JPS58222728A - Power receiving device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to demand control when receiving electric power.

[Technical background of the invention]

Demand control refers to control that attempts to keep the cumulative amount of electricity used per unit time within the contracted value with the electric power company, and in many cases this control is performed by cutting off the load.

FIGS. 1 and 2 illustrate a conventional demand control method. The horizontal axis is time, and the vertical axis is load type 7a,
7b to 7n represent the time during which the load is cut off.

Figure 1 shows the new priority method, in which the load to be shut off is prioritized, and when shutting off, the load with the lowest priority is applied, and when restoring, the load with the highest priority is applied. be.

Figure 2 shows what is called a cyclic method, in which the load to be shut off is ranked, but unlike Figure 1, it is not a priority order, but simply an order, and when the load is restored starting from the lowest number, This is a method of introducing players in the cut-off positions. Unlike the method shown in FIG. 1, this method does not have the disadvantage of always cutting off the same load.

However, both of these methods have the disadvantage that one load is interrupted for a long time.

For example, if it is predicted that if only level 1 is cut off in the 15th minute of a 30-minute demand, the demand will not be exceeded, then with the new method that gives priority to Figure 1, level 1 will always be cut off for 15 minutes, and Figure 2 In the click method, the load to be cut off changes every time the demand time changes, but it will not be cut off if the load is cut off for 15 consecutive minutes within a unit demand time. The conventional method has the disadvantage that if the same load is cut off for a long time, it will disappear, and this tendency will not change even if the predicted excess amount changes.

[Purpose of the invention]

The present invention is designed to eliminate this drawback and allow only the same load to be cut off.

[Summary of the invention]

The present invention relates to a power receiving and distributing device that includes a plurality of loads that distribute and use received power, a breaker that opens and closes these loads, and an integrated power needle with an oscillator that measures the integrated value of the received power. A function to calculate the predicted excess of the maximum demand power amount based on the output signal from the integrating wattmeter, a function to divide the loads into groups according to this predicted excess amount, and a predetermined power outage time for the divided loads. This is a power receiving and distributing device equipped with a maximum power demand control device that has the full function of controlling the opening and closing of circuit breakers evenly within a specified time. That is, the present invention provides a power demand control method for cutting off a load according to a predicted amount of excess demand, in which the loads are divided into a plurality of groups according to the predicted amount of excess demand, and the loads are sequentially divided into groups so that the cut-off times of the groups are equal within the same demand time. This is a power receiving and distributing device that performs demand control and is characterized by shutting off on a group-by-group basis.

Since the present invention is configured as described above, the demand control load is often cut off for a long time, and it is possible to avoid the situation where only the same load is cut off and the power supply service deteriorates.

[Embodiments of the invention]

Next, an embodiment of the present invention will be explained. FIG. 3 is a diagram showing the relationship between the demand control device and the cutoff load.
1 is an integrated electricity meter with an oscillator, 2 is a demand control device, 3a, 3b to 3n are circuit breakers, and 4a, 4b to 4n' are loads to be controlled by demand, each of which is in a pair with a circuit breaker. There is.

Figure 3 shows multiple loads 4 that distribute and use the received power.
a, 4b-4n, circuit breakers 3a, 3b to 3n that open and close loads 4a, 4b-4n, and an integrated power meter 1 with an oscillation device that measures the integrated value of received power. In this case, there is a function to calculate the predicted excess amount of the maximum demand power amount based on the output signal from the integrated power meter 1, a function to group the loads 4a, 4b to 4n according to this predicted excess amount, and a function to group the loads 4a, 4b to 4n, and It shows a power receiving and distributing device equipped with a demand control device 2 that has a function of controlling the opening and closing of circuit breakers 3a, 3b to 3n so that the power outage times of loads 4a, 4b to 4n are equalized within a predetermined time. .

FIG. 4 is a time chart explaining the present invention. The horizontal axis represents time, the vertical axis represents the type of load, and 7a to 7n represent the time during which the load is cut off. In this method, when an excess demand is predicted, the power corresponding to the excess amount is distributed among n loads to shorten the cut-off time per load. This method is effective when shutting off only the air conditioners in a certain system, such as a building, and the service there deteriorates, but for a short time, loads that are not affected by air conditioning conditions are targeted for demand control. Figure 4 shows the schedule for load shedding after the demand exceedance is predicted at the tth minute.

Scheduling is performed according to the following formula.

Here, Te is the remaining time Wd from the time when the demand exceedance is predicted to the end of the demand time, and the excess demand electric energy W is the amount of each shutoff load, and the loads are set so that they are approximately equal.

n is the number of groups of interrupted loads, nm is the number of loads that have already been interrupted, and is zero at the time when the excess is first predicted.

If it is predicted that the amount of electricity Wd will be exceeded in the remaining time Te, then W = " x Wd. Therefore, TD is the demand period (minutes) T.

W indicates that if the current instantaneous power is cut off by the reduced power W, the demand will not be exceeded.

Next, the load for cutting off only W is scheduled.

Since the load capacity of one shutoff station is W, demand will be exceeded unless multiple loads are shut off at the same time when W ) w .

Therefore, K (the number of cylinders in simultaneous operation) is determined so that KXw≧W>(K-1)xw.

Since the total number of loads is n, for the power reduction WK, let the integer value of rv' be the current number of cutoff groups, and set the cutoff time Ts so that the cutoff groups have equal time during the remaining time To. Determine and schedule f.

The cut-off time Ta of one group is T8”Te/L, and the cut-off time for K loads iTa is turned on. After the T!I time has elapsed, the cut-off loads are turned on, and the next load iT is turned on.
This operation is repeated until the demand is shut off for a time s and the demand is controlled.

In addition, demand monitoring is normally performed every minute, but it is sequentially predicted every minute, and when the power reduction is KXw≧KXw+W) (K-1)w, the status quo is maintained, and if not, the group is rearranged or Perform demand control recovery.

When rearranging groups, scheduling is performed using the above method using the load excluding the load that has already been cut off, and the demand is sequentially predicted every minute and the scheduling is changed one after another.The demand time ends at 9 o'clock. , all loads are turned on to prepare for demand control at the next demand time, but the load that will be the first group to be grouped in the next cycle is a load that was not cut off in the previous cycle, or if all loads were cut off in the previous cycle. Adjust so that the second load in the previous cycle becomes the first load in the current cycle,
This ensures that the same load is not always subject to interruption.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 are explanatory diagrams of a conventional demand control method, Fig. 3 is an explanatory diagram of a demand control device and a staff load showing an embodiment of the present invention, and Fig. 4 is an explanatory diagram of a demand control method of the present invention. FIG. 1... Integral power meter 2... Demand control device 3
a~3n... Breaker 7a~7n... Load breaker (7317) Agent Patent attorney Noriyuki Chika (
1 other person) Figure 1 T Figure 2 T

Claims (1)

[Claims] In a power receiving and distributing device consisting of a plurality of loads that distribute and use the received power, a breaker that opens and closes these loads, and an integrating wattmeter with an oscillation device that measures the integrated value of the received power. , a first means for calculating a predicted excess of the maximum demand power amount based on an output signal from the integrating wattmeter, a second means for dividing the loads into groups according to the predicted excess amount, and the loads divided into groups. A power receiving and distributing device comprising a maximum demand power control device having a third means for controlling opening/closing of the breaker so that the power outage time is equalized within a predetermined time.