is characterized in that the power load of the power load to be controlled is reduced to operate. A demand control method for controlling the plurality of power loads so that the demand power in the demand time limit of the plurality of power loads including at least the refrigeration cycle apparatus is equal to or less than the target power,
A power consumption acquisition step of acquiring power consumption of the plurality of power loads;
A power storage step for storing the power consumption acquired in the power consumption acquisition step;
The remaining time is assumed as the remaining time regardless of the timing, and a plurality of the remaining time is set within a range larger than 0 and shorter than the demand time period, and for each of the plurality of remaining remaining times, Predicted power for obtaining predicted power based on the used power amount acquired in the used power amount acquisition step, the past used power amount stored in the power amount storage step, the demand time limit, and the remaining time remaining A calculation step;
A demand limiting step for controlling operation of one or more of the power loads including at least the refrigeration cycle apparatus;
With
The demand limiting step includes
At least one of the plurality of predicted powers obtained exceeds a preset limit value, and the smallest remaining time of the estimated power exceeding the limit value is less than a second threshold value. The operation of the power load to be controlled is stopped,
At least one of the predicted powers obtained in a plurality exceeds a preset limit value, and the smallest remaining time of the estimated power exceeding the limit value is greater than or equal to a second threshold value. In this case, the demand control method is characterized in that the operation is performed by reducing the power consumption of the power load to be controlled.

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