JPH10143235A - Power system monitoring and controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to take a measure for stabilizing a power system before the system is turned to be in an instable state, by grasping the time sequential change of a margin amount from the present to a point of time in the future and calculating a time margin until becoming instable as an evaluation index. SOLUTION: A future time decision means 14 inputs the future time 15 and adds a time division width in the time division width 16 to it, a power equipment operation state decision means 18 decides the operation state of a power equipment at the decided time and a future power system state preparation means 19 prepares a power system state based on the decided operation state. A transient stability calculation means 5 performs transient stability calculation for an assumed fault to the future power system state 20, a stability discrimination means 21 discriminates stability based on a transient stability calculated result 6 and a stability time margin calculation means 22 calculates the time until becoming instable as a stability time margin from the present time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stability margin and a countermeasure for a power system monitoring and control device.

[0002]

2. Description of the Related Art Conventionally, in a power system monitoring and control device, the transient stability of the power system is evaluated, and the stability margin for the transient stability of the power system is evaluated by the transmission limit of the main trunk line for each assumed failure. The margin up to was used as an index.

FIG. 23 is a functional block diagram relating to the calculation of a stability margin regarding a conventional system monitoring and control device, and FIG. 24 is a flowchart thereof. First, the flow of each function will be described with reference to FIG. First, the current system state creation processing in step S241 creates the current power system state, and then the step S24
Proceed to Step 2 for increasing the tide.

[0004] Here, a system state after the increase of the power flow is created, and a transient stability calculation process of step S243 is performed on this form state. Then, the process proceeds to the stability margin stability determination processing in step S244. In the stability margin stability determination process, the stability calculation result is determined. If the stability calculation result is stable, the process proceeds to the power flow increase change process in step S246. Conversely, if the stability calculation result is unstable, the process proceeds to step S245. The process proceeds to the stability margin calculation process.

When the flow proceeds to the power flow increase change process S246, the power flow increase amount is further increased, and the process returns to the increase process of step S242 again, and the above process is repeated until the stability calculation result becomes unstable. If the flow becomes unstable and the process proceeds to the stability margin calculation process in step S245, the marginal tidal current in a stable state is calculated as the stability margin using the tide increase amount, and the process is terminated.

Next, data exchange of each function will be described with reference to FIG. 23, but before that, the overall configuration will be described. 1 is a current system state creating means, 2 is a current power system state, 3 is a power flow increasing means, 4 is a system state after power flow increase, 5 is a transient stability calculating means, 6 is a transient stability calculating result, and 7 is a stability margin. Amount discriminating means, 8 is a stability margin calculating means, 9 is a display means,
10 is a tidal current increase amount changing means, 11 is a tidal current increase amount, and 12 is a previous tidal current increase amount.

The current system state creation means 1 performs a power flow calculation using the current power system data 13 to create a current power system state 2. The power flow increasing means 3 connects the load based on the generated current power system state 2 to increase the power flow at the assumed failure point by the power flow increase amount 11, and creates the power flow increased power system state 4.

[0008] The transient stability calculation means 5 performs transient stability calculation for a supposed fault with respect to the system state 4 after the power flow increases, and outputs a transient stability calculation result 6. The stability margin stability determination means 7 performs stability determination using the transient stability calculation result 6. If the result is "stable", the process returns to the power flow increase amount changing means 10, and if the result is "unstable", the process proceeds to the stability margin calculating means 8.

[0009] The tidal current increase amount changing means 10 calculates the previous tidal current increase amount 12
The current increase in tide is stored in the, and the increase in tide 11 is increased.
The power flow increasing means 3, the transient stability calculating means 5, and the stability margin stability determining means 7 are repeated for the updated power flow increasing amount. The stability margin calculating means 8 outputs the sum of the previous power flow increment 12 and the current power flow value as the stability margin 9.

[0010]

The stability margin in the above-described power system monitoring and control apparatus uses the transmission limit of the main trunk as an evaluation index in the target power system state. Therefore, in order to prevent the system from becoming unstable, the power flow of the generator could not be suppressed unless the power flow exceeding the transmission limit was monitored by monitoring the main flow.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a power system monitoring and control apparatus capable of taking measures to stabilize a system before the system becomes unstable. The purpose is.

[0012]

According to a first aspect of the present invention, there is provided a power system monitoring and control apparatus which performs an evaluation on a transient stability of a power system, and evaluates the transient stability based on the evaluation result. In a power system monitoring and control device that determines and outputs whether or not a predetermined value has been exceeded, a future time determination unit that sets a future time starting from the current time and an operation state of the power system at the set future time are created. Power equipment operating state determining means, transient stability calculating means for calculating transient stability for a contingency with respect to the created system state, and stability determining means for performing system stability determination based on the calculation result. And a stability time margin calculating means for calculating and outputting a time until the state becomes unstable as a stability time margin from the current time.

In the power system monitoring and control apparatus according to claim 1 of the present invention, the future time determination means 14 sets the current time 15 as an initial value of the future time 17, and thereafter adds the time interval 16. The future time 17 is determined by updating. The power equipment operating state determination means 18 captures schedule data at a time corresponding to the future time 17 from the schedule data 24,
Output as future power system data 23. The future power system state creation means 19 performs a power flow calculation using the future power system data 23, obtains the voltage / phase angle of each node, and outputs it as the future power system state 20. The transient stability calculation means 5 performs a transient stability calculation for a supposed fault with respect to the future power system state 20, and outputs a transient stability calculation result 6. The stability determination means 21 performs stability determination using the transient stability calculation result 6, and returns to the future time determination means 14 when stable, and proceeds to the stability time margin calculation means 22 when unstable. The stability time margin calculation means 22 calculates the difference between the current time 15 and the future time 17 as the time at which the current power system state is temporally closest to the current power system state and the stability determination result becomes an unstable power system state. Is output to the display means 9.

According to a second aspect of the present invention, in the power system monitoring and controlling apparatus according to the first aspect, when the stability determination result is unstable, the system is prevented from becoming unstable. A means for avoiding the above was created. As shown in FIG. 4, a stability time margin until the method 100 of [Claim 1] becomes unstable is output.
Creates a countermeasure for when the stability determination result is unstable.

According to a third aspect of the present invention, there is provided a power system monitoring and controlling apparatus for evaluating the transient stability of a power system, and determining whether the transient stability evaluation exceeds a predetermined value based on the evaluation result. In the power system monitoring and control device that determines and outputs, current power system state creation means for performing a power flow calculation based on the current power system data at the current time, and obtaining and creating the voltage and phase angle of each node, For the system state after the power flow increased by intentionally increasing the dummy load at the assumed failure point, transient stability calculation means for performing transient stability calculation for the assumed failure and outputting the result, and the transient stability calculation result Based on the stability, the power flow increase is further added to create a system after the power flow increase if the result of the determination is stable, and the process is repeated until the transient stability calculation result becomes unstable. A first stage comprising stability margin stability determination means, stability margin calculation means for adding the first power flow value to the previous flow flow increase amount and outputting the result when the stability determination result becomes unstable; A future time determining means for setting a future time as a starting point; a power equipment operating state determining means for creating an operating state of the power system at the set future time; and a power flow of a supposed failure point with respect to the created system state. The future power system state creation means performing the calculation, and comparing the stability margin at the assumed failure point with the power flow at the assumed failure point at the future time starting from the current time, and determining whether the power flow exceeds the stability margin. And a second stage comprising stability time margin calculating means for outputting a time until the state becomes unstable as a stability time margin.

The power system monitoring and control apparatus according to claim 3 of the present invention comprises a future time determining means 14, a power equipment state determining means 18, a future power system state creating means 19, a stability determining means 21,
Since the stability time margin calculation means 22 is the same as that of [Claim 1], the description is omitted here. First, the current power system state creating means 1 performs a power flow calculation using the current power system data 13 and outputs the current power system state 2. Next, the tidal current increasing means 3 creates the tidal current increasing system state 4 in which the tidal current at the fault point is increased according to the tidal current increase amount 11. The transient stability calculating means 5 performs stability calculation for the supposed fault with respect to the system state 4 after the power flow increase, and outputs a transient stability calculation result 6. Then, the stability margin stability determination means 7 uses the transient stability calculation result 6 to determine the stability of the system state 4 after the power flow increase, and when stable, proceeds to the power flow increase amount changing means 10 and repeats the processing. If unstable, the process proceeds to the stability margin calculating means 8. The power flow increase changing means 10 outputs the current power flow increase as the previous power flow increase 12, and further increases the power flow increase 11. The stability margin calculating means 8 calculates the previous tide increase amount.
12 is output to the display means 9 as the stability margin. The stability determination means 21 is based on the stability margin created above,
Without performing the transient stability calculation processing shown in FIG. 1, the system is compared with the predicted power flow in the future power system state 20 to determine whether the system is stable or unstable.

According to a fourth aspect of the present invention, in the power system monitoring and control apparatus according to the third aspect, there is provided an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable. Therefore, after obtaining the stability time margin by the stability time margin calculation means, the avoidance measure creation means 41 is performed to determine the generator output suppression amount for the system state that becomes unstable at a future time.

According to a fifth aspect of the present invention, there is provided a power system monitoring and controlling apparatus for evaluating the transient stability of a power system, and determining whether the transient stability evaluation exceeds a predetermined value based on the evaluation result. In the power system monitoring and control device that determines and outputs whether or not the stability time margin is obtained at a fixed period by the second device described below, when the stability time margin becomes a predetermined value or less, the following second device The configuration is such that the device is switched to the first device. The future time determining means for setting a future time starting from the current time, the power equipment operating state determining means for creating an operating state of the power system at the set future time, and a contingency for the created system state Transient stability calculating means for calculating the transient stability, stability determining means for determining the stability of the system based on the calculation result, and a stability time margin from the current time until the state becomes unstable. And a stability time margin calculating means for calculating and outputting the result. Current power system state creation means that calculates the power flow based on the current power system data at the current time and calculates the voltage and phase angle of each node, and intentionally increases the dummy load to the assumed failure point A transient stability calculation means for performing transient stability calculation for a contingency with respect to the system state after the power flow increase and outputting the result, and determining stability based on the transient stability calculation result; In this case, the power flow increase amount is further added to create a system after the power flow increase, and the stability margin stability determination means which repeats until the transient stability calculation result becomes unstable, and the stability determination result becomes unstable. A first stage comprising stability margin calculating means for adding the first tidal current value to the previous tidal current increase and outputting the same; a future time determining means for setting a future time starting from the current time; Power equipment operating state determining means for creating an operating state of the power system at a future time, future power system state creating means for performing a power flow calculation of a supposed fault point with respect to the created system state, Stability margin comparing the power flow of the assumed failure point at the future time with the current time as a starting point, and a stability determining means for determining whether the power flow exceeds the stability margin, A second stage comprising stability time margin calculating means for outputting time as a stability time margin.

The power system monitoring and control apparatus according to claim 5 of the present invention always obtains the stability time margin by the method 300 of claim 3, and the stability time margin storage means 45 provides the stability time margin. Is stored as the previously calculated stability time margin 44.
Then, when the stability time margin storage data 44 falls within the switching set value 43, that is, when the time at which the stability becomes unstable approaches the switching set value 43, the stability determining means switching means 42 [Claim 1]. And switch to the method 100 to calculate the margin of stability time.

[0020] In the power system monitoring and controlling apparatus according to claim 6 of the present invention, in claim 5, the amount of generator suppression for avoiding an unstable state of the system is obtained as an avoidance measure. And means for creating avoidance measures to be shown to the operator in advance. Therefore, after the stability time margin is calculated by the stability time margin calculation means, the avoidance measure creation means 21 is performed to determine the generator output suppression amount for the system state that becomes unstable at a future time.

According to a seventh aspect of the present invention, in the power system monitoring and controlling apparatus according to the first aspect, the transient stability calculation result at the present time and the transient stability calculation result at the same time calculated in the past are calculated. A stabilization tendency judging means for judging a tendency of the system stability to increase or decrease from the obtained stability evaluation index, and a time step width for changing the time step width to omit the stability judgment depending on the stability tendency. Decision means.

In the power system monitoring and control apparatus according to claim 7 of the present invention, in the process of calculating the stability time allowance of the method 100 of claim 1, the stability time allowance storage means 45 stores the stability time allowance. The stability time margin is stored in the margin storage data 44. Then, the transient stability calculation result storage unit 51 stores the transient stability calculation result 6 as the transient stability calculation result storage data 54. Then, the stabilization tendency judging means 52 calculates the transient stability calculation result 6 and the transient stability calculation result storage data at the future time.
54. Comparing the calculation results of the same time predicted and calculated in the past in 54, and when the stability tends to decrease [Claim 1]
Then, the process proceeds to the future time determination means 14 to continue the processing. If the stability tends to increase, the process proceeds to the time interval determining means 53. If the time interval determining means 53 is in a more stable state as predicted if the stability tends to increase,
The time interval is increased to omit the calculation.

The power system monitoring and control apparatus according to claim 8 of the present invention is based on claim 7 in order to prevent the system from becoming unstable when the stability determination result is unstable. The amount of generator suppression was determined as an avoidance measure, and an avoidance measure creating means was provided to the operator in advance. Therefore, after obtaining the stability time margin by the stability time margin calculation means, the avoidance measure creation means is performed, and the generator output suppression amount for the system state that becomes unstable at a future time is obtained.

According to a ninth aspect of the present invention, in the power system monitoring and control apparatus according to the first aspect, the initial phase angle of the generator internal phase angle at the current time is compared with the previously calculated phase angle. In the case where there is no significant change, an initial phase angle comparing means is provided which adopts the past calculation result and omits the transient stability calculation processing.

The exchange of data of each function in the power system monitoring and control apparatus according to claim 9 of the present invention will be described with reference to FIG. The part surrounded by the dotted line is the same as [Claim 1], and the description is omitted here. [Claim 1] Method 100
In the process of calculating the stability time margin in the above, the initial phase angle storage means 60 stores the initial phase angle of the transient stability calculation result 6 as the initial phase angle storage data 63. The generator initial phase angle calculation means 61 calculates the generator initial phase angle 62 by performing the transient stability calculation only at the initial time with respect to the future power system state 20. The initial phase angle comparing means 64 calculates the generator initial phase angle 62 and the generator initial phase angle at the same time calculated in the past,
It is extracted from the transient stability calculation result storage data 63 and compared. The initial phase angle is determined depending on the initial state of the target system for stability calculation.If the initial phase angle does not change significantly, there is no significant change in the system state and the transient stability does not change. I can say. Therefore, when the initial phase angle has not changed significantly, the process returns to the future time determination means 14 without performing the transient stability calculation, and continues the processing.

According to a tenth aspect of the present invention, in the power system monitoring and control apparatus according to the ninth aspect, when the stability determination result is unstable, the system is prevented from becoming unstable. The amount of generator suppression was determined as an avoidance measure, and an avoidance measure creating means was provided to the operator in advance. Therefore, after obtaining the stability time margin by the stability time margin calculation means, the avoidance measure creation means is performed, and the generator output suppression amount for the system state that becomes unstable at a future time is obtained.

[0027] The power system monitoring and control apparatus according to claim 11 of the present invention is characterized in that, in claim 1, attention is paid to the local maximum point of the forecasted demand curve within the daily demand change, and the time of the local maximum demand point is calculated. Means for creating the state of the power system, and when the stability determination result of the transient stability for the created power system is unstable, the future power system at the time when the time is returned from the maximum point by a certain time interval. Means for creating a state, and a time at which the stability is determined as a result of performing the stability determination on the future power system state, based on the demand maximum point at which the transient stability becomes unstable, A stability time margin calculating means for calculating a stability time margin from the time being the state.

The power system monitoring and control apparatus according to claim 11 of the present invention will be described with reference to FIG. The part surrounded by the dotted line is the same as [Claim 1], and the description is omitted here. Maximum demand point calculation means 71
Fetches the forecast demand data 75, calculates the maximum point of the forecast demand, and outputs the maximum point time 72. The power equipment operation state determination means 18, the future power system state creation means 19, and the transient stability calculation means 5 are performed with respect to the maximum demand point, except that
Its operation is the same as that of [Claim 1]. Using the transient stability calculation result 6 calculated for the maximum demand point, the stability determination means 21 terminates the process if it is stable, and returns to [Claim 1] if it is unstable. However, in this claim, the time step width 16 in [Claim 1] is a negative value, and
By returning the time from 72 as the starting point, the difference between the time that is in a stable state with respect to the maximum demand point at which the stability becomes unstable and the current time is calculated as the stability time margin.

The power system monitoring and control apparatus according to claim 12 of the present invention provides the power system monitoring control apparatus according to claim 11 for preventing the system from becoming unstable when the stability determination result is unstable. The amount of generator suppression was determined as an avoidance measure, and an avoidance measure creating means was provided to the operator in advance. Therefore, after the stability time margin is calculated by the stability time margin calculation means, the avoidance measure creating means is performed to determine the generator output suppression amount for the unstable system state at the maximum demand point.

The power system monitoring and control apparatus according to claim 13 of the present invention is the power system monitoring and control apparatus according to claim 11, wherein the maximum power point limit power flow calculating means for obtaining the maximum power flow of the assumed failure point in the power system state of the maximum power point. And a designated margin holding time calculating means for calculating a difference between a current time and a time satisfying a preset margin by returning the time from the time of the maximum demand point as a stability time margin.

The power system monitoring and control apparatus according to claim 13 of the present invention will be described with reference to FIG. Here, the portion surrounded by the dotted line is the same as [Claim 11] except for the stability determining means 21, and the description is omitted here. [Claim 11] The stability determining means according to claim 11.
When the result of the stability determination at the maximum demand point 21 is stable, the flow proceeds to the maximum demand point limit power flow calculating means 81. The maximum demand point critical power flow calculating means 81 obtains the critical power flow at the assumed failure point in the power system state at the maximum power point, adds a specified margin to the critical power flow, and outputs the result as a specified margin power flow 83. The designated margin holding time calculation means 82 calculates the time when the margin designated power flow 83 is generated by creating a future system state, and sets the difference between the time at which the margin can be held and the current time as the stability time margin 16 as the display means 9. Output to

[0032]

FIG. 1 is a block diagram showing an embodiment according to [claim 1]. In FIG. 1, the same parts as those in FIG. In the figure, 14 is a future time determining means for inputting a current time 15 and adding a time step width to a time step width 16 to this, and 18 is a power equipment operation state determination for determining the operation state of the power equipment at the determined time. Means, 19 is a future power system state creation means for creating a power system state based on the determined operation state, 5 is a transient stability calculation means for performing transient stability calculation for a contingency for the created future power system state 20,
21 is a stability determining means for performing stability determination based on the transient stability calculation result 6, 22 is a stability time margin calculating means for calculating the time until instability as a stability time margin from the current time, 23 is The future power system data, which is obtained from the schedule data 24, the current power system data 25, and the future time 17.

FIG. 2 shows the contents of the schedule data in the first embodiment. In FIG. 2, the schedule data 24 includes phase setting data 24a, total load demand prediction data 24b, generator data 24c, and tap setting data 24d.

The operation of the embodiment will be described with reference to FIGS. Consider the system at the current time t. The future time determination means 14 adds the time interval (Δ
H) is added to advance the time, and the addition result (t + Δt) is stored in the future time 17 (step S31). Where Δt =
ΔH × n, n = 0, 1, 2,..., M. ΔH × m is a preset upper limit of the stability time margin. Although the accuracy of the future time determination means increases as the time interval (ΔH) becomes smaller, it may be about 10 minutes in consideration of the load on the computer.

The power system equipment operation state determining means 18 sets the current power system data 25, which is online data received as transmission data from the local power system, as fixed data in advance, or as variable data by input from a screen. From the schedule data 24, the future power system data 23, which is the operating state of the power equipment at the current and future times, is determined (step S32).

The current power system data 25 is data on the connection state of the system and is output as it is as future power system data 23. The schedule data 24 includes total load demand forecast data 24b, generator data 24c, tap setting data 24d, and phasing operation data 24a. Using these, the power equipment operating state determining means 18 determines what kind of future power system data 23. Will be described.

First, the active power and the reactive power of the load at the time (t + Δt) determined by the future time determining means 14 are determined from the total load demand forecast data 24b. First, the total demand data at the time (t + Δt) is extracted from the load total demand forecast data 24b for one day and set in advance as fixed data or set as variable data for each load by input from a screen. The load is distributed according to the total demand sharing ratio (the ratio of each load to the total demand), and the active power of the load at time (t + Δt) is determined.

Then, the reactive power of the load is determined in accordance with the Q / P ratio (the ratio between the reactive power and the active power) which has been previously set as fixed data or set as variable data by input from a screen. Next, the active power and voltage of the generator at the time (t + Δt) determined by the future time determining means 14 are determined from the active power of the load determined above and the generator data 24c.

Using the active power of the load at the time (t + Δt), the generator output for each generator is calculated by the economic load distribution calculation by the equal incremental fuel cost method. The calculation of the economic load distribution by the equal incremental fuel cost method is a well-known technique, and thus the description is omitted. Then, the generator voltage at the time (t + Δt) is extracted from the AVR reference voltage of each generator set as fixed data in advance or set as variable data by input from the screen.

Next, whether the data is set in advance as fixed data,
Or 1 set as variable data by input from the screen
The data at the time (t + Δt) is extracted from the tap setting data 24a, which is the operation data of the day tap, and the tap position of each tap at the time (t + Δt) is determined.

Finally, from the phase setting data 24a, which is the operation data of the phase of the day set in advance as fixed data or set as variable data by input from the screen, the data at the time (t + Δt) Is taken out, and the input amount of each phase at time (t + Δt) is determined.

The future power system state creating means 19 outputs the time (t +
Att), the power flow is calculated based on the future power system data 23, and the voltage and phase angle of each node are obtained after Δt,
A future power system state 20 is created (step S33). The transient stability calculating means 5 performs numerical integration of the differential equation by the Runge-Kutta method with respect to the created contingency for the future power system state 20, thereby simulating the fluctuation of the generator (step S34).

The temporal change of the simulated internal phase angle of the generator is output as the transient stability calculation result 6. For the method of calculating the transient stability, see G. W. Stagg, A .; H. E
"Computer Methods" by l-Abiad
in Power Systems Analysis
s "(McGraw-Hill Book Compa)
ny, New York) and so on, and a description thereof will be omitted. The transient stability calculation can be performed a plurality of times by setting a plurality of tentative faults. However, in order to simplify the description, the description will be made with one tentative fault.

Next, the stability determination means 21 checks whether or not the internal phase angle of the generator exceeds a preset threshold value (for example, 180 degrees) based on the transient stability calculation result 6 (see FIG. 6). Step S35). If not, it is determined as "stable", and if it is, it is determined as "unstable".

In the case of "stable", the process proceeds to the future time determining means 14. In the case of "unstable", the stability time margin calculating means 22
Go to (Step S36). The stability time margin calculation means 22 outputs the difference between the future time 17 and the current time 15 at which the time becomes unstable as the stability time margin. If the check result of the stability determination means 21 is “stable”, the future time determination means 14
Assuming +1 as a new n, a new Δt = ΔH × n is obtained,
The future time 17 is newly stored.

For the future time 17 updated by the future time determining means 14, the power equipment operating state determining means 18, the future power system state creating means 19, the transient stability calculating means 5, and the stability determining means 21 are repeated. The current time 15
Is obtained at a fixed period (for example, every 15 minutes), so that the stability of the power system that changes every moment can be monitored. For example, it is assumed that the result of obtaining the stability time margin at the current time of 0:00 is as shown in Table 1.

[Table 1]

At this time, the stability time allowance is one hour and fifteen minutes, which means the time required until the stability becomes unstable. If the result at the time 0:15, which is the next cycle, is shown in Table 2, the stability margin is one hour.

[Table 2]

In this embodiment, the generator output calculated by the economic load distribution calculation by the equal incremental fuel cost method is used. However, it is calculated by another distribution method, for example, the optimal power flow calculation by the secondary programming method. Generator output can also be used. The AVR reference value, tap schedule data, and phase adjustment schedule data also include
A reference value determined based on the voltage control method may be used.

According to this embodiment, the time until the system becomes unstable is calculated as an evaluation index of stability time margin by capturing the time series change of the margin from the present to the future. (1) The stability can be evaluated in consideration of a change in daily demand.

FIG. 4 is a block diagram showing an embodiment of a power system monitoring and control apparatus according to [claim 2]. In this example, FIG.
In the above configuration, when the stability determination result is unstable, it is avoided. Incidentally, reference numeral 41 denotes an avoidance measure creating means. Other configurations are the same as those in FIG.

The operation of the embodiment will be described with reference to FIGS. In FIG. 1, when the stability determination result is “unstable”,
Although the stability time margin at the current time is output, in the present embodiment, in addition to this, the avoidance measure means 41 creates an avoidance measure and presents a stabilization measure to the operator. In the present embodiment, as an avoidance measure, an example will be described in which a measure for preventing the power system from becoming unstable by suppressing the output of a step-out generator is created. Therefore, in the flowchart of FIG.
The only difference from the flowchart of FIG.

FIG. 6 shows the contents of the avoidance measure creating means 41. First, in the step-out generator extraction process of step S61, the output of the step-out generator at a future time determined to be unstable is extracted as the step-out generator output 62. In the post-suppression output calculation process in step S63, the post-suppression output 64 is calculated from the suppression rate 692 by the following equation.

## EQU1 ## Prdi = Poi-hi.times.Poi.times.Krd where Prdi: output after suppression of step-out generator i. Poi: Output before suppression of step-out generator i. Krd: inhibition rate. hi: hi = 1 when the target is the suppression target, hi when the target is not the suppression target
= 0. If Prdi <0, Prdi = 0

In the output-suppressed system state creation processing in step S65, a power flow calculation is performed using the calculated suppressed output 64, the voltage and phase angle of each node are obtained, and the output-suppressed system state 66 is created. In the transient stability calculation process of step S67, the transient stability calculation is executed for the supposed failure in the post-output suppression system state 66, and the result is output as the transient stability calculation result 68. The transient stability calculation can be performed a plurality of times by setting a plurality of tentative faults. However, in order to simplify the description, the description will be made with one tentative fault.

In the stability determination process in step S69, it is checked whether or not the internal phase angle of the generator exceeds a preset threshold value using the transient stability calculation result 68.
If not, it is determined as "stable", and if it is, it is determined as "unstable". In the case of "unstable", the flow proceeds to the suppression rate change processing in step S693. If "stable", step S69
The process proceeds to a zero suppression amount calculation process.

If the result of the stability determination is "unstable", the suppression rate change processing in step S693 changes the suppression rate 694, and for the changed suppression rate 692, the post-suppression output calculation processing in step S63 and the output suppression processing in step S65. Post system status creation processing,
The transient stability calculation process of step 67 is repeated.

The suppression rate is changed by setting an initial value and a change step width in advance. For example, if the initial value is 0.1 and the step size is 0.05, 0.10, 0.15, 0.20,
It will be changed to 0.25. If the stability determination result is "stable", the suppression amount calculation process of step S690 calculates the suppression amount 691 by the following equation.

ΔPrdi = Poi−Prdi where ΔPrdi: the amount of suppression of the step-out generator i. Poi: Output before suppression of step-out generator i. Prdi: output after suppression of step-out generator i.

According to the present embodiment, not only the effect of [Claim 1] by calculating the stability time margin, but also a countermeasure is created when the stability determination result is unstable. It is possible to evaluate stability and take measures for stabilization in consideration of changes in demand.

FIG. 7 is a block diagram showing an embodiment of a power system monitoring and control device according to [claim 3]. In the present embodiment, a first stage for finding a marginal tide at the current time;
And a second stage for obtaining a margin of stability time. The first stage is shown in FIG. 23 described as a conventional device and is shown within a dashed line. The second stage has a configuration in which the transient stability calculation means 5 and the transient stability calculation result 6 are excluded from the configuration shown in FIG. And the reference numerals of the figures are FIG.
23 is supported. Therefore, the configuration has already been described, and a description thereof will be omitted.

Next, the operation will be described with reference to FIGS. The current power system state creation means 1 performs a power flow calculation based on the current power system data 13 at the current time, obtains the voltage / phase angle of each node, and creates the current power system state 2 (step S241). It is assumed that the flow at the assumed failure point at this time is, for example, 1000 MW. The tidal current increasing means 3 intentionally increases the tidal flow at the supposed fault point by (50 MW) with the tidal flow increase amount 11 by connecting the dummy load (50 MW) to the bus connected to the supposed fault point, and the State 4 is created (step S242). FIG. 9 shows a connection diagram of the dummy load. The tide at the assumed failure point at this time is 1050
MW.

The transient stability calculation means 5 performs a transient stability calculation for the created contingency for the system state 4 after the power flow is increased, and outputs a transient stability calculation result 6 (step S243). The transient stability calculation can be performed a plurality of times by setting a plurality of tentative faults. However, in order to simplify the description, the description will be made with one tentative fault.

The stability margin judgment determining means 7 checks based on the transient stability calculation result 6 whether or not the internal phase angle of the generator exceeds a preset threshold value. "Stable" if not exceeded, "Unstable" if exceeded
Is determined. If the stability determination result is “stable”, the power flow increase amount changing means 10 changes the power flow increase amount 11 from 50 MW to 100 MW.
(Step S246). Further, the power flow increase amount (50 MW) before the change is stored in the previous power flow increase amount 12.

Returning to the power flow increasing means 11 again, the power flow increase amount (100 MW) is added to the power flow (1000 MW) at the assumed failure point, and the post-power flow system state 4 is created. At this time, the flow at the assumed failure point is 1100 MW. Thereafter, the transient stability calculating means 5 and the stability margin stability determining means 7 are repeatedly executed. This process is repeated until the stability determination result becomes “unstable”.

If the stability determination result becomes "unstable" when the power flow increase amount 11 is increased to 350 MW, the flow proceeds to the stability margin calculation means 8, and the stability margin calculation means 8 sets (300MW) and tidal current value (1000M
W), and 1300 is displayed on the display means 9 as a stability margin.
Output MW.

Next, the second stage of determining the stability by using the stability margin 9 determined above to determine the stability time margin will be described. The difference from FIG. 3 in which the stability time margin is obtained is that the transient stability calculation means 5 is not used. The future time determination means 14 (step S31), the power equipment operation state determination means 18 (step S32), and the future power system state creation means 19 (step S33) are the same as those in FIG.

The stability determining means 21 (step S35) compares the margin of stability at the assumed failure point with the flow of the assumed failure point at the future time starting from the current time, and the tide exceeds the margin of stability. In this case, it is determined as “unstable”, and when not exceeded, “stable”.

If the result of the determination is "stable" in the stability determination means 21, the flow advances to the future time determination means 14, in which the time step 16 is added to the future time 17 to advance the time, and the addition result is output as a new future time. And repeat the process. If the result of the determination by the stability determination means 21 is “unstable”, the stability time margin calculation means 22 outputs the time difference to the output means 9 as the stability time margin.

According to the present embodiment, the power flow calculation is performed instead of the transient stability calculation, and the number of times of the transient stability calculation is reduced. Therefore, the present embodiment has the effect of the one shown in FIG. Time can be reduced.

As another embodiment, in addition to the above configuration, an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable may be provided. As described above, in [Claim 3], when the stability determination result is "unstable", the stability time margin at the current time is output, but in addition, the avoidance measure creating means creates the avoidance measure and operates. Staff members were presented with stabilization measures. The operation of the avoidance measure creating means is as described in [Claim 2].

According to the present embodiment, not only the effect of [Claim 3] by calculating the stability time margin but also an avoidance measure is created when the stability determination result is unstable. It is possible to evaluate stability and take measures for stabilization in consideration of changes in demand.

FIG. 10 is a functional block configuration diagram according to [claim 5]. In the present embodiment, the device 100 of [Claim 1]
In addition to the device 300 of claim 3 and the device 300 of claim 3, a stability time margin storage means 45 for storing the calculated stability time margin, and when the stability time margin falls below a certain value, the means of claim 3 Item 1] Stability determining means switching means for switching to the means
Consists of 42. In addition, 43 is a switching set value, and 44 is stability time margin storage data.

Next, an embodiment will be described with reference to FIGS. As the whole process, the stability determining means switching means 42 uses the current time, the switching set value 43, and the previously calculated stability time margin to perform either the device of claim 1 or the device of claim 3. Is determined (step S111), [Claim 1]
Of the apparatus 100 or the apparatus 300 of claim 3 (steps S112 and S113). The stability time margin storage means 45 outputs the stability time margin calculated by the device 100 of claim 1 or the device 300 of claim 3 to the previous stability time margin 44 (step S114). By executing the above-described series of processes at regular intervals (for example, every 15 minutes), it is possible to monitor the stability of the power system that changes every moment.

FIG. 11 shows a flowchart of the stability determining means switching means 42. First, it is determined whether or not the previously calculated stability time margin, which is the calculation result of the previous execution in the execution at the fixed cycle, has been calculated (step S121). If the last calculated stability time margin has not been calculated, [Claim 3] is set as the determination means, and the process ends (step S122). If the stability time margin storage data 44 has been calculated, the stability time margin storage data 44> the switching setting value 43 is determined using the stability time margin storage data 44 and the switching setting value 43 (step S123). If the above is satisfied, [Claim 3] is set as the discriminating means (step S124). If not, set [Claim 1] (step S125).
). The switching setting value 43 is set in advance, and is set from several minutes to several tens of minutes in accordance with the cycle of the fixed cycle execution and the system characteristics of the calculation target system.

Thus, the stability determining means switching means 42 switches the stability determining means. That is, when there is a time until the device becomes unstable, a stability time margin is obtained by the device 300 of [Claim 3], and when the time of instability approaches, the stability time is obtained by the device 100 of [Claim 1]. Ask for room.

According to the present embodiment, the stability determining means is switched by the switching means. Therefore, the calculation time is reduced by the means of claim 3 to obtain a stability time margin, and the stability time margin is calculated. When approaching, the stability time margin can be obtained with high accuracy by the means of claim 1.

As another embodiment, in addition to the above configuration, an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable may be provided. As described above, in [Claim 5], when the stability determination result is "unstable", the stability time margin at the current time is output. In addition, the avoidance measure creating means creates the avoidance measure, and operates. Staff members were presented with stabilization measures. The operation of the avoidance measure creating means is as described in [Claim 2].

According to the present embodiment, not only the effect of [Claim 4] by calculating the stability time margin, but also an avoidance measure is created when the stability determination result is unstable. It is possible to evaluate stability and take measures for stabilization in consideration of changes in demand.

FIG. 13 is a block diagram showing an embodiment of a power system monitoring and control apparatus according to [claim 7]. In the present embodiment, a stabilization tendency is obtained from the calculation result of the transient stability and the stability value obtained in the past. Therefore, as a configuration, a portion surrounded by a chain line (this is [Claim 1]
) And the following configuration is added.

In addition to claim 1, the transient stability calculation result storage means 51 for storing the maximum value of the generator internal phase angle as the transient stability calculation result, and the transient stability calculation result at the current time and prediction in the past A stabilization tendency judging means 52 for judging whether or not the stability has increased by using the maximum value of the generator internal phase angle as a stability evaluation index from the calculated transient stability calculation result at the same time; and It comprises stability time margin storage means 45 for storing the degree time margin, and time step width determination means 53 for increasing the time step width when the stability of the system is increasing. Incidentally, 54 is transient stability calculation result storage data.

Next, the operation will be described with reference to FIG.
Steps S31 to S36 are the same as those in FIG. When the execution is considered to be performed at a fixed cycle of 15 minutes, it is assumed that the execution is first performed at 0:00. Table 3 shows the calculation result of [Claim 1] at this time. Here, the mark ○ indicates that the transient stability calculating means 5 for the time is performed. The time interval for determining the future time is 15 minutes.

[Table 3]

The stability time margin storage means 45 stores the stability time margin 16 calculated by the stability time margin calculation means 22 in the stability time margin storage data 44. Further, the transient stability calculation result storage unit 51 stores the maximum value of the generator internal phase angle, which is the transient stability calculation result 6 calculated by the transient stability calculation unit 5, in the transient stability calculation result storage data 54. In the example above,
The stability time margin of 1 hour and 15 minutes is stored, and the maximum value of the generator internal phase angle at each time is stored with time.

The stabilization tendency judging means 52 calculates the transient stability calculation result 6 at the current time and the generator internal phase angle maximum which is the stability calculation result at the same time extracted from the transient stability calculation result storage data 54 and calculated at the same time in the past. The values are compared, and the time interval determining means 53 increases the time interval.

A series of operations will be described with reference to the above example. When the current time becomes 0:15 and the stability time margin of the display means 9 is obtained again by executing the fixed period, the transient stability calculation result 6 at the current time is used. At this time, the maximum phase angle of the generator internal phase angle is 102 degrees, and the calculation result at the same time predicted by the stabilization tendency determination means 52 from the transient stability calculation result storage data 54 at 0:00, that is, 100 degrees. Compare.
Here, the result at the current time is large, and it can be said that the stability tends to decrease. Therefore, the time interval is not changed, the process returns to the future time determination means 14, and the process proceeds to the next time, 0:30.

The future time determination means 14, the power equipment operation state determination means 18, the future power system state creation means 19, the transient stability calculation means 5, and the stability determination means 21, which fall within the scope of claim 1, are provided. When the prediction calculation at 0:30 is performed, the maximum value of the generator internal phase angle is 108 degrees, and the stability increases compared with the result of the same execution stored by the stabilization tendency determination means 52 of 110 degrees. It is determined to be a trend, and therefore, if the result calculated in the past is stable, it is considered to be stable even now.

Then, the time step width is increased so that the time step width determining means 53 proceeds with the processing until the time calculated and stored in the past becomes unstable. In this example, the process proceeds until 1:15. Similarly, when the calculation is performed at 1:15, the maximum value of the generator internal phase angle becomes unstable at 140 degrees, and the stability time margin calculation means 22 sets the stability time margin 16 to 1
The time (the difference between the current time 0:15 and the future time 1:15) is set, and the stability time margin storage means 45 outputs the data to the stability time margin storage data 44. Table 4 shows the calculation results at 0:15 described above.

[Table 4]

As a criterion for determining an unstable tendency,
In the present embodiment, the generator internal phase angle maximum value δold at the same time calculated in the past is compared with the currently calculated generator internal phase angle maximum value δnew at the same time,
If δnew> δold, it was determined to be unstable. This is
New-δold> ε, and the determination constant ε can be set according to the characteristics of the target system.

According to the present embodiment, an increase / decrease tendency of the system stability is determined by using the transient stability calculation result calculated in the past, and if the stability tends to increase, the time interval is determined. , The transient stability calculation is efficiently performed in the calculation of the stability time margin, and the calculation processing time can be reduced.

As another embodiment, in addition to the above configuration, an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable may be provided. As described above, in [Claim 7], when the stability determination result is "unstable", the stability time margin at the current time is output. In addition, the avoidance measure creating means creates the avoidance measure and operates. Staff members were presented with stabilization measures. The operation of the avoidance measure creating means is as described in [Claim 2].

According to the present embodiment, not only the effect of [Claim 5] by calculating the stability time margin, but also an avoidance measure is created when the stability determination result is unstable. It is possible to evaluate stability and take measures for stabilization in consideration of changes in demand.

FIG. 15 is a block diagram showing an embodiment of a power system monitoring and control apparatus according to claim 9. In the present embodiment, the generator initial phase angle at the same time calculated in the past is compared with the initial phase angle when the transient stability calculation is performed at the initial time based on the future power system state, and there is no change in the result. In this case, the calculation of the transient stability is omitted. Therefore, as a configuration, the following configuration is added to a portion surrounded by a dashed line (this is the configuration of [Claim 1]).

In addition to the first aspect, an initial phase angle storage means 60 for storing an initial phase angle of the internal phase angle of the generator as a result of the transient stability calculation, and a transient stability calculation performed only at the initial time to generate the initial stability of the generator. The generator initial phase angle calculating means 61 for calculating the phase angle, and the initial phase angle comparing means 64 for comparing the calculated generator initial phase angle 62 with the generator initial phase angle 63 stored at the same time in the past.

Next, the operation will be described with reference to FIG.
Steps S31 to S33 have already been described, and a description thereof will be omitted. Here, the initial phase angle storage means 60 stores the initial phase angle of each generator internal phase angle, which is the transient stability calculation result 6 created by the transient stability calculation means 5, in the initial dependent angle storage data 63.

In step S161, the generator initial phase angle calculating means 61 calculates the transient stability only at the initial time based on the future state of the power system to calculate the initial phase angle of the generator. This initial phase angle is determined depending on the initial state of the system to be subjected to the stability calculation.
The change is examined at 162. Here, if the initial phase angle does not change significantly, it can be said that there is no significant change in the system state and the transient stability has not changed.

Therefore, the initial phase angle comparing means 64 compares the generator initial phase angle at a certain time created above with the previously calculated generator initial phase angle at the same time extracted from the initial phase angle storage data 63, and If the following expression is satisfied, the past result is adopted, and the process proceeds to the future time determination process (of step S31) without performing the transient stability calculation process at that time (step S163), and the calculation of the next time is performed. start.

Σ | (δ1−δ2) |> ε where δ1: the initial phase angle of the generator at the same time extracted from the transient stability calculation result storage data. δ2: generator initial phase angle by generator initial phase angle calculation means. ε: determination constant. Σ: Total for all generators.

Here, the judgment constant is set according to the characteristic of the system object. The transient stability calculation usually involves a simulation calculation for several seconds and requires a large amount of calculation. However, since the generator initial phase angle calculation means calculates only the phase angle at the initial time, it is obvious that the calculation amount is reduced. If the change is equal to or more than the predetermined value in step S162, the process proceeds to step S164 to calculate the transient stability. In step S165, the initial phase angle storage process is performed. In S167, the stability time margin is calculated.

According to the present embodiment, the stability time margin is always obtained, but when the initial phase angle of the generator internal phase angle has not changed significantly from the previously calculated initial phase angle at the current time. Assuming that there is no significant change in the system state and that the transient stability does not change, it is not necessary to newly calculate the stability time margin, so that it is possible to reduce the calculation time in obtaining the stability time margin.

As another embodiment, in addition to the above configuration, an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable may be provided. As described above, in [Claim 9], when the stability determination result is "unstable", the stability time margin at the current time is output. In addition, the avoidance measure creating means creates the avoidance measure and operates. Staff members were presented with stabilization measures. The operation of the avoidance measure creating means is as described in [Claim 2].

According to the present embodiment, not only the effect of [Claim 6] by calculating the stability time margin, but also a countermeasure is created when the stability determination result is unstable. Stability comparison and stabilization measures can be performed in consideration of changes in demand.

FIG. 17 is a block diagram showing an embodiment of a power system monitoring and control apparatus according to claim 11. In the present embodiment, in addition to the configuration of [Claim 1], there is provided a demand maximum point calculating means 71 which fetches forecast demand data and calculates a maximum point of the forecast demand.

Next, the operation will be described with reference to FIG.
First, the demand maximum point calculating means 71 uses the predicted demand data 75 to find the closest demand maximum point from the current time, and outputs that time as the maximum point time 72 (step S181).
). Regarding the maximum point time 72, the power equipment operating state determining means 18 creates the maximum point system data 73 based on the schedule data 24. Further, the future power system state creating means 19 creates the local maximum power system state 74 (step S183), and the transient stability calculating means 5 outputs the transient stability calculation result 6 of the maximum demand point (step S184).

The operation of these means is the same as that of claim 1, except that the future time 17 is changed to the maximum point time 72. The stability judging means 21 judges the stability at the maximum demand point based on the transient stability calculation result 6 calculated in this way (step S185). If it is stable, the process ends. If it is unstable, the following process is performed (step S185).

When the stability of the system at the maximum demand point is unstable, the time is returned to the time when the system becomes stable, and the stability time margin is calculated from the time and the current time. In claim 1, the maximum point time 72 is used as the initial value of the future time determination means 14.
Is set, and the time step width 16 is set to a negative value.

Thus, the future time setting means 14 sets the time back from the maximum point time 72 to the current time 15. Then, the stability time margin calculating means 22 outputs the difference between the time at which the stability becomes stable from the time of the maximum demand point at which the stability is unstable and the current time as the stability time margin. The operation of the other means is as described in [Claim 1], and the description is omitted here.

According to the present embodiment, since the stability time margin is obtained based on the maximum demand point, the stability comparison focusing on the point of the maximum demand point in the change of daily demand can be performed. .

FIG. 19 is a block diagram showing an embodiment of a power system monitoring and control apparatus according to claim 12. In the present embodiment, when the system at the maximum demand point is stable, the limit power flow at the assumed failure point is obtained for the system at the maximum demand point, and the time is predicted until the margin is set to a predetermined value. A state is created, and a stability time margin from the current time having a preset margin is calculated.

Therefore, the configuration is basically based on [Claim 7] surrounded by a dotted line, and based on this, the maximum demand point limit power flow calculating means 81 for obtaining the maximum power flow of the assumed failure point in the power system state of the maximum demand point; A designated margin holding time calculating means 82 for calculating the difference between the time which returns the time from the point time and satisfies the preset margin and the current time as the stability time margin is added.

Next, the operation will be described with reference to FIG.
In FIG. 19, if the result of the stability determination at the maximum demand point becomes stable, the maximum demand point limit power flow calculating means 81 and the designated margin holding time calculating means 82 operate. First, the demand maximum point limit calculation means 84 will be described. FIG. 20 is a flowchart showing the processing contents of the maximum demand point limit power flow calculating means 84.

In the third embodiment, the processing for obtaining the limit power flow at the assumed failure point for the current system state has been described. Here, the limit power flow for the state of the maximum demand point is obtained. Power flow increasing means 84, transient stability calculating means 5, stability margin stability determining means 87, power flow increasing amount changing means 893,
The operation of the stability margin calculating means 88 is as already described in [Claim 3], except that the state of the maximum demand point is targeted.

Steps S181 to S185 shown in FIG. 22 are the same as those shown in FIG. Further, as shown in FIG. 22, when the maximum demand point limit power flow calculation process is stable in step S185 of FIG.
Step S186 is inserted between them, and in the following process of calculating the reserved margin holding time, step S187 is inserted after step S186.

The specified margin power flow calculating means 890 includes a stability margin 89 calculated above and a preset specified margin 891.
Is output as the specified margin power flow 892. For example, when the stability margin 89 is 1000 MW and the designated margin 891 is 200 MW, the designated margin flow 892 is 800 MW.

Next, the designated margin holding time calculating means 82 shown in FIG. 19 will be described. FIG. 21 is a flowchart of the designated margin holding time calculating means 82. Although the process for obtaining the power flow of the system status at the future time 17 based on the current system status has already been described in [Claim 3], here, the time is returned from the time of the local maximum point to obtain the power flow at that time. The future time determination means 14, the power equipment operation state determination means 18, the future power system state creation means 19, and the stability time allowance calculation means 22 start from the time of the maximum demand point and set a negative value as the time step width. Except for returning the time, the operation is as described in [Claim 3].

The stability determining means 896 compares the specified marginal power flow 83 with the power flow in the future power system state 20, and determines the specified marginal power flow 83.
If smaller, the process proceeds to the stability time margin calculating means 22 as stable. If it is larger than the specified margin power flow 83, it returns to the future time determination means 14 as unstable. In this way, the difference between the time at which the stability time margin calculation means 22 becomes stable and the current time 15 is output as the stability time margin 16.

In the above example, the specified margin power flow 83 is 800 M
Since it is set to W, it is determined to be unstable if the tidal current value is larger than 800 MW, and to be stable if it is smaller than 800 MW. If the difference between the stable time and the current time is one hour, the stability time margin 16 is one hour, and one hour from the present is the marginal power flow 100
This means that a margin of 200 MW can be maintained for 0 MW.

According to the present embodiment, in addition to the effect of the method according to the above [Claim 7], which is performed when the system at the maximum demand point is unstable, the assumption for the system at the maximum demand point is stable when the system is stable. The limit power flow at the fault point is obtained, the time is returned until the preset margin is satisfied, a predicted state is created, and the stability time margin from the current time having the preset margin is calculated. The stability evaluation focusing on the point of the maximum demand point in the change of the demand can be performed.

[0114]

As described above, according to the present invention, the power system monitoring and control apparatus captures a time-series change in the amount of margin from the present to the future, and provides a time margin until the power becomes unstable. Can be calculated as an evaluation index,
The stability can be evaluated in consideration of a change in daily demand.

[Brief description of the drawings]

FIG. 1 is a functional block configuration diagram according to [claim 1] of the present invention.

FIG. 2 is a configuration diagram of schedule data according to [claim 1] of the present invention.

FIG. 3 is a flowchart showing processing contents according to [claim 1] of the present invention.

FIG. 4 is a functional block configuration diagram according to [claim 2] of the present invention.

FIG. 5 is a flowchart showing processing contents according to [claim 2] of the present invention.

FIG. 6 is a flowchart showing processing contents of an avoidance measure creating means according to [claim 2] of the present invention.

FIG. 7 is a functional block configuration diagram according to [claim 3] of the present invention.

FIG. 8 is a flowchart showing processing contents according to [claim 3] of the present invention.

FIG. 9 is a connection diagram of a dummy load according to [claim 3] of the present invention.

FIG. 10 is a functional block configuration diagram according to [claim 5] of the present invention.

FIG. 11 is a flowchart showing processing contents according to [claim 4] of the present invention.

FIG. 12 is a flowchart showing processing contents of a stability determination means switching means according to [claim 5] of the present invention.

FIG. 13 is a functional block configuration diagram according to claim 7 of the present invention.

FIG. 14 is a flowchart showing processing contents according to [claim 7] of the present invention.

FIG. 15 is a functional block configuration diagram according to claim 9 of the present invention.

FIG. 16 is a flowchart showing processing contents according to [claim 9] of the present invention.

FIG. 17 is a functional block configuration diagram according to claim 11 of the present invention.

FIG. 18 is a flowchart showing processing content according to claim 11 of the present invention.

FIG. 19 is a functional block configuration diagram according to claim 12 of the present invention.

FIG. 20 is a flowchart showing processing content according to [claim 12] of the present invention.

FIG. 21 is a flowchart showing processing contents of a demand maximum point limit power flow calculating unit according to [claim 12] of the present invention.

FIG. 22 is a flowchart showing processing contents of a designated margin time calculating means according to claim 12 of the present invention.

FIG. 23 is a functional block configuration diagram of a conventional power system monitoring and control device.

FIG. 24 is a flowchart illustrating processing performed by a conventional power system monitoring and control device.

[Explanation of symbols]

 1 Current power system state creation means 2 Current power system state 3 Power flow increase means 4 System state after power flow increase 5 Transient stability calculation means 6 Transient stability calculation results 7 Stability margin stability determination means 8 Stability margin calculation means 9 Stability margin display means 10 Power flow increase amount change means 11 Power flow increase amount 12 Previous power flow increase amount 13 Current power system data 14 Future time determination means 15 Current time 16-hour step width 17 Future time 18 Power equipment operation state determination means 19 Future Power system status creation means 20 Future power system state 21 Stability determination means 22 Stability time margin calculation means 23 Future power system data 24 Schedule data 25 Current power system data 41 Avoidance measure creation means 42 Stability determination means switching means 43 Switching set value 44 Stability time margin storage data 45 Stability time margin storage means 51 Transient stability calculation result storage means 52 Stabilization tendency judgment means 53 Time interval Determining means 54 for transient stability computation result storage data 60 initial phase angle storage means 61 the generator initial phase angle calculating means 62 generator initial phase angle 63 initial phase angle stored data 64 initial phase angle comparator means

Claims (13)

[Claims] 1. A power system monitoring and control device which evaluates transient stability of a power system, determines whether or not the evaluation of the transient stability exceeds a predetermined value based on the evaluation result, and outputs the result. A future time determining means for setting a future time starting from the time; a power equipment operating state determining means for creating an operating state of the power system at the set future time; and transient stability for a contingency with respect to the created system state. A transient stability calculating means for calculating the degree of stability, a stability determining means for determining the stability of the system based on the calculation result, and calculating a time until an unstable state is obtained as a stability time margin from the current time. And a stability time margin calculating means for outputting the output. 2. The electric power system monitoring control according to claim 1, further comprising an avoidance measure creating means for avoiding an unstable state of the system when the stability determination result is unstable. apparatus. 3. An electric power system monitoring and control device that evaluates the transient stability of an electric power system, determines whether or not the evaluation of the transient stability exceeds a predetermined value based on the evaluation result, and outputs the result. Current power system state creation means that calculates the power flow based on the current power system data at the time and calculates the voltage and phase angle of each node, and power flow created by intentionally increasing the dummy load at the assumed failure point For the increased system state, transient stability calculation means for performing transient stability calculation for a contingency and outputting the result, and determining stability based on the transient stability calculation result, wherein the determination result is stable. In the case, a power flow increase is further added to create a system after the power flow is increased, and a stability margin stability determination unit that repeats until the transient stability calculation result becomes unstable,
A first stage including stability margin calculating means for adding the first tidal current value to the previous tidal current increase amount and outputting the result when the stability determination result becomes unstable; and a future time setting for setting a future time starting from the current time. Means, a power equipment operating state determining means for creating an operating state of the power system at the set future time, and a future power system state creating means for performing a power flow calculation of a supposed failure point with respect to the created system state. A stability determination means for comparing the stability margin at the assumed failure point with the flow of the assumed failure point at a future time starting from the current time to determine whether or not the power flow exceeds the stability margin; and And a second stage comprising stability time margin calculating means for outputting a time until a stable state is reached as a stability time margin. 4. The power system monitoring and control device according to claim 3, further comprising an avoidance measure creating means for creating an avoidance measure when the stability determination result is unstable. 5. An electric power system monitoring and control device which evaluates the transient stability of an electric power system, determines whether or not the evaluation of the transient stability exceeds a predetermined value based on the evaluation result, and outputs the result. A power system characterized by switching from the second device to the first device when the stability time margin becomes equal to or less than a predetermined value as a result of obtaining the stability time margin at regular intervals in the second device. Monitoring and control equipment. The future time determining means for setting a future time starting from the current time, the power equipment operating state determining means for creating an operating state of the power system at the set future time, and a contingency for the created system state Transient stability calculating means for calculating the transient stability, stability determining means for determining the stability of the system based on the calculation result, and a stability time margin from the current time until the state becomes unstable. And a stability time margin calculating means for calculating and outputting the result. Current power system state creation means that calculates the power flow based on the current power system data at the current time and calculates the voltage and phase angle of each node, and intentionally increases the dummy load to the assumed failure point A transient stability calculation means for performing transient stability calculation for a contingency with respect to the system state after the power flow increase and outputting the result, and determining stability based on the transient stability calculation result; In this case, the power flow increase amount is further added to create a system after the power flow increase, and the stability margin stability determination means which repeats until the transient stability calculation result becomes unstable, and the stability determination result becomes unstable. A first stage comprising stability margin calculating means for adding the first tidal current value to the previous tidal current increase and outputting the same; a future time determining means for setting a future time starting from the current time; Power equipment operating state determining means for creating an operating state of the power system at a future time, future power system state creating means for performing a power flow calculation of a supposed fault point with respect to the created system state, Stability margin comparing the power flow of the assumed failure point at the future time with the current time as a starting point, and a stability determining means for determining whether the power flow exceeds the stability margin, A stability time margin calculating means for outputting time as a stability time margin. 6. An electric power system monitoring and control device according to claim 5, wherein a generator suppression amount for avoiding an unstable state of the system is determined as an avoidance measure, and the avoidance is indicated to an operator in advance. An electric power system monitoring and control device comprising a measure creating means. 7. The power system monitoring and control apparatus according to claim 1, wherein a system stability is calculated from a transient stability calculation result at a current time and a stability evaluation index obtained from a transient stability calculation result at the same time calculated in the past. A stabilization tendency determining means for determining a tendency of increase / decrease of stability, and a time step width determining means for changing a time step width to omit the stability determination depending on the tendency of the stability. Power system monitoring and control device. 8. The power system monitoring and control device according to claim 7, wherein a generator suppression amount for avoiding the system from becoming unstable when the stability determination result is unstable is obtained as an avoidance measure. An electric power system monitoring and control device, comprising: an avoidance measure creating means to be shown to an operator in advance. 9. The power system monitoring and control device according to claim 1, wherein an initial phase angle of the generator internal phase angle at the current time is compared with a previously calculated phase angle. A power system monitoring and control device characterized by comprising an initial phase angle comparison means for omitting the transient stability calculation processing by employing the calculation result of (1). 10. The power system monitoring and control device according to claim 9, wherein a generator suppression amount for avoiding the system from becoming unstable when the stability determination result is unstable is obtained as an avoidance measure. An electric power system monitoring and control device, comprising: an avoidance measure creating means to be shown to an operator in advance. 11. A power system monitoring and controlling apparatus according to claim 1, wherein a means is provided for focusing on a local maximum point of a predicted demand curve within a daily demand change, and creating a power system state at a time of the local maximum demand point. Means for creating a future power system state at a time when the time is returned from the maximum point by a certain time when the stability determination result of the transient stability for the created power system is unstable; and Based on the stable time obtained as a result of performing the stability determination on the system state, the stability time from the time at which the stable state is stable to the vicinity of the maximum demand point where the transient stability becomes unstable And a stability time margin calculating means for calculating a margin. 12. The power system monitoring and control device according to claim 11, wherein a generator suppression amount for avoiding the system from becoming unstable when the stability determination result is unstable is obtained as an avoidance measure. An electric power system monitoring and control device, comprising: an avoidance measure creating means to be shown to an operator in advance. 13. The power system monitoring and control apparatus according to claim 7, wherein a maximum power point limit power flow calculating means for obtaining a maximum power flow at an assumed failure point in the power system state at the maximum power point,
A designated margin holding time calculating means for calculating a difference between a time that satisfies a preset margin by returning the time from the time of the maximum demand point and a current time as a stability time margin. Power system monitoring and control device.