JP6016681B2 - Energy saving system - Google Patents

Description

  The present invention relates to an energy saving system that distributes target power of a power control device installed in each facility without exceeding the total target power within a demand time limit of a plurality of facilities.

  In a conventional energy saving system, a target power within a demand time limit (generally 30 minutes) is set in a demand control device, which is a power suppression device, and the maximum demand power is suppressed in units of individual facilities. As such a demand control device, for example, there is a demand control device disclosed in Patent Document 1 with improved demand control followability and stability. Conventionally, in order to suppress the total maximum demand power that is the sum of the maximum demand power of multiple facilities, the total target power value of the multiple facilities is determined in advance, and the sum of the target power values of each facility does not exceed the determined total target power value As described above, the fixed target power value is manually distributed to the demand control devices of each facility.

JP-A-6-78459

  When the total target power management of multiple facilities is performed using the conventional energy-saving system described above, load control is frequently performed at a facility to achieve the target power depending on the operating status, environmental conditions, and location conditions of each facility. In spite of this, there are situations where load control is not performed at other facilities. In order to correct this, conventionally, a method has been adopted in which the target power value is manually reset at the end of the demand time period based on the load control state of the previous demand time period.

  However, for example, when air-conditioning is the load to be controlled, the environmental conditions change frequently, such as the weather conditions where each facility is located and the operating conditions of each facility change. It took time to reset, and in fact, it was rare that resetting was performed frequently. For this reason, in the conventional energy saving system, load control is concentrated on a specific facility depending on the operation status, environmental conditions, and location conditions of each facility, and load control is not performed in a balanced manner.

The present invention has been made to solve such problems,
Power control devices installed in each facility that control the power consumption in the facility within the demand time period defined in an arbitrary unit time by controlling the power supply to the power-saving load. And calculate the target power value of each facility so that the total maximum demand power corresponding to the sum of the maximum demand power at each facility does not exceed the set target power value, and use the calculated target power value for each facility It is composed of a central control device that distributes to the control device, and a communication means that performs communication between the power control device and the central control device,
The power suppression device measures the load control execution time when the load control is performed within the demand time limit,
The central control unit collects the load control execution time measured by the power suppression device from each facility by communication means, and the load control execution time is short. By allocating to the target power of the load control facility for a long time, an energy saving system was constructed to balance the frequency of load control in each facility without changing the total target power value.

  According to this configuration, data is collected from the power suppression device of each facility by the central control device, and the total maximum demand power corresponding to the sum of the maximum demand power in each facility does not exceed the set total target power value. As described above, the target power value of each facility is calculated. The calculated target power value is distributed by the central control device to the power suppression device of each facility via the communication means. For this reason, the central control unit suppresses the total maximum demand power within the demand time limit at multiple facilities within the total target power value, and does not exceed the total target power value of the multiple facilities, so that each facility is not required. It becomes possible to perform load control. In addition, the central control unit collects the load control execution time for load control within the demand time limit from the power control device of each facility, and the target power assigned to the load control short-time facility with short load control execution time is obtained. The load control execution time is distributed to the target power of the load control long-time facility. For this reason, it is possible to balance the frequency of load control in each facility without changing the total target power value.

  In addition, the present invention sets an upper limit target power that can be set in the facility for the load control long-time facility, and each load control long-time facility for the load control short-time facility. The target power is redistributed by allocating the remaining power obtained by subtracting the total upper limit target power corresponding to the sum of the upper limit target powers in FIG.

  According to this configuration, in the load control long-time facility where the load control execution time is long and the maximum demand power is close to the target power, the upper limit target power that can be set in the facility is set by the central controller. For this reason, in the load control long-time facility, a margin is created between the target power and the maximum demand power, and the frequency of load control that has been frequently performed decreases. On the other hand, the load control execution time is short, and the load control short-time facility with a margin between the maximum demand power and the target power has a remaining power obtained by subtracting the total upper limit target power from the total target power value by the central controller. Redistribution will reduce the target power. However, since the load control short-time facility has a margin between the maximum demand power and the target power, even if the target power is lowered, the influence on the frequency of the load control is small. As a result, the load control frequency in each facility is balanced without changing the total target power value.

  Further, according to the present invention, the central control device collects power-saving power that is power consumption of the power-saving load at the end of the demand time period from each facility by communication means, and the power consumption power capacity that is the power capacity of the power-saving load is collected. The ratio of the marginal power to the total marginal power equivalent to the total power of the marginal power equivalent to the sum of the marginal power and the marginal power that is obtained by subtracting the power saving potential from the power saving potential power capacity for the load control short-time facility where the ratio of the power saving potential is less than 1 The margin rate is calculated, and the remaining power is distributed according to the margin rate.

  According to this configuration, for the load control short-time facility in which the ratio of the power-saving power to the power-saving power capacity is less than 1 and there is a margin in the power-saving power, the total upper limit target power is subtracted from the total target power value. Electric power is distributed. For this reason, even if it is a load control short-time facility, the ratio of the power saveable power to the power saveable power capacity is 1 or more, and the remaining power is distributed to the load control short-time facility where there is no margin for the power saveable power. Not done. Also, the remaining power is distributed to the load control short-time facilities whose ratio is less than 1 according to the margin ratio, which is the ratio of the surplus power to the total surplus power. Will be allocated less. For this reason, the remaining power is distributed to the load control short-time facilities whose ratio is less than 1 fairly according to the surplus power of each facility, and load control is not concentrated on a specific load control short-time facility. Each load control is performed in good balance between the facilities for a short time.

  According to the present invention, it is possible to perform load control of each facility without exceeding the total target power value of a plurality of facilities, and without load, and load control in each facility without changing the total target power value An energy saving system capable of balancing the frequency of the above is provided.

It is a block diagram which shows the outline of a structure of the energy saving system by one embodiment of this invention. It is a block diagram which shows the internal structure of the demand control apparatus used in the energy saving system shown in FIG. It is a block diagram which shows the internal structure of the central control apparatus used in the energy saving system shown in FIG. It is a flowchart which shows the time unit target electric power calculation process performed in the central control apparatus shown in FIG.

  Next, an embodiment of the energy saving system according to the present invention will be described.

  FIG. 1 is a block diagram showing an outline of the configuration of an energy saving system 1 according to the present embodiment.

  Each facility 2 is provided with a controlled load 3 such as an air conditioner, a watt-hour meter 4 for measuring the power consumption of the entire facility, and a demand control device 5 having a function of suppressing the maximum demand power. Yes. The control target load 3 is a power-saving load that can save power by stopping power supply, and is composed of a single or a plurality of loads. The demand control device 5 constitutes a power suppression device that performs control to suppress the power used in the facility 2 within the demand time period defined in an arbitrary unit time, 30 minutes in this embodiment, to a target power value or less, Installed in each facility 2 to suppress the maximum demand power of each facility 2.

  There are a plurality of facilities 2 and are not limited to the three facilities illustrated in the figure. The demand control device 5 of each facility 2 is connected to the central control device 6.

  FIG. 2 is a block diagram showing an internal configuration of the demand control device 5. The demand control device 5 measures the received power data output from the watt-hour meter 4 by the received power measuring unit 7 and predicts the demand power amount at the end of the demand time limit by the calculating unit 9. Then, when it is predicted that the preset target power will be exceeded, by performing load control that suppresses energization to the control target load 3 via the control output unit 10, the demand power at the end of the demand time limit is obtained. Prevent exceeding the target power. Further, the power saving possible power measurement unit 8 measures the power used by the control target load 3 as the power saving possible power from the output signal of the watt hour meter 4 or from the output signal of the control target load 3. The calculation unit 9 measures the load control execution time in which the load control is performed on the control target load 3 within the demand time limit, and from the power saving possible power measured by the power saving possible power measurement unit 8 at the end of the demand time limit. Predict and calculate power that can be saved. As for the power prediction method at the end of the demand time period, there is a method of calculating from the amount of power used until the middle of the demand time period and the rate of increase, for example, the rate of increase in unit time, but either method was used. Even in this case, the details of the present invention are not described because they are not related to the essence of the present invention. The communication unit 11 performs bidirectional communication with the central control device 6.

  FIG. 3 is a block diagram showing the internal configuration of the central controller 6. The central control device 6 is connected to each demand control device 5 via a communication unit 12 capable of bidirectional communication with the demand control device 5 of each facility 2. The communication unit 11 in the demand control device 5 and the communication unit 12 in the central control device 6 constitute communication means for performing communication between the demand control device 5 and the central control device 6. The energy saving system 1 includes a demand control device 5, a central control device 6, and communication means.

  The data storage unit 13 stores data sent from the demand control device 5 of each facility 2 through the communication unit 11 and the communication unit 12. In the condition setting unit 14, the power saving capacity of each facility 2 is set in advance. In the condition setting unit 14, a reference time and an upper limit target power that can be set for each facility 2 are also set in advance. The reference time is used as a reference for determining the length of the load control execution time within the demand time limit in the time-unit target power calculation process described later. Moreover, the target power of the upper limit that can be set is contract power that each individual facility 2 contracts with an electric power company, or target power that has a margin for this contract power.

  Based on the data in the data storage unit 13 and the condition setting unit 14, the central controller 6 uses the time-unit target power calculation unit 15 and the intra-time demand calculation unit 16 to perform time-unit target power calculation processing and intra-time demand calculation. The processing is performed as described later, and an operation of transmitting setting data and command data to the demand control device 5 is performed.

  The central control device 6 collects data from the demand control device 5 of each facility 2 in the above time-unit target power calculation processing, and the total maximum demand power corresponding to the sum of the maximum demand power in each facility 2 is set. The target power value of each facility 2 is calculated so as not to exceed the total target power value thus calculated, and the calculated target power value is distributed to the demand control device 5 of each facility 2. At this time, in this embodiment, the central control device 6 collects the load control execution time for the control target load 3 measured by the demand control device 5 from each facility 2 by communication means, and the load control execution time is short. By distributing the target power allocated to the control short-time facility 2 to the target power of the load control long-time facility 2 having a long load control execution time, the frequency of load control in each facility 2 can be changed without changing the total target power value. Try to balance. Specifically, the central controller 6 sets an upper limit target power that can be set for the facility 2 for the load control long-time facility 2, and each load control for the load control short-time facility 2. The target power is redistributed by allocating the remaining power obtained by subtracting the total upper limit target power corresponding to the total upper limit target power in the long-time facility 2 from the total target power value.

  Further, the central control device 6 uses the communication means to calculate the predicted maximum demand power at the end of the demand time period from the demand control device 5 of each facility 2 at any time within the demand time period in the demand calculation within the time period. When the total predicted maximum demand power that is the sum of the predicted maximum demand power of each facility 2 exceeds the set total target power value, the load control device 5 of each facility 2 A cut control command is forcibly issued via the communication means. At this time, in the present embodiment, the central control device 6 collects the predicted power-saving power at the end of the demand time period from the demand control device 5 of each facility 2 by the communication means at an arbitrary time within the demand time period. The cut-off control command is issued in preference to the facility 2 having a small ratio of the predicted power-saving power to the power-saving power capacity.

  Next, means for allocating the target of the maximum demand power at the end of the demand time limit, that is, the time unit target power to each facility 2 will be described.

  FIG. 4 is a flowchart showing the operation of the time-unit target power calculation process for allocating the time-unit target power to each facility 2 performed in the central controller 6.

  The central controller 6 uses the procedure of S1 to measure the demand power at the end of the demand period measured by the received power measuring unit 7 from the demand control apparatus 5 of each facility 2 after the end of the demand period, and the power saving possible power measuring unit 8 Collect power that can be saved in Subsequently, the load control execution time for the control target load 3 measured by the calculation unit 9 within the demand time period is collected from the demand control device 5 of each facility 2 in the procedure of S2. The collected data is stored in the data storage unit 13. The collection timing of each data is performed immediately after the start of the demand time period because the calculation result needs to be reflected in the current demand time period.

  Next, in the procedure of S3, the load control execution time of each facility 2 stored in the data storage unit 13 is compared with the reference time set in the condition setting unit 14, and the length of the load control execution time is determined. . The reference time is set to, for example, 10 minutes, which is shorter than the demand time of 30 minutes, but can be changed by setting.

  As a result of determining the length of the load control execution time, the load control execution time is equal to or greater than the reference time (load control execution time ≧ reference time). In the procedure, the upper limit target power set for the facility 2 in the condition setting unit 14 is set as the target power for the next demand time limit. At this time, when there are a plurality of load control long-term facilities 2, the central control device 6 uses the sum of the upper limit target power of each load control long-time facility 2 as the total upper limit target power, and the time-unit target power calculation unit 15 is calculated.

In addition, as a result of determining the length of the load control execution time, the load control execution time is less than the reference time (load control execution time <reference time), and for the load control short-time facility 2 in which the determination of S3 is NO, In step S5, the power saving rate is calculated. The power saving rate is a ratio of the power saving possible power stored in the data storage unit 13 to the power saving possible power capacity, and is calculated by the time-unit target power calculation unit 15 by the following equation (1).
[Power saving rate] = [Power saving potential] ÷ [Power saving capacity] (1)

  After calculating the power saving possibility rate for each load control short-time facility 2, next, the target power newly allocated to each load control short-time facility 2 is calculated in the procedure of S6. This calculation is performed as follows, for example.

  First, the power saving possible rate is set to 1 for the load control short-time facility 2 in which the ratio of the power saving possible power to the power saving possible power capacity is 1 or more. When the power-saving power capacity is the maximum demand power of the previous year, the ratio of power-saving power to the power-saving power capacity can be 1 or more depending on the operating status of the power-saving load. However, this ratio is a value used to determine whether there is a margin of power that can be allocated when distributing target power from the facility 2 with a short load control execution time to the facility 2 with a long load control time. Even if the rate is 1 or more, it does not make sense. For this reason, when the ratio of the power saving power to the power saving power capacity is 1 or more, the power saving rate is set to 1 as described above. For the load control short-time facility 2 with a power saving rate of 1, the target power is set to the target power for the next demand time period without changing the target power set for the previous demand time period.

Moreover, for the load control short-time facility 2 in which the ratio of the power-saving power capacity to the power-saving power capacity is less than 1, that is, the surplus facilities, the surplus power obtained by subtracting the power-saving power capacity from the power-saving power capacity is expressed as Calculated by (2).
[Reserved power] = [Power saving capacity]-[Power saving power] (2)

Further, the sum of the surplus power in each load control short-time facility 2 is defined as the total surplus power, and the ratio of the surplus power to the total surplus power is calculated as a margin rate as shown in the following equation (3).
[Margin rate] = [Marginal power] ÷ [Total marginal power] (3)

Here, since the target power of the load control long-time facility 2 having a long load control execution time is already set to the upper limit value in the procedure of S4, in order to prevent the total maximum demand power from exceeding the total target power. The remaining power calculated by subtracting the total upper limit target power from the total target power is distributed to the load control short-time facility 2 according to the margin rate. This distribution is performed, for example, by setting a new target power calculated as shown in the following formula (4) in a margin facility.
[New target power for surplus facilities]
= [Total target power-Total upper limit target power] x [1-margin ratio] (4)

  As a result of this distribution, the new target power is reduced by a margin for the load control short-time facility 2 with a margin. Further, in the procedure of S3, when the load control execution time of all facilities 2 is longer or shorter than the reference time and all the facilities 2 are facilities 2 having a long or short load control execution time, the target power is redistributed particularly. There is no need, and the same target power as the previous demand time limit is set as the new target power.

  After calculating the new time unit demand target power of each facility 2 by the above calculation, the new target power is transmitted to the demand control device 5 of each facility 2 in the procedure of S7. When the procedure of S7 is completed, the central controller 6 ends the time-unit target power calculation process.

  As described above, in the energy saving system 1 according to the present embodiment, the central control device 6 collects data from the demand control device 5 of each facility 2, and the total maximum demand power corresponding to the sum of the maximum demand power in each facility 2 is obtained. The target power value of each facility 2 is calculated so as not to exceed the set total target power value. The calculated target power value is distributed to the demand control device 5 of each facility 2 by the central control device 6 via the communication unit 12 and the communication unit 11. For this reason, the central control device 6 suppresses the total maximum demand power within the demand time limit in the plurality of facilities 2 within the total target power value, and does not exceed the total target power value of the plurality of facilities 2, and does not require labor. Thus, the load control of each facility 2 can be performed. Also, the central control device 6 collects the load control execution time during which the load control is performed within the demand time period from the demand control device 5 of each facility 2 and assigns it to the load control short-time facility 2 with a short load control execution time. The target power is distributed to the target power of the load control long-time facility 2 having a long load control execution time. For this reason, it is possible to balance the frequency of load control in each facility 2 without changing the total target power value.

  In the present embodiment, the load control long-time facility 2 in which the load control execution time is long and the maximum demand power is constrained to the target power, the upper limit target power that can be set in the facility 2 by the central controller 6 is shown in FIG. , S4 is set. For this reason, in the load control long-time facility 2, a margin is created between the target power and the maximum demand power, and the frequency of the load control that has been frequently performed decreases. On the other hand, in the load control short-time facility 2 where the load control execution time is short and there is a margin between the maximum demand power and the target power, the central control device 6 uses the central control device 6 to subtract the total upper limit target power from the total target power value. The power is calculated and redistributed as shown in Equation (4), and the target power is lowered. However, since the load control short-time facility 2 has a margin between the maximum demand power and the target power, even if the target power is lowered, the influence on the frequency of the load control is small. As a result, the frequency of load control in each facility 2 is balanced without changing the total target power value.

  Further, in the present embodiment, in the procedure of FIGS. 4, S5 and S6, the ratio of the power saving possible power to the power saving possible power capacity is less than 1, and the sum total is applied to the load control short-time facility 2 having a margin in the power saving possible power. The remaining power is distributed by subtracting the upper limit target power from the total target power value. For this reason, even in the load control short-time facility 2, the ratio of the power-saving power to the power-saving power capacity is 1 or more, and the load control short-time facility 2 having no margin for power-saving power Allocation is not performed. Further, the distribution of the remaining power to the load control short-time facility 2 with the ratio less than 1 is performed according to the margin ratio, which is the ratio of the margin power to the total margin power, as shown in Equation (4), and the power can be saved. The remaining power 2 is allocated to the facility 2 having a margin. For this reason, the distribution of the remaining power to the load control short-time facilities 2 having the ratio of less than 1 is performed fairly according to the surplus power of each facility 2, and the load control is concentrated on the specific load control short-time facilities 2. Without being performed, each load control is performed in a balanced manner between the facilities 2 for a short time.

  Note that, as the time-unit target power calculation processing for distributing the time-unit target power to each facility 2 in a balanced manner, the following processing can be considered instead of the processing shown in FIG. 4 described in the present embodiment. That is, the central control device 6 collects the power consumption of the control target load 3 at the end of the demand time period as the power saving power from each facility 2 by the communication means, and the sum of the target power value of each facility 2 is less than the total target power value. Thus, the target power of the facility having a small ratio of the power saving power capacity to the power saving power capacity is reduced preferentially, and the target power is redistributed. According to this time-unit target power calculation processing, the facility 2 having a small ratio of the power saving power to the power saving power capacity, that is, the facility 2 having the control target load 3 that can greatly reduce power consumption by cutting off the power supply. Therefore, the target power is reduced with priority, and the frequency of load control in the entire facility 2 can be reduced.

  However, the power-saving capacity is often set as a fixed value such as the capacity of the air conditioner that is the load to be controlled 3 or the previous year's maximum power. Since the power supply may be forcibly stopped in advance, the value set in the condition setting unit 14 needs to be frequently changed. Here, when it is forgotten to change the setting of the power-saving power capacity, the actual power-saving power capacity value is smaller than the value set in the condition setting unit 14, and the power-saving power capacity is set with respect to the set power-saving power capacity. The ratio of power that can be saved may be smaller than the ratio of the actual power saving capacity. In such a case, the facility 2 is misrecognized as a facility 2 that always has a small proportion when the target power is redistributed, and the target power is low so that the load control is frequently activated even after the demand time period is updated. Will be allocated. For this reason, the above-mentioned time-unit target power calculation processing that preferentially decreases the target power of the facility having a small ratio of the power saving possible power capacity to the power saving possible power capacity and redistributes the target power is the purpose of the energy saving system. It is conceivable that it is difficult to maintain a balanced load control frequency for each facility 2.

  For example, when the power saving power capacity of the facility A 2 is 800 kW and the power saving power capacity is 200 kW, the ratio of the power saving power capacity to the power saving power capacity is 0.25 (= 200 kW / 800 kW). However, when the load of 300 kW has already stopped and cannot be made the load 3 to be controlled, the actual power-saving power capacity is 500 kW (= 800 kW-300 kW), and the power-saving power with respect to the actual power-saving power capacity The ratio is 0.4 (= 200 kW / 500 kW). On the other hand, when all the control target loads 3 in the facility B are controllable and the power-saving power capacity is 300 kW and the power-saving power is 100 kW, the ratio of the power-saving power to the power-saving power capacity is 0.33 (= 100 kW / 300 kW). In this case, the ratio of the power saving possible power to the power saving possible power capacity calculated by the central controller 6 is that 0.25 of the A facility 2 is the smallest, so that the smallest target power is redistributed to the A facility 2. become. For this reason, in the A facility 2, it becomes necessary to always operate with the target power accompanied by load control.

  However, when the timed unit target power calculation process shown in FIG. 4 described in the present embodiment is performed, the central processing unit 6 causes the demand control device 5 of each facility 2 to have a power demand within a preset target power value. To grasp the load control execution time when the automatic load control is started to suppress the load. For facilities 2 with a long load control execution time, a high target power that makes it difficult to start load control is set, and for facilities 2 with a short load control execution time, load control is easier to start than before. Set a lower target power. Thus, once the target power of the facility 2 having a long load control execution time is once increased, the load control long-time facility 2 does not activate further load control. Accordingly, the target power can be redistributed in a well-balanced manner without causing the above-described inconvenience. As a result, further load control is performed on the facility 2 where load control has already been performed by the demand control device 5 without exceeding the total target power of the plurality of facilities 2 and without frequently changing the power saving capacity. Provided is an energy saving system that makes it possible to distribute well-balanced target power without being concentrated.

  In the above embodiment, the energy saving system according to the present invention has been described for the case where the load control is performed so that the sum of the maximum demand power in each facility does not exceed the set sum target power value. However, the energy saving system according to the present invention is not limited to this, and the total target power value to be set is also limited for load control when there is a power usage restriction request based on information such as demand power tightness of the power system. By setting the required power value, it can be applied in the same manner, and the same effect can be obtained.

1 ... Energy-saving system 2 ... Facility 3 ... Control target load (load that can save power)
4 ... Electricity meter 5 ... Demand control device (power suppression device)
6 ... Central control device 7 ... Received power measurement unit 8 ... Power saving possible power measurement unit 9 ... Calculation unit 10 ... Control output unit 11, 12 ... Communication unit (communication means)
DESCRIPTION OF SYMBOLS 13 ... Data storage part 14 ... Condition setting part 15 ... Time-unit target electric power calculation part 16 ... In-time demand calculation part

Claims (3)

Power control devices installed in each facility that control the power consumption in the facility within the demand time period defined in an arbitrary unit time by controlling the power supply to the power-saving load. And calculating the target power value of each facility so that the total maximum demand power corresponding to the sum of the maximum demand power in each facility does not exceed the set total target power value, and the calculated target power value A central control device that distributes power control devices, and communication means that communicates between the power control device and the central control device,
The power suppression device measures a load control execution time in which the load control is performed within a demand time period,
The central control device collects the load control execution time measured by the power suppression device from each facility by the communication means, and sets the target power allocated to the load control short-time facility with the short load control execution time as the target power. An energy saving system that balances the frequency of the load control in each facility without changing the total target power value by allocating to the target power of the load control facility having a long load control execution time.   The central control unit sets an upper limit target power that can be set for the load control long-time facility, and for the load control short-time facility, the load control long-time facility 2. The energy saving system according to claim 1, wherein the target power is redistributed by allocating a remaining power obtained by subtracting a total upper limit target power corresponding to a total of the upper limit target power from the total target power value.   The central control device collects power-saving power that is power consumption of the power-saving load at the end of the demand time period from each facility by the communication means, and the power-saving power capacity that is the power capacity of the power-saving load is collected. For the load control short-time facility whose ratio of possible power is less than 1, the margin power obtained by subtracting the power saving potential power from the power saving potential power capacity, and the total margin power corresponding to the sum of the margin power The energy saving system according to claim 2, wherein a margin ratio that is a ratio of margin power is calculated, and the remaining power is distributed according to the margin ratio.

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