JPS6019214B2 - Demand monitoring and control device in power generation, reception, and distribution monitoring and control systems - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a demand monitoring control device and method for suppressing the amount of received power to a maximum required power amount or less in a power generation/reception/distribution monitoring and control system.

Ordinary consumers purchase most of their electricity from electric power companies, but since electric power companies have a limit to the amount of power they can generate, they have to make contracts with electric power companies, such as at certain time intervals (
It is stipulated that so-called demand operation is performed, in which the maximum demand power amount, that is, the contract value, is controlled for each demand period (demand cycle).

Therefore, consumers constantly monitor the amount of power used and operate within the contracted demand range. To perform such demand operation, a private power generation facility is installed, and the output of this power generation facility is controlled so that the amount of electricity used from the commercial source to the load does not exceed the maximum demand amount within the demand cycle. This is to prevent demand overflow. FIG. 1 is a system diagram showing an embodiment of a conventional demand monitoring and control device, in which power from a commercial power source 1 is supplied to a load 3 via a power transformer 2.

The power receiving power amount detector 6 receives signals from the current transformer 4 and the instrument transformer 5, detects the power receiving power from the commercial power source 1, and outputs the amount of power used. The demand monitoring controller 7 inputs the amount of fin power used at every set time Δt, monitors the demand based on it, and outputs the fin power from the private power generation equipment 8 to the member flow 3.
Controls the output to. FIGS. 2 and 3 are graphs showing the state of control by the demand monitoring controller 7, in which the vertical axis represents the amount of power used P, and the horizontal axis represents the time t from the start of the demand, respectively. .

The maximum demand power amount in the demand cycle T is represented by P on the right axis. In FIG. 2, when the power consumption P at an arbitrary time t, for example, exceeds the line segment 50, that is, when the power consumption P/TL is exceeded, the demand monitoring controller 7
immediately issues an alarm and issues a control command to the power generation equipment 8 at the same time.

Then, the power generation equipment 8 increases the output to the load 3, thereby reducing the output from the commercial power source 1 to the load 3. After that, when the amount of electricity used becomes less than 50 lines after t8,
The alarm is stopped and the control command of the demand monitoring controller 7 is stopped. In FIG. 3, the rate of change ΔP/Δ in the amount of power used is input to the demand monitoring controller 7 every set time Δt.
An alarm and control are indicated when t exceeds a certain selected value (eg, average power P/T within period T).

For example, when the power usage is P2 at t2 and P200P at t2, if the rate of change ΔP/Δt between Δt is greater than P/T, the demand monitoring controller 7 At 10 Δt, an alarm and control is performed in the same manner as in the case of FIG. 2, and then at t2', when the rate of change in the amount of power used at Δt becomes equal to or less than P/T, the system is stopped. It should be noted that the demasod supervisory controller 7 performs supervisory control of both the systems shown in FIGS. 2 and 3. As described above, in the conventional demand monitoring and control method, the amount of power used that changes from moment to moment is detected, and when a demand overflow is predicted, the demand monitoring controller 7 issues an alarm and controls the output of the boxing equipment. The control is released when the amount of power used falls within the power limit range.

By repeating such control, power monitoring control is performed so that the amount of power used is kept below the maximum power demand P at the demand end time. When demand control is performed using this conventional supervisory control method, alarm control is performed many times within one demand cycle, which has the disadvantage of being undesirable in terms of the lifespan and maintenance of the control equipment. was.

This invention has been made in view of the above points, and provides power generation/reception distribution monitoring control that reduces unnecessary demand alarms and the number of demand controls, thereby extending the life of the control equipment and being advantageous in terms of maintenance. It is an object of the present invention to provide a demand control device in a system and a method thereof.

The demand monitoring control device and its method according to the present invention will be explained below.

In this invention, demand is predicted by detecting the amount of power used from moment to moment, as in the past, but in this invention, even if a demand over is predicted, control is not performed immediately at that point. different from that of

FIG. 4 shows an embodiment of the demand monitoring and control device according to the present invention, in which the demand monitoring and control device 7' is connected to the power generation equipment 8.
The output from the load 3 to the load 3 is controlled.

The power generator 11 includes a current transformer 9 and an instrument transformer 10.
The power supplied from the power generation equipment 8 to the load 3 is detected in response to a signal from the power generation equipment 8 . In addition to the received power amount detector 6, a power change rate monitoring time setting device 12 and a controllable output setting device 13 are connected to the input side of the demand monitoring controller 7'. The controllable output setting device 13 receives the detected value from the generating force detector 11 and provides a signal representing the controllable output to the demand monitoring controller 7'. Controllable output is power generation equipment 8
This is the so-called surplus power of the power generation equipment 8, which is obtained by subtracting the value detected by the detector 11 from the maximum power that can be supplied. 5 and 6 show a method of controlling this supervisory control device.

In FIG. 5, the amount of power used P is P at an arbitrary time t3.
'Tt3 is exceeded, that is, when demand over is predicted, a warning is issued at that point, but no control output is issued to the power generation equipment 8.

The demand monitoring controller 7' receives the signal from the controllable output setting device 13 and calculates how much time, for example, how many minutes, control is required to avoid demand overflow when the power generating equipment 8 is fully operated. Taking this calculated value as T', the time from the time the alarm goes off to the end of the demand (T-t3
) is calculated by adding some margin time a to the calculated value r (T'+
a), that is, (T'10a)<(T
1) Then, if the alarm time is 1, then the demand monitoring controller 7
' does not issue a control command to the power generation equipment 8.

After that, at the time when (r0a) ≧ (T-shi) /-shi2 (T-T'-a), the power generation equipment 8 starts full operation, and the amount of electricity used at the end of the demand decreases. The maximum power demand amount P is not exceeded.

Note that the calculated value of T' is performed at constant time intervals (for example, every Δt) and is constantly corrected. In FIG. 6, while the change rate monitoring time Δt in FIG. 3 is set to the same value, the change rate monitoring time is changed in advance according to the remaining time of the demand cycle.

The power change rate monitoring time setting device 12 is provided for this purpose, and when the remaining time of the demand cycle is long, the change rate monitoring time is set to be long, and in some cases, the change rate monitoring time is set to be shortened. . For example, in section A shown in Figure 6, the change rate monitoring time is (△t+sha), in section B (△t 10), in section C (△t 1 b), and in section D △t. , which gradually becomes smaller for each partition as the demand period approaches the end. However, b is a certain fixed time.
In this embodiment, the time for monitoring the rate of change in the amount of power used is set proportionally, but as the remaining time becomes shorter, the time becomes shorter, or any value may be used.

Furthermore, although power control is shown using only one power generation facility, it is possible to provide two or more power generation facilities. Furthermore, it goes without saying that two or more power generation facilities may be switched and used in appropriate combinations as necessary. As described above, according to the present invention, even if a demand over is predicted by detecting the amount of electric power, control is not performed immediately, but an alarm is issued when the demand over prediction continues during the change rate monitoring time that changes depending on the remaining time of the demand cycle. and the above matter (T'10a)≧
(T-t), in other words, the control is started at a time when the control time, which takes into consideration the margin of the power generation equipment that does not cause over-demand, becomes approximately the same as the remaining demand time.

According to the demand monitoring control method of the present invention, the following advantages can be obtained.

[The number of alarms and controls within the 111 demand period is reduced as much as possible (about 1 or 2 times), which is effective in terms of the lifespan and maintenance of the control equipment.

'2} In the conventional method, for example, when control is performed at the beginning of a demand cycle, and the amount of power used by the load decreases rapidly thereafter, the amount of power used at the end of the demand cycle is equal to the maximum demand fin. The capacity will not be met and there will be excess power.

In the supervisory control method according to the present invention, since the operation is performed near the end of the demand cycle, even in the above-mentioned case, the amount of remaining power is very small. As a result, the control time can be counted accurately, and the control time becomes the minimum necessary, and in some cases, it may be possible to dispense with control.

As described above, the present invention provides a demand monitoring control method in a power generation/reception/distribution monitoring control system that can reduce the number of alarms and alarms and is therefore advantageous in terms of the life span and maintenance of control devices.

[Brief explanation of drawings]

Figure 1 is a system diagram showing a demand monitoring control device of a conventional power generation/reception/distribution control system, and Figures 2 and 3 are diagrams showing the relationship between demand cycle and power consumption to explain the demand monitoring control shown in Figure 1. FIG. 4 is a diagram showing the relationship; FIG. 4 is a system diagram showing a demand monitoring and control device for a power generation and distribution control system according to an embodiment of the present invention; FIGS. 5 and 6 illustrate a demand monitoring and control method according to the present invention. FIG. 2 is a diagram showing the relationship between the demand period and the amount of power used. In the figure, 1' is a commercial power source, 2 is a power transformer, 3 is a load, 6 is a received power amount detector, 7' is a demand monitoring controller, 8 is a private power generation equipment, 11 is a generated power detector, and 12 is a power change rate monitoring time setter; 13 is a controllable output setter;
50 is a line segment representing the amount of power used at time t (P=P/T·t). Note that the same reference numerals in the figures indicate corresponding parts in the same areas. Depart! Figure 2 Hakama Figure 3 Figure Miscellaneous Figure 5 Figure Sei 6 Figure

Claims (1)

[Claims] 1 Equipped with a power receiving power amount detector that detects the electric power given to the load from the commercial power supply, and a power generation equipment that is controlled by a signal from this detector and supplies the electric power to the load, In a demand monitoring and control device in a power generation, reception, and distribution monitoring and control system that suppresses the amount of used power given to a load to be below the maximum demand power p, a power generation power detector detects the power given to the load from the power generation equipment. and a controllable output setting device that sets a controllable output of the power generation equipment from the signal of the detector;
Used at the end of the demand period T when the rate of change with respect to time of the signal representing the amount of power used from the power receiving power amount detector is greater than a certain selected value for a preset rate of change monitoring period. A warning is issued as the amount of electricity is predicted to exceed the maximum demand amount p, and when the amount of electricity used from the start of the demand to any time t within the demand period T exceeds P/Tt, Similarly, at the end of the demand period T, a warning is issued because the amount of power used is predicted to exceed the maximum amount of power demand P, and at the end of the demand period T, the amount of power used exceeds the maximum amount of power demand P. a demand monitoring controller that calculates the control time from the power generating equipment to the load from the controllable output at a time when the demand period T is predicted to exceed the demand period; a power change rate monitoring time setting device for setting the change rate monitoring time to be long at an early stage and shorten the change rate monitoring time as the end of the demand cycle T approaches; power generation/reception/distribution monitoring control for providing a controlled output from the power generating equipment to the load during the control time at the end of the demand cycle T so that the amount of power used does not exceed the maximum demand power P at the end of the period T; Demand monitoring control device in the system.