JP2008219974A - Device, method and program for making power system contraction model - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a high precision contraction model of a large scale power system efficiently. <P>SOLUTION: A turbulence characteristics specification section 140 specifies the main modes of a system model before and after contraction, and a system characteristics combination section 150 combines the main modes before and after contraction. A turbulence mode searching section 141 specifies a temporary main mode by waveform analysis of time series analysis, a turbulence mode confirmation section 143 specifies a true main mode by confirming the mode of an eigenvector, and a pairing section 151 confirms the mode of the eigenvector when pairing of the main modes before and after contraction is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power system contracted model creating apparatus, a power system contracted model creating method, and a power system contracted model creating program for creating a contracted model by contracting parts other than the system of interest from a power system model. In particular, the present invention relates to a power system contracted model creating apparatus, a power system contracted model creating method, and a power system contracted model creating program capable of efficiently contracting a large-scale power system with high accuracy.

  In the stability analysis of the power system, it is necessary to consider the characteristics of the control system of each generator. It takes a long time to calculate. In view of this, it has been carried out that a system other than the system of interest is contracted and analyzed using the contracted system.

  As a power system contraction method, a physical contraction method (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1) that contracts while leaving a physical image of a generator, a transmission line, and the like is used. There is a mathematical reduction method that formulates the characteristics of the target system and reduces the eigenvalue.

  FIG. 23 is an explanatory diagram for explaining a Q method (eQuivalence method) which is an example of a physical reduction method. As shown in the figure, in the Q method, when systems other than the system of interest are “external system 1” and “external system 2”, “external system 1” is reduced to the generator “G1” and “external system” 2 ”is reduced to the generator“ G2 ”. Here, the power generation capacity of “G1” is the sum of the power generation capacities in “external system 1”, the control system of “G1” is the control system of the maximum generator in “external system 1”, and the power generation capacity of “G2” The capacity is the sum of the power generation capacities in “external system 2”, and the control system of “G2” is the control system of the maximum generator in “external system 2”.

  On the other hand, FIG. 24 is an explanatory diagram for explaining a mode reduction method which is an example of a mathematical reduction method. As shown in the figure, in the mode contraction method, contraction is performed by mode-decomposing the contraction target system on the mathematical formula and merging the modes obtained by the decomposition.

JP 2006-5992 A Japanese Patent Application Laid-Open No. 10-56735 Hiraiwa, Hayashi, Uchida "Improvement of accuracy of engineering system reduction by modal analysis", Electron Theory B, Vol. 124, No. 7, 2004

  However, the physical reduction method is easy to physically understand the reduction target system, but there is no guarantee that the main oscillation mode is preserved before and after reduction, and there is a problem that analysis accuracy is poor. On the other hand, the mathematical reduction method has a problem that the mode of interest can be saved, but the reduction target system is expressed as a linear differential equation and is difficult to understand physically, and is difficult to combine with an existing simulation program.

  The present invention has been made in order to solve the above-described problems caused by the prior art, and includes a power system contraction model creation device, a power system contraction system, and a power system contraction model creation device capable of efficiently contracting a large-scale power system with high accuracy. It is an object to provide an approximately model creation method and a power system contraction model creation program.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 is a power system contracted model creating apparatus that creates a contracted model by contracting a part other than the system of interest from the model of the power system. A physical contracted model creation means for creating a physical contracted model by contracting the system model by physical contraction, and each of a plurality of main modes of the model before contracting as the main mode before contracting A main mode specifying means for specifying each of a plurality of main modes of the physical contracted model created by the physical contracted model creating means as a main mode after contracting, and the physical contracted model creating means By adjusting the parameters of the generator control system of the created physical contraction model, the main mode is stored by combining the pre-contraction main mode and the post-contraction main mode. The main mode specifying means is a temporary main mode extracting means for extracting a plurality of temporary main modes by analyzing the waveform of the oscillation at the time of the accident by time series analysis, and the temporary main mode extracting means And a true main mode specifying means for performing eigenvalue analysis on each of the plurality of temporary main modes extracted by the above and specifying a true main mode corresponding to each temporary main mode.

  Further, in the invention according to claim 2, in the above invention, the true major mode specifying means performs eigenvalue analysis using an inverse iteration method, and a plurality of major modes that are candidates for the true major mode are obtained. In some cases, one major mode is specified as a true major mode based on the aspect of the eigenvector from a plurality of candidate major modes.

  Further, in the invention according to claim 3, in the above invention, the true main mode specifying means sets the main mode of the local mode as the true main mode when a plurality of main modes that are candidates for the true main mode are obtained. It is excluded from the mode.

  Further, in the invention according to claim 4, in the above-mentioned invention, the main mode storage means extracts main mode feature extraction means for extracting features of each of a plurality of true main modes specified by the true main mode specifying means, Based on the features extracted by the main mode feature extraction means, a before / after reduction set determining means for determining a combination of each pre-contraction main mode and each after reduction main mode, and determined by the reduction before / after set determination means For each combination of the pre-contraction main mode and the post-contraction main mode, the physical reduction model creation means creates the physical reduction model so that the post-contraction main mode matches the pre-contraction main mode. And a parameter adjusting means for adjusting the parameters of the generator control system of the general contraction model.

  Further, the invention according to claim 5 is the above invention, wherein the main mode specifying means corrects the excitation system so that the response speed of the generator is increased when the main mode after reduction is specified. Features.

  Further, the invention according to claim 6 is characterized in that, in the above invention, the main mode storage means stores the main mode with respect to a tidal current at the time of occurrence of an accident at a connection point between the system of interest and the system not of interest. .

  The invention according to claim 7 is characterized in that, in the above invention, the main mode storing means stores the main mode by adjusting a phase advance time constant, a phase delay time constant and a gain of the PSS.

  In the invention according to claim 8, in the above invention, the main mode specifying means further specifies an area contributing to the main mode, and the main mode storage means is an area specified by the main mode specifying means. By adjusting parameters of the generator control system, the main mode before contracting and the main mode after contracting are combined to store the main mode.

  The invention according to claim 9 is a power system contracted model creation method by a power system contracted model creating device that creates a contracted model by contracting a part other than the system of interest from the model of the power system. , A pre-contraction main mode identification process that identifies each of the multiple principal modes of the model before reduction as a pre-contraction main mode, and physics to create a physical reduction model that reduces the system model by physical reduction A contracted main mode specifying step of specifying each of a plurality of main modes of the physical contracted model created by the physical contracted model creating step as a contracted main mode; By adjusting the parameters of the generator control system of the physical reduction model created by the physical reduction model creation process, the main mode before reduction and the main mode after reduction are combined. A main mode preserving step for preserving the required mode, wherein the pre-contraction main mode specifying step and the post-contraction main mode specifying step are a plurality of temporary Temporary main mode extraction step for extracting the main mode, and a true main mode corresponding to each temporary main mode by performing eigenvalue analysis on each of the plurality of temporary main modes extracted by the temporary main mode extraction step And a true main mode identifying step for identifying

  The invention according to claim 10 is a power system contracted model creation program for creating a contracted model by contracting a part other than the system of interest from the model of the power system, wherein the system model is obtained by physical contraction. A physical contraction model creation procedure for creating a physical contraction model in which the contraction is performed, and a plurality of main modes of the model before contraction are identified as main modes before contraction, and the physical contraction model creation procedure A main mode specifying procedure for specifying each of a plurality of main modes of the physically contracted model created by the above as a contracted main mode, and a generator of the physically contracted model created by the physical contracted model creating procedure A main mode storing procedure for storing the main mode by adjusting the parameters of the control system so as to match the main mode before contracting with the main mode after contracting. The main mode identification procedure is extracted by a temporary main mode extraction procedure for extracting a plurality of temporary main modes by analyzing a waveform of an oscillation at the time of an accident by time series analysis and the temporary main mode extraction procedure. It is characterized by causing a computer to execute a true main mode specifying procedure for performing eigenvalue analysis for each of a plurality of temporary main modes and specifying a true main mode corresponding to each temporary main mode.

  According to the invention of claim 1, 9 or 10, a physical contracted model is generated by contracting the system model by physical contraction, and each of a plurality of main modes of the model before contracting is performed as the main mode before contracting. Each of the main modes of the created physical contraction model is identified as the main mode after contraction, and the main mode before contraction is adjusted by adjusting the parameters of the generator control system of the physical contraction model. After contracting, the main mode is adjusted and saved. Then, when specifying the main mode, the waveform of the vibration at the time of the accident is analyzed by time series analysis to extract a plurality of temporary main modes, and eigenvalue analysis is performed for each of the extracted plurality of temporary main modes. In order to identify the true major mode corresponding to each provisional major mode, it is possible to efficiently identify the major mode even for a large-scale power system and store the major mode before and after contraction. It is possible to reduce a large-scale power system with high accuracy and efficiency.

  According to the invention of claim 2, when eigenvalue analysis is performed using an inverse iteration method and a plurality of main modes that are true main mode candidates are obtained, a plurality of main modes that are candidates are obtained. Since one major mode is identified as a true major mode based on the aspect of the eigenvector, the major mode can be accurately identified.

  Further, according to the invention of claim 3, when a plurality of main modes that are candidates for the true main mode are obtained, the main mode of the local mode is excluded from the true main mode. Major modes can be specified.

  According to the invention of claim 4, the features of each of the specified plurality of true main modes are extracted, and the combination of each pre-contraction main mode and each post-contraction main mode is determined based on the extracted features. For each combination of the determined pre-contraction main mode and the post-contraction main mode, the physical contraction model generator control system is configured so that the post-contraction main mode matches the pre-contraction main mode. Since the parameters are adjusted, the main modes before and after contraction can be accurately combined, and the main modes can be accurately stored.

  According to the invention of claim 5, when the main mode after contraction is specified, the excitation system is corrected so that the response speed of the generator is increased. Can be specified.

  According to the invention of claim 6, since the main mode is stored with respect to the power flow at the time of the accident at the connection point between the focused system and the unfocused system, the characteristics of the unfocused system are accurately stored. be able to.

  According to the seventh aspect of the present invention, since the main mode is stored by adjusting the phase advance time constant, the phase delay time constant and the gain of the PSS, the accuracy of the contraction model can be improved.

  According to the invention of claim 8, the area contributing to the main mode is further specified, and the parameters of the generator control system in the specified area are adjusted to match the main mode before reduction and the main mode after reduction. Since the main mode is saved and the main mode is saved, the parameters can be adjusted efficiently.

  Exemplary embodiments of a power system contracted model creating apparatus, a power system contracted model creating method, and a power system contracted model creating program according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, the system contraction method of the system contraction model creation apparatus according to the present embodiment will be described. FIG. 1 is an explanatory diagram for explaining a system contraction method of the system contraction model creation apparatus according to the present embodiment. As shown in the figure, the system contracted model creating apparatus according to the present embodiment creates a contracted model in which an external detailed system other than the system of interest in the power system is contracted using a physical contraction method.

  Then, for the system model before contraction (hereinafter referred to as the “original system model”) and the contract model, the major modes are identified by analyzing the current waveform at the time of the accident at the interconnection point of the target system and the external system. (1). In this example, the waveform analysis is performed using the tidal waveform of the tidal current at the connection point of the target system and the external system. However, the waveform analysis of the tidal current of other transmission lines and the oscillatory waveform of the generator output is performed. It is also possible to specify the main mode.

  Then, the eigenvalue obtained by specifying the main mode, specifically, the true eigenvalue is obtained by applying the inverse iteration method in the S method using the attenuation rate and the frequency as a temporary eigenvalue (2). Here, the S method is an eigenvalue analysis method, and the inverse iterative method in the S method is a method of calculating a true eigenvalue by iterative calculation from an approximate value of the eigenvalue.

  However, since waveform analysis is used for estimation, the search for eigenvalues must be performed in the vicinity. In addition, it is confirmed whether the eigenvalue really appears from the fluctuation waveform and the eigenvector for the searched eigenvalue.

  Then, if the eigenvalue obtained from the original system model is the target eigenvalue and the eigenvalue obtained from the reduced model is the adjustment eigenvalue, the eigenvalue is matched to the pair of the adjusted eigenvalue and the target eigenvalue. The mode is saved (3).

  In the pairing of the adjusted eigenvalue and the target eigenvalue, a pair whose eigenvector shows the same aspect is used as a pair. Further, the eigenvalues are adjusted by adjusting the PSS parameters so that the distance between the eigenvalues is minimized by using the eigenvalue sensitivity of the PSS (Power System Stabilizer) parameter. Here, the PSS parameter is adjusted, but an AVR (Automatic Voltage Regulator) parameter can also be adjusted.

  As described above, the system contraction model creation device according to the present embodiment identifies the main mode by performing the waveform analysis of the power flow at the time of the accident at the connection point of the system of interest and the external system, so that the large-scale power system Therefore, it is possible to efficiently specify the main mode, and it is possible to create a highly accurate contracted model by storing the specified main mode.

  Next, the configuration of the system contraction model creation device according to the present embodiment will be described. FIG. 2 is a functional block diagram illustrating the configuration of the system contraction model creation apparatus according to the present embodiment. As shown in the figure, the system contraction model creation apparatus 100 includes a data reading unit 110, a system data storage unit 120, a physical contraction unit 130, a fluctuation characteristic specifying unit 140, and a system characteristic integration unit. 150, an initial state changing unit 160, and a data output unit 170.

  The data reading unit 110 is a processing unit that reads the system configuration data defining the system model and the assumed accident data from a storage device such as a file and stores them in the system data storage unit 120.

  In addition to the system configuration data and assumed accident data read by the data reading unit 110, the system data storage unit 120 has tidal current waveform data, reduced model data, eigenvalues, etc. at the time of an accident at the connection point between the target system and the external system. It is a storage unit for storing data necessary for creating a contracted model.

  The physical reduction unit 130 is a processing unit that uses a system configuration data stored in the system data storage unit 120 to reduce a system other than the system of interest by a physical method and create a contract model. The reduced model data is stored in the system data storage unit 120.

  The fluctuation characteristic specifying unit 140 generates a tidal current waveform at the time of an accident at the connection point of the target system and the external system using the assumed accident data for each of the original system model and the contracted model, and generates the generated tidal current waveform. It is a processing unit that identifies a main mode by performing waveform analysis, and includes a shaking mode searching unit 141, a shaking mode specifying unit 142, and a shaking mode confirmation unit 143.

  The sway mode search unit 141 performs transient stability calculation using the assumed accident data, generates a tidal current waveform at the time of the accident at the connection point between the target system and the external system, and performs a temporary analysis by analyzing the generated tidal current waveform. Is a processing unit for extracting the main modes.

  FIG. 3 is an explanatory diagram for explaining the extraction of the provisional main mode by the fluctuation mode search unit 141 when the original system model is targeted. As shown in the figure, the sway mode searching unit 141 extracts a temporary main mode by performing waveform analysis on a tidal current waveform at the time of an accident at the connection point between the system of interest and the external detailed system.

  Here, the oscillation mode search unit 141 performs waveform analysis using online step-out prediction logic. That is, the oscillation mode search unit 141 decomposes the power flow waveform into a plurality of sine wave components by time series analysis using the voltage phase difference between substations and the time series data of the generator oscillation waveform. In this way, the oscillating mode searching unit 141 can specify the main modes included in the tidal current waveform by the time series analysis, so that the temporary main mode can be specified efficiently.

  The sway mode identifying unit 142 performs eigenvalue analysis using the inverse iteration method with the tentative main mode extracted by the sway mode search unit 141, that is, the tentative eigenvalue as an approximate value, to thereby obtain a true main mode candidate, that is, a true eigenvalue Is a processing unit for identifying the candidates. Specifically, the shaking mode specifying unit 142 specifies the eigenvalue as follows.

That is, the eigenvalue λ _{i of the} matrix A is assumed, and one approximate value σ is obtained. At that time, the following equation holds.

Here, since the eigenvalue of (A−σI) is λ _k −σ, the eigenvalue taking the maximum absolute value of the matrix (A−σI) ⁻¹ is (λ _k −σ) ⁻¹ . Since this corresponds to the power method, the true eigenvalue λ _k can be _obtained by taking the reciprocal of the approximate value of the calculated eigenvalue and adding σ.

  The oscillation mode confirmation unit 143 is a processing unit that identifies the true eigenvalue by confirming the aspect of the eigenvector from the true eigenvalue candidates identified by the oscillation mode identification unit 142. FIG. 4 is an explanatory diagram for explaining confirmation of the aspect of the eigenvector by the oscillation mode confirmation unit 143. The shaking mode confirmation unit 143 identifies the true eigenvalue by confirming the aspect of the eigenvector as shown in FIG. In addition, the shaking mode confirmation unit 143 confirms the aspect of the eigenvector and specifies an area contributing to the main mode.

  In addition, as shown in FIG. 5, when a plurality of modes are close to each other, even if the result of waveform analysis is input as the initial value of the inverse iteration method, it does not necessarily indicate the true sway mode. Therefore, when confirming the eigenvector corresponding to the main mode, the oscillation mode confirmation unit 143 confirms whether the mode extends from the eigenvector distribution to the entire system or the local mode that can be seen only by a specific generator. In the case of the local mode, it is excluded from the target, and in the case of the entire system mode, it is confirmed whether the aspect of the eigenvector and the fluctuation of the generator (Ag: internal phase angle, Sg: rotational speed deviation, etc.) match. If they match, the true main mode is set.

  Here, the sway mode confirmation unit 143 displays the aspect of the eigenvector and determines whether or not it is a true major mode from the user, or accepts designation of an area contributing to the major mode and determines the true major mode. We will check it. However, it is also possible for the shaking mode confirmation unit 143 to automatically confirm whether or not it is the true main mode and to specify an area that contributes to the true main mode.

  In addition, the true main mode confirmed by the shaking mode confirmation unit 143 becomes the major mode identified by the shaking characteristic identification unit 140.

  The system characteristic merger 150 is a processing unit that combines the characteristics of the original system model and the contracted model using the main mode identified by the oscillation characteristic identifying unit 140. Part 152.

The pairing unit 151 is a processing unit that specifies a main mode of a pair that performs matching between main modes specified from the system model before and after contraction. In the case where it is difficult to perform pairing only with eigenvalues, the pairing unit 151 selects a pair having the same aspect of the eigenvector as a pair. When there are a plurality of candidate eigenvalues / eigenvectors (similar modes), the eigenvector related to the slip Sg of the generator in the main system excluding the external system is selected closest to the target eigenvector. This is expressed as follows.

  If the mode changes significantly due to physical contraction, or if an appropriate pair is not found, leave the area that is largely caused by vibration in the system before contraction, even after contraction. Can be confirmed. However, if different coherency items are combined, the effect on shaking may be increased.

  The parameter adjustment unit 152 is a processing unit that adjusts the system characteristics by adjusting the PSS parameter of the contracted model for each pair specified by the pairing unit 151. FIG. 6 is an explanatory diagram for explaining system characteristic adjustment by the parameter adjustment unit 152. As shown in the figure, the parameter adjustment unit 152 adjusts the PSS parameter so as to make the reduced system eigenvalue (the eigenvalue of the reduced model) coincide with the original system eigenvalue (the eigenvalue of the original system model).

FIG. 7 is a diagram illustrating a generator control system in which the parameter adjustment unit 152 adjusts parameters. This figure shows PSS and AVR. Here, the parameter adjustment unit 152 adjusts the phase delay time constants T _P2 and T _P4 , the phase advance time constants T _P1 and T _P3 and the gain _GP of the PSS. It is also possible to adjust the parameters.

8A and 8B are explanatory diagrams for explaining a method of adjusting the PSS parameter by the parameter adjusting unit 152. FIG. As shown in FIG. 8A, the parameter adjustment unit 152 converts the n eigenvalue pairs identified by the pairing unit 151 into λ _Oi (original system eigenvalue) and λ _Ri (reduced system eigenvalue) (i = 1 to n). As shown below, the PSS parameter is adjusted using the steepest gradient method so that the square sum F of the distance is minimized.

  That is, if α is a set of PSS parameters, F is minimized by moving α in the direction in which the slope ∂F / ∂α of F becomes steep.

As illustrated in FIG. 8B, the parameter adjustment unit 152 calculates ∂F / ∂α using the eigenvalue sensitivity ∂λ _R / ∂α as follows.

Then, the parameter adjusting unit 152 minimizes F by sequentially changing the PSS parameter α based on the following formula.

  Here, the case where α, which is a set of PSS parameters, is changed, that is, the case where all the PSS parameters are changed at a time, has been described, but F can be minimized by changing only one parameter at a time.

FIG. 9 is an explanatory diagram for explaining parameter adjustment in which only one parameter is changed at a time to minimize the distance between eigenvalues. The figure, the three parameters alpha ₁ to? _3, identifies the parameter alpha ₁ of the contracted system eigenvalues can most close to meeting the target characteristic value (original strain eigenvalues) by varying a particular parameter alpha ₁ This shows a case where the distance between eigenvalues is minimized by changing the distance.

  Returning to FIG. 2, the initial state changing unit 160 determines the main mode when the shaking mode identifying unit 143 confirms the major mode of the original system model when the shaking characteristic identifying unit 140 identifies the major mode of the contracted model. This is a processing unit that replaces the excitation system of the area identified as having a significant influence on the necessity as needed. When the initial state changing unit 160 replaces the excitation system in an area that greatly affects the main mode, parameter adjustment by the parameter adjusting unit 152 can be performed efficiently.

  The data output unit 170 is a processing unit that reads out and outputs the reduced model data after parameter adjustment from the system data storage unit 120, and the output reduced model data is used for stability analysis and the like.

  Next, a processing procedure of the system contraction model creation device 100 according to the present embodiment will be described. FIG. 10 is a flowchart illustrating the processing procedure of the system contraction model creation device 100 according to the present embodiment.

  As shown in the figure, in the system contraction model creating apparatus 100, the data reading unit 110 reads the system configuration data and the assumed accident data and stores them in the system data storage unit 120 (step S1). Referring to the system data storage unit 120, the oscillation characteristics at the time of the accident before contracting are specified, that is, the main mode is specified (step S2), and information on the specified main mode is stored in the system data storage unit 120.

  Then, the physical contraction unit 130 reads the system configuration data from the system data storage unit 120 to perform physical contraction, and stores the contracted model data in the system data storage unit 120 (step S3). Then, the initial state changing unit 160 replaces the excitation system of the area identified as the fluctuation mode confirming unit 143 significantly affecting the main mode as necessary (step S4), and the reduced model of the system data storage unit 120 is changed. Update the data.

  Then, the oscillation characteristic specifying unit 140 refers to the system data storage unit 120 to specify the oscillation characteristics at the time of the accident after contraction, that is, to specify the main mode (step S5), and to store information on the specified main mode in the system data Store in the storage unit 120.

  Then, the system characteristic merger 150 performs pairing of main modes before and after contraction, and adjusts the PSS parameter to perform system characteristic alignment for each pair (step S6). That is, the reduced model PSS parameter is adjusted so that the eigenvalues of each pair match, and the reduced model in the system data storage unit 120 is updated. Then, when the system characteristic integration by the system characteristic integration unit 150 is completed, the data output unit 170 reads out the data of the contracted model from the system data storage unit 120 and outputs it (step S7).

  Thus, the accuracy of the contracted model can be improved by matching the system characteristics to the main mode pairs before and after contraction.

  Next, a processing procedure of main mode specifying processing by the fluctuation characteristic specifying unit 140 will be described. FIG. 11 is a flowchart showing a processing procedure of main mode specifying processing by the fluctuation characteristic specifying unit 140.

  As shown in the figure, in this main mode specifying process, the fluctuation mode searching unit 141 performs transient stability calculation using the assumed accident data stored in the system data storage unit 120 (step S21), and Generate a tidal current waveform at the time of an accident at the connection point of the external system.

  Then, the oscillation mode searching unit 141 analyzes the generated tidal current waveform by time series analysis (step S22), and specifies a provisional main mode (step S23). Then, the oscillation mode specifying unit 142 performs eigenvalue analysis by the inverse iteration method using the temporary main mode as an approximate value (step S24), and specifies a true main mode candidate (step S25).

  Then, the shaking mode confirmation unit 143 confirms the appearance of each candidate eigenvector (step S26), identifies the true major mode, and identifies the area contributing to the true major mode (step S27).

  As described above, the oscillation mode search unit 141 efficiently identifies the main mode by analyzing the power flow waveform at the time of the accident at the connection point of the system of interest and the external system by time series analysis and identifying the provisional main mode. can do.

  Next, an example of creating a contracted model by the system contracted model creating apparatus 100 according to the present embodiment will be described. FIG. 12 is a diagram illustrating an example of a power flow waveform at the time of an accident at a connection point between the target system and an external system with respect to the original system model. FIG. 13 is a diagram showing a temporary main mode obtained by analyzing the waveform shown in FIG. Here, since the “mode 3” has a small amplitude, the system contraction model creation apparatus 100 excludes “mode 3” from the provisional main mode.

  Then, the system reduction model creation apparatus 100 obtains eigenvalues corresponding to “mode 1” and “mode 2” by applying the inverse iteration method, and obtains eigenvalue candidates shown in FIG. 14, that is, true main mode candidates. In FIG. 14, a plurality of eigenvalues are obtained as candidates for “mode 2”. This is because the search is performed in the vicinity of the waveform analysis result so that there is no omission.

  In FIG. 14, “mode A” and “mode 1” have a one-to-one correspondence, and as shown in FIG. 15, the mode of the eigenvector greatly fluctuates over the entire system. 100 identifies “Mode A” as the true primary mode.

  On the other hand, for “mode 2”, the system contraction model creation apparatus 100 confirms the aspect of the eigenvector corresponding to “mode B” to “mode E”. FIG. 16 is a diagram illustrating aspects of eigenvectors corresponding to “mode B” to “mode E”. FIG. 17 is a diagram showing the characteristics of “mode B” to “mode E” obtained from the aspect of the eigenvector shown in FIG.

  Based on the characteristics of “mode B” to “mode E” and the characteristics of the waveform of “mode 2” shown in FIG. 18, the system contraction model creation apparatus 100 sets “mode C” to “true” corresponding to “mode 2”. Specify as the main mode. That is, the system reduction model creation apparatus 100 identifies “mode C” in which “area 6” and “area 3” are in phase in the entire system mode as a true main mode corresponding to “mode 2”.

  Similarly, the system contraction model creation apparatus 100 analyzes the power flow waveform at the time of an accident at the connection point between the system of interest and the external system with respect to the model subjected to physical contraction, and identifies a provisional main mode. FIG. 19 is a diagram showing provisional principal modes obtained for the model after physical reduction, and FIG. 20 is a diagram showing true principal mode candidates obtained by applying the inverse iteration method. It is.

  Then, the system contraction model creation apparatus 100 checks the aspect of the eigenvector to pair the “mode A” before contraction with the “mode L” after contraction, and the “mode C” before contraction. "And the reduced" mode M ".

  Then, the system contraction model creation apparatus 100 matches the paired “mode A” and “mode L”, “mode C”, and “mode M” with reference to the eigenvalue sensitivity of the PSS parameter. At this time, since the sensitivity of the generator system of “Area 1” is large with respect to the fluctuations of “Mode A” and “Mode L”, the phase lag time constant, phase advance time constant of PSS in “Area 1”, and Gain is controlled. Further, since the sensitivity of the generator of “Area 4” is high with respect to the fluctuations of “Mode C” and “Mode M”, the PSS parameter of the area reduced from “Area 4” is set as the control target.

  FIG. 21 is a diagram showing interconnected power flow waveforms before and after adjusting the PSS parameter. FIG. 6A shows the interconnected power flow waveform before the PSS parameter adjustment, and FIG. 5B shows the interconnected power flow waveform after the PSS parameter adjustment. Comparing (a) and (b) in the figure, it can be confirmed that the interconnected line waveforms before and after contraction are in good agreement after PSS parameter adjustment.

  As described above, in the present embodiment, the sway mode searching unit 141 specifies the provisional main mode by the waveform analysis based on the time series analysis, so that the main mode can be specified efficiently. Further, in the present embodiment, the sway mode confirmation unit 143 identifies the true main mode by confirming the aspect of the eigenvector, so that the main mode can be accurately identified. Further, in the present embodiment, the pairing unit 151 confirms the aspect of the eigenvector when performing the pairing of the main mode before and after contraction, so that the pairing of the main mode can be performed accurately.

  In the present embodiment, the system contraction model creation apparatus has been described. However, by realizing the configuration of the system contraction model creation apparatus with software, a system contraction model creation program having the same function can be obtained. it can. Therefore, a computer that executes this system contraction model creation program will be described.

  FIG. 22 is a functional block diagram illustrating a configuration of a computer that executes a system contraction model creation program according to the present embodiment. As shown in the figure, the computer 200 includes a RAM 210, a CPU 220, an HDD 230, a LAN interface 240, an input / output interface 250, and a DVD drive 260.

  The RAM 210 is a memory that stores a program and a program execution result, and the CPU 220 is a central processing unit that reads the program from the RAM 210 and executes the program. The HDD 230 is a disk device that stores programs and data, and the LAN interface 240 is an interface for connecting the computer 200 to other computers via the LAN. The input / output interface 250 is an interface for connecting an input device such as a mouse or a keyboard and a display device, and the DVD drive 260 is a device for reading / writing a DVD.

  The system contraction model creation program 211 executed in the computer 200 is stored in the DVD, read from the DVD by the DVD drive 260, and installed in the computer 200. Alternatively, the system contraction model creation program 211 is stored in a database or the like of another computer system connected via the LAN interface 240, read from these databases, and installed in the computer 200. The installed system reduction model creation program 211 is stored in the HDD 230, read into the RAM 210, and executed by the CPU 220.

  In this embodiment, the system contraction model creation apparatus has been described. However, the present invention is not limited to this, and the system model after contraction by inputting the system model before and after physical contraction is the main. The present invention can be similarly applied to a reduced model adjusting apparatus that adjusts a reduced model so as to preserve the mode. That is, it is possible to remove the physical contraction unit 130 from the system contraction model creation apparatus 100 and input data of the physical contraction model.

  As described above, the power system contracted model creation device, the power system contracted model creation method, and the power system contracted model creation program according to the present invention are useful for power system stability analysis, etc. This is suitable for analyzing a complex power system.

It is explanatory drawing for demonstrating the system | strain reduction method of the system | strain reduction model creation apparatus which concerns on a present Example. It is a functional block diagram which shows the structure of the system | strain reduction model production apparatus which concerns on a present Example. It is explanatory drawing for demonstrating extraction of the temporary main modes by the sway mode search part at the time of making the system | strain model before contraction into object. It is explanatory drawing for demonstrating confirmation of the aspect of the eigenvector by a sway mode confirmation part. It is a figure which shows the case where several modes adjoin. It is explanatory drawing for demonstrating the fitting of the system characteristic by a parameter adjustment part. It is a figure which shows the generator control system which a parameter adjustment part adjusts a parameter. It is explanatory drawing (1) for demonstrating the adjustment method of the PSS parameter by a parameter adjustment part. It is explanatory drawing (2) for demonstrating the adjustment method of the PSS parameter by a parameter adjustment part. It is explanatory drawing for demonstrating the parameter adjustment which changes only one parameter at a time and minimizes the distance between eigenvalues. It is a flowchart which shows the process sequence of the system | strain reduction model creation apparatus which concerns on a present Example. It is a flowchart which shows the process sequence of the main mode specific process by a fluctuation characteristic specific part. It is a figure which shows an example of the tidal current waveform at the time of the accident of the connection point of an attention system and an external system regarding the system model before contraction. It is a figure which shows the temporary main mode obtained by analyzing the waveform shown in FIG. It is a figure which shows an eigenvalue candidate. It is a figure which shows the aspect of the eigenvector of "mode A". It is a figure which shows the aspect of the eigenvector corresponding to "mode B"-"mode E". It is a figure which shows the characteristic of "mode B"-"mode E" obtained from the aspect of the eigenvector shown in FIG. It is a figure which shows the waveform of "mode 2". It is a figure which shows the temporary main mode obtained with respect to the model after a physical reduction. It is a figure which shows the candidate of the true main mode obtained by applying the inverse iteration method. It is a figure which shows the interconnection line power flow waveform before and behind PSS parameter adjustment. It is a functional block diagram which shows the structure of the computer which executes the system | strain reduction model creation program which concerns on a present Example. It is explanatory drawing for demonstrating Q method which is an example of the physical reduction method. It is explanatory drawing for demonstrating the mode reduction method which is an example of the mathematical reduction method.

Explanation of symbols

100 System Reduction Model Creation Device 110 Data Reading Unit 120 System Data Storage Unit 130 Physical Contraction Unit 140 Oscillation Characteristics Identification Unit 141 Oscillation Mode Search Unit 142 Oscillation Mode Identification Unit 143 Oscillation Mode Confirmation Unit 150 System Characteristics Integration Unit 151 Pair Ring unit 152 Parameter adjustment unit 160 Initial state change unit 170 Data output unit 200 Computer 210 RAM
211 System Reduction Model Creation Program 220 CPU
230 HDD
240 LAN interface 250 I / O interface 260 DVD drive

Claims (10)

A power system contracted model creation device that creates a contracted model by contracting a part other than the system of interest from the model of the power system,
A physical reduced model creating means for creating a physical reduced model obtained by reducing the system model by physical reduction;
A plurality of main modes of the model before reduction are identified as pre-contraction main modes, and each of the plurality of main modes of the physical reduction model created by the physical reduction model creating means is the main mode after reduction. A main mode identifying means to identify as,
By adjusting the parameters of the generator control system of the physical contraction model created by the physical contraction model creation means, the main mode before the contraction and the main mode after contraction are combined to select the main mode. Main mode storage means for storing, and
The main mode specifying means includes
Temporary main mode extraction means for extracting a plurality of temporary main modes by performing waveform analysis by time-series analysis of the fluctuation waveform at the time of the accident,
A true main mode specifying means for performing eigenvalue analysis on each of the plurality of temporary main modes extracted by the temporary main mode extracting means and specifying a true main mode corresponding to each temporary main mode; A power system contraction model creation device characterized by that.   The true principal mode specifying means performs eigenvalue analysis using an inverse iteration method, and when a plurality of principal modes that are candidates for the true principal mode are obtained, the aspect of the eigenvector from the plurality of candidate principal modes. The power system contraction model creation apparatus according to claim 1, wherein one major mode is identified as a true major mode based on the above.   3. The true major mode specifying means excludes the major mode of the local mode from the true major mode when a plurality of major modes that are candidates for the true major mode are obtained. Power system reduction model creation device. The main mode storage means includes
Main mode feature extracting means for extracting the features of each of the plurality of true main modes specified by the true main mode specifying means;
Before and after contraction determining means for determining a combination of each main mode before contracting and each main mode after contracting based on the features extracted by the main mode feature extracting means;
For each combination of the pre-contraction main mode and the post-contraction main mode determined by the pre-contraction group determining means, the physical contraction is performed so that the post-contraction main mode matches the pre-contraction main mode. 4. The power system contraction model according to claim 1, further comprising: a parameter adjustment unit that adjusts a parameter of the generator control system of the physical contraction model created by the about model creation unit. Creation device.   The said main mode specific | specification means correct | amends an excitation system so that the response speed of a generator may become quick, when specifying the main mode after the said reduction | contraction. The power system contraction model creation device described.   The electric power according to any one of claims 1 to 5, wherein the main mode storage means stores the main mode with respect to a power flow at the time of an accident at a connection point between the system of interest and the system of no interest. System reduction model creation device.   7. The power system reduction according to claim 1, wherein the main mode storage unit stores the main mode by adjusting a phase advance time constant, a phase delay time constant and a gain of the PSS. About model creation device. The main mode specifying means further specifies an area contributing to the main mode,
The main mode storage means adjusts the parameters of the generator control system in the area specified by the main mode specifying means, and adjusts the main mode before contracting and the main mode after contracting to select the main mode. The power system contraction model creation device according to any one of claims 1 to 7, wherein the power system contraction model creation device is stored. A power system contracted model creation method by a power system contracted model creating device that creates a contracted model by contracting a part other than the system of interest from a power system model,
A pre-contraction main mode specifying step for specifying each of a plurality of main modes of the model before reduction as a main mode before reduction;
A physical contraction model creation step for creating a physical contraction model in which the system model is contracted by physical contraction;
A post-contraction main mode specifying step of specifying each of a plurality of main modes of the physical contraction model created by the physical contraction model creation step as a post-contraction main mode;
By adjusting the parameters of the generator control system of the physical contraction model created by the physical contraction model creation process, the main mode is saved by combining the main mode before contraction and the main mode after contraction. Including a main mode storage process to
The pre-contraction main mode specifying step and the post-contraction main mode specifying step are:
Temporary main mode extraction process to extract a plurality of temporary main modes by analyzing the waveform of the vibration at the time of the accident by time series analysis,
A true main mode specifying step of performing eigenvalue analysis on each of the plurality of temporary main modes extracted by the temporary main mode extracting step and specifying a true main mode corresponding to each of the temporary main modes. A power system contraction model creation method characterized by the above. A power system contracted model creation program for creating a contracted model by contracting parts other than the system of interest from the power system model,
A physical contraction model creation procedure for creating a physical contraction model in which the system model is contracted by physical contraction;
A plurality of main modes of the model before reduction are identified as pre-contraction main modes, and each of the plurality of main modes of the physical reduction model created by the physical reduction model creation procedure is the main mode after reduction. The main mode identification procedure to identify as,
By adjusting the parameters of the generator control system of the physical contraction model created by the physical contraction model creation procedure, the main mode is adjusted by combining the pre-contraction main mode and the post-contraction main mode. Let the computer execute the main mode save procedure and
The main mode specifying procedure is:
Temporary main mode extraction procedure to extract a plurality of temporary main modes by analyzing the waveform at the time of the accident by time series analysis,
A true main mode specifying procedure for performing eigenvalue analysis on each of the plurality of temporary main modes extracted by the temporary main mode extraction procedure and specifying a true main mode corresponding to each temporary main mode. A power system contraction model creation program characterized by being executed.

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