JP6129758B2 - Power system monitoring apparatus and power system monitoring method - Google Patents

Description

  The present invention relates to a technique for monitoring a power system.

  Since it takes time to calculate a large-scale power system, it is necessary to reduce the calculation time by equivalently reducing the less affected part to reduce the calculation time. Further, when simulating a system from which online data cannot be obtained, a contracted model using offline data of that system is created.

  The reduced model of the power system has a problem that the accuracy decreases when the change from the detailed model that is the basis of the model becomes large. Patent Document 1 describes a technique for improving accuracy by adjusting a contraction model so that main swing modes before and after contraction coincide. Further, Patent Document 2 records the interconnected line fluctuation waveform in the interconnected line, thereby creating a contracted model that minimizes the difference between the recorded waveform and reducing the power system details even if the details are unknown. About techniques that can create models are described.

Japanese Patent No. 5255924 JP 2012-114996 A

  The characteristics of the power system may change due to changes in the operation of the power equipment in the power system that is the target of the reduction model. Even if a reduced model is created from the details of the electric power system, such a change in operation is not reflected in the reduced model, so the accuracy of the reduced model is lowered.

  In order to solve the above problems, a power system monitoring apparatus according to one aspect of the present invention includes a first power system model that is a model of the first power system, and a second power system that is linked to the first power system. A storage unit for storing a second power system model, a plurality of patterns of power transmission paths that can be formed according to the state of power equipment in the second power system, a first power system, and a second power system Using a communication unit that receives first measurement information indicating the state of the first series of points periodically measured by the first measurement device provided at the first series point between By contracting the second power system model, a contracted model candidate corresponding to each pattern is created, a feature amount indicating the feature of each contracted model candidate is calculated, and based on the first measurement information, The reference feature value that is the feature value of the second power system The reduced model candidate corresponding to the feature quantity closest to the reference feature quantity is selected as a reduced model from a plurality of reduced model candidates, and the first power system model and the reduced model are used to select the first reduced model model. A calculation unit that calculates a state of the power system.

  According to one aspect of the present invention, a contracted model can be created in consideration of changes in operation of power equipment in the power system.

The structure of the electric power system of Example 1 and a monitoring system is shown. The reduced model creation process is shown. The reduced model display screen is shown. The structure of the electric power system and monitoring system of Example 2 is shown. The calculation model display screen is shown.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this embodiment, a monitoring system for monitoring a power system linked to another power system will be described.

  FIG. 1 shows a configuration of a power system and a monitoring system according to the first embodiment.

  The monitoring system includes a control device 100, an input / output device 200, and a PMU (Phasor Measurement Unit) 210. Another system 430 that is another power system is connected to the own system 410 that is a power system via a connection line 420. The power system includes power facilities such as transmission lines, loads, and generators. The other system 430 includes a partial system 430a and several generators 430b connected to the partial system 430a. A PMU 210 is connected to the interconnection line 420. The control device 100 is connected to the PMU 210. An input / output device 200 is connected to the control device 100. The control device 100 monitors and controls the own system 410. The PMU 210 is synchronized with GPS (Global Positioning System), measures a phasor, a tidal current, and the like in the interconnection line 420 at a predetermined sampling period, and transmits the measurement information to the control device 100 as measurement information. The phasor may be a voltage or a current.

  The other system 430 is connected to a control device 300 that performs monitoring and control. The control device 100 and the control device 300 are connected to each other via a communication network.

  Here, the own system 410, the PMU 210, the control device 100, and the input / output device 200 are operated by the first electric power company. Further, the other system 430 and the control device 300 are operated by a second electric power company. In the following description, the first electric power company may be called its own company, and the second electric power company may be called another company.

  Control device 100 includes a storage unit 110, a calculation unit 120, and a communication unit 130. The storage unit 110 stores a program and data for processing of the control device 100. The arithmetic unit 120 is a microprocessor such as a CPU (Central Processing Unit), for example, and performs processing of the control device 100 in accordance with a program stored in the storage unit 110. The communication unit 130 is connected to the power equipment in the PMU 210 or the own system 410 and performs communication.

  Note that the program of the control device 100 may be stored in a computer-readable storage medium. In this case, the arithmetic unit 120 reads the program from the storage medium and writes the program to the internal storage unit 110.

  The control device 100 creates a calculation model of the power system including the own system 410 and the other system 430, and monitors and controls the own system 410 using the calculation model. Therefore, the control apparatus 100 needs to simulate the own system 410 in detail and calculate, and simulates the own system 410 using a detailed model of the own system 410. The detailed model indicates components such as a generator and a load in the own system 410, connection relations and impedances of transmission lines, an operation plan, and the like. In addition, the control device 100 generates a contracted model by contracting the detailed model of the other system 430 for which data that can be acquired is limited. This contraction model shows the impedance of the power transmission network in the other system 430, the load connected to the power transmission network, the generator output, and the like. The present invention can also be applied when a plurality of other systems are connected to the own system 410.

  In this embodiment, it is assumed that there is equipment in the other system 430 from which the control device 100 can acquire online data. Here, it is assumed that the control device 300 of another company acquires online data of the generator output of the generator 430b of another company and transmits it to the control device 100 of the company with the liberalization of power. In addition to the generator 430b, the control device 100 can be used in the same manner as long as online data of a power facility such as a load in the other system 430 can be acquired. In addition, the other system 430 may not have equipment that allows the control device 100 to acquire online data.

  The storage unit 110 stores the detailed model of the own system 410 and the detailed model of the other system 430. The arithmetic unit 120 receives online data from the own system 410 and stores it in the storage unit 110. The detailed model of the own system 410 uses online data. Further, the communication unit 130 receives online data of the generator output of the generator 430 b from the control device 300 and stores it in the storage unit 110. Further, the communication unit 130 receives online data of measurement information of the PMU 210 and stores it in the storage unit 110.

  The input / output device 200 includes a display device such as a display and an input device such as a keyboard and a pointing device. The input / output device 200 displays information received from the control device 100, receives input from the user, and transmits it to the control device 100. The input / output device 200 may be a terminal device such as a computer or a mobile communication terminal.

  The control device 100 performs a reduced model creation process for creating a reduced model of the other system 430.

  The power system includes a plurality of power transmission lines and components such as switches. The connection state of the transmission line changes depending on whether the component device is on or off. The control device 100 cannot acquire on / off information indicating the on / off state of the component devices in the other system 430. However, in other systems 430 during normal operation, power transmission paths that can be formed according to the state of the component devices are represented by a plurality of patterns. In the following description, each of these patterns is called an operation pattern candidate. The plurality of operation pattern candidates are input to the input / output device 200 by the user of the control device 100 and stored in the storage unit 110.

  FIG. 2 shows a contracted model creation process.

  In S110, the arithmetic unit 120 changes the detailed model corresponding to each of the plurality of operation pattern candidates, and reduces the changed detailed model to create a reduced model candidate. Here, the calculation unit 120 can use a short-circuit capacitance method, a spectrum method, or the like as a reduction method. The present invention is not particularly dependent on the reduction technique. Here, the reduced model candidate uses the generator output of the generator 430 b as online data obtained from the other system 430. By using online data for the reduced model of the other system 430, the simulation accuracy of the other system 430 can be improved.

  Subsequently, in S120, the calculation unit 120 calculates the feature amount of the reduced model candidate corresponding to each operation pattern candidate. Here, the calculation unit 120 uses one or a plurality of combinations as feature values from eigenvalues, frequencies, attenuation factors, eigenvectors, spectra, and the like. For example, the arithmetic unit 120 uses, as a feature amount, a dominant eigenvalue that is an eigenvalue corresponding to the main oscillation mode among a plurality of eigenvalues of the power system. In addition, the arithmetic unit 120 may use, as a feature amount, an eigenvalue that is least attenuated among a plurality of eigenvalues of the power system. The eigenvalue indicates damping (real part) and frequency (imaginary part). By using eigenvalues, frequencies, attenuation factors, eigenvectors, spectra, etc. as feature quantities, it is possible to calculate feature quantities from reduced model candidates of other systems 430, and also from online data of the PMU 210 at the connection point of other systems 430. Amounts can be calculated and compared.

  In S <b> 130, the calculation unit 120 obtains the feature amount of the other system 430 using the online data and sets it as the reference feature amount. The online data here is measurement information such as a phasor and a tidal current in the interconnection line 420 measured by the PMU 210. The calculation unit 120 can calculate the feature amount of the other system 430 viewed from the connection point by using the measurement information at the connection point of the own system 410 and the other system 430.

  In S140, the calculation unit 120 selects the feature quantity closest to the reference feature quantity by comparing the feature quantity of each reduced model candidate with the reference feature quantity, and reduces the contraction amount corresponding to the selected feature quantity. An approximate model candidate is selected as a contracted model, and an operation pattern candidate corresponding to the selected contracted model candidate is selected as an operation pattern. Thereby, the contracted model candidate closest to the measured information can be selected as the contracted model, and the calculation model of the power system can be created with high accuracy. In addition, an operation pattern can be estimated from a plurality of operation pattern candidates.

  When the control device 100 can acquire a part of connection information of the other system 430, the operation pattern candidates are narrowed down based on the connection information, and reduced model candidates corresponding to the operation pattern candidates are created. good.

  According to the reduced model creation process described above, the feature amount of the reduced model candidate corresponding to a plurality of operation pattern candidates is calculated, and the operation pattern is estimated by comparing with the reference feature amount based on the measurement data of the PMU 210. be able to. Further, by creating a contracted model using online data in the other system 430, the accuracy of the contracted model can be improved.

  When the contracted model is determined by the contracted model creation process, the calculation unit 120 causes the input / output device 200 to display a contracted model display screen showing the determined contracted model, for example. Furthermore, the calculation unit 120 monitors and controls the own system 410 using a calculation model including a detailed model of the own system 410 and a contracted model of the other system 430.

  FIG. 3 shows a reduced model display screen.

  The reduced model display screen shows the configuration of the reduced model, the connection state of the operation pattern, and the like as a result of the reduced model creation process. For example, the contracted model display screen shows the configuration diagram of the contracted model and the position of the switch in the other system 430 defined by the operation pattern. Further, the contracted model display screen shows the open / close state 510 defined by the operation pattern for the switch.

  According to this reduced model display screen, the user can know the operation pattern selected by the reduced model creation process.

  In this embodiment, when a PMU is installed in another system and the control device 100 can acquire online data from the PMU, the accuracy of the calculation model can be improved.

  FIG. 4 shows the configuration of the power system and the monitoring system of the second embodiment.

  It is assumed that the other system 430 of the first embodiment can be divided into other systems 450 and 470. Other system 450 is connected to own system 410 via interconnection line 420. The other system 470 is connected to the other system 450 via the interconnection line 460. The other system 450 includes a partial system 450a and several generators 450b connected to the partial system 450a. Other system 470 includes partial system 470a and several generators 470b connected to partial system 470a. A PMU 210 is connected to the interconnection line 420. A PMU 220 is connected to the interconnection line 460. The PMUs 210 and 220 are synchronized with each other using GPS.

  The storage unit 110 includes a detailed model of the own system 410, a detailed model of the other system 450, a detailed model of the other system 470, a plurality of operation pattern candidates of the other system 450, and a plurality of operation pattern candidates of the other system 470. Is stored. The communication unit 130 receives online data indicating measurement information of the PMUs 210 and 220 and stores it in the storage unit 110. Further, the communication unit 130 receives online data indicating the generator outputs of the generators 450 b and 470 b and stores the online data in the storage unit 110.

  The computing unit 120 first performs a reduced model creation process for the other system 470 far from the own system 410 and then performs a reduced model creation process for the other system 450.

  The contracted model creation process for the other system 470 is the same as the contracted model creation process of the first embodiment. The reduced model candidate of the other system 470 created in S110 uses the online data of the generator 470b. In S <b> 130, the arithmetic unit 120 calculates the reference feature amount of the other system 470 using the online data of the PMU 220.

  The reduced model candidate of the other system 450 created in S110 of the reduced model creation process for the other system 450 uses the online data of the generator 450b. In S <b> 140, the calculation unit 120 determines the reference feature amount of the feature amount of the other system 450 between the PMU 210 and the PMU 220 using the online data of the PMU 210 and the online data of the PMU 220. By calculating the reference feature amount using the measurement values of the two PMUs 210 and 220 that are synchronized with each other in this manner, the reference feature amount is calculated using the measurement value of one PMU as in the first embodiment. Thus, the accuracy of the reference feature amount can be improved. Here, an example in which one PMU is provided in another system has been described, but a plurality of PMUs may be provided in another system.

  In the contracted model creation process for the other system 450, the calculation unit 120 may create a simple contracted model candidate represented by equivalent synthetic impedance or loss. The feature quantity in this case also becomes the equivalent synthetic impedance or loss. When the measurement information of the PMUs 210 and 220 includes a tidal current, in S140, the calculation unit 120 obtains an equivalent combined impedance of the other system 450 from the difference between the tidal current measured by the PMU 210 and the tidal current measured by the PMU 220. Alternatively, the loss of the other system 450 may be obtained from the active power measured by the PMU 210 and the active power measured by the PMU 220. By creating a simple contracted model candidate using equivalent synthetic impedance or loss, it is possible to reduce the amount of computation of the contracted model creation process and the amount of computation of monitoring the own system 410 using the ruled line model.

  However, it is difficult to accurately represent all the other systems 450 using the equivalent synthetic impedance or loss. Therefore, in S140, the calculation unit 120 may determine whether or not the difference between the feature quantity closest to the reference feature quantity and the reference feature quantity is equal to or smaller than a predetermined threshold value. When the difference is equal to or smaller than the threshold value, the calculation unit 120 selects a reduced model candidate corresponding to the feature quantity closest to the reference feature quantity as the reduced model. When the difference is not less than or equal to the threshold value, the calculation unit 120 performs the contracted model creation process again using the contraction method similar to that of the first embodiment. As described above, when the other system 450 cannot be represented by a simple reduced model, a reduced model with higher accuracy can be created.

  According to the contracted model creation process for the other system 450, the reference feature value of the other system 450 is calculated using the online data of the PMUs 210 and 220 at both ends of the other system 450, thereby improving the accuracy of the reference feature value. And the accuracy of the reduced model can be improved.

  Since the PMUs 210 and 220 are synchronized with each other, the phase difference between the phase measured by the PMU 210 and the phase measured by the PMU 220 can be calculated. Therefore, after the contracted model creation process, the calculation unit 120 periodically calculates the phase difference between the PMUs 210 and 220 and determines whether or not the magnitude of the phase difference change exceeds a predetermined change amount threshold value. You may do it. When it is determined that the magnitude of the change in the phase difference exceeds the predetermined change amount threshold, the calculation unit 120 determines that a change in the other system 450 has occurred and outputs information indicating that the other system 450 has changed. To do. In addition, when it is determined that a change in the other system 450 has occurred, the arithmetic unit 120 may execute a reduced model re-creation process for creating a reduced model again. The contracted model re-creation process may be the same as the contracted model creation process, or only S130 and S140 of the contracted model creation process may be executed. In this case, the calculation unit 120 calculates a new reference feature amount using new online data of the PMUs 210 and 220, and selects a new reference feature from a plurality of reduced model candidates created by the reduced model creation process. A reduced model candidate corresponding to the feature quantity closest to the feature quantity is selected as a new reduced model.

  In this way, by detecting the change of the other system 450 based on the measurement information of the PMUs 210 and 220, the contracted model of the other system 450 is changed according to the change of the other system 450, and the accuracy of the calculation model is improved. Can do. In addition, the reduced model re-creation process calculates a new reference feature and selects a new reduced model from the multiple reduced model candidates created by the reduced model creation process. Compared with the creation process, the amount of calculation can be reduced.

  When it is determined that the change of the other system 450 has occurred, the arithmetic unit 120 may display, for example, change information indicating that the other system 450 has changed on the input / output device 200 or a preset destination. Change information may be sent to

  FIG. 5 shows the display of change information.

  The calculation model display screen includes a system display unit 610 indicating a power system corresponding to each model, a system instruction unit 620 indicating a system in which a change is detected, and a message display unit 630 indicating change information of the system. This example of the calculation model display screen shows a case where a change in the other system 450 is detected. In this case, the system instruction unit 620 indicates the other system 450 displayed on the system display unit 610, and the message display unit 630 indicates that the other system 450 has changed. Here, the user may input a contracted model re-creation process instruction to the input / output device 200 while viewing the display of the change information. In this case, the arithmetic unit 120 executes a reduced model re-creation process in accordance with an instruction from the user.

  According to this calculation model display screen, the user can know that there is a change in the other system 450 and the contracted model of the other system 450 needs to be changed.

  The control apparatus 100 can calculate the influence of shaking when an accident occurs in the power system by using the calculation model, and can calculate the control at that time. Further, when the power system changes due to work in the power system, it is possible to calculate changes in voltage and frequency due to the influence, and to calculate countermeasures. In addition, when the control device 100 is applied to a system stabilization system, when an accident occurs, control for reducing the influence of the accident can be calculated, and operation guidance can be output.

  Terms for the expression of the present invention will be described. The power system monitoring device corresponds to the control device 100 or the like. The storage unit corresponds to the storage unit 110 or the like. The calculation unit corresponds to the calculation unit 120 or the like. The communication unit corresponds to the communication unit 130 and the like. The first power system corresponds to the own system 410 and the like. The second power system corresponds to other systems 430, 450, and the like. The third power system corresponds to the other system 470 and the like. The first measuring device corresponds to the PMU 210 and the like. The second measuring device corresponds to the PMU 220 or the like. The first power system model corresponds to a detailed model of the own system 410 and the like. The second power system model corresponds to a detailed model of the other systems 430 and 450. The pattern corresponds to an operation pattern or the like. The first series point corresponds to the interconnection line 420 and the like. The second interconnection point corresponds to the interconnection line 460 and the like.

  The present invention is not limited to the above embodiments, and can be modified in various other forms without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Control apparatus 110 ... Memory | storage part 120 ... Operation part 130 ... Communication part 200 ... Input / output device 300 ... Control apparatus 410 ... Own system 420, 460 ... Interconnection line 430, 440, 460 ... Other systems 430a, 440a, 460a ... Partial system 430b, 450b, 470b ... Generator

Claims (10)

A first power system model that is a model of the first power system; a second power system model that is a model of the second power system linked to the first power system; and power equipment in the second power system A storage unit that stores a plurality of patterns of power transmission paths that can be formed according to the state of
First measurement information indicating a state of the first series system point periodically measured by a first measurement device provided at a first series system point between the first power system and the second power system. A communication unit to receive,
By contracting the second power system model using each pattern, a contracted model candidate corresponding to each pattern is created, a feature amount indicating a feature of each contracted model candidate is calculated, Based on the first measurement information, a reference feature amount that is a feature amount of the second power system is calculated, and a contraction corresponding to a feature amount closest to the reference feature amount among the plurality of contraction model candidates Selecting a model candidate as a contracted model, and calculating a state of the first power system using the first power system model and the contracted model;
Comprising
Power system monitoring device. The storage unit stores a third power system model that is a model of a third power system linked to the second power system,
The communication unit indicates a state of the second interconnection point periodically measured by a second measuring device provided at a second interconnection point between the second power system and the third power system. Receive the second measurement information,
The calculation unit calculates the reference feature amount based on the first measurement information and the second measurement information.
The power system monitoring apparatus according to claim 1. The first measuring device and the second measuring device are synchronized with each other,
The first measurement information indicates a first phase measured by the first measurement device,
The second measurement information indicates a second phase measured by the second measurement device.
The power system monitoring apparatus according to claim 2. The calculation unit periodically calculates a phase difference between the first phase and the second phase, calculates a change amount indicating a magnitude of the change in the phase difference, and the change amount is a predetermined change amount. It is determined whether or not a threshold value is exceeded, and when it is determined that the change amount exceeds the change amount threshold value, information indicating that the second power system has changed is output.
The power system monitoring apparatus according to claim 3. The calculation unit periodically calculates a phase difference between the first phase and the second phase, calculates a change amount indicating a magnitude of the change in the phase difference, and the change amount is a predetermined change amount. It is determined whether or not the threshold value is exceeded, and when the change amount is determined to exceed the change amount threshold value, the reduced model is changed based on the first measurement information and the second measurement information.
The power system monitoring apparatus according to claim 3. When it is determined that the change amount exceeds the change amount threshold, the calculation unit updates an update reference feature amount that is a feature amount of the second power system based on the first measurement information and the second measurement information. Calculating a reduced model candidate corresponding to the feature quantity closest to the update reference feature quantity as a new reduced model from the plurality of reduced model candidates.
The power system monitoring apparatus according to claim 5. The feature amount is equivalent synthetic impedance.
The power system monitoring apparatus according to claim 3. The feature amount includes any one of an eigenvalue, an eigenvector, a frequency, and an attenuation rate.
The electric power system monitoring apparatus as described in any one of Claims 1 thru | or 6. The calculation unit displays information indicating a pattern corresponding to the contracted model.
The electric power system monitoring apparatus as described in any one of Claims 1 thru | or 6. A first power system model that is a model of the first power system; a second power system model that is a model of the second power system linked to the first power system; and power equipment in the second power system Memorize a plurality of patterns of power transmission paths that can be formed according to the state of
First measurement information indicating a state of the first series system point periodically measured by a first measurement device provided at a first series system point between the first power system and the second power system. Receive
By reducing the second power system model using each pattern, a reduced model candidate corresponding to each pattern is created,
Calculate the feature value indicating the characteristics of each reduced model candidate,
Based on the first measurement information, a reference feature amount that is a feature amount of the second power system is calculated,
From among the plurality of reduced model candidates, select a reduced model candidate corresponding to a feature quantity closest to the reference feature quantity as a reduced model,
Calculating a state of the first power system using the first power system model and the reduced model;
To be prepared,
Power system monitoring method.

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