JP2013240229A - Utility grid load frequency control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load frequency control system which can improve the demand/supply operation and the control performance of a utility grid, and which is effective for the improvement of economy and can lighten burdens on the operator.SOLUTION: A utility grid load frequency control system includes: an AR calculation unit 24 which calculates area requiring power (AR) by using a frequency change amount (ΔF) and an interconnection tidal current change amount (ΔPT); an AR decomposition unit 25 which decomposes the calculated AR by frequency; an AR distribution unit 26 which distributes the frequency decomposed AR to each power generator; a target command value creation unit 22 which calculates a target command value from the distributed AR and an ELD schedule calculated by economic load distribution control (ELD); and a command value transmission unit 23 which transmits the target command value to the power generators. Further, the system includes on the output side of the AR calculation unit 24 an LFC object/exclusion switchover unit 6 which, according to a standard deviation of the AR, switches a power generator which is the object of load frequency control to the one which is excluded from load frequency control or switches a power generator which is excluded from load frequency control to the one which is the object of load frequency control.

Description

  Embodiments described herein relate generally to a power system load frequency control system capable of improving the supply and demand control performance of a power system.

  In general, the reliability of the power system includes voltage, frequency, and uninterruptible supply. Among them, frequency stabilization is performed by load frequency control (LFC). This load frequency control is a control method for maintaining the frequency of the entire system at a specified value by adjusting the output of the generator.

In LFC, it can mainly be classified into the following three systems.
The first method detects a frequency change amount (ΔF), adjusts the output of the generator so as to reduce it, and keeps only the system frequency at a specified value (FFC: Flat Frequency Control Method). Control).

  The second method detects constant interconnection power flow variation (ΔPT), adjusts the output of the generator so as to reduce it, and keeps only the interconnection power flow at a specified value. This is a control method (FTC: Flat Tie Line Control).

  The third method detects the amount of change in frequency (ΔF) and the amount of change in interconnected power flow (ΔPT), calculates the regional demand power (AR) that is an unbalanced supply-demand balance from these, and according to the amount This is a frequency bias link line power control system (TBC) that adjusts the output of the generator.

  Of the above three methods, the TBC method is currently used in most Japanese electric power companies. This TBC method is performed in the following procedure.

  First, using the frequency change amount (ΔF) and the interconnected line power flow change amount (ΔPT), the regional required power (AR) is calculated by the equation (1).

  If the value of the regional required power (AR) is positive, it is necessary to increase the generator output as a whole system. Conversely, if the value is negative, it is necessary to decrease the generator output as a whole system.

  In order to filter the regional required power (AR), filtering is performed by exponential smoothing using the past regional required power (AR), and the regional required power (AR) is reduced to a low speed machine (for example, a thermal power machine having a slow output change rate). ) And a high-speed machine (for example, a hydraulic machine with a fast output change speed). In addition, there is a method in which the regional required power (AR) is frequency-resolved, and those having a short period component are shared by a low speed machine, and those having a long period component are shared by a high speed machine.

  When distributing the filtered or frequency-resolved regional demand power (AR) to each generator, the output change of the generator for all the generators for which load frequency control is performed for each low-speed machine and high-speed machine Allocate by speed ratio or output margin ratio.

  Moreover, when calculating the target command value of each generator, it calculates by adding the allocated regional demand power (AR) and the ELD schedule calculated by the economic load distribution control (ELD).

  Furthermore, each generator receives the target command value from the central power supply command station, and the output of each generator fluctuates. As a result, the system frequency and the interconnection current flow change.

Japanese Patent No. 3930218

"Power System Engineering" Maruzen P163

  As shown in the above procedure, the regional required power (AR) that has been filtered or frequency-resolved is distributed to each generator, but the operator has a large fluctuation in the regional required power (AR) that changes from moment to moment. Accordingly, the number of LFC target generators is determined.

  Generally, since the number of generators in parallel is operated at night or the like, the number of LFC target generators is small. Conversely, operation can be performed with a large number of generators in parallel during the daytime, and a relatively large number of LFC target generators can be secured. Under these conditions, according to the rules of thumb of the operator, the LFC target generator and the LFC excluded generator were manually switched. It has become.

  Usually, in the time zone when the regional required power (AR) fluctuates relatively greatly, in order to secure a large amount of adjustment (distribution amount for each generator), the number of LFC target generators should be increased. However, if it was operated with a small number of LFC target generators, if the switching timing of the LFC target generators by the operator was delayed, the regional heavy power (AR) could not be fully allocated, and the control There is a risk that the remaining performance will increase and the control performance will decrease.

  On the contrary, during the time period when the regional required power (AR) fluctuates relatively small, the adjustment amount (distribution amount for each generator) only needs to be kept small, and the number of LFC target generators should be reduced. It is. However, if it was operated with a large number of LFC-targeted generators, it would be necessary to reduce the regional demand power even for generators that do not want the output to fluctuate as much as possible from the output of the ELD schedule that was originally obtained by economic load distribution. (AR) will be allocated. For this reason, it may deviate from the base output, which may hinder economic efficiency.

  An embodiment of the present invention has been made in view of the above circumstances, and is a load frequency control system that can improve the supply and demand operation and control performance of an electric power system, is effective in improving economy, and reduces the load on the operator. The purpose is to provide.

  In order to achieve the above-described object, an embodiment of the present invention includes a ΔF detection unit that detects a frequency change amount (ΔF) in a power system, a ΔPT detection unit that detects a connection power flow change amount (ΔPT), An AR calculation unit that calculates the regional required power (AR) using the frequency change amount (ΔF) and the interconnection power flow change amount (ΔPT), and an AR decomposition unit that frequency-decomposes the calculated local request power (AR) A target command value from an AR distribution unit that distributes frequency-resolved regional required power (AR) for each generator, and an ELD schedule calculated by the allocated regional required power (AR) and economic load distribution control (ELD) In a power system load frequency control system having a target command value creation unit for calculating the target command value and a command value transmission unit for transmitting the target command value to the generator, the regional required power (AR) is provided on the output side of the AR calculation unit. Based on a representative value that represents the tendency of fluctuations, a switching unit is provided that switches a generator that is not subject to load frequency control to a load frequency control subject, or that switches a generator that is subject to load frequency control to a subject outside load frequency control. It is characterized by.

The block diagram which shows the structure of the electric power system load frequency control system of each embodiment of this invention. The flowchart which shows the distribution procedure of the area | region request | requirement electric power (AR) to the generator using the electric power grid load frequency control system of FIG. The flowchart which shows the procedure which determines distribution of the area | region required electric power (AR) by the LFC object / exclusion switching part of FIG. The flowchart which shows the switching procedure from the LFC exclusion generator in 1st Embodiment to the LFC object generator. It is an image figure which shows the switching timing from the LFC exclusion generator in 1st Embodiment to a LFC object generator, (a) is a waveform figure of local request | requirement electric power (AR), (b) is standard deviation of AR, and LFC object The figure which shows the relationship of the switching timing to a generator. The flowchart which shows the switching procedure from the LFC exclusion generator in 2nd Embodiment to the LFC object generator. It is an image figure which shows the switching timing from the LFC exclusion generator in 2nd Embodiment to a LFC object generator, (a) is a waveform figure of local demand electric power (AR), (b) is a standard deviation of AR, and LFC object The figure which shows the relationship of the switching timing to a generator. The flowchart which shows the switching procedure from the LFC object generator in 3rd Embodiment to the LFC exclusion generator. It is an image figure which shows the switching timing from the LFC object generator in 3rd Embodiment to a LFC exclusion generator, (a) is a waveform figure of area | region required electric power (AR), (b) is a standard deviation of AR, and LFC exclusion. The figure which shows the relationship of the switching timing to a generator. The flowchart which shows the switching procedure from the LFC object generator in 4th Embodiment to the LFC exclusion generator. It is an image figure which shows the switching timing from the LFC object generator in 4th Embodiment to an LFC exclusion generator, (a) is a waveform figure of local request electric power (AR), (b) is a standard deviation of AR, and LFC exclusion The figure which shows the relationship of the switching timing to a generator. The flowchart which shows the priority determination procedure according to the incremental fuel cost in 5th Embodiment. The flowchart which shows the change procedure to the priority order mode in 6th Embodiment.

Embodiments of the present invention will be specifically described below with reference to the drawings.
(System configuration)
FIG. 1 is a block diagram showing a configuration of a power system load frequency control system according to each embodiment of the present invention.

  In FIG. 1, a power system 1 has a plurality of generators G 1, G 2,..., Gn inside thereof, and is connected to another system 3 via a connection line 4.

  Each generator G1, G2,..., Gn is connected to a respective generator output signal input unit 20-1, 20-2,..., 20-n in the computer 2 via a detection signal line 11. It is connected to each command value transmission unit 23-1, 23-2,..., 23-n via a control signal line 12. Further, the generator output signal input units 20-1, 20-2,..., 20-n and the command value transmission units 23-1, 23-2,. , 22-2,..., 22-n.

  In addition, a data detection unit 10 having a ΔPT detection unit and a ΔF detection unit is provided inside the electric power system 1, and is connected to an AR calculation unit 24 provided inside the computer 2 through a signal line 13. ing.

  Further, on the output side of the AR calculation unit 24, an LFC target / exclusion switching unit 6, an AR decomposition unit 25, and an AR distribution unit 26 are arranged in order. The AR decomposition unit 25 is also connected to an ELD schedule calculation unit 30, and this ELD schedule calculation unit 30 is further connected to target command value creation units 22-1 to 22-n. In addition, a power generation end total demand calculation unit 27 is disposed on the output side of the generator output signal input units 20-1, 20-2,..., 20-n, and online on the output side of the power generation end total demand calculation unit 27. A forecast demand unit 28 is provided. Both the online forecast demand unit 28 and the previous day operation plan unit 29 are connected to the ELD schedule calculation unit 30.

  The generator output signal input units 20-1, 20-2,..., 20-n output the generator output signals to the target command value creating units 22-1, 22-2,. . Target command value creation units 22-1, 22-2,..., 22-n create each generator output signal based on the received signal, and command value transmission units 23-1, 23-2,. 23-n.

  The AR calculation unit 24 inputs the frequency change amount (ΔF) and the interconnection power flow change amount (ΔPT) detected from the data detection unit 10 of the power system 1 and calculates the AR value. The output from the AR calculation unit 24 is input to the AR decomposition unit 25, and the target command value generation unit 22-for each generator G 1, G 2,. 1, 22-2,..., 22-n.

  In addition, the LFC target / exclusion switching unit 6 has a function of switching the generator that performs AR distribution in the AR distribution unit 26.

  The power generation end total demand calculation unit 27 takes in the generator outputs from the respective generator output signal input units 20-1, 20-2,..., 20-n, and calculates the power generation end total demand. The online forecast demand by the online forecast demand unit 28 and the previous day operation plan by the previous day operation plan unit 29 are arranged to be input to the ELD schedule calculation unit 30. The calculation result (ELD value) of the economic load distribution by the ELD schedule calculation unit 30 is input to each target command value creation unit 22-1, 22-2, ..., 22-n.

  As described above, the inputs to the target command value creation units 22-1, 22-2,..., 22-n are input to the generator output input units 20-1, 20-2,. There are an output, a distribution amount from the AR distribution unit 26, and an economic load distribution calculation result (ELD value) from the ELD schedule calculation unit 30. Each of the target command value creation units 22-1, 22-2,..., 22-n inputs the output signal, the AR value, and the ELD value of each generator G1, G2,. create.

  The computer 2 is provided with an MMI (Man Machine Interface) 5 for exchanging information between the worker and the machine.

(Processing procedure in the system)
FIG. 2 is a flowchart showing a procedure for allocating regional required power (AR) to generators using the power system load frequency control system of FIG.

  First, in step S20, the amount of change in frequency (ΔF) and the amount of change in interconnected power flow (ΔPT) detected from the power system 1 are input to the AR calculation unit 24 in the computer 2, where the regional required power (AR). Is calculated.

  Next, in step S <b> 21, the AR required power (AR) is frequency-resolved by the AR decomposition unit 25. In step S22, the AR distribution unit 26 calculates the distribution amount of the regional required power (AR) for each of the generators G1, G2,..., Gn, and in step S23, the target command value generation units 22-1 and 22-22. 2,..., 22-n.

  Thereafter, in step S24, the target command values from the target command value creation units 22-1, 22-2,..., 22-n are transmitted to the command value transmission units 23-1, 23-2,. In step S25, a command is issued to each of the generators G1, G2,.

  On the other hand, in step S201, the online predicted demand operation data is created by the online predicted demand unit 28, and the previous day operation plan operation data is created by the previous day operation plan unit 29.

  Further, in step S202, the calculation result (ELD value) of the economic load distribution is created by the ELD schedule calculation unit 30 and input to each target command value creation unit 22-1, 22-2, ..., 22-n.

  In step S205, the LFC target / exclusion switching unit 6 switches the generators G1, G2,.

  FIG. 3 is a flowchart showing a procedure for determining the distribution of the regional required power (AR) by the LFC target / exclusion switching unit 6.

  First, in step S31, the LFC target / exclusion switching unit 6 determines whether the generator is an LFC target based on a setting determined in advance for each of the generators G1, G2,. Judge whether or not. If the generator is an LFC target (Yes in step S31), the regional required power (AR) is allocated in step S32. On the other hand, in the case of a generator that is not subject to LFC (No in step S31), the regional required power (AR) is not distributed in step S33.

  In addition, the generator targeted for LFC is not limited to a thermal power or hydraulic (pumped water) generator, but a nuclear power generator or a secondary battery such as a lead storage battery can be used.

  The system configuration common to each embodiment of the present invention and the relationship between the processes have been described above. The processing procedure in each embodiment will be described below.

[First Embodiment]
(Procedure for switching from an LFC-excluded generator to an LFC target generator)
When performing LFC, regional power requirements (AR) will be allocated only to the LFC target generators. However, the number of LFC target generators in the operation in a time zone where the regional power requirements (AR) are relatively large. When there is little or the remaining capacity of those generators (the difference between the current output and the maximum output, or the difference between the current output and the minimum output) is small, the regional required power (AR) cannot be fully allocated, resulting in a residual distribution. There is a possibility that the control performance may be hindered.

  Therefore, in the present embodiment, the trend of fluctuation of the regional required power (AR) is reconstructed by calculating the standard deviation of the regional required power (AR) every predetermined period, and the standard of the regional required power (AR) is calculated. When the deviation exceeds a certain threshold, one or a plurality of LFC-excluded generators are automatically switched to LFC target generators, and the regional required power (AR) can be allocated to these generators.

  Hereinafter, the switching procedure from the LFC excluded generator to the LFC target generator in this embodiment will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a flowchart showing a switching procedure from the LFC excluded generator to the LFC target generator. As shown in FIG. 4, in step S <b> 41, the LFC target / exclusion switching unit 6 determines whether or not the standard deviation of the regional required power (AR) from the AR calculation unit 24 exceeds a specific threshold A. If exceeded (Yes in step S41), switching from LFC-excluded generators to LFC target generators and increasing the number of LFC target generators will enable local power demand (AR) to be allocated to those generators. (Step S42).

  On the other hand, if the standard deviation of the regional required power (AR) is equal to or less than the threshold value A (No in step S41), the process ends without performing the process.

  That is, the processing procedure is normally operated with the basic number of LFC target generators (for example, three), and if the regional required power (AR) fluctuates excessively, the LFC This is based on the idea of increasing the number of target generators and eliminating the remaining allocation of regional demand power (AR).

  Here, the period for increasing the number of LFC target generators is only the period in which the standard deviation of the regional required power (AR) exceeds the threshold A and enters the area I shown in FIG. In this case, the generator is switched again to the LFC excluded generator, and the number of LFC target generators becomes the basic number.

  In the LFC-excluded generator, a generator that can be switched to an LFC target generator can be selected in advance, and an operator can arbitrarily change the generator selection.

(effect)
According to the present embodiment, when the regional required power (AR) fluctuation exceeds a certain threshold, the number of LFC target generators is increased, so that the remaining distribution is reduced and the control performance can be improved. In addition, the number of LFC target generators can be automatically adjusted, and the burden on the operator can be reduced.

[Second Embodiment]
(Switching procedure from LFC-excluded generator to LFC generator (2 steps))
Hereinafter, the switching procedure from the LFC excluded generator to the LFC target generator in the second embodiment will be described with reference to FIGS. 6 and 7.

  FIG. 6 is a flowchart showing a switching procedure from the LFC excluded generator to the LFC target generator. As shown in FIG. 6, in step S43, the LFC target / exclusion switching unit 6 determines whether or not the standard deviation of the regional required power (AR) from the AR calculation unit 24 exceeds a specific threshold A. If exceeded (Yes in step S43), the two LFC-excluded generators are switched to the LFC target generators, and the number of LFC target generators is increased from the basic number by two (step S44 and the area of FIG. 7B) I).

  On the other hand, when the standard deviation of the regional required power (AR) does not exceed the threshold A (No in step S43) in step S43 of FIG. 6, the standard deviation of the regional required power (AR) is determined in step S45. It is determined whether or not a specific threshold A ′ (threshold A> threshold A ′) has been exceeded. If exceeded (Yes in step S45), one LFC-excluded generator is switched to the LFC target generator, and the number of LFC target generators is increased by one from the basic number (step S46 and the area of FIG. 7B) II).

  On the other hand, if the standard deviation of the regional required power (AR) is equal to or less than the threshold value A ′ in step S45 (No in step S45), the number of LFC target generators remains the basic number without performing the process.

  In the LFC-excluded generator, a generator that can be switched to an LFC target generator can be selected in advance, and an operator can arbitrarily change the generator selection.

(effect)
According to the present embodiment, by providing two thresholds and increasing the number of LFC target generators in stages, the control performance is further improved compared to the first embodiment, and the economy is further improved. It becomes possible to improve. Further, similarly to the first embodiment, the number of LFC target generators can be automatically adjusted, and the burden on the operator can be reduced.

[Third Embodiment]
(Procedure for switching from an LFC target generator to an LFC excluded generator)
When performing LFC, the regional power requirement (AR) may fluctuate greatly, or may vary relatively during the daytime when the number of parallel units is large. If the regional required power (AR) is relatively small, even if the number of LFC target generators is small, distribution is possible. However, if it is operated with a large number of LFC target generators, the base of ELD schedule etc. Regional power demand (AR) is also distributed to generators that do not want to fluctuate their output as much as possible from the output, which is considered to be a factor that deviates from the specified value (base output) and deteriorates economy.

  Therefore, in this embodiment, when the standard deviation of the regional required power (AR) falls below a certain threshold, one or a plurality of LFC target generators are automatically switched to LFC-excluded generators, and their power generation In the machine, the regional power requirement (AR) is not allocated.

  Hereinafter, the switching procedure from the LFC target generator to the LFC excluded generator in this embodiment will be described with reference to FIGS.

  FIG. 8 is a flowchart showing a switching procedure from the LFC target generator to the LFC excluded generator. As shown in FIG. 8, in step S51, the LFC target / exclusion switching unit 6 determines whether or not the standard deviation of the regional required power (AR) from the AR calculation unit 24 is less than a specific threshold value B.

  If it is less than the threshold B (Yes in step S51), switch from the LFC target generator to the LFC excluded generator, reduce the number of LFC target generators, and do not distribute the regional required power (AR) in the LFC excluded generator. (Step S52).

  On the other hand, if the standard deviation of the regional required power (AR) is greater than or equal to the threshold value B in step S51 (No in step S51), the process ends without performing the process.

  In other words, the processing procedure is normally performed with the number of basic LFC target generators (for example, three), and when the regional required power (AR) is small, the regional required power (AR) is calculated. Based on the idea of not distributing.

  Here, the period when the generator is excluded from the LFC is a period where the standard deviation of the regional required power (AR) is less than the threshold B as shown in FIG. If it is only the period in which it is in III and it is out of region III, it is switched to the LFC target generator, and the number of LFC target generators becomes the basic number.

  In the LFC target generator, a generator that can be switched to an LFC-excluded generator can be selected in advance, and an operator can arbitrarily change the generator selection.

(effect)
According to the present embodiment, when the regional required power (AR) fluctuation is less than a certain threshold, the number of LFC target generators is reduced, so that the generators near the base output such as the ELD schedule The required power (AR) may not be allocated. For this reason, operation close to the most economical is possible, which is effective for improving economic efficiency. In addition, the number of LFC target generators can be automatically adjusted, and the burden on the operator can be reduced.

[Fourth Embodiment]
(Switching procedure from LFC generator to LFC exclusion generator (2 steps))
Hereinafter, the switching procedure from the LFC target generator to the LFC excluded generator in the fourth embodiment will be described with reference to FIGS. 10 and 11.

  FIG. 10 is a flowchart showing a switching procedure from the LFC target generator to the LFC excluded generator. As shown in FIG. 10, in step S53, the LFC target / exclusion switching unit 6 determines whether or not the standard deviation of the regional required power (AR) from the AR calculation unit 24 is less than a specific threshold value B.

  If it is less than the threshold B (Yes in step S53), the two LFC target generators are switched to LFC excluded generators, and the number of LFC target generators is reduced from the basic number by two (step S54 and FIG. 11B). Region III).

  On the other hand, if the standard deviation of the regional required power (AR) is greater than or equal to the threshold B in step S53 of FIG. 10 (No in step S53), the standard deviation of the regional required power (AR) is specified in step S55. It is determined whether or not it is less than threshold value B ′ (threshold value B <threshold value B ′). If it is less (Yes in step S55), one LFC target generator is switched to an LFC excluded generator, and the number of LFC target generators is reduced by one from the basic number (step S56 and the area of FIG. 11B) IV).

  On the other hand, if the standard deviation of the regional required power (AR) is greater than or equal to the threshold B ′ in step S55 (No in step S55), the number of LFC target generators remains the basic number without performing the process.

  In the LFC target generator, a generator that can be switched to an LFC-excluded generator can be selected in advance, and an operator can arbitrarily change the generator selection.

(effect)
According to the present embodiment, by providing two thresholds and gradually reducing the number of LFC target generators, compared with the third embodiment, the control performance is further improved and the economy is further improved. It becomes possible to improve. Further, as in the third embodiment, the number of LFC target generators can be automatically adjusted, and the burden on the operator can be reduced.

[Fifth Embodiment]
(Priority determination procedure according to incremental fuel costs)
In the above embodiment, the LFC target / exclusion is switched according to the change in the regional required power (AR). However, the number of generators to be switched is not limited to one, and the second and fourth embodiments. As in the case of multiple units. In that case, it is possible to simultaneously switch all applicable generators, but in this embodiment, the priority order is determined so as to be economical according to the fuel cost, and the LFC target generators are determined. A procedure for increasing or decreasing.

  In general, since the output of the ELD schedule is determined so as to be the most economical, it is desirable to operate according to the ELD schedule as much as possible. Therefore, it can be said that it is more economical not to use generators with high incremental fuel costs as LFC target generators. For this reason, the LFC excluded generators are switched to the LFC target generators in order from the generator with the lowest incremental fuel cost, and the number of LFC target generators is increased. On the other hand, switching of the LFC target generators to LFC excluded generators is performed in order from the generator with the higher incremental fuel cost to reduce the number of LFC target generators.

  FIG. 12 is a flowchart showing a priority order determination procedure according to the incremental fuel cost in the fifth embodiment. As shown in FIG. 12, first, in this embodiment, in step S61, the LFC target / exclusion switching unit 6 determines whether the standard deviation of the regional required power (AR) from the AR calculation unit 24 exceeds a specific threshold C. Determine whether or not. When it exceeds (Yes in step S61), the generator is switched from the LFC excluded generator to the LFC target generator in order from the generator with the lowest incremental fuel cost, and the number of LFC target generators is increased (step S62).

  On the other hand, if the standard deviation of the regional required power (AR) does not exceed the specific threshold value C (No in step S61) in step S61 of FIG. 12, the standard of the regional required power (AR) is determined in step S63. It is determined whether or not the deviation is smaller than a specific threshold D smaller than the threshold C. If it is smaller (Yes in step S63), the generator is switched from the LFC target generator to the LFC excluded generator in order from the generator with the higher incremental fuel cost, and the number of LFC target generators is reduced (step S64).

  On the other hand, if the standard deviation of the regional required power (AR) is greater than or equal to the specific threshold value D in step S63 (No in step S63), the process ends without performing the process.

(effect)
According to the present embodiment, a more economical operation is possible by setting priorities in order of fuel costs for the generators that are subject to / exclude LFC.

[Sixth Embodiment]
(Procedure for changing to priority mode by the operator)
In the above embodiment, LFC target / exclusion switching is performed according to the regional required power (AR), but the number of generators to be switched is not limited to one, as in the second and fourth embodiments. In addition, there may be multiple units. In that case, it is possible to simultaneously switch all of the generators, but in this embodiment, so that the operator can arbitrarily set the priority and select the generator, The procedure has a selection mode so that it is possible to arbitrarily determine whether or not to switch the generator.

  FIG. 13 is a flowchart illustrating a procedure for changing to the priority order mode according to the sixth embodiment. As shown in FIG. 13, first, in this embodiment, it is determined in step S71 whether or not there is only one LFC target / excluded generator. In the case of one unit, the process is performed in the normal switching mode described in the first embodiment (step S72). On the other hand, in the case of a plurality of units (No in step S71), the operator can arbitrarily set a priority and select a generator, or can arbitrarily determine whether or not to switch the generator. Processing is performed according to the mode (step S73).

(effect)
According to the present embodiment, it is possible to arbitrarily select a generator to be a target / excluded LFC. Therefore, operation according to the driving situation is possible.

[Other embodiments]
(1) In each of the above embodiments, the standard deviation is used as a representative value representing the tendency of fluctuation in regional required power (AR). However, in addition to the standard deviation, for example, an average value or a weighted moving average for a certain period, Any method can be used as long as it can provide a tendency of fluctuation in regional power requirements (AR) such as an exponential moving average.

(2) In each of the embodiments described above, one or two threshold values are used, but three or more threshold values may be provided.

(3) Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Electric power system 2 ... Computer 3 ... Other system 4 ... Interconnection line 5 ... MMI
6 ... LFC target / exclusion switching unit 10 ... data detection unit 11 ... detection signal line 12 ... control signal line 13 ... signal lines 20-1, 20-2, ..., 20-n ... generator output Signal input units 22-1, 22-2,..., 22-n... Target command value creation units 23-1, 23-2,. ... AR decomposition part 26 ... AR distribution part 27 ... Power generation end total demand calculation part 28 ... Online prediction demand part 29 ... Previous day operation planning part 30 ... ELD schedule calculation part

Claims (8)

In the power system, a ΔF detection unit that detects a frequency change amount (ΔF), a ΔPT detection unit that detects a connection power flow change amount (ΔPT), the frequency change amount (ΔF) and the connection power flow change amount ( AR calculation unit for calculating regional required power (AR) using ΔPT), AR decomposition unit for frequency-resolving calculated regional required power (AR), and frequency-resolved regional required power (AR) for each generator An AR distribution unit to distribute, a target command value creation unit to calculate a target command value from an ELD schedule calculated by the allocated regional demand power (AR) and economic load distribution control (ELD), and a target command to the generator In a power system load frequency control system having a command value transmission unit for transmitting a value,
On the output side of the AR calculation unit, based on a representative value indicating a tendency of fluctuation of the regional required power (AR), a generator that is not subject to load frequency control is switched to a load frequency control subject, or a load frequency control subject is selected. A power system load frequency control system, characterized in that a switching unit is provided for switching the generator to be outside the load frequency control target.   The switching unit switches a generator that is not subject to load frequency control to a generator that is subject to load frequency control when a representative value representing a tendency of fluctuation in the regional required power (AR) exceeds a predetermined threshold value. The power system load frequency control system according to claim 1.   3. The electric power according to claim 2, wherein a plurality of the threshold values are provided, and a generator that is not subject to load frequency control is gradually switched to a generator that is subject to load frequency control to increase the number of LFC target generators. System load frequency control system.   The switching unit is configured to switch a load frequency control target generator to a load frequency control target out of a load frequency control target when a representative value indicating a tendency of variation in the regional required power (AR) is smaller than a predetermined threshold value. The power system load frequency control system according to claim 1.   5. The electric power according to claim 4, wherein a plurality of the threshold values are provided, and the number of LFC target generators is reduced by gradually switching the generators to be subjected to load frequency control to generators that are not subject to load frequency control. System load frequency control system.   The power system load frequency control system according to any one of claims 1 to 5, wherein a standard deviation is used as a representative value representing a tendency of fluctuation in the regional required power (AR).   When there are a plurality of generators subject to load frequency control or not subject to load frequency control, the switching unit selects the generator according to the priority order based on the incremental fuel cost and switches the generator. The power system load frequency control system according to any one of claims 1 to 6.   When there are a plurality of generators subject to load frequency control or not subject to load frequency control, the switching unit selects a generator according to the priority assigned by the operator and switches the generator. The power system load frequency control system according to any one of claims 1 to 6, wherein the power system load frequency control system is performed.

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