JPH0974679A - Method and device for stabilizing power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for stabilizing power system by which the power control amount required by the present state of a power system can be estimated by using the past power control selection information and can control the electric power of the power system by preventing the power from becoming excessive and deficient. SOLUTION: A method and device for stabilizing power system use the history of power control selection information which is updated at time intervals of several minutes in normal time. To be specific, whenever the power control selection information is updated at the time intervals, the data pair of the power control amount to each assumed fault and the then fault-point power flow rate is stored as power control amount data (603). Then the relation between the fault-point power flow rate and power control amount is estimated in advance from a simple expression at every assumed fault (604). When a fault actually occurs, the power is controlled by calculating the required power control amount from the then fault-point power flow rate and the previously found relational expression and finding the combination of power controls at which the power control amount becomes the minimum (605).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for maintaining stability of a power system, and more particularly, to preliminarily obtain control contents in case of emergency by pre-calculation regarding stability of system, and in case of actual emergency. , And to a power system stabilizing method and device for performing control in accordance therewith.

[0002]

2. Description of the Related Art A power system stabilizing device is a system that shuts off a generator (hereinafter referred to as "electric control") in an amount necessary for maintaining transient stability of the system against a failure of a transmission line or the like. . There are a pre-calculation method and a post-calculation method for determining the transient stability of the system. The present invention is based on the former pre-calculation method.

An example of a power system stabilizer using a pre-calculation method is, for example, the Institute of Electrical Engineers of Japan, Volume B115, No. 1 (1995).
January, 1) "Development of out-of-step prevention system (TSC) by online stability calculation" is described in detail. This system constantly captures the grid status online
Transient stability calculations are performed in advance for multiple contingency cases to find the required amount of electric control generators (called electric control machines) and create this as electric control machine selection information. . Then, this is updated at intervals of several minutes, and when a failure actually occurs, electric control is performed according to the latest electric control machine selection information to stabilize the electric power system. This method can perform control suitable for the current system state by using the electronic control unit selection information updated at intervals of several minutes.

[0004]

Since the above-mentioned conventional technique uses the latest electric control unit selection information updated at intervals of several minutes, electric control suitable for the current system state can be performed.
However, considering the case where this electric control machine selection information is not updated due to some kind of failure, electric control that does not match the system state will be performed as time elapses. In particular, when the system condition is gradually becoming severe, the electric control unit selection information in the relatively gradual condition of the system condition is used, so that the electric control amount may be insufficient.

An object of the present invention is to use the past electric control unit selection information to determine the electric control amount required in the present system state even when the electric control unit selection information is not updated due to some kind of failure. The present invention provides a method and apparatus for stabilizing a power system, which can be estimated by the above method and can perform electric control to reduce excess and deficiency of the electric control amount.

[0006]

In order to solve the above-mentioned problems, the present invention normally uses a history of electric control unit selection information updated every few minutes. Specifically, every time the control device selection information is updated every few minutes, a data pair of the control amount for each contingency and the current flow at the fault point at that time is calculated as the control amount data.
Accumulate as data. Then, based on these data, the relationship between the power flow at the fault point and the electric control quantity is estimated in advance for each contingency using a simple equation. In fact, when a failure occurs, the necessary flow rate is calculated using the flow rate at the failure point and the relational expression obtained in advance at that time, and the minimum power control volume that exceeds this is calculated. It seeks a combination and performs electronic control.

Therefore, according to the first aspect of the present invention, a power system stability is provided in which a number of generators required to maintain transient stability for a plurality of faults in the power system are shut off (called electric control). In this method, the system status is always taken online and the transient stability calculation is performed in advance for multiple contingency cases to obtain the total output of the generator to be shut down (hereinafter referred to as the amount of electricity control). This is repeated at intervals of several minutes, and a data pair of the electric control quantity for each contingent fault obtained here and the tidal flow rate at the fault point at that time is accumulated as electric control quantity data which is two-dimensional data, Based on these data,
For each contingency, a relational expression showing the relationship between the power flow at the fault point and the electric control amount is obtained in advance, and when the actual fault occurs, the flow at the fault point at that time and the relational formula obtained in advance are used. , Calculate the required amount of electric control, determine the generator combination that gives the minimum electric control amount whose total output exceeds the calculated electric control amount, and determine the generator to perform electric control. There is provided a power system stabilizing method characterized by the above.

The above relational expression can be obtained by the least-squares method based on the linear expression. In that case, the above relational expression divides the electric control amount of the electric control amount data by a predetermined step width,
It is possible to determine a representative point for the electric control quantity contained in each of the sections, and use the least-squares method by using the electric control quantity data for the representative point. Further, the linear expression obtained by the approximation can be translated in the positive direction of the electric control amount by a predetermined amount to make a final approximate expression. At that time, the linear expression obtained by approximation is translated so that it passes through any of the electric control data points and the parallel movement amount in the positive electric control direction is maximized. The linear expression obtained by the above may be used as the final approximate expression.

The first information processing system stores the electric quantity data and obtains the relational expression in the first information processing system. The relational expression is pre-loaded and the necessary electric control is used by using this relational expression. The second information processing system performs the calculation of the quantity and the determination of the generator that performs the electric control, and the second information processing system calculates the relational expression obtained by the first information processing system. It is possible to take in and calculate the necessary amount of electric control. Then, when a failure actually occurs, the amount of electric control data generated in the first information processing system is normally fetched, and this data is used to control the electric control in the second information processing system. When the generator to be performed is determined and the amount of electricity control data cannot be taken in, the second information processing system calculates the amount of electricity control using the relational expression that has been incorporated in advance, and based on this amount of electricity control ,
It is possible to determine a generator that performs electric control.

At this time, the generator to be electrically controlled can be determined by determining the set of the electrically controlled machines which exceeds the calculated electrically controlled quantity and has the minimum electrically controlled quantity.

According to another aspect of the present invention, a power system stability is provided in which a plurality of generators are shut down (referred to as "electric control") to maintain transient stability for a plurality of power system failures. In case of multiple contingency cases,
From the generator group connected to the power system, the electric machine determination system that pre-generates electric machine selection information for selecting the generator to be shut down (hereinafter referred to as the electric machine), and the failure It is equipped with a disconnection control system that detects and captures the information on the selection of the electric control machine and commands the interruption of the electric control machine. For the failure case, the transient stability calculation is performed in advance based on the imported system state information to obtain the required amount of electric control generator (called electric control machine) and create it as electric control machine selection information. In addition, a means for obtaining the total output amount of the generator to be shut down for each contingency (hereinafter referred to as "electrical control amount") and a data pair of the calculated electrical control amount and the tidal flow rate at the failure point are two-dimensionally -A means for accumulating as electric control data which is data, Based on the control data, a relational expression showing the relationship between the power flow at the fault point and the electric control is obtained in advance for each contingency, and means for sending the relational expression to the interruption control system is provided. A means for detecting a failure in the system, and when a failure is detected, it is judged whether or not the latest electric control device selection information is available, and if so, the electric control device is determined based on that information. If the latest information on the selection of the electric control device cannot be obtained by issuing a command to shut off the electric control device, the necessary electric control amount is calculated using the flow rate at the fault point at that time and the relational expression obtained in advance. And a means for activating the electric control by calculating a combination of electric control machines having a minimum electric control amount exceeding the above, and providing a power system stabilizing device.

The means for activating the electric control determines whether or not the latest electric control machine selection information is available, based on whether or not the electric control machine selection information is updated within a certain period of time. can do.

Further, the means for obtaining the relational expression in advance and sending it to the shutoff control system uses the above relational expression as a minimum of 2 by a linear expression.
It can be calculated by multiplication. At that time, as described above,
It is possible to obtain a representative point and then obtain a relational expression based on the representative point. Further, the linear expression obtained by the approximation can be translated in the positive direction of the electric control amount by a predetermined constant amount to obtain the final approximate expression. At that time, a linear expression obtained by performing parallel movement so as to maximize the parallel movement amount in the positive direction of the electric control quantity through any of the electric control data points is finally approximated. It can also be an expression.

Further, according to the present invention, the electronic control device determination system is installed in the master station, the cutoff control system is installed in each of the plurality of slave stations, and the master station and each slave station are connected by a communication line. It can be configured to.

[0015]

According to the present invention, even if the electronic control unit selection information cannot be obtained due to some failure, the electric control amount is calculated by using the relational expression obtained in advance, and the electric control unit is calculated based on the calculated electric control amount. You can decide. For example, by calculating the necessary electric control amount using the relational expression between the tidal flow at the fault point and the electric control amount for each fault point, the electric control device selection information that should be updated every few minutes may cause some trouble. Even if the system is no longer updated, and even if the system condition gradually becomes severer at that time, there is a small possibility that the system configuration will change significantly. Therefore, the possibility of excess or deficiency in electric control is reduced.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an outline of functions of a power system stabilizing device to which the present invention is applied.

The electric power system 1 supplies electric power generated by a plurality of generators 2 to a plurality of loads 4 via a plurality of power transmission lines 3. The system stabilizing device 6 controls the circuit breaker 5 that disconnects / connects the connection between the generator 2 and the power transmission line 3.

The system stabilizing device 6 periodically takes in system information 8 such as voltage and current of the power system 1 via a communication network 7, and at each time, a generator to be cut off (hereinafter referred to as an electric control device). ) Is determined, and the failure occurrence information 9 is received via the communication network 7 and the electronic machine determination system 6a that performs processing for generating and outputting the electronic machine selection information, and based on the electronic machine selection information, , A disconnection control system 6b for transmitting the disconnection information 10 to a specific circuit breaker 5 via the communication network 7.
The cutoff control system 6b is not limited to one, but is generally provided separately at a plurality of locations. The electric machine determination system 6a and the cutoff control system 6b are connected by a communication line different from the communication network 7. For example, they are connected by a LAN or the like.

Here, when a fault occurs in the power system 1, for example, a ground fault occurs at a certain point of the power transmission line 3 due to a lightning strike or the like, the ground fault is detected by a protection relay (not shown) or the like. The power transmission line 3 in the protection section including the failure point is disconnected. At the same time, the failure occurrence information 9 is also sent to the system stabilizing device 6, in particular, the interruption control system 6b, the generator 2 to be interrupted is determined according to the failure occurrence information 9, and the interruption information 10 is sent to the corresponding breaker 5. It is sent to shut off the generator 2.

The essence of the present invention is to provide a method of determining the generator 2 to be shut off by the system stabilizing device 6. In particular, when the electric control machine selection information generated by the electric control machine determination system 6a is not provided to all or some of the cutoff control systems 6b due to some abnormality, the cutoff control system 6b itself. , Based on the relational expression generated based on the latest information up to that point in time, to estimate the electronically controlled machine selection information and perform electrical control.

FIG. 2 is a functional block diagram of the system stabilizing device 6. As shown in FIG. 2, the electric machine determination system 6a
Is a system status acquisition unit 601 and an electric control amount calculation unit 602.
And a power consumption data storage unit 603 and a relationship estimation unit 604 as main functions. These are realized by a hardware system that constitutes one computer system. Although not shown, this hardware system has an interface device for communication, a computing device for computing and controlling the system, and a storage device for storing data. Note that a plurality of arithmetic devices may be used.

Further, the shutoff control system 6b has a failure detection section 606 and an electric control activation section 605. Then, these functions are realized by a hardware system other than the above. Although not shown, this other hardware system has an interface device for communication, a computing device for computing and controlling the system, and a storage device for storing data. Also, the shutoff control system 6b
Are generally present as a plurality of systems in the power system 1.

The system status fetching unit 601 fetches the system information 8 from the communication network 7 as online data.

Based on the fetched online data, the electric control amount calculation unit 602 targets all the expected fault cases and outputs the total output amount of the electric control device required to stabilize the system when a fault occurs. Ask for. This is repeated cyclically. The total output of the electric control machine is called the electric control quantity. The calculation of the electric control amount will be described later. In this embodiment, the electric control amount calculation unit 602 determines the electric control device when calculating the electric control amount, so that the electric control device selection information to be cut off is also obtained.

The electric energy control data storage unit 603 stores the electric energy control for each contingency determined here as the electric power control data 607 by forming a data pair with the current flow at the fault point at that time. To do. It should be noted that the electric energy control data storage unit 603 deletes the stored electric energy control data when the system configuration changes significantly.

FIG. 11 shows the electric energy control data storage unit 603.
An example of the data storage format in is shown. That is,
A data pair of the tidal flow rate and the electric control amount at the failure point is stored for each failure point and failure aspect.

The relationship estimating unit 604 calculates the fault flow rate and the electric power amount for each contingency based on all the electric power amount data stored in the electric power amount data storage unit 603. The relational expressions are estimated, and the relational expressions 608 relating to all contingencies are output to the electronic control activation unit 605. Although the details of the estimation method will be described later, when the relational expression cannot be estimated, the uncontrollable information is sent to the electronic control activation unit 6
Output to 05. The obtained relationship is represented as y = Fα (x).
α is a contingency case, x is a tidal flow at a failure point, and y is an electric control quantity. Further, these relational expressions are cyclically updated based on the online data.

When the electronically controlled activation unit 605 receives the unestimable information, it sets an unestimable information flag.

When a failure actually occurs, the failure detection section 606 detects it through the communication network 7 and sends failure occurrence information 9 to the electronic control activation section 605.

Upon receipt of the failure occurrence information 9, the electronically controlled activation unit 605 normally obtains the latest electronically controlled machine selection information corresponding to the failure based on the failure occurrence information 9 and the electronically controlled quantity calculating unit 602. , The interruption information is generated based on this, and the interruption information 10 is transmitted to the corresponding breaker. On the other hand, when the latest electric control device selection information cannot be fetched from the electric control amount calculation unit 602, estimation is performed using a relational expression. That is, based on the received failure occurrence information 9, the current flow rate at the failure point of the online data is substituted into the relational expression Fα related to the failure content α that has occurred, and the amount of electric control required for stabilization is calculated. To do. If there is information that cannot be estimated,
The electric control amount is calculated using the relational expression that the electric control activation unit 605 has as a default. Then, a plurality of electric generators to be electrically controlled are selected so that the total of their current outputs exceeds the calculated electric control amount and becomes the minimum. Here, when there are a plurality of selection methods, the generators are selected in accordance with the priority set in advance for each generator. Regarding the method of selecting the electric control machine by the electric control starting unit 605,
It will be described later.

Next, the electric control activation unit 605 transmits the cutoff information 10 to the corresponding breaker in order to cut off the obtained electric control machine. The circuit breaker 5 that has received the cutoff information 10 disconnects the connection and the electronic control is executed.

Next, a procedure for calculating the electric control amount performed in the electric control amount calculation unit 602 in the electric control device determination system will be described.

As a procedure for calculating the amount of electric control, first, an electric control device is obtained for each fault case, and the generator output values of this electric control device are summed up to determine the electric control for each fault case. It is conceivable to calculate the quantity. Regarding the method of obtaining the electric control device for each failure case, for example, one of the methods is "The out-of-step prevention system (TSC) by online stability calculation", B 115, No. 1 (January 1995). "Development". The basic procedure of the electronic control device determination method will be described with reference to FIG.

First, the failure for which the electric control machine is sought is
Assume two (step 3100). Then, the transient stability calculation is performed in the case where there is no electrical control of the contingency, and stability determination is performed (steps 3200 and 3300). If it is stable, it is determined that there is no electric control machine for this contingency, and then a failure for which an electric control machine is desired is assumed (step 340).
0,3500). If it is unstable, one generator which is considered to have the maximum electric control effect is selected from the results of the transient stability calculation (step 3600). This is the first electric control machine.
Next, the transient stability calculation is performed again this time by inserting the interruption sequence of the previously selected generator at a predetermined electric control time, and the stability is determined (steps 3200 and 33).
00). If it is stable, the currently obtained electric control machines are all the electric control machines for this contingency (step 3400), and if it is unstable, the electric control effect is maximized from the result of the transient stability calculation. One more generator that seems to be selected is selected (step 3600). This is the second electric machine. Thereafter, this is repeated until the result of the transient stability calculation becomes stable, and the electric control machine for one failure is determined.
This is repeated for all the failures, and finally the electric control machine for all the failures is determined.

Next, the estimation of the relationship between the power flow at the fault point and the electric control quantity, which is performed by the relationship estimating unit 604, will be described in detail.

FIG. 4 is a graph showing a change in the amount of electrical control when a tidal flow rate at a failure point changes with time for a certain failure. The horizontal axis (x axis) shows the tidal flow rate at the failure point, and the vertical axis (Y axis) shows the electric control amount. For example, the x-coordinate of the point p is the power flow at the fault point at the time t, and the y-coordinate of the point p is the electric control amount required for stabilization when the fault occurs at the time t. That is, each point represents each data stored in the electricity quantity data storage unit 603.

The relation estimating unit 604 receives these two-dimensional data.
The target is to estimate the relationship between x and y. That is, the relational expression showing the relation between x and y is obtained based on the measurement data. There are countless methods of estimating the relational expressions, and some examples are listed below.

(1) Estimation method 1 All data stored in the electric energy control data storage unit 603 are approximated by a linear equation by the least square method, and this linear equation is used as an estimation result. . This state is shown in FIG. The plotted points are the respective data stored in the electric energy data storage unit 603, and the straight line shows the linear equation which is the estimation equation.

Although the approximation function in the method of least squares is a linear expression here, this is only an example.
An n-th order expression (n is an integer of 2 or more), an exponential function, a logarithmic function, and the like can be considered, and any approximate function that can be used in the least square method can be considered.

(2) Estimating method 2 This method is a method of determining a representative value for each section of the electricity quantity data, and using this to obtain a relational expression by linear approximation. This is shown in FIG. First, the (fault point tidal flow rate x electric control quantity) space is divided by the electric control step size d (in the figure,
(shown by the parallel Naha line on the x-axis), one representative point is calculated by averaging the electric control data included in each electric control classification.
Next, a straight line approximation is performed on all the representative points by the least square method.
Let this straight line be L. Further, the straight line L is translated in the positive direction of the Y axis. The parallel movement amount may be given in advance and fixed, or the movement amount may be changed based on the total electric control data. For example, the approximate straight line passes through any one of the electric control amount data, and the parallel movement amount is moved so as to be the maximum in the positive direction of the y-axis.

As in the case of (1), the approximation function in the least squares method is a linear expression here, but this is an example, and consider any approximation function that can be used in the least squares method. You can

(3) Estimating method 3 In the estimating method 2, the presence of N or more representative points and the presence of M or more electric control data is added as an execution condition for approximation. If the execution conditions are not satisfied, the approximation is not possible.

In this embodiment, of the above methods, the estimation method 2 is used for estimation.

As described above, in the present invention, the relationship between the power flow at the fault point and the electrical control amount is approximated by a linear expression for each set of system configuration, fault point, and fault appearance. Then, this linear equation is
By updating using the latest data, when a failure occurs, even if the electric control data cannot be captured for some reason, the latest relational expression is used to estimate the electric control data. be able to.

Next, a method of determining the electric control machine from the estimated electric control amount, which is performed in the electric control activation unit 605, will be described.

First, in order to make this determination, it is necessary to prepare in advance a list of generator groups that can be electrically controlled.
This electric power controllable generator group is a range of selection given in advance for each failure point when the electric power control unit is determined from the electric power control amount obtained by the above relational expression. This list is provided in advance from the electronic control device determination system 6a to the interruption control system 6b and stored in the storage device of the interruption control system 6b.

The electric control activation unit 605 determines the electric control machine by judging that the following conditions are satisfied. That is, it is determined that the total value of the outputs of the selected electric control machines is equal to or larger than the electric control amount and is as small as possible. Therefore, for example, the following process is performed.

(1) The generator group is classified into a generator with a large output and a generator with a small output, based on a certain threshold value.

(2) From the generator group having a large output, those having a large output are selected in order from the generator having a larger output, until the total output value is exceeded.

(3) When the total output value is less than or equal to the electric control amount, but there is no generator with a large output,
Select multiple machines in descending order of output from the generator group with small output, and when the total output value of them exceeds the electric control amount,
End selection.

(4) In the process of selecting a generator with a large output, when the electric control amount is exceeded, the relationship between the exceeded amount X and the maximum output value Y in the generator group with a small output is shown. Accordingly, the generators with small output are additionally selected one by one in the following two ways.

(I) If X ≧ Y, select from the generator group having a small output in descending order of output.

(Ii) In the case of X <Y, the generators having a small output are selected in ascending order of output.

Next, a second embodiment of another system stabilizing device to which the present invention is applied will be described.

FIG. 7 is a functional block diagram of the system stabilizing device 6. The same components as those in the first embodiment are designated by the same reference numerals, and the description of the same components will be omitted.

The system stabilizing device 6 of this embodiment is composed of an electronic control device determination system 6a and a shutoff control system 6b, as in the first embodiment. The electronic control device determination system 6a and the interruption control system 6b are connected to the electric power system 1 via a communication network 7, respectively. In addition, the electric machine determination system 6a
The cutoff control system 6b are connected to each other via a communication line.

The electric control device determination system 6a includes a system state acquisition unit 601, an electric control table generation unit 609, an electric control amount data generation unit 610, an electric control amount data storage unit 603, and a relationship estimation unit 604. Has as a main function. Although not shown, these are realized by a computer system having a hardware resource configuration similar to that of the first embodiment.

The shutoff control system 6b has a failure detection unit 606 and a power control activation unit 605 which are realized by a computer system different from the computer control system 6a, as in the first embodiment.

The electric control table generating unit 609 generates the electric control table 611 by using the system information 8 acquired as online data by the system state acquiring unit 601 via the communication network 7. The electric control table 611 is, for example, as shown in FIG. 12, a table in which each contingency case specified by a failure point and a failure appearance is associated with an electric control machine that needs to be shut down. The electric control table generating unit 609 obtains an electric control machine necessary for stabilizing the system at the time of occurrence of a failure for all contingency cases based on the taken-in online data, The electronically controlled table 611 is created and output to the electronically controlled activation unit 605 and the electrically controlled amount data generation unit 610. This is repeated cyclically. The method for determining the electric control machine is as described in the first embodiment.

The power control amount data generation unit 610 receives the power control table 611 from the power control table generation unit 609, and receives the power system information 8 from the power status acquisition unit 601. And
The power control data generation unit 610 generates a power pair of the power flow at the fault point and the required power control as data pairs for each contingency from these, and generates them as the power control data 607. The data is stored in the electric energy data storage unit 603 in the format shown.

The relation estimating unit 604 generates the relational expression and sends it to the electronic control starting unit 605, as described in the first embodiment.

In normal times, the electronically controlled activation unit 605 cyclically receives the electronically controlled table 611 from the electronically controlled table generation unit 609. However, the electronic control table 609 could not be generated successfully, or the electronic control table to the electronic control activation unit 605 was not generated.
If the electronic control table of the electronically controlled activation unit 605 has not been updated for a certain period of time due to a failure of transmission of the electronic control unit 609, the electronically controlled activation unit 605 stores the electronically controlled data in its own memory. -Set a flag for bull failure information. Further, the electronically controlled table generation unit 609 may directly send the electronically controlled table defect information to the electronically controlled activation unit 605. Also in this case, the electronically controlled starting unit 605 sets a flag of electronically controlled table failure information. The electronic control activation unit 605 further receives the relational expression 608 or the unestimable information from the relation estimation unit 604.

When an actual failure occurs, the failure occurrence information 9 is sent to the failure detection unit 606 via the communication network 7, and this is sent to the electronic control activation unit 605. Upon receiving the failure occurrence information, the electronically controlled activation unit 605 implements electrical control according to the electrically controlled table when the electrically controlled table failure information flag is not set. On the other hand, if the electronic control table defect information flag is set,
Further, when the unestimable information does not stand, the necessary electric control amount is calculated according to the relational expression Fα and the electric control is executed as in the first embodiment. When the electronic control table failure information flag is set and the unestimable information is set, the electronic control is performed according to the latest electronic control table.

Next, FIG. 8 shows one structural example of the system stabilizing device 6.

The system is basically composed of a master station 6s1 and a plurality of slave stations 6s2. Master station 6s1 and slave station 6s
The two are connected by a transmission line 6s3, and various information can be transmitted. Further, the master station 6s1 and the slave station 6s2 can take in online data of the electric power system through the communication network 7, and the slave station corresponds to shut off a part of the generators 2 from the system. It is possible to transmit the interruption information 10 to the circuit breaker 5 that operates.

Regarding the sharing between the master station and the slave stations, FIG.
This will be described with reference to FIG. The example shown in FIG. 9 is basically the same as that shown in FIG. That is, the electronic control device determination system 6a constitutes the master station 6s1, and the cutoff control system 6b constitutes the slave station. The master station 6s1 has a system status acquisition unit 60.
1, a quantity control unit 602, a quantity data storage unit 603,
It is composed of a relationship estimation unit 604. The slave station 6s2 includes a failure detection unit 606 and a power control activation unit 605.

Next, an example is shown in which the master station 6s1 is associated with the electronic control device determination system 6a of the embodiment shown in FIG. 7, and the slave station 6s2 is associated with the cutoff control system 6b. FIG. 10 shows an example thereof. In FIG. 10, the master station 6s1 has the system status acquisition unit 6
01, electric power control table generation unit 609, electric power control amount data generation unit 610, electric power control amount data storage unit 603, relationship estimation unit 604
It consists of. The slave station 6s2 includes a failure detection unit 606 and a power control activation unit 605.

[0069]

According to the present invention, the relational expression between the tidal flow rate at the fault point and the electric control amount is obtained in advance for each fault point, and at the time of an actual failure, the relational expression required by the relational expression is used. The control is calculated, and electric control is performed with a combination of electric control machines with the minimum electric control exceeding this, so the electric machine selection information that should be updated every few minutes is no longer updated due to some kind of failure. In this case, even if the system condition gradually becomes severer at that time, it is possible to obtain the electric control amount that was in the system state while there is no significant change in the system configuration, and the electric control amount may be insufficient. Sex becomes low. Moreover, excess can be suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing the function of a power system stabilizing device to which the present invention is applied.

FIG. 2 is a functional block diagram of the first embodiment of the power system stabilizing device of the present invention.

FIG. 3 is a flowchart showing an example of an electric control device determination method in a power system stabilizing device to which the present invention is applied.

FIG. 4 is a graph showing a change in the required amount of electric control when a tidal flow rate at a failure point changes with time for a contingency failure.

FIG. 5 is an explanatory diagram illustrating an example of an approximation method of a relationship between a power flow rate at a failure point and a necessary electric control amount for each contingency.

FIG. 6 is an explanatory diagram illustrating an example of an approximation method of a relationship between a power flow at a fault point and a necessary electric control amount for each contingency.

FIG. 7 is a functional block diagram of a second embodiment of the power system stabilizing device of the present invention.

FIG. 8 is a block diagram illustrating a configuration example of a power system stabilizing device to which the present invention is applied.

FIG. 9 is a block diagram illustrating one configuration example of the power system stabilizing device according to the first embodiment.

FIG. 10 is a block diagram illustrating a configuration example of a power system stabilizing device according to a second embodiment.

FIG. 11 is an explanatory diagram showing an example of a storage format of electricity quantity data.

FIG. 12 is an explanatory diagram showing an example of a storage format of a power control table.

[Explanation of symbols]

1 ... Power system, 2 ... Generator, 3 ... Transmission line, 4 ... Load, 5
... Circuit breaker, 6 ... System stabilization device, 7 ... Communication network, 8 ... System information, 9 ... Failure occurrence information, 10 ... Shutdown information, 601 ... System state acquisition unit, 602 ... Electricity control amount calculation unit, 603 ... Electric energy control data storage unit, 604 ... Relationship estimation unit, 605 ... Electric power activation unit, 606 ... Failure detection unit, 607 ... Electric power control data, 60
8 ... Relational expression, 609 ... Electric control table generation unit, 610 ... Electric control amount data generation unit, 611 ... Electric control table, 6s1 ... Master station, 6s2 ... Slave station, 6s3 ... Transmission line.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Tokuhiro Sugiura 1 Higashishinmachi, Higashi-ku, Nagoya, Aichi Chubu Electric Power Co., Ltd. (72) Inventor Yoshio Ariura 1-1-1, Shibaura, Minato-ku, Tokyo Stocks Company Toshiba Head Office

Claims (15)

[Claims] 1. A power system stabilizing method for interrupting a number of generators required to maintain transient stability for a plurality of failure cases of the power system (referred to as "electric control"), thereby maintaining the system state at all times. , Online capture, multiple contingency cases
In a power stabilization method in which the transient output stability is calculated in advance and the total output of the generator to be shut down (hereinafter referred to as "electrical control") is repeated at intervals of several minutes, A data pair of the power control quantity for the contingency and the tidal flow rate at the fault point at that time is accumulated as the power control data which is two-dimensional data, and based on these data, each contingency failure is calculated. In advance, a relational expression indicating the relationship between the tidal flow rate at the failure point and the electric control quantity is obtained in advance, and when the actual failure occurs, the required flow rate is calculated using the tidal flow rate at the fault point and the relational expression obtained in advance. It is characterized in that the generators that perform electric control are determined by calculating the electric control amount, and finding the combination of generators whose total output is the minimum electric control amount that exceeds the calculated electric control amount. Power system stabilization method. 2. The power system stabilizing method according to claim 1, wherein the relational expression is obtained by a least squares method based on a linear expression. 3. The relational expression according to claim 2, wherein the electric control amount of the electric control amount data is divided by a predetermined step, and the electric control amount contained in each division is calculated. The method of stabilizing the electric power system is characterized in that the representative point is determined and the electric power control data for the representative point is used to obtain the least squares method. 4. The method according to claim 2 or 3, wherein the linear expression obtained by approximation is translated in the positive direction of the electric control amount by a predetermined constant amount to obtain a final approximate expression. A characteristic power system stabilization method. 5. The method according to claim 2 or 3, wherein the linear expression obtained by approximation passes through one of the electric quantity control data points,
A power system stabilizing method, wherein a linear approximation obtained by performing parallel movement so that the amount of parallel movement in the positive direction of the electric control amount is maximized is a final approximate expression. 6. The first information processing system according to claim 1, 2, 3, 4 or 5, wherein the electric energy control data is accumulated and the relational expression is obtained.
The second information processing system performs the above-mentioned relational expression in advance, calculates the necessary amount of electric control using this relational expression, and determines the generator that performs electric control, and A method for stabilizing an electric power system, wherein the second information processing system takes in the relational expression obtained by the information processing system, and calculates a necessary electric control amount. 7. The method according to claim 6, wherein when a failure actually occurs, the quantity control data normally generated by the first information processing system is fetched and the second quantity is used by using this data.
In the above information processing system, when the generator that performs electric control is determined and the electric control amount data cannot be taken in, the second information processing system calculates the electric control amount using the relational expression that has been taken in beforehand. Then, a power system stabilizing method is characterized in that a generator that performs electric control is determined based on the electric control amount. 8. The method according to claim 7, wherein the generator to be electrically controlled is determined by determining a set of electrically controlled machines which exceeds the calculated electrically controlled quantity and has the minimum electrically controlled quantity. A characteristic power system stabilization method. 9. A power system stabilizing device for interrupting a number of generators required to maintain transient stability for a plurality of power system failure cases (called electric control), wherein a plurality of expected failure cases are provided. -An electronic control device determination system that pre-generates electronic control device selection information for selecting a generator to be shut down (hereinafter referred to as an electronic control device) from among a group of generators connected to the electric power system. And a disconnection control system that takes in the electric control unit selection information, detects a failure, and commands the electric control unit to be shut off.The electric control unit determination system constantly captures the system status online. For multiple contingencies, the transient stability is calculated in advance based on the imported system status information to obtain the required amount of electric control generators (called electric control machines), and the electric control machines are selected. It is created as information and electronic control for each contingency The system includes means for obtaining the total output amount of the electric machine (hereinafter referred to as electric control amount) and means for transmitting electric control device selection information to the interruption control system. The interruption control system includes means for detecting a failure in the power system and electric control. A means for fetching electrical control unit selection information from the control system, and when a failure is detected, an electrical control unit is determined based on the electrical control unit selection information, and an instruction to shut off the electronic control unit is given to control the electrical control. In the electric power system stabilizing device including a means for starting, the electric control device determination system stores a data pair of the calculated electric control amount and the tidal flow rate at the failure point at that time as electric control data which is two-dimensional data. And a means for obtaining a relational expression showing the relationship between the power flow at the fault point and the electric control quantity for each contingency based on the electric control quantity data and sending the relational expression to the cutoff control system. Is detected, the latest electronic control unit selection information If it is available, determine the electric control machine based on that information, command the cutoff of the electric control machine, and if the latest electric control machine selection information cannot be obtained. Calculates the required amount of electric control using the flow rate at the fault point at that time and the relational expression obtained in advance, and finds the combination of electric control devices that gives the minimum amount of electric control that exceeds this, and And a means for starting the power system. 10. The device for activating electric control according to claim 9, wherein whether or not the latest electric control device selection information is available is updated within a certain time. A power system stabilizing device characterized by making a judgment based on whether or not it is. 11. The means according to claim 9, wherein the means for obtaining the relational expression in advance and sending it to the cutoff control system is 1
A power system stabilizing device characterized by being obtained by a least squares method according to the following equation. 12. The means according to claim 9, wherein the means for obtaining a relational expression in advance and sending it to the cutoff control system divides the relational expression into a predetermined amount of electric control amount of the electric control amount data. Then, a representative point for the electric control quantity contained in each section is determined, and the electric power control device is characterized in that the electric control quantity data for the representative point is used to obtain the least squares method. . 13. The method according to claim 11 or 12, wherein the linear expression obtained by approximation is translated in the positive direction of the electric control amount by a predetermined constant amount to obtain a final approximate expression. A characteristic power system stabilizer. 14. A parallel movement amount according to claim 11 or 12, wherein a linear expression obtained by approximation is passed through one of the electric quantity control data points, and the electric control quantity is in a positive direction. The power system stabilizing device is characterized in that a linear equation obtained by performing parallel movement so that is maximized is a final approximate equation. 15. The master station according to claim 9, 10, 11, 12, 13 or 14, wherein an electronic control device determination system is installed in a master station, and an interruption control system is installed in each of a plurality of slave stations. A power system stabilizing device, characterized in that the power station and each of the slave stations are connected by a communication line.