JP2006034063A - Method for calculating current prediction value - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly operate power transmission lines by enabling prediction of the transmission current at the specified section of the transmission line in a short time. <P>SOLUTION: The method for calculating a current prediction value comprises a step of checking the current value of a given transmission line at every given period by a current detection means, storing the current value thus detected in a data base, patterning past current change states based on the given time, searching the same pattern in the past from the data base based on the patterns, calculating current amount of change based on the current value when the given period is passed from the reference time of the same pattern in the past, and calculating the current prediction value after the elapse of the given period from the given time based on the current amount of change in the past. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for monitoring a current carrying capacity of a transmission line.

  An allowable current (electric power) that can be energized in a steady state or in a short time is determined in advance in the power transmission line, and power supply exceeding the allowable current causes a mechanical strength reduction due to heat to the electric wire.

  On the other hand, in recent years, due to the difficulty in configuring the power system due to restrained investment in power facilities, there are many cases where transmission lines exceeding the current carrying capacity have been generated in high demand and high temperature periods such as in the summer, and the actual situation is difficult to operate. There is.

That is, it is known that if the amount of current change in a transmission line can be predicted more reliably, it is possible to accurately manage the operation of the transmission line in consideration of other transmission lines.
JP-A-2002-238147 discloses a prior art for measuring the wire temperature of a monitoring line in consideration of the influence of wind.
JP 2002-238147 A

  By the way, it is difficult to predict the future current change because it is the increase and decrease of the load after the measurement time (future) on the transmission line that determines the operation management of the transmission line. Operation management that relies on intuition.

  In addition, it has been found that the increase or decrease in the allowable current of the transmission line is influenced by the outside air temperature and the wind speed at the place where the transmission line is installed.

  Therefore, during high demand and high temperatures, equipment maintenance personnel go to specific locations on the transmission line that exceed the allowable power supply, measure the outside air temperature and wind speed at the site, and notify the center of the data by verbal information such as by telephone. The center calculates the allowable current in consideration of the received data.

However, depending on the location, it is often difficult to reach a specific location on the transmission line at a distance and in a mountainous area.
In addition, due to the geographical difficulty as described above, it was necessary to go to the site in advance at the t taste point, assuming that the allowable energization current value was exceeded.

  On the other hand, it is conceivable to install a measuring device for the outside air temperature and wind speed (wind direction / wind force) on the transmission line and collect this information at the center by communication. How should these collected information be used? The current situation is that no accurate proposal has been made.

  This invention is made in view of such a point, and makes it a technical subject to enable the short-term prediction of the transmission current of the specific location of a transmission line, and implement | achieve accurate operation of a transmission line. .

  In order to solve the above problems, the present invention employs the following means.

That is, the present invention detects a current value of a predetermined transmission line every predetermined time from the current detection means, accumulates it in a database, patterns past current change states based on a predetermined time,
The same pattern in the past is searched from the database based on the pattern, a current increase / decrease change amount is calculated based on a current value when a predetermined time elapses from a reference time of the past same pattern, and the past current increase / decrease change amount is calculated. This is a current predicted value calculation method for calculating a current value predicted value after elapse of a predetermined time from the predetermined time.

  According to the present invention, the state of change of the current value is patterned, a pattern that matches the pattern of the same type in the past is searched for, and the amount of change in subsequent current increase / decrease in the past pattern is determined after a predetermined time. A predicted current value can be calculated.

  If the present invention is further embodied, the current value of a predetermined transmission line every predetermined time is detected by the current detection means and stored in the database, and the current value Ir0 at the predetermined time t0 and ts than the predetermined time are stored. The current value Ir1 before the time and the current value Ir2 before ts × 2 hours are read from the database, and the current change amounts ΔI1 (ΔI1 = Ir0−Ir1) and ΔI2 (ΔI2 = Ir1-Ir2) are determined from the current values. ) Is converted into a numerical value (current increase / decrease pattern) in which the change state from ΔI2 to ΔI1 is pre-patterned, and a past current increase / decrease pattern that matches the current increase / decrease pattern code is retrieved from the database. The current value Ir after ts time based on the current value Ir0 of the current increase / decrease pattern is read from the database, this current increase / decrease value is set as ΔI, Si = Δ / Calculates the current increase and decrease change coefficient Si after ts time by ts, by Ip = Ir0 + (Si × ts), it is possible to calculate the current prediction value Ip after ts time from a predetermined time.

  According to the present invention, it is possible to more reliably predict a future current value based on a predetermined time based on a past current change state pattern.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a processing flow diagram according to the embodiment of the present invention. The processing in the figure is executed by the current prediction server shown in FIGS.

  The current prediction server is connected to the current detection system, the wind direction / anemometer, and the thermometer installed on the transmission line via the TCP / IP network (LAN), and the current value of the transmission line and the installation of the transmission line The wind direction, wind speed, temperature, etc. of the place are input as data.

  The data of the wind direction / anemometer and thermometer provided on the transmission line is transmitted as an electrical signal by a modem (MODEM), converted into an optical signal by a photoelectric conversion device (E / O), and the joint BOX and light. It is converted back to an electrical signal by a photoelectric conversion device (O / E) on the network (LAN) side through a fiber composite ground wire (OPGW, hereinafter simply referred to as an optical cable), and converted into a TCP / IP network (LAN) through a modem. It is supposed to be sent. The modem and the photoelectric conversion device (E / O) provided on the power transmission line side are supplied with operating power by a solar cell or a battery.

  The current prediction server is a general-purpose computer system, and is composed of a central processing unit (CPU), a main memory (MM), a hard disk device (HD), a display device (DISP), an output device (KBD), and the like. Yes. These and the central processing unit (CPU) are connected by a bus (BUS) so that data and control signals can be transmitted and received between them.

Input data such as current value and wind direction from the TCP / IP network (LAN) is received via the network interface (NW I / F), and the database in the hard disk device (HD) is controlled by the central processing unit (CPU). To be stored in.

  An operating system, application programs, databases, and various tables are registered in the hard disk device (HD).

  The processing shown in FIG. 1 is realized by the central processing unit (CPU) processing data from a database with reference to various tables based on an application program.

  As shown in FIG. 5 and FIG. 8, the database stores the date and current values, respectively.

  Next, the processing procedure based on FIG. 1 will be described.

  First, the central processing unit (CPU) develops a program stored in the hard disk device (HD) on the main memory (MM), sequentially reads it, and starts processing.

  Based on the program, the central processing unit (CPU) first determines the current value Ir1 one hour ago and the current value Ir2 two hours ago from the current value database (see FIG. 5) based on the predetermined time Ir0. read out.

  Then, a current change amount ΔI1 from Ir1 to Ir0 and a current change amount ΔI2 from Ir2 to Ir1 are calculated (S101). In the case of the data shown in FIG. 5, ΔI1 = Ir0−Ir1 = 200 and ΔI2 = Ir1−Ir2 = −100.

  Next, the pattern value is determined with reference to the threshold value table shown in FIG. In this example, since the transmission line rated current Ico = 600 and Ico × 0.05 = 30, Ij = 10, so a1 = 2 and a2 = 0, resulting in a pattern of 02.

  Next, the central processing unit (CPU) reads out the current value Dx days ago from the current value database (S103). At this time, it is examined whether the day to which the reference time belongs and the day before Dx coincide on weekdays, Saturdays, holidays, and Sundays (S104). If they do not match, 1 is added to Dx and reexamined (S105). In this way, data having the same attribute as the day to which the reference time belongs is set as the search target.

  In this way, when corresponding to the day of the week having the same attribute, current values at the same time before Dx days are read from the current value database.

  Then, the current change amount at the same time before Dx days is calculated by the same calculation formula as S101 (S106). Then, the pattern value is determined by the same method as that performed in S102 for the increase / decrease due to the current change amount (S107). In this example, a1 = 2 and a2 = 0, and the pattern is 02.

Next, the central processing unit (CPU) determines whether or not the current increase / decrease pattern at the same time before Dx days matches the current increase / decrease pattern at the reference time (S108). If they do not match, it is determined whether or not the day before Dx is the same day before 365 days (S109). If it is not the same day before 365 days, 1 is further added to Dx and the process returns to S103. . If it is determined in S109 that it is 365 days ago, it is considered that there is no pattern that coincides with the same time in the past 365 days, and the current change amount ΔI1 closest to the predetermined value on that day is assumed to continue in the immediate future, and ΔI Is substituted for ΔI1 (S111).

  In S108, if the current increase / decrease pattern at the same time before the Dx day coincides with the current increase / decrease pattern at the reference time, the current increase / decrease after ts minutes with reference to the current value Ir0 corresponding to the past reference time. The amount of change (slope SI) is calculated from SI = ΔI / ts (see FIG. 9: S112). Specifically, a similar current increase / decrease pattern that occurred in the past is read to determine the current increase / decrease change amount (SI), and the current value, that is, the current value after ts minutes based on the predetermined time is predicted. It means to use for calculation.

  Finally, the predicted current value Ip after ts minutes can be calculated from Ip = Ir0 + (Si × ts) (S113).

  In the above description, the case where the current is predicted based on the current value database has been described. However, the present invention can also be applied to temperature prediction as shown in FIG.

  The present invention can be applied to power line current prediction in the electric power business field.

Process flow diagram in embodiment of the present invention (1) Overall system configuration diagram of the present invention Hardware diagram of current prediction server The graph which shows an example of the relationship between the electric current detected with the electric current detection system, and time The figure which shows the contents of the current value record database The figure which shows the contents of threshold value table of current increase / decrease judgment Figure showing the contents of the current increase / decrease pattern table The figure which shows the contents of the past current value record database Graph for explaining calculation of predicted current after elapse of a predetermined time from a predetermined time Processing flow diagram (2) in the embodiment of the present invention

Explanation of symbols

CPU Central processing unit MM Main memory BUS Bus HD Hard disk device DISP Display device KBD Input device O / E, E / O Photoelectric conversion device OPGW Optical fiber composite ground wire (optical cable)

Claims (2)

The current value of a predetermined transmission line for each predetermined time is detected by the current detection means and stored in the database,
Pattern the past current change state based on a predetermined time,
Based on the pattern, the past same pattern is retrieved from the database,
Calculate the current increase / decrease change amount based on the current value when a predetermined time has elapsed from the reference time of the same pattern in the past,
A predicted current value calculation method for calculating a predicted current value after a predetermined time has elapsed from the predetermined time based on the past current increase / decrease change amount. The current value of a predetermined transmission line for each predetermined time is detected by the current detection means and stored in the database,
The current value Ir0 at a predetermined time t0, the current value Ir1 ts time before the predetermined time, and the current value Ir2 ts × 2 hours before are read from the database,
From the current values, current change amounts ΔI1 and ΔI2 are calculated based on the following formulas,
ΔI1 = Ir0−Ir1
ΔI2 = Ir1−Ir2
The change state from ΔI2 to ΔI1 is converted into a pre-patterned numerical value (current increase / decrease pattern),
Search the current increase / decrease pattern that matches the current increase / decrease pattern code from the database,
The current value Ir after ts time based on the current value Ir0 of the past current increase / decrease pattern is read from the database, and this current increase / decrease value is set as ΔI. To calculate
Si = ΔI / ts
A method for calculating a predicted current value of a power transmission line, wherein a predicted current value Ip after ts time from the predetermined time is calculated by the following formula.
Ip = Ir0 + (Si × ts)

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