JP6796533B2 - Demand control system - Google Patents

Description

The present invention relates to a demand control system.

Generally, when a recipient of high-voltage electricity contracts with an electric power company for electricity usage, the basic electricity rate is set based on a demand value (electricity demand). The demand value is the average power consumption per unit time period (generally 30 minutes). The power consumption from the start of the unit time is integrated, and the integrated power consumption at the end of the unit time is divided by the unit time. It is calculated by. The maximum demand value (maximum demand value) in the weighing period (generally one month) is the basis for calculating the basic charge in the weighing period. If the maximum demand value exceeds the contract value with the electric power company, the power receiver violates the contract, and the basic charge for the next year is penalized based on the maximum demand value exceeding the contract value.

In order to avoid such a penalty, a technique has been proposed in which a demand value at the end of a unit time period is predicted and the power supply is controlled using the predicted demand value (see, for example, Patent Document 1). In the demand control device described in Patent Document 1, a target value of the demand value at the end of the unit time period is set, the power supply is cut off when the predicted demand value exceeds the target demand value, and the demand value is the target. The power supply is controlled so as not to exceed the demand value.

Special Publication No. 63-266414

By the way, in the demand control device of Patent Document 1, the predicted demand value is calculated based on the latest change amount (increase amount) of the power consumption amount supplied from the power system to the power load. When the predicted demand value is calculated only by such a calculation method, if the power consumption fluctuates suddenly, the predicted demand value is the target demand even if the fluctuation is an initial fluctuation or a temporary fluctuation. The value will be greatly exceeded, and power supply control will be performed unnecessarily. In particular, when the power supply is cut off as power supply control, if the power load is the equipment of the production factory, there is a problem that the power supply cutoff causes a large production delay and a subsequent start-up loss. It was.

Therefore, an object of the present invention is to provide a demand control system capable of more preferably performing power supply control by more accurately predicting a demand value.

In order to solve the above problems, in the first invention, one or a plurality of power loads, a power consumption acquisition means for sequentially acquiring the power consumption consumed by all the power loads, and the power consumption acquisition means. The predicted demand value that predicts the demand value, which is the average power consumption per unit time period, is calculated by using the power consumption amount acquired by the above, so that the predicted demand value does not exceed the preset target demand value. A demand control system including a power supply control means for controlling the power supply to the power load, the power consumption amount acquired at predetermined time intervals is used as a sample value, and a plurality of calculations are performed using the sample value. The predicted demand value is calculated by the method, and the power consumption at the time when the sample value is acquired is converted into the power consumption at the end of the unit time based on the elapsed time from the start of the unit time, and the converted value. The demand value is calculated from the above and used as the reference demand value, and the one having the smallest difference from the reference demand value among the predicted demand values is selected as the predicted demand value to be compared with the target demand value. The power supply control means has a selection means, and the power supply control means is selected by the predicted demand value selection means as the comparison target predicted demand value based on the power consumption acquired until the sample value is next acquired. It is characterized in that the predicted demand value calculated by the calculation method for calculating the comparison target predicted demand value is adopted.

In the second invention, in the first invention, each time the power consumption amount is acquired by the power consumption amount acquisition means, the power consumption amount acquired this time and the power consumption amount acquired before that are obtained. It is provided with an average value calculation means for calculating a moving average value of the power consumption amount using the power consumption amount, and as the plurality of calculation methods, the amount of change in the power consumption amount is obtained based on the power consumption amount acquired by the power consumption amount acquisition means. , A first calculation method for calculating the predicted demand value based on the change amount, and a second calculation method for obtaining the change amount of the moving average value and calculating the predicted demand value based on the change amount. It is characterized by being.

In the third invention, in the second invention, the second calculation method is characterized in that, as the moving average value, there are a plurality of calculation methods in which the time for taking the moving average is different.

In the fourth invention, in any one of the first to third inventions, when the predicted demand value exceeds the target demand value, the power supply control means is described from the power system by the excess amount. It is characterized by performing control to reduce the power supply supplied to the power load.

According to the first invention, the power consumption amount acquired at predetermined time intervals is used as a sample value, and the predicted demand value is calculated by a plurality of calculation methods using the sample value. Each of these predicted demand values is compared with the reference demand value, and the one with the smallest difference is selected as the comparison target predicted demand value at the time of sample acquisition. Then, until the sample value is acquired next time, the predicted demand value calculated based on the calculation method for calculating the comparison target predicted demand value selected this time is adopted as the comparison target predicted demand value.

Here, the reference demand value is calculated based on the actually measured value of the power consumption, and even if the power consumption fluctuates abruptly, it is not easily affected by the slope of the change. The predicted demand value closest to the reference demand value is selected as the comparison target predicted demand value. As a result, the demand value can be predicted more accurately, and the power supply control can be performed more preferably.

According to the second invention, as a plurality of calculation methods for calculating the predicted demand value, not only the first calculation method using the acquired power consumption itself but also the consumption calculated by using the power consumption acquired in the past. It also includes a second calculation method that uses the moving average value of electric energy. By adopting the second calculation method using the moving average value as one of the calculation methods, the changes in the power consumption acquired in the past are leveled, and the effects of sudden or temporary changes in the power consumption are achieved. The predicted demand value is calculated using the value obtained by reducing. As a result, a more accurate predicted demand value can be calculated.

According to the third invention, as the moving average value, a plurality of calculation methods having different times for taking the moving average, for example, a calculation method using the moving average value of the past 10 minutes and the moving average value of the past 1 hour are used. The calculation method used was adopted. If the time to take the moving average is long, the degree of leveling will increase, but it will be difficult to catch the latest changes in power consumption. Conversely, if the time to take the moving average is short, it will be easier to catch the latest changes in power consumption. On the other hand, the degree of leveling becomes low and it becomes easy to be affected by sudden changes. Therefore, by making the time for taking the moving average different, for example, the predicted demand value can be calculated using both the case where the time is set to be relatively short and the time when the time is set to be relatively long, and the predicted demand value can be calculated. It is possible to predict the demand value more accurately by increasing the choices of the calculation method for calculating.

According to the fourth invention, when the predicted demand value exceeds the target demand value, the power supplied from the power system to the power load is reduced by the excess amount, so that unnecessary power limitation is performed. This is suppressed, and the power supply can be reduced as much as the power reduction is required. As a result, it is possible to limit the efficient power supply and reduce the occurrence of production delay, start-up loss after the power supply is lowered, and the like.

A block diagram showing the system configuration of the demand control system. A flowchart showing the demand control process. A flowchart showing a predicted demand value selection process. As an example showing the average value calculation method, (a) shows the average value calculation acquired in the past 10 minutes, and (b) shows the average value calculation acquired in the past 1 hour. The graph which shows the transition of the integrated power consumption amount from the start of a unit time period, and the calculation method of the 1st predicted integrated power consumption amount by a normal calculation method. An example of a data table of normally acquired values showing a method for selecting predicted demand values.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. In this embodiment, a demand control system applied to factory equipment using extra high voltage will be described as an example. The demand value is the average power consumption per unit time period T (generally 30 minutes) as explained in the background technology column.

First, the system configuration of the demand control system of the present embodiment will be described. As shown in FIG. 1, the demand control system 10 includes an extra-high voltage receiving / transforming device 11, a high-voltage power receiving / transforming device 12, a power load 13, a power supply control device 14, and a demand control device 15.

The extra-high voltage power receiving / transforming device 11 receives the extra-high voltage power supplied from the power system A, has a transformer and a distribution device, transforms the received extra-high voltage power to the level of the high-voltage power, and is a high-voltage power receiving / transforming device. It is a device that transmits power to the power load 13 via the power supply control device 14. The high-voltage power receiving / transforming device 12 is a device that is connected to the power load 13 and receives high-voltage power transmitted from the extra-high voltage receiving / transforming device 11. The high-voltage power receiving / transforming device 12 has a transformer device and a power distribution device, transforms the received high-voltage power to a power level corresponding to the power load 13, and transmits the power to the power load 13 via the power supply control device 14.

The electric power load 13 is, for example, various factory equipment such as an electric furnace installed in a casting factory, air conditioning equipment, and the like. The number of power loads 13 constituting the demand control system 10 may not be one but may be a plurality or a large number. If a plurality or a large number of power loads 13 are installed, the high-voltage power receiving / transforming device 12 is provided for each power load 13 and transforms the power load 13 to a power level corresponding to each power load 13 to transmit power to the power load 13.

The power supply control device 14 is a device that controls the supply power supplied to the power load 13. The power supply control device 14 is also provided for each power load 13 when a plurality or a large number of power loads 13 are installed. The power supply control device 14 has a built-in inverter device, and the numerical value of the power supply can be arbitrarily changed. For example, if the power supplied from the power system A becomes excessive and the power continues to be supplied as it is, the demand value exceeds the target demand value, and it is predicted that the contract will be violated. In this case, the power supply control device 14 reduces the power supply supplied from the power system A to the power load 13 by the control signal output from the demand control device 15. Further, once the power supply is lowered and then the demand value is predicted to be lower than the contract value, the power supply control device 14 limits the power supply by the control signal output from the demand control device 15. Is released and the power supply is restored.

The demand control device 15 is a device that plays a central role in the demand control system 10, and includes a controller 21, a storage unit 22, a watt hour meter 23, an input operation unit 24, a display unit 25, and a signal output unit 26.

The controller 21 controls demand control by the demand control device 15, and is mainly composed of a well-known microcomputer having a CPU or the like. The controller 21 has a built-in timer, and the time information can be acquired by the timer.

The storage unit 22 is connected to the controller 21 and stores a control program for demand control executed by the controller 21. In addition, the storage unit 22 sequentially stores various data associated with the execution of the control program. The contents of the control program executed by the controller 21 will be described later.

The watt hour meter 23 measures the power consumption of the power consumed by the power load 13 supplied to the extra-high power receiving / transforming device 11 from the power system A. When a plurality of power loads 13 are installed, the power meter 23 acquires the total power consumption of all the power loads 13. The watt-hour meter 23 is connected to the controller 21, and the measurement data of the power consumption measured by the watt-hour meter 23 is sequentially input to the controller 21.

The input operation unit 24 includes an operator (for example, a button, a switch, a keyboard, etc.), and by operating the operator assigned to each operation content, various input processes to the controller 21 can be performed. The power receiver (system user) uses the input operation unit 24 to perform various input operations such as setting a target demand value. If the display unit 25 described later is a touch panel, the operator may be displayed on the display unit 25.

The display unit 25 includes a display such as a CRT or an LCD, and is connected to the controller 21. The display unit 25 shows demand such as total power value and power consumption value used by all power loads 13, power consumption value used for each power load 13, predicted demand value, set target demand value, and the like. Various information associated with the control is displayed according to the instruction of the controller 21. Further, a warning display when the predicted demand value exceeds the target demand value is also made according to the instruction of the controller 21. The power receiving person can acquire various information based on the information displayed on the display unit 25.

The signal output unit 26 is connected to the controller 21 and is also connected to the power supply control device 14 provided for each power load 13. When the predicted demand value exceeds the target demand value, the signal output unit 26 transmits a control signal output from the controller 21 to each power supply control device 14 for power adjustment.

Next, the content of the control program executed by the controller 21, that is, the content of the demand control process will be described with reference to the flowcharts of FIGS. 2 and 3. This demand control process is started by the start operation of the demand control by the input operation unit 24, and is a cycle every predetermined time (for example, 1 msec or 1 sec) by the controller 21 until the end operation is performed by the input operation unit 24. Is repeated in.

As shown in FIG. 2, in the demand control process, in step S101, the controller 21 acquires the power consumption data consumed by all the power loads 13 from the watt-hour meter 23. In addition, the power consumption from the start of the unit time period is sequentially integrated. Therefore, the controller 21 and the watt-hour meter 23 correspond to the power consumption acquisition means.

In step S102 following this, a moving average value using the power consumption data acquired in the past is calculated based on the power consumption data acquired in step S101. Therefore, the controller 21 corresponds to the average value calculating means. Here, two moving average values with different times for taking the moving average are calculated. One is the average value of the power consumption acquired in the past 10 minutes, as shown in FIG. 4A, which is an example of the power consumption data table. The other is, as shown in FIG. 4B, the average value of the power consumption acquired in the past hour. For convenience of explanation, the former average value is used as the minute average value, and the latter average value is used as the hourly average value. The data table shown in FIG. 4 is power consumption data assuming an electric furnace having a maximum output of 3000 kW at the time of melting as the power load 13.

In the following step S103, the controller 21 determines whether or not it is the sample acquisition time by the built-in timer that synchronizes with the time. The sample acquisition time is set every predetermined time (for example, 1 minute). Therefore, every hour and every minute, for example, "10:00 AM, 10:01 AM, 10:02 AM, ..." Is the sample acquisition time. If it is the sample acquisition time, the determination is affirmed and the process proceeds to step S104. On the other hand, if it is not yet the sample acquisition time, the determination is denied and the process proceeds to step S105 described later.

In step S104, the controller 21 executes the predicted demand value selection process. In the predicted demand value selection process, the power consumption data acquired at the sample acquisition time is used as the sample value. Using this sample value, one predicted demand value is selected as a comparison target predicted demand value to be compared with the target demand value from the predicted demand values calculated by each of a plurality of calculation methods. The controller 21 corresponds to the predicted demand value selection means. This predicted demand value selection process will be described in more detail with reference to the flowchart shown in FIG.

As shown in FIG. 3, in the predicted demand value selection process, in step S201, the controller 21 calculates the predicted demand value using the sample value and the moving average value. There are three calculation methods for the predicted demand value: a normal calculation method, a minute average usage calculation method, and an hour average usage calculation method. Each method is basically the same as the conventional general calculation method, and is calculated by the following formula based on the amount of change (increase) in power consumption per unit time. ..

"First predicted power consumption integrated amount Pa" = Pt1 + (ΔP / Δt) × (T−t2)
"Predicted demand value" = Pa / (T / 60)
Here, the first predicted power consumption integrated amount Pa is an integrated value of the power consumption amount at the end of the unit time period T (the unit is minutes, generally 30 minutes). t1 is the previous sample acquisition time, and Pt1 is the power consumption at that time (t1). t2 is the sample acquisition time this time. ΔP is an increase in the power consumption at the current sample acquisition time (t2) from the power consumption at the previous sample acquisition time (t1). Δt is the sample acquisition time interval (predetermined time), which is 1 minute here.

However, the data used for calculating the first predicted power consumption integrated amount Pa are different between the normal calculation method, the minute average usage calculation method, and the time unit average usage calculation method. In the normal calculation method, the first predicted power consumption integrated amount Pa is calculated using the sample value itself, and then the predicted demand value is calculated. Therefore, the normal calculation method corresponds to the first calculation method. FIG. 5 is a graph showing the transition of the integrated power consumption amount from the start of the unit time period and the calculation of the first predicted integrated power consumption amount Pa by the normal calculation method. On the other hand, in the minute unit average usage calculation method and the hour unit average usage calculation method, the first predicted power consumption integrated amount Pa is calculated using the moving average value. Therefore, the minute-based average usage calculation method and the time-based average usage calculation method correspond to the second calculation method.

Of these, in the minute unit average usage calculation method, the first predicted power consumption integrated amount Pa is calculated using the minute unit average value which is the moving average value of the power consumption acquired in the past 10 minutes. In the hourly average usage calculation method, the first predicted power consumption integrated amount Pa is calculated by using the time unit average value which is the moving average value of the power consumption acquired in the past one hour. Therefore, in step S201, the predicted demand value is calculated by each of the normal calculation method, the minute average usage calculation method, and the time unit average usage calculation method.

In the next step S202, the controller 21 calculates the reference demand value using the power consumption data at the time of sample acquisition. The reference demand value is calculated by the following formula.

"Second predicted power consumption integrated amount Pb" = ("Power consumption at sample acquisition time" / "Elapsed time from the start of the unit time period") x T
"Reference demand value" = Pb / (T / 60)
Here, the second predicted power consumption integrated amount Pb is the integrated value of the power consumption amount at the end of the unit time period T (the unit is minutes, generally 30 minutes), like the first predicted power consumption integrated amount Pa. Is. However, the calculation method is different from the first predicted power consumption integrated amount Pa. That is, the second predicted power consumption integrated amount Pb is obtained by converting the power consumption at the sample acquisition time into the power consumption at the end of the unit time T based on the elapsed time from the start time of the unit time T. ..

After calculating the reference demand value, the process proceeds to step S203. In step S203, the controller 21 performs a comparison process with the reference demand value calculated in step S202 for the three predicted demand values calculated in step S201. Then, when the difference between the predicted demand value (X value) calculated by the normal calculation method and the reference demand value is the smallest, the following step S204 is affirmed, and in the subsequent step S205, the X value is compared with the sample acquisition time. Select as the predicted demand value. At the same time, until the next sample acquisition time is reached, the predicted demand value calculated by the normal calculation method is set to be adopted as the comparison target predicted demand value to be compared with the target demand value. After that, the predicted demand value selection process is terminated. On the other hand, if the difference between the predicted demand value (Y value) calculated by the minute average usage calculation method or the predicted demand value (Z value) calculated by the time average usage calculation method and the reference demand value is the smallest, this is the case. Step S204 is denied, and the process proceeds to the next step S206.

When the difference between the predicted demand value (Y value) calculated by the hourly average usage calculation method and the reference demand value is the smallest, the controller 21 affirms step S206, and in the following step S207, predicts the Y value at the sample acquisition time. Select as the demand value. At the same time, the predicted demand value calculated by the minute-by-minute average usage calculation method is set to be adopted as the comparison target predicted demand value until the next sample acquisition time is reached. After that, the predicted demand value selection process is terminated. On the other hand, when the difference between the predicted demand value (Z value) calculated by the hourly average usage calculation method and the reference demand value is the smallest, this step S206 is denied and the process proceeds to the next step S208.

In the next step S208, since it is known at this stage that the difference between the predicted demand value (Z value) calculated by the time-based average usage calculation method and the reference demand value is the smallest, the controller 21 uses this Z value. Is selected as the predicted demand value at the sample acquisition time. At the same time, the predicted demand value calculated by the time-based average usage calculation method is set to be adopted as the comparison target predicted demand value until the next sample acquisition time is reached. After that, the predicted demand value selection process is terminated.

Returning to the flowchart of the demand control process shown in FIG. 2, as described above, if the determination is denied because it is not yet the sample acquisition time in step S103, the process proceeds to step S105 without proceeding to step S104. In step S105, the controller 21 determines the predicted demand value adopted as the comparison target predicted demand value at that time among the normal calculation method for calculating the predicted demand value, the minute average usage calculation method, and the time unit average usage calculation method. As the calculation method, the calculation method currently being set is read out. In the following step S106, the controller 21 selects the predicted demand value calculated by the calculation method being set from the predicted demand values calculated based on the power consumption data as the comparison target predicted demand value.

The comparison target predicted demand value based on the power consumption data acquired during the sample acquisition time is adopted as follows. Each predicted demand value is calculated using all of the normal calculation method, the minute average usage calculation method, and the hourly average usage calculation method, and the predicted demand value based on the calculation method being set is used as the comparison target predicted demand value. select. In this case, the predicted demand value may be calculated using only the calculation method being set, and the predicted demand value may be selected as the comparison target predicted demand value.

The above series of processes will be described more specifically with reference to FIG. 6, which is an example of a power consumption data table. As shown in FIG. 6, for example, “AM10: 16:00” and “AM10:” The power consumption data acquired at "17:00" and "10:18: 00 AM" is the sample value. Using the sample values at the time of each sample acquisition, the controller 21 calculates the predicted demand value by the normal calculation method, the minute average usage calculation method, and the time unit average usage calculation method. Further, the controller 21 calculates the reference demand value from the power consumption data at the sample acquisition time. The data table shown in FIG. 6 assumes an electric furnace with a maximum output of 3000 kW at the time of melting as the power load 13, and assumes a case where the target demand value is set to 1700 kW.

For example, at "10:16: 00 AM", which is the sample acquisition time, the predicted demand value calculated by the minute-by-minute average usage calculation method has the smallest difference from the reference demand value among the predicted demand values. Therefore, a numerical value calculated by the minute-by-minute average usage calculation method is selected as the comparison target predicted demand value at this time. Then, until the next sample acquisition time of "10:17 AM", the predicted demand value calculated by the minute-by-minute average usage calculation method is used as the comparison target predicted demand value based on the acquired power consumption data. adopt.

When the next sample acquisition time is "10:17: 00 AM", the predicted demand value calculated by the time-based average usage calculation method among the predicted demand values has the smallest difference from the reference demand value. Therefore, a numerical value calculated by the hourly average usage calculation method is selected as the comparison target predicted demand value at this sample acquisition time. Then, until the next sample acquisition time is "10:18: 00 AM", the predicted demand value calculated by the time-based average usage calculation method is used as the comparison target predicted demand value based on the acquired power consumption data. Is adopted.

After finishing the prediction demand value selection process in step S104 and selecting the comparison target prediction demand value, and after selecting the comparison target prediction demand value in step S106, the process proceeds to step S107. In step S107, the controller 21 compares the comparison target predicted demand value with the target demand value. The target demand value is a set value arbitrarily set by the power receiver using the input operation unit 24, and a contract value with the electric power company is set or a value lower than the contract value is set. In step S107, the controller 21 determines whether or not the comparison target predicted demand value exceeds the target demand value. If the predicted demand value to be compared exceeds the target demand value, the determination is affirmed, the process proceeds to step S108 to execute the alarm process, and the subsequent step S109 executes the power supply control process.

In the alarm processing in step S108, the controller 21 causes the display unit 25 to display a warning, or outputs a control signal from the signal output unit 26 to an alarm device (not shown) such as an alarm device to operate the controller 21. Issue an alarm to the recipient. Further, in the power supply control process in step S109, the controller 21 executes a control for reducing the power supply supplied from the power system A to the power load 13. As the control content, the controller 21 outputs a control signal from the signal output unit 26 to the power supply control device 14 so that the power supply is reduced by the power consumption in which the comparison target predicted demand value exceeds the target demand value. To do. Upon receiving this control signal, the power supply control device 14 controls the power supply to the power load 13 so that the comparison target predicted demand value decreases only by the power exceeding the target demand value according to the instruction of the controller 21. To do. The controller 21 corresponds to the power supply control means.

If the predicted demand value for comparison falls below the target demand value after the power supply is once reduced, the controller 21 releases the power supply restriction by the control signal to the power supply control device 14. The power supplied to the power load 13 is restored.

After passing through the steps S108 and S109, and after denying the determination because the comparison target predicted demand value is equal to or less than the target demand value in the step S107, the process proceeds to step S110. In step S110, the controller 21 determines whether or not it is the end time of the unit time period T (here, 30 minutes). If it is the end time of the unit time period T (just hourly or 30 minutes per hour), the determination is affirmed and the process proceeds to step S111. In step S111, the controller 21 resets the integrated value of the power consumption amount sequentially integrated from the start time of the unit time period T. At this time, the power consumption data and the sample values that have been sequentially acquired so far are not reset, and the state stored in the storage unit 22 is maintained. After that, a series of demand control processes is terminated. On the other hand, if the end time of the unit time period T has not yet been reached, the determination in step S110 is denied, and the series of demand control processes is terminated as it is.

The configuration and operation of the demand control system 10 of the present embodiment are as described above, and the effects obtained by the demand control system 10 are listed below.

(1) The controller 21 uses the power consumption data acquired sequentially at the sample acquisition time as the sample value. Then, using the sample value, the predicted demand value is calculated by the normal calculation method, the minute average usage calculation method, and the time unit average usage calculation method, respectively. Each of these predicted demand values is compared with the reference demand value, and the one with the smallest difference is selected as the comparison target predicted demand value at the time of sample acquisition. After that, until the sample value is acquired next time, the predicted demand calculated by the calculation method for calculating the comparison target predicted demand value selected at the sample acquisition time as the comparison target predicted demand value based on the acquired power consumption data. The value is adopted.

Here, the reference demand value is obtained by calculating the power consumption per unit time from the power consumption from the start of the unit time period to the time of sample acquisition, converting it into the power consumption amount at the end of the unit time period, and ending the unit time period. It is a demand value calculated from the power consumption at the time. That is, this reference demand value is calculated based on the measured value of the power consumption. The predicted demand value of the value closest to the reference demand value is adopted, and the calculation method for calculating the predicted sample value is adopted as the calculation method until the next sample acquisition time. As a result, the demand value can be predicted more accurately, and the power supply control can be performed more preferably.

(2) As a plurality of calculation methods for acquiring the predicted demand value, not only a normal calculation method using the acquired power consumption data itself, but also a calculation method using a moving average value based on the power consumption data acquired in the past. In other words, it also includes a minute average usage calculation method and an hour average usage calculation method. By adopting the calculation method using the moving average value as one of the calculation methods, the power consumption acquired in the past was leveled, and the influence of sudden or temporary changes in the power consumption was reduced. The predicted demand value is calculated using the numerical value. As a result, a more accurate predicted demand value can be calculated.

(3) As a calculation method using the moving average value, a calculation method using the moving average value of the past 10 minutes and a calculation method using the moving average value of the past 1 hour are adopted. If the time to take the moving average is long, the degree of leveling will increase, but it will be difficult to capture the latest changes in power consumption. On the contrary, if the time for taking the moving average is short, it becomes easier to grasp the latest change in power consumption, but the degree of leveling becomes low. Therefore, by making the time for taking the moving average different, for example, the predicted demand value is calculated using both the relatively short 10-minute average value and the relatively long 1-hour average value, and the optimum values are compared. can do. As a result, it is possible to increase the choices of the calculation method for calculating the predicted demand value and contribute to more accurate prediction of the demand value.

(4) When the predicted demand value to be compared exceeds the target demand value, the power supply control device 14 reduces the power supplied from the power system A to the power load 13 by the excess amount. Therefore, unnecessary power limitation is suppressed, and the power supply can be reduced by the amount required for power reduction. After that, when the predicted demand value to be compared falls below the target demand value, the power supply restriction is released and the power supply is restored. As a result, it is possible to limit the efficient power supply.

The present invention is not limited to the demand control system 10 of the above-described embodiment, and for example, the following configuration may be adopted.

(A) In the above embodiment, the time for taking the minute average value is set to 10 minutes and the time for taking the time unit average value is set to 1 hour, but different times may be set for each. For example, the time for taking the average value in minutes may be any minute from 2 minutes to 59 minutes, for example, 15 minutes or 20 minutes. Further, the time for taking the time unit average may be any time (1 hour unit) from 2 hours to 24 hours, for example, 2 hours or 3 hours. Further, in the case of calculating the predicted demand value using the average value, instead of adopting two different averages of the minute unit average and the hour unit average, the average value to be used may be any one.

(B) In the above embodiment, the controller 21 reduces the supplied power by the amount that the comparison target predicted demand value exceeds the target demand value by the power supply control device 14, but as a control for reducing the supplied power. May also employ other control methods.

As one example thereof, it is conceivable to execute stepwise control in which a preset power value is gradually lowered. In this case, when the predicted demand value to be compared exceeds the target demand value, only the power value of the first stage (for example, 500 kW) is first lowered, and when the target demand value is still exceeded, the second stage is further reduced. Try to reduce the power value of the stage (eg 500 kW). If the predicted demand value to be compared falls below the target demand value after the power is reduced once, the limitation on the power supply is released and the power supply is restored. By sequentially lowering or increasing the predetermined power in multiple stages in this way, rather than shutting off all the power supply at once, a large production delay due to the power supply cutoff and subsequent startup loss, etc. Can be prevented.

Further, as another method, when a plurality of power loads 13 are provided, priority is set for each power load 13 according to its importance and the degree of influence on production, and the power load 13 having the lower priority is set. It is also conceivable to cut off the power supply in order to reduce the power supplied from the power system A.

In addition, when the power load 13 also has a plurality of power loads 13, the power load 13 is not the production equipment of the factory, and for the equipment having a small influence on the production such as the air conditioning equipment, the order of the equipment that cuts off the supplied power is given. It is also conceivable to change them in order. For example, when the first to third air conditioners are installed, the first air conditioner, the second air conditioner, and the third air conditioner are set as the order of reducing the power supply at a certain point in time. , The order at the next time is the control method of setting the second air-conditioning equipment, the third air-conditioning equipment, and the first air-conditioning equipment.

(C) In addition to the above embodiment, the storage unit 22 may store the transition of the data of the normally acquired value for each unit time period T to create a database. Past transition data similar to the transition of the data of the normally acquired value in the unit time period T may be selected from the database, and the past transition data may be used for demand control. For example, it can be used as a correction value when calculating a predicted demand value, or can be used to simulate a control method for power supply control.

(D) Although the demand control system 10 of the above embodiment is assumed to be applied to factory equipment that uses extra high voltage power, it may be applied to equipment that uses high voltage power or low voltage power. For example, the demand control system 10 may be applied to a small factory, a commercial facility, a commercial building, or the like.

10 ... Demand control system, 21 ... Controller (power consumption acquisition means, power supply control means, predicted demand value selection means, average value calculation means), 23 ... Electricity meter (power consumption acquisition means), 24 ... Power supply Control device (power supply control means), A ... Power system.

Claims (4)

With one or more power loads
A power consumption acquisition means for sequentially acquiring the power consumption consumed by all the power loads, and a power consumption acquisition means.
Using the power consumption acquired by the power consumption acquisition means, a predicted demand value that predicts a demand value that is an average power consumption per unit time period is calculated, and the predicted demand value is a preset target demand value. Power supply control means for controlling the power supply to the power load so as not to exceed
It is a demand control system equipped with
The power consumption amount acquired at each predetermined time is used as a sample value, and the predicted demand value is calculated by a plurality of calculation methods using the sample value, and the sample value is calculated based on the elapsed time from the start time of the unit time. Converted to the power consumption at the end of the unit time period, the demand value is calculated from the converted value and used as the reference demand value, and the one having the smallest difference from the reference demand value among the predicted demand values is described above. It has a predictive demand value selection means for selecting as a predictive demand value to be compared with the target demand value.
The power supply control means is the comparison target prediction selected by the prediction demand value selection means as the comparison target prediction demand value based on the power consumption acquired until the sample value is next acquired. A demand control system characterized by adopting a predicted demand value calculated by using a calculation method for calculating a demand value. Every time the power consumption amount is acquired by the power consumption amount acquisition means, the moving average value of the power consumption amount is calculated by using the power consumption amount acquired this time and the power consumption amount acquired before that. Equipped with an average value calculation means
As the plurality of calculation methods
The first calculation method of obtaining the change amount of the power consumption amount based on the power consumption amount acquired by the power consumption amount acquisition means and calculating the predicted demand value based on the change amount.
The demand control system according to claim 1, further comprising a second calculation method of obtaining a change amount of the moving average value and calculating a predicted demand value based on the change amount. The demand control system according to claim 2, wherein the second calculation method has a plurality of calculation methods in which the time for taking the moving average is different as the moving average value. The power supply control means is characterized in that when the predicted demand value exceeds the target demand value, the power supply supplied from the power system to the power load is reduced by the excess amount. Item 3. The demand control system according to any one of Items 1 to 3.

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