JPH11234905A - Power system stabilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate the various characteristics of a separated system after the power supply limitation is practiced when the system is separated, select the machine whose power supply is to be limited and maintain the characteristics, such as the frequency characteristics, etc., of the separated system properly after the power supply limitation is practiced. SOLUTION: A power system stabilizer is composed of a monitoring means 71 which monitors the outputs of a plurality of generators 4 in a separated system which is expected to be separated while the system is still in an ordinary state, a memory means 73 in which various constants related to the characteristics of the plurality of generators are stored and a power supply limiting means 72 which practices control for the stabilization of the separated system when the system is separated. When the machines whose power supplies are to be limited are selected in accordance with a power supply limit value calculated for the stabilization, the power supply limiting means 72 makes the summation of the outputs of the plurality of generators selected as control object candidates correspond to the power supply limit value and, further, performs the estimation operation of the various characteristics of the separated system after the power supplies to the control object candidates are limited to judge whether conditions are satisfied or not. If the conditions are satisfied, the plurality of generators which are the control object candidates are determined to be the objects of the power supply limitation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power system stabilizing device, and more particularly, in a case where a power system is separated, by taking online information from the separated system, performing an operation, and limiting a power supply. The present invention relates to a power system stabilizing device for maintaining a separation system, and particularly for improving a frequency characteristic of the separation system.

[0002]

2. Description of the Related Art In the operation of an electric power system, when a power line route is disconnected due to a transmission line accident or the like, and the system is separated, a frequency deviation occurs in the separated system due to supply and demand imbalance. In order to eliminate this and stabilize the frequency fluctuation of the separation system, it is necessary to quickly correct the supply-demand imbalance in the separation system. As a measure, the power supply or the load is forcibly shut off.

Normally, it is difficult to grasp the supply-demand imbalance in the separation system by monitoring, and the current system estimates the supply-demand imbalance. For example, a load drop due to a voltage drop is estimated, the tidal flow of the interconnection line is added to the estimated load drop amount, and this is considered as a supply-demand imbalance that should be eliminated. Then, a combination of generators satisfying the supply-demand imbalance amount is determined, and emergency shutoff control is performed on those generators to balance supply-demand in the separation system and stabilize the frequency of the separation system.

Japanese Patent Publication No. Hei 7-108063 and Japanese Patent Laid-Open Publication No. Hei 7-184324 disclose that a supply-demand imbalance to be eliminated is estimated, a supply-demand imbalance amount is calculated, and a corresponding electric control amount and negative control amount. Is shown. Regarding a method of selecting a control target paying attention to such a supply-demand imbalance amount, Japanese Patent Publication No. 63-107421 and Japanese Patent Publication No. 63-107422 describe a specific method for load shedding. I have.

[0005]

However, all of the above prior arts focus on the amount of active power in correcting the supply and demand balance, but the characteristics of the separation system, particularly the object of power limitation in the separation system. No consideration is given to balancing the supply and demand of the remaining separation system in consideration of the characteristics of the electric power generator, which is a generator to be used.

In recent years, as the configuration of power supply types has become more complicated, such as the introduction of large-capacity combined cycles, depending on the combination of electrical control units, the difference between the various characteristics of the separated system remaining after the electronic control and the various characteristics before the system is separated. Will occur. As in the prior art, when a control device is selected without focusing only on the amount of power generation, various characteristics of the separation system after power control are deteriorated, and the risk of maintaining the separation system increases.

[0007] For example, if only a thermal boiler is left in a separation system where the supply becomes excessively large, there is a concern about the risk of boiler trip. Conversely, if only combined cycle machines and gas turbines that operate without spinning reserve remain in the separation system, problems will occur in the spinning reserve and output reserve of the entire separation system. Concerns arise with grid maintenance during rapid load recovery.

[0008] Each generator to be controlled is in an output state that changes every moment, and the entire generator that combines them also has an output state that changes every time with characteristics that change according to operation. Therefore, when considering various characteristics of the remaining separation system, it is important to perform processing in line with the configuration and operating state of the generator.

In view of the above points, the present invention appropriately maintains various characteristics of the separation system, such as the frequency characteristics of the separation system, the spinning reserve and the output reserve of the separation system, when the system separation occurs. The purpose is to select the electrical control so that

[0010]

The present invention employs the following means in order to solve the above-mentioned problems.

In a power system to which electric power is supplied from a plurality of generators, monitoring means for monitoring the outputs of the plurality of generators in a separation system in which system separation is assumed from normal times, and characteristics of the plurality of generators A power supply stabilizing device comprising: storage means for storing various constants relating to the power supply; and power supply limiting means for performing emergency power-off control for stabilizing the separated system when the power system is separated. When selecting a control unit for the control amount calculated for the stabilization, the output sum of the plurality of generators selected as control target candidates is made to correspond to the control amount, and the storage means Based on the predetermined number, the estimation of various characteristics of the separation system after controlling the candidate for control is performed, and it is determined whether or not a condition is satisfied. If the condition is satisfied, the candidate for control is determined. Multiple generators With and determining a target power emergency shutdown limit.

In addition to the above-mentioned monitoring means, in addition to monitoring the generator output, means for monitoring a control command value of a plurality of generator outputs in the separation system from normal times is provided. In the calculation of the separation system after
The calculation is performed based on the control command value in addition to the various constants of the storage means.

In a power system to which power is supplied from a plurality of generators, monitoring means for monitoring the output of the plurality of generators in a separation system where system separation is assumed from normal times, and the plurality of generators A stabilizing device for a power system, comprising: storage means for storing various constants relating to characteristics of the power supply; and power supply limiting means for performing an emergency power-off control for stabilizing the separated system when the system is separated. The limiting means, when selecting a control for the control amount calculated for the stabilization, while making the output sum of the plurality of generators selected as the control target candidate correspond to the control amount, Based on a predetermined number of the storage means, an estimation calculation of various characteristics of the separation system after controlling the candidate for control is performed, and it is determined whether or not a condition is satisfied. Multiple candidate candidates A power storage unit that constantly updates and stores the power as an object of the emergency power supply cutoff with the electric machine; and, when the system is separated, the power generation to be controlled from the calculation storage unit in accordance with the power control amount calculated for stabilization. The machine is selected and determined.

In addition to the above-mentioned monitoring means, in addition to monitoring the generator output, a means for monitoring a control command value of a plurality of generator outputs in the separation system from a normal state is provided. In the calculation of the separation system after
The calculation is performed based on the control command value in addition to the various constants of the storage means.

[0015] The various characteristics of the post-electrically controlled separation system obtained by calculation based on the plant type as various constants of the generator are determined by the separation system with respect to a sudden change in the supply and demand condition in the post-electrically controlled separation system. It is characterized by frequency characteristics.

The various characteristics of the separated system after the power control, which are obtained by calculating based on the stabilization rate of the governor of the generator as the various constants of the generator, are the power generation of the separated system after the power control. It is characterized by frequency characteristics with respect to excessive load or excessive load.

Further, various characteristics of the separated system after the power control, which are obtained by calculating based on the inertia constants of the rotating systems of the respective generators as the constants of the power generator, are determined by the supply and demand in the separated system after the power control. It is characterized in that it is a frequency maintenance characteristic of the separation system against a sudden change in state.

[0018] Further, the above calculation and calculation are performed based on the instantaneous power reserve and output reserve of the generator as various constants of the generator, or a load set value and a load limit value as control command values for the generator. The various characteristics of the separated system after electrification are characterized in that it is a spinning reserve and an output reserve of the whole separated system after electrification.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is an overall configuration diagram of a power system stabilizing apparatus according to this embodiment.

In the figure, reference numeral 1 denotes a plurality of assumed points of a system separation accident, 2 denotes a separated system caused by system separation, and 3 denotes monitoring data of a tidal flow of the interconnection line at the assumed point 1 of a system separation accident to a monitoring device. 4 is a generator existing in the separation system, 5 is a line for transmitting monitoring data of the generator output of the generator 4 to the monitoring device, and 6 is a control command value from a supply and demand adjustment system (not shown). Is a line for inputting the monitoring data of the monitoring device into the online database of the monitoring device, 7 is a power limiting device for calculating and determining a generator to be controlled and outputting a power control command, and 71 is obtaining monitoring data through lines 3, 5, and 6. Monitoring means for storing and storing the obtained monitoring data; 711, based on data from the online database and the parameter database; Power supply limiting means for determining a generator to be controlled and outputting a power control command; 721, a system separation determining means for determining the occurrence of system separation; The control amount determining means 723 is a power control target determining means for determining a combination of power control target generators so that the separated system after power control has optimal characteristics, and 73 is a power generation that may be included in the separation system. A parameter database storing parameters independent of the operation of the generator, for example, a plant type of each generator, a governor adjustment rate, and an inertia constant of a rotating system of the generator in a parameter database; This is a line for transmitting an electric control command to the generator 4 of FIG.

Next, the operation of the apparatus for stabilizing a separation system according to this embodiment will be described with reference to FIG.

First, in the electric power system, the tidal flow of the interconnection line at the assumed point 1 of a plurality of system separation accidents is constantly output from the plurality of generators 4 in the separation system 2 caused by the line 3 and the separation accident at the assumed point 1. The ability is periodically monitored by the line 5 and stored in the online database 711 of the monitoring means 71. In addition, the online database 711 acquires and stores the load set value and the load limit value of each generator 4 instructed by the system for adjusting supply and demand in operation through the line 6.

Next, when a system separation occurs at one of the supposed points 1, the power is limited to the power supply limiting means 72 through the monitoring means 71. When the occurrence of system separation is recognized by the system separation determining means 721, the power supply limiting means is activated. 72 immediately enters a power control process for limiting the power supply for the purpose of maintaining the separation system and stabilizing the frequency.

Next, the power control amount determining unit 722 recognizes, from the online database 711, the generators having the currently valid generator outputs connected in parallel in the separation system, and outputs the generator outputs of these generators. Input and calculate the amount of electricity required to maintain the separation system or stabilize the frequency.

Next, the control target determining unit 723 determines the generator to be controlled based on the calculated control amount and the various constants of each generator in the separation system stored in the parameter database 73. If the selected generator is electrified and the selected generator is de-energized, the remaining characteristics of the separation system, such as the frequency characteristics of the separation system and various characteristics such as the spinning reserve and the possible output increase, are satisfied. When the determination is satisfied, the selected generator is determined as a generator to be controlled, and a control command is output through the line 8.

Next, details of the arithmetic processing in the electric power control target determining means 723 will be described with reference to FIGS.

In FIG. 2, reference numeral 7231 denotes a priority electronic device selecting means for selecting an electronic device in accordance with the electronic control priority.
Is an election machine restriction judging means for judging whether or not the elected electric machine is a proper electric machine, and 7233, when it is judged that the elected electric machine is appropriate, the electric machine is switched to The electronic control adopting means 7234 employed as the electronic control to be electronically controlled is a control amount determining means 7234 for determining whether the electronic control amount of the adopted electronic control is appropriate. Other configurations are the same as those in FIG.

FIG. 3 is a power control priority list 9 for each generator type for each plant type, and lists the power control priority for each generator category for each category and the generators belonging to each category. Are stored in the parameter database 73.

Next, the operation of the control target determining means 723 will be described with reference to FIGS. First, the priority electrical machine selection means 7231 is provided, based on the plant type of the generator and the governor adjustment rate stored in the parameter database 73 without considering the individual generator output.
First, a generator that may cause a problem in continuation of operation if left in the separation system or a generator that deteriorates the frequency characteristics of the separation system is selected as a generator to be controlled. Next, the priority control device selecting means 7231 performs a plant type control priority list 9 as shown in FIG.
, The plant type to be selected is specified, and subsequently, a plurality of generators of the same plant type are selected from those having a large governor adjustment rate, and the processing of the priority electric machine selecting means 7231 is completed.

Next, in the elected machine restriction judging means 7232, the electric machine selected by the preferential electric machine selecting means 7231 is assumed to be a candidate combination of electric machines, and the characteristics of the separated system after electric control are satisfied. It is determined whether or not to perform. Here, the output reserve of the entire separated system after the system separation is calculated from the load set value and the load limit value of each generator stored in the online database 711. In this case, it is determined whether or not the remaining separation system can maintain the output reserve capacity equal to or greater than the calculated constant value, and determine whether or not to adopt the selected combination of the electrical control units.

The calculation of the output reserve of the entire separation system after the system separation can also be obtained by calculating various constants of the generator stored in the parameter database.

Here, the calculation of the output reserve of the entire separation system after the system separation is performed by summing the output reserve with respect to the load limit value of each generator for the generators in the separation system and determining based on the calculated value. I do. That is, as shown in FIG. 4, in the frequency characteristic 10 of the separated system after the system separation, it is determined whether or not the output reserve 11 having a predetermined value or more can be secured within a predetermined frequency deviation with respect to the overload. .

If the election machine restriction judging means 7232 judges that the candidate of the combination of electrical machines violates the constraint, the generator selected by the prioritized election machine selecting means 7231 is excluded. Select a new priority electrical machine.

If the election unit restriction judging unit 7232 judges that the candidate of the combination of electric machines satisfies the restriction, the election unit 7233 adopts the prioritized election unit 7
The generator selected in 231 is added and adopted as a candidate for a combination of electric control units.

Next, the control amount determination means 7234 applies the control amount determination means 7234 to the control device candidate adopted as the control device combination candidate.
It is determined whether or not the control amount determined by the control amount determining unit 722 is satisfied. If the control amount is not satisfied, the process of adding a new control unit is repeatedly performed from the priority control unit selection unit 7231. When the determination of the control amount determination means 7234 is satisfied, the control target determination means 723 finally determines the combination candidate of the selected control equipment as the generator to be controlled.

For the determination of the control amount, the control unit 722 determines the combination of the maximum control amount that does not exceed the control amount and the minimum control amount that exceeds the control amount. Creation of combinations is possible.

The relationship between the calculated amount of control and the combined amount of control will be described below with reference to FIGS.

As shown in FIG. 5, the maximum combination of the electric control amounts that does not exceed the calculated electric control amount is the combination electric control amount 14 in the combination of the individual electric control units 12, and the calculated control amount 13 Below, and the maximum relationship. Similarly, the minimum combination of the control amounts exceeding the calculated control amount is, as shown in FIG.
4 exceeds the calculated control amount 13 and has the minimum relationship.

The relationship between the calculated control amount and the combined control amount can be arbitrarily switched by the control target and the operator.

Next, the improvement of the frequency characteristics in the separated system after the system separation will be described with reference to FIGS. 7 and 8 in comparison with the case where the present embodiment is implemented and the conventional case.

These figures are diagrams showing the state of change of the frequency deviation in the separated system after power control for the excess power generation side and the excess load side, respectively. Reference numerals 15 and 19 denote the frequency of the conventional separated system after power control. Characteristic curves, 16 and 20 are frequency characteristic curves of the separated system after electrical control of the present embodiment, 18 is the output reserve of the conventional separated system after electrical control, and 17 is the output reserve of the separated system after electrical control of the present embodiment. Indicates output reserve.

According to FIG. 7, when the control results of the conventional control and the control of the present embodiment are compared with each other under the same control amount, the frequency characteristic 16 when the present embodiment is implemented is compared with the conventional frequency characteristic 15. As shown in (1), an improvement in frequency finish can be expected. At the same time, as shown in FIG. 8, when the control results of the present embodiment and that of the present embodiment are compared under the same control amount, as shown in the output reserve 18 of the conventional frequency characteristic 19, In contrast to the fact that the output reserve is small, there is a danger to a rapid recovery of the load, etc., but in the case of implementing this embodiment, as shown by the output reserve 17, a certain level of output reserve is secured. As a result, it is possible to expect improvement of the reliability of maintaining the separation system and stabilizing the frequency.

Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 9 is an overall configuration diagram of the power system stabilizing device according to the present embodiment, and FIG. 10 is a diagram showing details of the arithmetic processing of the list-referred power control target determining means shown in FIG.

In FIGS. 9 and 10, reference numeral 725 denotes a list-referred control target determining means, reference numeral 741 denotes a control order list database, reference numeral 7251 denotes a priority control device selecting means, and reference numeral 7252 denotes a control device adopting means. Reference numeral 7253 denotes a control amount determining means, and the other configuration is the same as that shown in FIGS.

FIG. 11A is a category-based control priority list 21 for each plant type generator stored in the parameter database, and FIG. 11B is a category-specific control priority list. 21 based on
It is a power control priority list 24 stored in a power control priority list database 741. This electrical control priority list 24
Lists the prioritized individual generator names 22 and the current generator output 23 of those generators.

Next, the control ranking list database 741
Will be described with reference to FIG.

Numeral 74 denotes operation storage means for performing calculation based on the data in the online database 711 and the parameter database 73 to create the control order list data and storing the data in the control order list database 741, and reference numeral 742 denotes the control order list database 741 743 is a cycle time waiting means for updating the control order at a fixed cycle, 743 is a power control order erasing means for deleting old control order list data, 7231, 7
232 and 7233 have the same functions as those shown in FIG. 2 respectively. Priority electric machine selecting means, elected machine restriction judging means and electric machine adopting means, and 7273 perform this processing until a predetermined electric power control amount is reached. Is an end-of-list determining means for continuing.

The control order list database 741 is constantly updated periodically before the occurrence of system separation, and is periodically executed in the cyclic loop 744. The periodic time waiting means 742 waits for the elapse of a fixed time or the update of online data, and then the power control order erasing means 743 resets the power control order list database 741 and starts the list creation processing.

The priority electrical machine selection means 7231 specifies the plant type to be selected according to the category-specific electrical priority list 21 of the plant type stored in the parameter database 73 as shown in FIG. I do. Subsequently, after the plant type is specified, a plurality of generators of the same plant type are selected from those having a large governor adjustment rate, and the processing of the priority electrical machine selecting means 7231 is completed.

Next, in the elected machine restriction judging means 7232, the electric machine selected by the preferential electric machine selecting means 7231 is assumed to be a candidate combination of electric machines, and the characteristics of the separated system after electric control are satisfied. It is determined whether or not to perform. Here, from the load set value and the load limit value of each generator stored in the online database 711, the output reserve of the entire separated system after the system separation is calculated, and the selected electric machine is controlled. In such a case, it is determined whether or not the separated system after the electric power can maintain the output reserve capacity equal to or higher than the calculated constant value, and whether to adopt the selected combination of the electric motors is determined.

In the electric machine adopting means 7233, the electric power generation order list database 741 is additionally updated for the adopted electric generator, including the current electric generator output.

The above control list database 741
The addition updating process is repeated until the list end determination unit 7273 creates a sufficient list for the assumed maximum value of the power control amount.

As a result, as shown in FIG. 11 (b), a constantly updated electrical control ranking list 24 is obtained.

Next, the operation of the power system stabilizing device of the present embodiment will be described with reference to FIGS.

As in the first embodiment, when system separation occurs and the separation determination unit 721 recognizes that system separation has occurred, the power supply for maintaining the separation system and stabilizing the frequency is immediately limited. Enter the electronic control process. The control amount determining means 722 calculates the control amount necessary for maintaining the separation system or stabilizing the frequency from the online database 71.

Next, based on the calculated control amount, the list-referred control target determining means 725, ie, FIG.
In the priority electrical machine selection means 7251 shown in (1), a generator candidate to be electrical controlled is selected from the electrical control order list database 741, and then in the electrical power adoption means 7252, the generator candidate to be electrical controlled is selected by the electrical control priority. Since it is determined at the stage of creating the ranking list 24 that the various characteristics of the separated system after power control are satisfied, they are adopted unconditionally as power generators to be controlled.

Next, in the case where the control amount determination means 7253 determines that the generator combination candidate adopted in the above does not satisfy the control amount by the control amount determination means 722, the first As in the case of the embodiment, the process of adding a new electrical machine is repeatedly performed from the priority electrical machine selecting unit 7251.

In this determination of the control amount, as in the first embodiment, the maximum combination of control amounts within a range not exceeding the control amount by the control amount determining means 722 and the control amount are determined. A minimum combination of power control that exceeds can be created.

As described above, in the first embodiment, the determination of the electrical control is performed after the generation of the combination of the generators that satisfies the various characteristics of the separated system after the electrical control has been performed. By performing the processing before the system separation and storing the results, it is possible to reduce the processing amount after the system separation. In addition, in the process of selecting a control target, a calculation amount that increases due to consideration of various characteristics of the separation system after the control is allocated before separation occurs. Therefore, in addition to the effect of the first embodiment, it is possible to perform quick control after the occurrence of separation, and it is possible to consider various characteristics of more separation systems as compared with the first embodiment. Advanced control can be expected.

[0062]

According to the present invention, when a system separation occurs, the combination of generators to be controlled is adjusted in consideration of various characteristics of the separated system after power control. It is possible to maintain or improve the characteristics appropriately, as a result, it is possible to flexibly adapt to changes in the state of the separation system such as a sudden recovery of the load, Separation system maintenance becomes easy.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a power system stabilization device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing in detail a calculation process of an electric power control target determining unit shown in FIG. 1;

FIG. 3 is a diagram showing an outline of a category-based power control priority list of generators stored in a parameter database of the embodiment.

FIG. 4 is a diagram for explaining necessary output reserve in the separation system of the present embodiment.

FIG. 5 is a diagram for explaining a combined control amount with respect to a calculated control amount.

FIG. 6 is a diagram for explaining another combined control amount with respect to a calculated control amount.

FIG. 7 is a diagram showing a comparison between a frequency characteristic in a case where the present embodiment is implemented in a separation system and a conventional system.

FIG. 8 is a diagram showing a comparison between an output reserve and a conventional one in a case where the present embodiment is implemented in a separation system.

FIG. 9 is an overall configuration diagram of a power system stabilizing device according to a second embodiment of the present invention.

FIG. 10 is a diagram showing in detail the calculation processing of the list-referred power control target determining means shown in FIG. 9;

FIG. 11 shows a power control priority list for each category of a generator stored in a parameter database and a power control priority list stored in a power control priority list database.

FIG. 12 is a diagram showing a process of creating an electrical control priority list.

[Explanation of symbols]

 1 assumed point of system separation accident 2 separation system 3 line 4 generator 5 line 6 line 7 power supply limiting device 71 monitoring means 711 online database 72 power supply limiting means 721 system separation determining means 722 power control determining means 723 power control target determining means 7231 priority electric machine selecting means 7232 electing machine restriction judging means 7233 electric machine adopting means 725 list reference electric control object determining means 7251 priority electric machine selecting means 7252 electric machine adopting means 73 parameter database 74 arithmetic storage means 741 electronic control Order list database 742 Period time waiting means 743 Electricity order erasing means 8 Line 9 Electricity priority list by category 21 Electricity priority list by category 24 Electricity priority list

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tomoji Nakamura 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Hitachi, Ltd. Kokubu Plant (72) Inventor Mototaka Tsubouchi 2--13 Suehirocho, Kariya City, Aichi Prefecture -7 Chubu Electric Power Co., Inc.Kariya Electric Power Center (72) Inventor Masamichi Kojima Inside the Okazaki branch of Chubu Electric Power Co., Inc.

Claims (9)

[Claims] In a power system supplied with power from a plurality of generators, monitoring means for monitoring, from normal times, outputs of a plurality of generators in a separation system in which system separation is assumed, and the plurality of generators A stabilizing device for a power system, comprising: storage means for storing constants relating to characteristics of the power supply; and power supply limiting means for performing an emergency power-off control for stabilizing the separated system at the time of system separation. The limiting unit, when selecting a control for the control amount calculated for the stabilization, while making the output sum of the plurality of generators selected as control target candidates correspond to the control amount, Based on a predetermined number of the storage means, an estimation calculation of various characteristics of the separation system after controlling the candidate for control is performed, it is determined whether or not a condition is satisfied, and when the condition is satisfied, the control is performed. Multiple occurrences of target candidates An electric power system stabilizing apparatus characterized in that an electric machine is determined as an object of emergency power supply cutoff. 2. The power supply according to claim 1, further comprising, as the monitoring means, means for monitoring a control command value of a plurality of generator outputs in a separation system from normal times, in addition to monitoring the generator output. The stabilizing device for an electric power system, wherein the limiting unit performs an operation based on the control command value in addition to the constants in the storage unit when estimating the separated system after power control. 3. In a power system supplied with power from a plurality of generators, monitoring means for monitoring, from normal times, outputs of a plurality of generators in a separation system in which system separation is assumed, and the plurality of generators A stabilizing device for a power system, comprising: storage means for storing constants relating to characteristics of the power supply; and power supply limiting means for performing an emergency power-off control for stabilizing the separated system at the time of system separation. The limiting unit, when selecting a control for the control amount calculated for the stabilization, while making the output sum of the plurality of generators selected as control target candidates correspond to the control amount, Based on a predetermined number of the storage means, an estimation calculation of various characteristics of the separation system after controlling the candidate for control is performed, and it is determined whether or not a condition is satisfied. Multiple occurrences of target candidates An operation storage unit that constantly updates and stores the electric power as an object of the power supply emergency cutoff restriction, and, when the system is separated, the power generation to be controlled from the operation storage unit in accordance with the control amount calculated for stabilization. A stabilizing device for a power system, wherein a stabilizing device is selected and determined. 4. The method according to claim 3, further comprising, as the monitoring unit, a unit that monitors a control command value of a plurality of generator outputs in a separation system from a normal state, in addition to monitoring the generator output. The stabilizing device for a power system, wherein the storage means performs a calculation based on the control command value in addition to the constants of the storage means, when performing an estimation calculation of the separated system after power control. 5. The separated power system according to claim 1, wherein the various characteristics of the separated power system obtained by calculating based on a plant type as various constants of the generator are obtained. A power system stabilizing device characterized in that it is a frequency characteristic of a separated system with respect to a sudden change in supply and demand conditions in the power system. 6. The various characteristics of the separated system after electric control, which are obtained by calculating based on a stabilization rate of a governor of the generator as various constants of the generator, according to claim 1 and 3, A power system stabilizing device characterized by frequency characteristics with respect to excessive power generation or excessive load of the separated system after the power control. 7. The various characteristics of the separated system after electric power control, which are obtained by calculating based on inertia constants of rotating systems of the respective generators as various constants of the generator, according to claim 1 and 3, An electric power system stabilizing device, characterized in that it is a frequency maintenance characteristic of the separated system with respect to a sudden change in the supply and demand condition in the separated system after the power control. 8. The method according to claim 1, wherein the various characteristics of the separated system after the power control obtained by calculating based on a load set value and a load limit value as control command values for the generator are: An electric power system stabilizing device characterized by a spinning reserve and an output reserve in a separated system after power control. 9. The characteristic of the separated system after power control according to claim 1, wherein the characteristic is obtained by calculating based on a spinning reserve and an output reserve of the generator as various constants of the generator. Is a spinning reserve and an output reserve of the entire separated system after the power control, wherein