JPH10164756A - Method and apparatus for controlling power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a monitoring point automatically according to the condition change of a power system by monitoring the change of the quantity of a system condition of a monitoring point candidate by a computer, and setting it as a monitoring point, when the variation exceeds a set range. SOLUTION: A power system controller is constituted containing a fetch data fetching apparatus 102, a data base 102, a monitoring point determining apparatus 104, an input data forming apparatus 105, a control calculation execution apparatus 106, a control command outputting apparatus 107 and a result outputting apparatus 108. And the monitoring point determining apparatus 104 adds as a new monitoring point a nonmonitoring point where the variation of the quantity of a system condition such as a voltage, etc., is large. Besides, when the quantity of the system condition such as a voltage, etc., is kept near a lower limit for a long time, the nonmonitoring point is added to monitoring points, and the quantity of the system condition at that monitoring point is approached to a reference value as much as possible. In this way, a monitoring point candidate which has a large variation in the quantity of the system condition, or is kept in the vicinity of the lower limit value for a long time, is set as a monitoring point automatically.

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 controlling a power system, and more particularly to adjustment of a voltage, a reactive power and the like of a power system.

[0002]

2. Description of the Related Art In order to supply high-quality power while suppressing voltage fluctuations in a power system, conventionally, in response to fluctuations in system state quantities such as power system voltage and reactive power flow,
2. Description of the Related Art A control method and a control device are known which control an adjusting device such as a generator, a tap of a transformer, and a phase adjustment facility so as to suppress a fluctuation width of the system state quantity.

For example, the technical report of the Institute of Electrical Engineers of Japan (1979)
According to the conventional technology (1) described in “Measures for maintaining voltage stability of power system”, a plurality of monitoring points for monitoring the system state quantity are set in the power system, and the voltage and reactive power flow at those monitoring points are set. Detected, a deviation from these predetermined reference values is obtained, and the adjusting device is controlled so that the deviation falls within a predetermined operation range.
Then, in determining the adjustment amount of the adjustment device, a change amount (decrease amount) of the determination function with respect to the adjustment amount of each adjustment device is calculated using a determination function obtained by normalizing a deviation from a reference value according to an operation width. That is, an amount correlated with the amount of decrease in deviation from the reference value is calculated for each adjustment device, and the adjustment device with the largest decrease in the determination function is selected. By operating the selected adjusting device within the unique adjustable upper and lower limits specified for the device, and repeatedly performing this operation until constraints such as the operation width set for each monitoring point are satisfied. , So as to maintain an appropriate voltage.
In addition, the adjustment amount of the above-described adjustment device is also determined so as to minimize the power transmission loss.

On the other hand, according to the prior art (2) of the power system voltage stability monitoring and control system described in Japanese Patent Application Laid-Open No. 6-284581, the power system to be monitored and controlled is a power system including many generators. Power system reactive power index Qs of the power system and its maximum value Qmax are calculated, and the reactive power supply target is set so as to reduce the transmission loss of the target power system. It is performed to set a value and determine an operation order of the adjusting device so as to meet the target value.

[0005]

However, the monitoring points of the above-mentioned prior art (1) are predetermined by the system operator and are fixed, so that the monitoring points during the daytime when the power demand is large are large. Even if the state quantity such as power flow changes significantly or suddenly, such as when there is a time zone when the power demand at night is small, the voltage of the same fixed monitoring point should be driven into the operation range. Therefore, there is a problem that it is not always possible to perform appropriate voltage and reactive power control. Also, when the target power system expands or the power system shrinks due to a natural disaster, etc., new monitoring points must be reset, but the monitoring points must be set manually by the advanced power system. There is a problem that it is necessary to spend a great deal of time on the basis of know-how for the above.

Further, according to the prior art (2), it is not necessary to determine or set a monitoring point, but since the voltage is controlled in accordance with the goal of minimizing the power transmission loss,
The solution obtained by the computer tends to regulate the voltage higher throughout the system. That is, in general,
In many cases, the amount of adjustment such as the output of the reactive power of the generator or the input amount of the phase adjustment equipment for supplying the reactive power to the system is set to the upper limit value of the equipment. As a result, there is a possibility that a large range of voltage drop may be caused when the capacity range for increasing and adjusting the voltage is reduced and the load is rapidly increased. Therefore, it is not preferable to perform voltage control using only the transmission loss as an index, and it is necessary to set a monitoring point and appropriately maintain the system state quantity of the monitoring point.

Therefore, an object of the present invention is to enable a monitoring point to be automatically changed according to a change in the state of a power system.

[0008]

The object of the present invention is to set a plurality of monitoring point candidates in a power system, input a system state quantity at the monitoring point candidate to a computer, and monitor a change in the system state quantity. This can be solved by setting a monitoring point candidate whose change amount exceeds the set range as a monitoring point. In this case, as the setting range of the change amount, in addition to the upper and lower limit values set for the system state quantity, a margin upper and lower limit value having a certain margin on the safe side from the upper and lower limit values can be applied.

Alternatively, a plurality of monitoring point candidates are set in the power system, and the system state quantity at the monitoring point candidate is input to the computer to monitor a change in the system state quantity. A monitoring point candidate in which the time during which the state quantity is held near the upper and lower limits within the set range exceeds the set value can be set as the monitoring point. Furthermore, those 2
One monitoring point setting method can be combined.

[0010] Another object of the present invention is to set a plurality of monitoring point candidates in an electric power system, input a system state quantity of each monitoring point candidate to a computer, and use the computer to set at least one of the monitoring point candidates as a monitoring point. In order to keep the system state quantity in the provisionally set monitoring point candidate within the preset range, the adjustment device controlling the system state quantity is controlled by simulation, and based on the result of the simulation control, This can also be solved by obtaining an evaluation function representing the effect of control by the monitoring point candidate and setting a good evaluation function as a monitoring point.

The above-mentioned setting of the monitoring point may be performed at each timing of controlling the system state quantity of the control object. High quality power with little fluctuation can be supplied. On the other hand, in a time zone in which the change in the power demand is small, such as at night, the processing cycle of the monitoring point setting can be lengthened, whereby the redundant arithmetic processing for the monitoring point setting can be reduced.

Further, the automatic setting means of the monitoring point according to the feature of the present invention is incorporated in a voltage / reactive power control device and applied to real-time control. It can be applied to an arrangement plan of monitoring points according to the power system configuration of the present invention.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a procedure for automatically setting a monitoring point according to a feature of the present invention. FIG. 1 shows an example in which a new monitoring point is additionally set to a current monitoring point, and FIG. The example which removes a monitoring point is shown. FIG. 3 is an overall configuration diagram of a power system control device according to an embodiment, which is provided with a monitoring point determination device that automatically sets monitoring points and is configured by a computer.

As shown in FIG. 3, a power system control apparatus to which the present invention is applied includes a data capturing apparatus 10 for capturing.
2. It includes a database 103, a monitoring point determination device 104, an input data creation device 105, a control calculation execution device 106, a control command output device 107, and a result output device 108.

The data acquisition device 102 acquires a system state quantity such as a voltage and a reactive power flow required for desired control from the power system 101 to be controlled via a communication line or the like.
The data is converted into data in a format as shown in FIG. These data are taken in at a predetermined control cycle or at an arbitrarily set time, and the equipments constituting the system # in the format shown in FIG.
1, # 2,..., Data such as generator active power, generator reactive power, load active power, load reactive power, voltage magnitude, and the like are stored.

The database 103 stores data relating to the equipment of the power system to be controlled in advance in a format as shown in FIG. These data include data such as resistance between components # 1, # 2,..., Induction (inductance), capacitance (capacitance), tap ratios of transformers, and the like.

The monitoring point determining device 104 is a part according to the features of the present invention, and a detailed functional configuration will be described below with reference to FIGS. Here, description will be made assuming that the system state quantity to be controlled is voltage and reactive power. Also, a description will be given assuming that a monitoring point is deleted or added from a state preset by the method of the present invention or some method.

First, an example of a condition for adding or deleting a monitoring point will be described. As shown in FIG. 5, the system state quantity at the monitoring point has an upper limit value 301 and a margin upper limit value 3
02, reference value 303, lower limit value 304, margin lower limit value 30
5, control conditions such as an upper security area 306 and a lower security area 307 are defined and stored in the database 103. Among these control conditions, for example, the upper limit value 3 for the voltage
01, the reference value 303, and the lower limit 304 are previously set to the same value for the power system to be controlled. The set value of the voltage can be changed for each control time. The margin upper limit 302 and the margin lower limit 305 are determined in consideration of the reference value 303 and the upper and lower limits 301 and 304. The range between the upper limit value 305 and the upper limit value 301 is defined as the upper limit alert area 306, and the lower limit value
The range sandwiched between 5 and the lower limit 304 is defined as a lower limit alert area 307.
Is defined.

Based on such control conditions, it is added that the change of the system state quantity at the monitoring point to be judged satisfies, for example, one or both of criterion 1 shown in the following equation 1 and criterion 2 shown in the following equation 2. The condition of the monitoring point is defined as a condition of the deletion monitoring point that does not satisfy one or both of them.

[0020]

(Equation 1)

[0021]

(Equation 2)

The criterion 1 means that a non-monitoring point having a large change in the system state quantity such as voltage is added to a new monitoring point. Criterion 2 is to incorporate the non-monitoring point into the monitoring point when the system state quantity such as voltage is kept near the lower limit for a long time, and to make the system state quantity at the monitoring point as close to the reference value as possible. is there. It should be noted that, even when the time for which the value is kept near the upper limit is long, it can be similarly incorporated into the monitoring point. However, it is important to avoid unforeseen situations, such as a chain of power failures in the event of an accident. , It is preferable to delete.

The processing procedure of the monitoring point determination device 104 based on such conditions for adding or deleting monitoring points will be described with reference to FIGS. FIG. 1 shows a processing procedure for adding a new monitoring point to a currently set monitoring point. First,
The database 103 is searched, and a non-monitoring point that is not currently set as a monitoring point is extracted from preset monitoring point candidates, and is set as a non-monitoring point set N (step 501). Next, one monitoring point n in the set N of non-monitoring points is selected (step 502), and whether to add the monitoring point n as a new monitoring point is determined based on the above-described criterion 1 or criterion 2. Then, it is determined whether or not the condition of the additional monitoring point is satisfied (step 503). If the determination result is affirmative, the non-monitoring point is newly added as a monitoring point (step 504). If the determination in step 503 is negative and after the addition of the monitoring point in step 504, the non-monitoring point is deleted from the set N (step 5).
05), the process returns to step 502 via step 506, and the process is repeated until the set N of non-monitoring points is exhausted, that is, until the determination in step 506 becomes N = φ.

FIG. 2 shows a processing procedure for monitoring a change in the system state quantity of a currently set monitoring point and deleting the monitoring state according to the change. As in the case of FIG. 1, the database 103 is searched to extract a set N of currently set monitoring points (step 601). Next, one monitoring point n in the set N is selected (step 602),
First, it is determined whether or not the monitoring point n is the monitoring point added in the processing of FIG. 1 (step 603). If the determination result is affirmative, that is, if the monitoring point is not a newly added monitoring point, it is determined whether the condition of the additional monitoring point is satisfied by referring to the above-described reference 1 or reference 2 (step 6).
04). If the determination result is negative, the monitoring point is deleted and set as a non-monitoring point (step 605). Step 6
03, if the determination in step 604 is negative, or after performing the monitoring point removal processing in step 605, the monitoring point is deleted from the set N (step 606), and the process returns to step 602 via step 607 to verify Until the target monitoring point set N is exhausted, that is, step 607
The process is repeated until the determination in (2) becomes N = φ.

In this way, a monitoring point candidate having a large fluctuation in the system state quantity or a monitoring point candidate having a long time maintained near the lower limit is automatically set as a monitoring point.

Next, returning to FIG. 3, based on the monitoring points determined as described above, the control processing after the input data creating device 105 is performed. That is, the monitoring point determination device 104
Based on the monitoring points determined in step (1), data necessary for voltage and reactive power control is created. This data includes the equipment information of the power system shown in FIG. 4A stored in the database 103, the data of the system state quantity shown in FIG. 4B, and the data shown in FIG. 6A. Information such as equipment types, equipment capacities, equipment unit operation amounts of equipment # 1, # 2,... And monitoring indicating whether equipment # 1, # 2,. Consists of point setting information. In FIG. 1A, taps represent transformer taps, SC / ShR represents phase adjustment equipment, and AVR represents an automatic voltage regulator.

The control calculation execution device 106 calculates a control command for the voltage and reactive power adjusting device based on the set system state quantity of the monitoring point by calculation. can do.
For example, it is described in detail in Japanese Patent Application No. 7-78587 or the technical report of the Institute of Electrical Engineers of Japan, "Measures for maintaining stable voltage in power systems" (1979). Here, an example is shown in FIG. 7 and briefly described. First, in step 901, data including the system state quantity in the monitoring point candidate of the power system at the time of the control target is read, and the monitoring point determination device 104 determines in FIG.
The monitoring points of the voltage and reactive power control are set according to the data shown in. Then, a set N of adjustment devices corresponding to the read system state quantity is extracted and set (step 90).
3). Then, in step 904, the counter MM
And NN are initialized. The counter MM indicates the number of departure monitoring points at which the system state quantity at the monitoring points exceeds a predetermined upper and lower limit value, as will be described later, and NN is a counter of the number N of adjustment devices to be controlled. At step 905, it is determined whether or not the system state quantity at the monitoring point exceeds a predetermined upper and lower limit value. If it does, it is detected as a deviation, and the number of deviating monitoring points is set to M. . Next, the content of the counter M is checked in step 906, and if there is at least one deviating monitoring point, the process proceeds to step 907. If there is no deviating monitoring point, there is no need to perform control. finish. In step 907, the amount of change in the system state quantity at the monitoring point with respect to the minute operation amount of the adjusting device is obtained by calculating the power flow of the power system or solving a simple linear network (Q-ε network). That is, control sensitivity calculation is performed. This sensitivity calculation is performed in steps 908 and 90.
9, the process returns to step 907, and the process is repeated by the number N of adjusting devices. Then, in step 910, the adjustment device having the highest sensitivity is selected. This selection is executed by the number M of monitoring points where deviation has occurred through step 911, and a control command for the selected adjusting device is output to the control command output device 107 (step 912).

The control command output device 107 executes control by sending, for example, a control pulse corresponding to the control command to each adjusting device based on the processing result of the control calculation execution device 106. Further, the operation status of the adjusting device based on the control calculation result and the actual control result are output and displayed on the result output device 108. That is, as shown in FIG. 8, the change of the input amount of the phase adjustment equipment (1001), the change of the tap of the transformer (1002), the change of the terminal voltage of the AVR generator (1003), The change (1004) of the voltage at the monitoring point is displayed on the monitoring screen 1005 of the result output device 108 or the like. The content displayed on the monitoring screen 1005 is the switch button 1
By operating 006 to 1009, the entire screen can be viewed at once or for each required part.

As described above, according to the monitoring point setting method shown in FIGS. 1 and 2, a monitoring point which requires control or is effective for control is automatically determined according to a change in the state of the power system. It can be set or changed, thereby realizing high-quality power system control such as voltage.

Next, the monitoring point determining apparatus 10 according to the present invention
Another embodiment 4 will be described with reference to FIG. In the present embodiment, a monitoring point is determined for each control execution cycle (time) by using an optimization technique called modern heuristic represented by mathematical programming or a genetic algorithm, or a search algorithm. The example shown in FIG. 9 is an example using a search algorithm. While the monitoring point determination method shown in FIGS. 1 and 2 makes a determination as to whether to add or delete a monitoring point based on the constraint on the system state quantity at the monitoring point, the example in FIG. , While determining the appropriate number and location of monitoring points. That is, based on the reference value and the upper and lower limit values of the system state quantity at the monitoring point, the number and the location of the monitoring points are set so that the deviation from the reference value of each system state quantity is minimized.

As shown in FIG. 9, in step 701, the state of the power system to be controlled is created using the data stored in the database 103. A set N of monitoring point candidates of the voltage bus or the reactive power flow is created based on the system determined in this way (step 702). In the next step 703, variables such as a counter T and a monitoring point list necessary for this processing are initialized. Next, step 704
, A monitoring point candidate that does not need to be monitored in a specific control (for example, voltage control) is detected, and a list of the monitoring point candidate is created as a non-target monitoring point candidate. That is, the monitoring point candidates included in this list are not searched for after step 705.

Next, at step 705, a set S of other monitoring point candidates not included in the list of monitoring point candidates not to be considered is extracted. Then, one element (monitoring point candidate) s is selected from the set S (step 706).
The element s selected at this time can be a single or a plurality of monitoring point candidates. Next, a monitoring point candidate of the selected element s is provisionally set as a monitoring point, and a control simulation is executed based on this (step 707). Note that the execution content of this step 707 is, for example, to execute the processing content of the control calculation execution device 106 of FIG. 3 by simulation. Based on the result of the simulation, a predetermined evaluation function is calculated (step 708), and the evaluation function value as a result is stored in a storage unit such as a memory (step 709). Then, the element s whose examination has been completed is deleted from the set S (step 71).
1) Returning to step 701, another element s is selected, and the same processing is repeated until there is no set S.

After calculating the evaluation functions for all the elements s of the set S of the monitoring point candidates, in step 712, the case where the evaluation function is the smallest or the case where the evaluation function is smaller than that at the time of the previous execution is determined. It is determined whether or not there is. If the result of this determination is affirmative, that is, if there is no case where the evaluation function has decreased from the previous execution, the counter L is incremented by one (step 713), and the counter L reaches the upper limit set value (step 713). In the illustrated example, it is determined whether 2) has been exceeded (step 714). If this judgment is affirmative, that is, if it is determined that there is no more appropriate monitoring point cloud,
In step 721, a monitoring point search end message is output, and the process ends. On the other hand, if the counter L does not exceed the upper limit value, the monitoring point candidate added at the previous search (T-1) is deleted, and the monitoring point whose evaluation function is next good at the previous search is added to the list. Then, the process returns to step 706 to repeat the processing.

If it is determined in step 712 that the evaluation function has decreased in some cases, step 717
To add a monitoring point candidate having the best evaluation function among the evaluation functions to the monitoring point. Then, steps 718, 719
Then, the value of the counter T is incremented by one, and it is determined whether or not the processing for all the monitoring point candidates has been completed. If the processing has not been completed, the process returns to step 704 to repeat the processing of the monitoring point search. Run. If the monitoring has been completed, the monitoring point candidates stored in the monitoring point list are output to the control calculation execution device 106 as set monitoring points (step 7).
20).

As described above, according to the embodiment shown in FIG. 9, it is possible to automatically set a monitoring point having a high evaluation function, thereby controlling the power system with high voltage quality, that is, with little voltage fluctuation. Can be realized. Also, since the evaluation function is obtained by simulation,
The present invention can also be applied at a planning stage such as expansion or reduction of a power system.

[0036]

As described above, according to the present invention,
The monitoring point can be automatically changed in accordance with a change in the state of the power system, thereby realizing high-quality power system control with little voltage fluctuation or the like.

[Brief description of the drawings]

FIG. 1 shows an example of a procedure for automatically setting a monitoring point according to a feature of the present invention, in which a new monitoring point is additionally set to a current monitoring point.

FIG. 2 shows an example of a monitoring point automatic setting processing procedure according to a feature of the present invention, in which a monitoring point is removed from a currently set monitoring point.

FIG. 3 is an overall configuration diagram of a power system control device according to an embodiment configured by a computer including a monitoring point determination device according to a feature of the present invention.

FIG. 4 is a diagram illustrating an example of data on a system state quantity of a power system and data on equipment of a power system to be controlled.

FIG. 5 is a diagram illustrating a control condition set for a system state quantity at a monitoring point.

FIG. 6 is a diagram showing equipment information of a power system to be controlled and a monitoring point setting list.

FIG. 7 is a diagram showing a processing procedure of the control calculation execution device.

FIG. 8 is a diagram illustrating an example of a control result displayed on a display screen of a result output device of the power system control device according to the present invention.

FIG. 9 is a diagram for explaining another embodiment of the processing procedure of the monitoring point automatic setting according to the feature of the present invention.

[Explanation of symbols]

 Reference Signs List 101 power system 102 data reading device 103 database 104 monitoring point determination device 105 input data creation device 106 control calculation execution device 107 control command output device 108 result output device

Claims (8)

[Claims] 1. A system state quantity to be controlled at a monitoring point set in an electric power system is input to a computer, and the computer controls an adjusting device such that the system state quantity is kept within a preset range. In the power system control method, a plurality of monitoring point candidates are set in the power system, the system state quantity at the monitoring point candidate is input to the computer, and the computer calculates the system state amount at the monitoring point candidate. A power system control method, wherein a change is monitored and a monitoring point candidate whose change amount exceeds a set range is set as the monitoring point. 2. A system state quantity to be controlled at a monitoring point set in an electric power system is input to a computer, and the computer controls the adjusting device so as to maintain the system state quantity within a predetermined range. In the power system control method, a plurality of monitoring point candidates are set in the power system, the system state quantity at the monitoring point candidate is input to the computer, and the computer calculates the system state amount at the monitoring point candidate. A power system control method, wherein a change is monitored, and a monitoring point candidate whose time during which the system state quantity is held near upper and lower limits within a set range exceeds a set value is set as the monitored point. 3. A power system control method characterized by combining the power system control methods according to claim 1 and 2. 4. A computer, comprising: a computer which inputs a system state quantity to be controlled at a monitoring point set in an electric power system, and holds the system state quantity within a preset range. In a power system control device that outputs a control command to an adjustment device that controls the system state quantity, a plurality of monitoring point candidates are set in the power system,
The computer is supplied with a system state quantity at the monitoring point candidate to monitor a change in the system state quantity, and sets the monitoring point candidate whose change amount exceeds a set range as the monitoring point. Power system controller. 5. A computer comprising a computer, a system state quantity to be controlled at a monitoring point set in the power system is input to the computer, and the system state quantity is held within a preset range. In a power system control device that outputs a control command to an adjustment device that controls the system state quantity, a plurality of monitoring point candidates are set in the power system,
The system state quantity at the monitoring point candidate is input to the computer to monitor a change in the system state quantity, and the time when the system state quantity is held near the upper and lower limits in the set range exceeds the set value. A monitoring point candidate that is set as the monitoring point. 6. A power system control device comprising a combination of the power system control devices according to claim 1 and 2. 7. A system state quantity to be controlled at a monitoring point set in an electric power system is input to a computer, and the computer controls the adjusting device so as to maintain the system state quantity within a preset range. In the power system control method, a plurality of monitoring point candidates are set in the power system, the system state quantity at each monitoring point candidate is input to the computer, and the computer monitors at least one of the monitoring point candidates. The adjustment device is tentatively set as a point, and the adjusting device is controlled by simulation so as to maintain the system state quantity in the tentatively set monitoring point candidate within a preset range, and the monitoring is performed based on the result of the simulation control. Finding an evaluation function representing the effect of the control by the point candidates, and setting a good evaluation function as the monitoring point. Power system control method. 8. A computer, comprising: a computer which inputs a system state quantity to be controlled at a monitoring point set in an electric power system, and holds the system state quantity within a preset range. A power system control device that outputs a control command to an adjusting device that controls the system state quantity, wherein a plurality of monitoring point candidates are set in the power system, and the system state quantity at each of the monitoring point candidates is input to the computer. The computer temporarily sets at least one of the monitoring point candidates as the monitoring point, and adjusts the system state quantity in the temporarily set monitoring point candidate within a predetermined range. Is controlled by simulation, and an evaluation function representing the effect of the control by the monitoring point candidate is obtained based on the result of the simulation control. A power system control device, wherein a power system is set as the monitoring point.