JPH05111159A - Demand controller - Google Patents

Abstract

PURPOSE:To get a demand controller which never repeats an alarm output and load output frequently by optionally issuing or stopping alarm and load control signals. CONSTITUTION:An input interface part 51 counts the pulse signal proportionate to the quantity of used power from a power meter 4 fitted with a transmitter, and based on this count, the demand time limit and the left time limit of the demand time limit from a timer 53, and the arithmetic signal for deciding the intervals between the operations, a processor 52 outputs a first alarm signal to an alarm output part 57 in case that the estimate of the demand value at finish of the demand time limit is over the target demand value of a setter 60. And, in case that the estimate is over the break power value of the setter 60, it outputs a second alarm signal and a load control signal to an alarm output part 57 and a control output part 58, respectively. Then, even if it fulfills the above alarm signal output condition, if within the mask time set by a realarm mask time setter 56, it stops the output of the first and second alarm signal and the load control signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a demand control device for controlling an amount of electric power used during a demand time period (for example, 30 minutes) so as not to exceed a maximum demanded electric power amount.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a conventional demand control device disclosed in, for example, JP-A-55-49931. In the figure, 1 is a load, 2 is a measuring transformer for detecting the voltage of the load 1, 3 is a measuring current transformer for detecting the current of the load 1, 4 is the output of the transformer 2 and 3 of the current transformer 3. A power meter with a transmitter 5 for measuring the amount of power used by the load 1 based on the output is a demand control device 5 for controlling the load 1 based on the output of the power meter 4 with a transmitter.

In the demand control device 5, 6
9 is a time zone setter for setting the time zone of the sampling time Δt, 10 is a remaining time clock circuit for outputting the remaining time (T-t) of the demand time period T (t is the current time), 11 is a time zone setter A selection circuit for comparing the outputs of 6 to 9 and the output of the remaining time clock circuit 10, 12 to 16 set sampling time Δt in each time zone, and a selection circuit corresponding to each time zone of this sampling time Δt The length setter selected by 11 and 17 are the current value W of the used electric energy based on the output of the electric energy meter 4 with the transmitter.
Current value counter that outputs ₁ ; 18 is a current value display that displays the output of the current value counter 17; 19 is a sampling time changing circuit to which the commands of the length setters 12 to 16 are input; 20 is power with transmitter Output of quantity meter 4 and sampling time changing circuit 19
A sampling value counter that outputs a sampling value ΔW / Δt per unit time at a sampling time Δt based on the output of the current value, 21 indicates the current power consumption based on the output of the remaining time clock circuit 10 and the output of the sampling value counter 20. A multiplication circuit for calculating the amount of electric power in the remaining time (T−t) when the amount continues, 22 is a remaining time indicator for displaying the output of the remaining time clock circuit 10, and 23 is a multiplication with the output of the present value counter 17. Circuit 21
And an adder circuit 24 for calculating a predicted value W _x of the power consumption at the end of the demand time period T based on the output of
Predicted value display that displays the output of 3, 25 is a target value setter that sets the target value W _{b of the} amount of power used at the end of the demand time limit, 26 is the output of the adder circuit 23 and the target value setter 25 A subtraction circuit for obtaining a difference from the output, 27 is an alarm display circuit for outputting an alarm based on the output of the subtraction circuit 26, and 28 is for controlling the load 1 based on the output of the subtraction circuit 26 and the output of the remaining time clock circuit 10. multiplication and division circuit obtains a correction value P _x to, 29-th power correction value display for displaying the output of the divider circuit 28, 30 is corrected value P _x
The cutoff return value setting circuit for setting the cutoff return value of 31 is a comparison circuit for comparing the output of the multiplication / division circuit 28 with the output of the cutoff return value setter 30. It is a load control circuit for controlling.

Next, the operation of the conventional demand control device will be described. The power meter with transmitter 4 measures the amount of power used by the load 1 based on the output of the transformer 2 and the output of the current transformer 3, and transmits a pulse proportional to the amount of power used to the demand control device 5. .. Subsequently, in the demand control device 5, the current value counter 17 counts the pulses transmitted from the power meter 4 with a transmitter, converts the count value into the amount of power used in the demand time period T, and obtains the obtained value. The current value W ₁ is displayed on the current value display 18 and is output to the adding circuit 23. Here, it is assumed that the demand time period T is, for example, 30 minutes, and the unit of the current value W ₁ is not KWH but KWT (T = 30) which is twice KWH. Further, the pulse transmitted from the watt hour meter 4 with the transmitting device is also input to the sampling value counter 20, and the sampling value counter 20
The number of pulses at the sampling time Δt is counted by, and the count value is converted to the sampling value ΔW / Δt per unit time (1 minute) of the amount of electric power used at the sampling time Δt and multiplied by the conversion value ΔW / Δt. It is output to the circuit 21.

Further, the time zone setting device 6 is controlled by the selection circuit 11.
The time set in 9 to 9 is compared with the remaining time (T-t) (t is the current time) output by the remaining time clock circuit 10, and the sampling time Δt in each time is set. Bowl 12 ~
16 is selected. Here, from the setting example of the time zone setters 6 to 9 and the setting example of the length setters 12 to 16 shown in FIG. 3, the sampling time Δt is 5 minutes in the time zone from the start of the demand time period to 5 minutes, 4 from 5 to 13 minutes
Minutes, 3 minutes for 13 to 19 minutes, 2 minutes for 19 to 23 minutes, and 1 minute for 23 minutes to the demand period of 30 minutes. That is, within the demand time limit of 30 minutes, 5 minutes sampling is once and 4 minutes sampling is 2
2 times 3 minutes sampling 2 times 2 minutes sampling
1 minute sampling 7 times.

In the time period from the start of the demand time period to 5 minutes, the length setting device 17 is selected by the selection circuit 11, and the length setting device 17 sends a command to the sampling time changing circuit 19, which causes the sampling time changing circuit. 19 changes the sampling time Δt of the sampling value counter 20 to 5 minutes. Then, the sampling time changing circuit 19 changes the sampling time Δt of the sampling value counter 20 in the same manner in other time zones. The sampling time Δt of the sampling time changing circuit 19 is changed, for example, by changing the time for resetting the sampling value counter 20 to 0, or by providing one minute counter to n minutes counter, and selecting any one of them. Achieved by.

Remaining time The remaining time (T-
As described above, t) is input to the selection circuit 11, is displayed on the remaining time display 22 and is input to the multiplication circuit 21. The multiplication circuit 21 multiplies the remaining time (T−t) by the sampling value ΔW / Δt output from the sampling value counter 20 to obtain the remaining time when the current power consumption continues.
Calculate the electric energy (ΔW / Δt) × (T−t) at (T−t),
The amount of electric power (ΔW / Δt) × (T−t) is output to the adder circuit 23.

The adder circuit 23 has a power amount (ΔW / Δt) × (T-
t) and the current value W ₁ output from the current value counter 17 described above are added to calculate a predicted value W _x of the power consumption at the end of the demand time period of 30 minutes, and the obtained prediction is obtained. Value W _x
Is displayed on the predicted value display 24 and is output to the subtraction circuit 26. The subtraction circuit 26 subtracts the target value W _{b of the} amount of power used at the end of the demand time limit 30 minutes set by the target value setting unit 25 from the predicted value W _x , and the difference (W _x −W _b ) is +. If so, that is, if the predicted value W _x exceeds the target value W _b , the alarm display circuit 27 is operated to issue an alarm such as sounding a buzzer or lighting or blinking an alarm light or another indicator. Output.

The difference (W _x −W _b ) obtained by the subtraction circuit 26 is input to the multiplication / division circuit 28, and the correction value P is set in the multiplication / division circuit 28.
_{x = T (W x -W b} ) / (T-t) is determined by calculation.
The correction value P _x means the load capacity that should be shut off or turned on within the remaining time (T−t) in order to match the power consumption at the end of the demand time limit of 30 minutes with the target value W _b. display
It is displayed on 29 and is output to the comparison circuit 31.

The comparison circuit 31 compares the correction value P _x with the cutoff return value set by the cutoff return value setting unit 30. If the positive correction value P _x exceeds the cutoff return value, the load control is performed. Circuit 3
A load cutoff signal is output to the load control circuit 32
Shuts off part of load 1. If the negative correction value P _x exceeds the cutoff return value, the comparison circuit 31 causes the load control circuit 32 to apply a part of the cut load 1.
The sampling time changing circuit 19 may be included in the sampling value counter 20.

[0011]

Since the conventional demand control device is constructed as described above, the predicted value W _x exceeds the target value W _b , an alarm is once output, and a load cutoff signal is output. If the power consumption is not reduced, the alarm and load cutoff signal will remain output.If the delay until the power consumption is reduced is large even if the load is cut off, the alarm and load cutoff signal will remain output. Is. When the power consumption decreases, the alarm and the load cutoff signal are not output. However, when the power consumption decrease is small, the alarm and the load cutoff signal are output again. Therefore, there has been a problem that alarm output and load control are frequently performed in a short period of time. In this case, operations such as alarm resetting are performed, but especially when it is installed in a remote place or at a high place, it is necessary to bother to go to the installation location and perform operations such as alarm resetting. was there.

The present invention has been made in order to solve such a problem, and when the load changes, the alarm and load control signals are arbitrarily turned on and off so that the alarm output and the load control are frequently performed in a short period of time. The purpose is to obtain a demand control device that is not repeated.

[0013]

A demand control device according to the present invention comprises an input interface section for outputting a count value of the number of pulses proportional to the amount of electric power used, a demand time limit signal indicating a demand time limit, and a remaining time of the demand time limit. , A setting unit for setting a target demand value and a breaking power value, a re-alarm mask time setting unit for setting a mask time, a demand at the end of the demand time period based on the count value and the remaining time. The predicted value of the value is calculated, a first alarm signal is output when the predicted value exceeds the target demand value, and the adjusted power is calculated based on the predicted value, and the adjusted power is cut off. When the power value is exceeded, the second warning signal is output and the load control signal is output, and the first warning signal, the second warning signal, and the load control signal are If it is within the mask time after being output by the user, an arithmetic processing unit that stops outputting the first alarm signal, the second alarm signal, and the load control signal, and controls the load according to the load control signal. A control output unit and an alarm output unit for generating a first alarm and a second alarm according to the first alarm signal and the second alarm signal are provided.

[0014]

In the present invention, the clock section outputs the demand time limit signal indicating the demand time limit and the remaining time of the demand time limit, the setting unit sets the target demand value and the cutoff power value, and the re-alarm mask time setting unit sets. Mask time is set. Further, the arithmetic processing unit obtains a predicted value of the demand value at the end of the demand time period by calculation based on the count value of the pulse signal proportional to the amount of power used and the remaining time, and the predicted value is the target value. If the demand value is exceeded, the first alarm signal is output, and the adjusted power is calculated based on the predicted value.
If the adjusted power exceeds the cutoff power value, the second
Of the first alarm signal and the load control signal are output, and the first alarm signal, the second alarm signal and the load control signal are once output, and then the first alarm signal is within the mask time. Is stopped, and the output of the second warning signal and the load control signal is stopped. The alarm output unit outputs the first alarm and the second alarm according to the first alarm signal and the second alarm signal, and the control output unit controls the load according to the load control signal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. Figure 1
FIG. 3 is a block diagram showing an embodiment of the present invention. In the figure, 4 is a power meter with a transmitter similar to that shown in FIG. 3, and 5A is a demand control device connected to this power meter with a transmitter 4. In the demand control device 5A, reference numeral 51 is an input interface unit that is connected to the power meter with transmitter 4 and counts the pulses output from the power meter with transmitter 4 in proportion to the amount of power used.
Is an arithmetic processing unit that is connected to this input interface unit 51 to perform arithmetic, 53 is connected to this arithmetic processing unit 52, and measures the current time, and also measures the demand time period, for example, 30 minutes,
A clock unit that outputs a demand time limit signal indicating a demand time limit of 30 minutes, a remaining time from the current time to the demand time limit of 30 minutes, and a calculation signal that determines a calculation interval for each predetermined time to the calculation processing unit 52, and 54 is a calculation processing unit 52. Connected to the storage unit 54, 55 for storing information for the calculation in the calculation processing unit 52 and for storing the calculation result of the calculation processing unit 52, a printer unit 56 for outputting the calculation result of the calculation processing unit 52, 56 Is a re-alarm mask time setting unit that sets a mask time of about 0 to 20 minutes and outputs the set mask time to the arithmetic processing unit 52, and 57 is a calculation result of the arithmetic processing unit 52 connected to the arithmetic processing unit 52. An alarm output unit for generating first and second alarms according to the above, 58 a control output unit connected to the arithmetic processing unit 52 for controlling the load according to the arithmetic result of the arithmetic processing unit 52, and 59 an arithmetic processing unit Display unit connected to 52 to display calculation results, etc., 60 connected to calculation processing unit 52 The setting unit is configured to set the target demand value.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.
This will be described based on the flowchart showing the operation of the arithmetic processing unit. In step s1, the calculation processing unit 52 calculates, for example, the current value at the first calculation interval based on the count value counted by the input interface unit 51 and the remaining time and the calculation signal output from the clock unit 53. .. continue,
In step s2, the calculation processing unit 52 calculates the predicted value of the demand value at the end of the demand time limit of 30 minutes based on the current value. Also, in step s3,
The calculation processing unit 52 calculates the adjusted power based on the predicted value.

Subsequently, in step s4, the arithmetic processing section 52 determines whether or not the predicted value exceeds the target demand value set by the setting section 60, and when it judges that the predicted value exceeds the target demand value (in the case of YES). To step s5, step s
At 5, the first alarm signal is output to the alarm output unit 27 to generate the first alarm. Also, in step s6,
The arithmetic processing unit 52 determines whether or not the regulated power exceeds the cutoff power value set by the setting unit, and if it determines that the adjusted power exceeds the cutoff power value (YES), the process proceeds to step s7, and at step s7, The second alarm signal is output to the alarm output unit 57 and the load control signal is output to the control output unit 58. As a result, the alarm output unit 57 issues a second alarm, and the control output unit 58 cuts off the load.

Subsequently, in step s8, the arithmetic processing unit 52 reads the mask time, for example, 5 minutes from the re-alarm mask time setting unit 56, and outputs an alarm if the processing timing is within the mask time (in the case of YES). First and second to part 57
The output of the alarm signal is stopped, the output of the load control signal to the control output unit 58 is stopped, and the calculation at the first calculation interval is completed. In this case, the alarm output unit 57 is the first and second
No alarm is generated and the control output unit 58 does not cut off the load. The calculation processing unit 52 masks the processing timing at the next calculation interval even if the alarm signal output condition is satisfied, that is, the predicted value exceeds the target demand value and the adjusted power exceeds the cutoff power value. If time has passed, step s
In 8, it is determined that the mask time is not reached (NO), and the calculation at the next calculation interval is completed.

In step s4, the arithmetic processing unit
If 52 determines that the predicted value does not exceed the target demand value set by the setting unit 60 (in the case of NO), step s
Return to 1. In step s6, the arithmetic processing unit 52
Is determined that the regulated power does not exceed the cutoff power
If (NO), the process returns to step s1.

[0020]

As described above, the present invention provides an input interface section for outputting a count value of the number of pulses proportional to the amount of power used, a timepiece for outputting a demand time limit signal indicating a demand time limit, and a remaining time of the demand time limit. Unit, a setting unit for setting a target demand value and a breaking power value, a re-alarm mask time setting unit for setting a mask time, a predicted value of the demand value at the end of the demand time period based on the count value and the remaining time When the predicted value exceeds the target demand value, the first alarm signal is output, and the adjusted power is calculated based on the predicted value, and the adjusted power exceeds the cutoff power value. The second warning signal is output, the load control signal is output, and the first warning signal is output.
A calculation for stopping the output of the first alarm signal, the second alarm signal and the load control signal within the mask time after the second alarm signal and the load control signal have been output once. A processing unit, a control output unit that controls a load according to the load control signal, and an alarm output unit that issues a first alarm and a second alarm according to the first alarm signal and the second alarm signal. By so doing, an alarm and a load control signal can be arbitrarily started and stopped when the load changes, and an alarm output and a load control are not frequently repeated in a short period of time, and an inexpensive and demand control device having many control functions can be obtained. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional demand control device.

[Explanation of symbols]

 5A Demand control device 51 Input interface unit 52 Arithmetic processing unit 53 Clock unit 56 Re-alarm mask time setting unit 57 Alarm output unit 58 Control output unit 59 Setting unit

Claims (1)

[Claims] 1. An input interface unit that outputs a count value of the number of pulses proportional to the amount of power used, a clock unit that outputs a demand time limit signal indicating a demand time limit, and a remaining time of the demand time limit, a target demand value and a cutoff power value. Setting section for setting the mask time, re-alarm mask time setting section for setting the mask time, the predicted value of the demand value at the end of the demand time period is calculated based on the count value and the remaining time, and the predicted value is When the target demand value is exceeded, the first alarm signal is output, and the adjusted power is calculated based on the predicted value. When the adjusted power exceeds the cutoff power value, the second alarm signal is output. And the load control signal is output, and the first alarm signal, the second alarm signal, and the load control signal are once output, and then within the mask time, the first alarm signal is output. An arithmetic processing unit for stopping the output of a report signal, the second alarm signal and the load control signal, an alarm for generating a first alarm and a second alarm according to the first alarm signal and the second alarm signal A demand control device comprising an output section and a control output section for controlling a load according to the load control signal.