JPS609412B2 - Demand power monitoring device - Google Patents

Description

[Detailed Description of the Invention] The present invention displays how much power needs to be reduced at a certain point so that the demand power does not exceed the contract power, and generates an alarm signal if there is a risk of the power demand exceeding the contract power. This invention relates to a power monitoring device.

Generally, if the demand power passes the contract power, you will have to pay a relatively high penalty fee for the excess amount, so if there is a risk that the demand power will exceed the contract power, it is necessary to be aware of it and prevent the excess. be.

For this purpose, the emitted pulses of the electricity meter with a transmitter are counted,
Calculate the predicted power demand from the current power demand, the amount of increase in the power demand over a certain period of time, and the remaining time of the demand period,
There has been a power demand monitoring system that calculates the adjusted power by dividing the difference between this value and the target power demand by the remaining time of the demand time limit and displays this. Furthermore, an alarm value is set for this regulated power, and when the regulated power exceeds the alarm value, an alarm is generated,
There were also devices with alarms to notify when load control was to be carried out.
However, with these conventional devices, if the power demand is not cut off at the same time as the alarm occurs, there is a risk that the power demand will exceed the contract power, so if the power demand increases abnormally or an alarm is generated, the load should be cut off immediately. The power demand monitor had to be on standby at all times so that the power demand could be monitored.

As a result, supervisors were often subject to time constraints on things such as eating and using the toilet, and were required to be in a constant state of tension, causing immeasurable mental and physical fatigue. The present invention has been made in view of this point, and it predicts and calculates the regulated power after a certain period of time from the present time, displays this and generates an alarm, thereby informing the demand power monitor of the future of regulated power. An object of the present invention is to provide a device that can set a guideline for load control in advance by informing the value of .

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a time chart showing the principle of calculating predicted adjusted power according to the present invention.

In this figure, the key axis is time, where the demand time limit is T and the elapsed time of the demand time limit is t. The vertical axis is the power demand, Q is the target power demand, for example, the contract power, and P is the power demand at the elapsed time t, that is, the current power demand. Further, the curve connecting the origin ○ to the point A is an increase curve of power demand. Now, at the elapsed time t, a certain time Δt is taken retroactively from that time, and the increase in the demand power within that time is set as ΔP.

Here, by calculating △P/△t, the rate of increase in power demand can be found. Adding the remaining time of power demand to this value and adding the value of current power demand yields the predicted value of power demand, that is, the predicted demand. The electric power is calculated. This value is expressed as R by the following formula: R = P + Tatsumi (T-t) (1)
This value is represented by the intersection R of the broken line extending from point A and the straight line extending parallel to the vertical axis from the demand time limit T in FIG.

Next, by multiplying the value obtained by dividing the difference between the predicted power demand R and the target power demand Q by the remaining time Tt by the value of the demand time limit, the adjusted power at the present time is obtained.

If this adjusted power is U, it can be expressed as follows.
U = T Chapter Three - - - - ■ What is regulated power? According to Figure 1, draw a straight line parallel to the vertical axis through point A, take point B where it reaches Q, and draw this point B. It shows the slope of the straight line connecting R.

In other words, the excess amount of power demand R−Q. This is the amount that indicates how much load should be controlled during the remaining time Tt in order to reduce the This means that when the excess amount of power demand is converted into electric energy, it becomes (R-Q.)/band slope・Remaining time T-t(
Minutes) is converted into hours, so the adjusted power is U = Prosthetic Techniques T - Kei Miyumi 1T.

In FIG. 1, if the angle 2R8Q is set as , then the '2} equation can be further expressed as the following equation.

U: T Chapter 3 = Ttah's・-----'3} In other words, adjusted power is the predicted excess value of demand power (R-Q,)
It is the value obtained by multiplying the demand time by the triangular Masatoshi created by the remaining time (T-t) and the remaining time (Tt), and is the slope of the straight line BR in the figure.

Based on this idea, it is possible to obtain the adjusted power after a certain period of time from the current point.

In other words, the time △t after the elapsed time t is t + △t
If a straight line parallel to the vertical axis is drawn and the point where the target power demand Q is reached is C, a right triangle ΔCQ,R is created. If the angle RCQ in this triangle is 2, then the adjusted power UR at this point is expressed as follows. UR=TT
t): Ttan's 2...--{4} (Equation 4' is the predicted adjusted power reached at t+Δt.

The present invention calculates and displays the predicted adjusted power expressed by equation {4), and generates an alarm when the predicted adjusted power exceeds a predetermined alarm value.One embodiment thereof will be described with reference to FIG.

In the figure, reference numeral 1 denotes a power meter with a transmitter that transmits a number of pulses proportional to the amount of power used. Reference numeral 2 denotes a current demand power counter that counts the transmitted pulses of the electricity meter 1 with a transmitting device, and is reset every demand time period T by a signal from the clock section 4.

Reference numeral 3 denotes a demand power incremental force counter that counts pulses during a certain period of time Δt, and is reset every certain period of time Δt by a signal from the clock section 4.

Reference numeral 4 denotes a clock unit that measures the demand time limit T and the fixed time t, and outputs a signal for resetting the two counters at each time interval.

A remaining time counter 5 measures the remaining time Tt of the demand time limit based on the reference signal from the clock section 4.

Reference numeral 6 denotes a first arithmetic circuit, which calculates the predicted power demand R from the above formula 1) and the output code signals of the current demand power counter 2, the demand power incremental power counter 3, and the remaining time counter 5 and a fixed time Δt.
Calculate based on the value of.

Reference numeral 7 denotes a target power demand setting device for manually setting a target power demand, for example, contract power.

Reference numeral 8 denotes a second arithmetic circuit, which performs predictive adjustment expressed by the above equation {4' based on the output code signals of the first arithmetic circuit 6, the target power demand setter 7, and the remaining time counter 5, and the value of the demand power time limit T. Calculate power UR.

Reference numeral 9 denotes a display for displaying the output of the arithmetic circuit, that is, the predicted adjusted power.

This is the alarm setting device for setting the alarm value for the predicted adjusted power.

Reference numeral 12 denotes a comparison circuit that compares the alarm value with the predicted adjusted power, and when the latter exceeds the former, an alarm output is generated and the alarm circuit 12 is activated to draw the attention of the supervisor.

Note that the first and second arithmetic circuits 6 and 8 can be configured using general-purpose ICs, but they can be replaced by using, for example, a microcomputer, and the circuit configuration can be extremely simplified. .

Further, it is also possible to provide a setting device so that the fixed time for measuring the increment ΔP of the power demand can be varied. As described above, the present invention is configured to display the predicted adjusted power after a certain period of time and to issue an alarm when this exceeds a predetermined alarm value, so it is useless to the supervisor unlike conventional devices. It has the advantage of being able to appropriately and smoothly monitor power demand without being constrained or creating a sense of tension. The effects of the invention are extremely remarkable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a time chart illustrating the operating principle of the present invention. FIG. 2 is a block diagram showing one embodiment of the present invention. In the figure, 1 is a power meter with a transmitter, 2 is a current demand power counter, 3 is a demand power incremental power counter, 4 is a clock section, 5 is a remaining time counter, 6 is a first calculation circuit, and 7 is a target power demand 8 is a second arithmetic circuit, 9 is a display, 10 is an alarm setting device, 11 is a comparison circuit, and 12 is an alarm circuit. The same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2

Claims (1)

[Claims] 1. A first means for counting the transmitted pulses of a power consumption meter with a transmitting device, and a predicted power demand based on the count value which is the output of this first means, the increment of said count value over a certain period of time, and the remaining time of the demand time period. and a second means for calculating the predicted adjusted power by dividing the difference between the predicted power demand and the target power demand by the remaining time of the demand time limit after a certain period of time, and multiplying this division value by the demand time limit. 3, a fourth means for displaying the predicted adjusted power, and a fifth means for generating an alarm when the predicted adjusted power exceeds a predetermined alarm value. Device.