Information processing device, information processing method, and information processing program

Abstract

To provide an information processing device capable of assisting an operator in searching for a point of failure more accurately.SOLUTION: There is provided an information processing device comprising: a locating unit configured to implement a plurality of methods of locating a point of failure in the event of power system failure; and an output unit configured to output information on a point of failure based on respective results of implementing the plurality of methods.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an information processing device, an information processing method, and an information processing program. [Background technology]

[0002] An electric power system transmits electric power from a distribution substation to each consumer through high-voltage distribution lines. If a ground fault occurs due to a tree, bird, or animal coming into contact with the high-voltage distribution line, abnormal voltage or current may be generated. When such an abnormality occurs, a switch in the section where the fault occurred operates, causing a power outage in the section where the fault occurred. To recover from the power outage, it is necessary to locate the fault point using visual inspection by on-site workers or a support system (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-156645 [Patent Document 2] Patent No. 4906498 [Patent Document 3] Patent No. 4564615 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the techniques disclosed in Patent Documents 1 to 3, there are cases where it is difficult to accurately locate a fault point due to errors in measuring instruments, modeling errors in power distribution lines, and the like.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an information processing device, an information processing method, and an information processing program capable of assisting an operator in locating a fault point with higher accuracy. [Means for solving the problem]

[0006] One invention for achieving the above-mentioned object is an information processing device including a location unit that executes multiple methods to locate a fault point when a fault occurs in a power system, and an output unit that outputs information regarding the fault point based on the execution results of each of the multiple methods.

[0007] The information processing method also includes a step in which an information processing device executes a plurality of methods for locating a fault point when a fault occurs in a power system, and a step in which information regarding the fault point is output based on the execution results of each of the plurality of methods.

[0008] The present invention also provides an information processing program that causes a computer to realize a location unit that executes a plurality of methods for locating a fault point when a fault occurs in a power system, and an output unit that outputs information about the fault point based on the execution results of each of the plurality of methods. Other features of the present invention will become apparent from the description of this specification. Effect of the Invention

[0009] According to the present invention, it is possible to assist a worker in locating a fault point with higher accuracy. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing an example of a power system 1 in which an information processing device 2 locates a fault point. [Diagram 2] FIG. 1 is a diagram illustrating a node branch model. [Diagram 3] 4A and 4B are schematic diagrams showing a data structure and an example of node data; [Figure 4] 4 is a schematic diagram showing a data structure and an example of branch data; FIG. [Diagram 5] 4A and 4B are schematic diagrams showing a data structure and an example of measurement data. [Figure 6] FIG. 2 is a schematic diagram showing a data structure and an example of substation data. [Figure 7] 2 is a diagram illustrating a hardware configuration of an information processing device 2. FIG. [Figure 8] FIG. 2 is a diagram showing functional blocks of an information processing device 2. [Figure 9] 13 is a flowchart illustrating a fault point location process executed by the information processing device 2. [Figure 10] 10A and 10B are schematic diagrams showing a data structure and an example of converted measurement data. [Figure 11] 11A and 11B are diagrams illustrating a process of determining whether a resonant frequency can be identified. [Figure 12] 13 is a flowchart illustrating an effective value method location process executed by the information processing device 2. [Figure 13] 4 is a schematic diagram showing a data structure and an example of effective value analysis data; FIG. [Figure 14] 4 is a schematic diagram showing a data structure and an example of resonance frequency data; FIG. [Figure 15] FIG. 13 is a diagram illustrating a resonance frequency analysis. [Figure 16] 11 is a diagram illustrating a process of identifying a location range of a fault point. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] == Implementation form == <<Power system 1>> 1 is a diagram showing an example of a power system 1 in which an information processing device 2 described later locates a fault point P. The power system 1 includes a distribution substation 10, a distribution line 11, a circuit breaker 12, one or more measuring devices 13 installed at predetermined positions on the distribution line 11, and automatic switches 14a and 14b installed at predetermined positions on the distribution line 11.

[0012] [Distribution Substation 10] The distribution substation 10 transforms the voltage supplied from a transmission line (not shown) and outputs a voltage of 6.6 kV to the distribution line 11.

[0013] [Power distribution line 11] A plurality of distribution lines 11 are radially connected to the distribution substation 10, with the distribution substation 10 serving as an origin (sending node). Only one distribution line 11 is shown in Fig. 1. The distribution line 11 is a power line for supplying three-phase AC power having a-phase, b-phase, and c-phase.

[0014] [Circuit Breaker 12] The circuit breaker 12 is a device, such as a distribution circuit breaker or a feeder circuit breaker, that interrupts a current to protect the power system 1 when an accident, such as a short circuit or a ground fault, occurs in the power system 1. In the illustrated example, one circuit breaker 12 is installed for one distribution line 11.

[0015] [Measuring instrument 13] Measuring device 13 is a switch having a sensor capable of measuring measurement values ​​at a fixed period at the installed position (switch with sensor). The measurement values ​​of measuring device 13 include at least the voltage of distribution line 11 and the current flowing through distribution line 11 at the installation point of measuring device 13. The measurement values ​​of measuring device 13 are output to and stored in a database DB (described later).

[0016] [Automatic switch 14a, 14b] The automatic switches 14a and 14b are power devices that are installed on utility poles 15 and automatically open and close electric circuits. A plurality of pole-mounted transformers are connected between the automatic switch 14a and the automatic switch 14b, and power is supplied to each consumer. When a ground fault or the like occurs in the power system 1, the automatic switches 14a and 14b at both ends of a fault point P caused by the ground fault are automatically opened by the power distribution system 20, and a power outage occurs in the section between the opened automatic switches 14a and 14b. Hereinafter, the section that has been blacked out due to a ground fault is referred to as the "blacked out section SC." The blacked out section SC includes the fault point P. In this embodiment, a case where there are a plurality of pole-mounted transformers between the automatic switch 14a and the automatic switch 14b will be described, but there may be only one.

[0017] [Power distribution system] The power distribution system 20 is a system that controls the power system 1. For example, when the power distribution system 20 detects a ground fault or the like based on the operation of a protective relay, the power distribution system 20 opens the automatic switches 14a, 14b so that a fault point P caused by the ground fault is included in the power outage section SC. The power distribution system 20 has a database DB and an information processing device 2.

[0018] In this embodiment, a case will be described in which the power distribution system 20 includes the database DB and the information processing device 2, but the database DB and the information processing device 2 may be provided in another system (for example, a cloud or the like).

[0019] Next, various data stored in the database DB will be described before describing the information processing device 2. The database DB pre-stores node data and branch data related to a node-branch model described later, measurement data, and substation data.

[0020] <Node Branch Model> FIG. 2 is a diagram for explaining the node-branch model. The node-branch model is a model of the power system 1, in which utility poles 15 are nodes and distribution lines 11 are branches. For the sake of convenience, the node with the node name "NOi (i is a natural number)" will be referred to as node N. i The node name is identification information for identifying each node N. For example, a node N with a node name of "NO1" is written as node N1. i For matters common to all of the above, the node number will be omitted and simply referred to as "node N" or "each node N." Additionally, the direction of the distribution line 11 toward the distribution substation 10 is defined as the "upstream side," and the direction away from the distribution substation 10 is defined as the "downstream side."

[0021] [node] In this embodiment, the node N is an aggregation unit managed on a utility pole (not shown) basis. A load and a consumer such as a solar power generation facility are connected to the node N via a pole transformer. The power output from the distribution substation 10 to the distribution line 11 is supplied to the consumer via the node N.

[0022] In the example shown in FIG. 2, the node N n (n is a natural number) to node N of the automatic switch 14b n+5 The blackout section SC is the section between the power outage and the node N n+1 to node N n+4 Customers connected to the network will experience a power outage.

[0023] <node data> FIG. 3 is a schematic diagram showing a data structure and an example of node data. As shown in the figure, the node data has items of node name, type, load active power, and load reactive power. The type is the type of auxiliary equipment installed at the node N (electric pole 15). Examples of auxiliary equipment include a circuit breaker 12 (FCB), a measuring instrument 13, automatic switches 14a and 14b, or a pole transformer (not shown). The load active power is the active power (unit: kW (kilowatt)) of a load connected to the auxiliary equipment. The load reactive power is the reactive power (unit: kvar (kilovar)) of a load connected to the auxiliary equipment. The load active power and the load reactive power are calculated from the measured value of the measuring instrument 13 or the measured value of a smart meter or the like installed at each load (consumer).

[0024] The node data may include location information. The location information is information for identifying the location of the node N. The location information is a location on a map. The location on the map can be expressed by latitude and longitude.

[0025] <branch data> 4 is a schematic diagram showing a data structure and an example of the branch data. As shown in the figure, the branch data has items of substation side node name, end side node name, span length, positive sequence component, negative sequence component, and zero sequence component. The substation side node name is the node name of the node N provided on the upstream side of the branch. The end side node name is the node name of the node N provided on the downstream side of the branch. The span length is the span length (in meters (m)) of the distribution line 11 in the branch.

[0026] Although details will be described later, the information processing device 2 locates the fault point using voltage, current, and impedance expressed in a symmetrical coordinate system expressed by zero-phase, positive phase, and negative phase. The positive-phase components are the positive-phase resistance (R) (unit: Ω (ohm)), inductive reactance (ωL) (unit: Ω), and capacitive reactance of the capacitance to earth (1 / ωC) (unit: MΩ) expressed using the symmetrical coordinate system. The negative-phase components are the negative-phase resistance (R), inductive reactance (ωL), and capacitive reactance of the capacitance to earth (1 / ωC) expressed using the symmetrical coordinate system. The zero-phase components are the zero-phase resistance (R), inductive reactance (ωL), and capacitive reactance of the capacitance to earth (1 / ωC) expressed using the symmetrical coordinate system. The resistance (R), inductive reactance (ωL), and capacitive reactance (1 / ωC) of each phase are values ​​calculated in advance based on the geometric structure of the power system 1, such as the line-to-line distance (span length) of the distribution lines 11 and the height of the utility poles 15.

[0027] <Measurement data> FIG. 5 is a schematic diagram showing a data structure and an example of the measurement data. The measurement data is a measurement value measured by the measuring device 13 within a predetermined period in the past (for example, one week). The measurement data includes a measurement value D1 before a fault occurred in the power system 1 and a measurement value D2 after the fault. The measurement value of the measuring device 13 is used when the information processing device 2 locates the position of the fault point P. As shown in the figure, the measurement data has items of a measuring device ID, a measurement time, an a-phase voltage, an a-phase current, a b-phase voltage, a b-phase current, a c-phase voltage, and a c-phase current. The measuring device ID is identification information for identifying the measuring device 13. The measurement time is the date and time (year, month, day, hour, minute) when the measurement values ​​(a-phase voltage, a-phase current, b-phase voltage, b-phase current, c-phase voltage, and c-phase current) of the measuring device 13 were measured. The a-phase voltage is the voltage of the a-phase (unit: V (volts)). The a-phase current is the current (unit: A (amperes)) flowing through the a-phase. The b-phase voltage is the voltage of phase b. The b-phase current is the current flowing through phase b. The c-phase voltage is the voltage of phase c. The c-phase current is the current flowing through phase c.

[0028] <Substation data> 6 is a schematic diagram showing the data structure and an example of the substation data. As shown in the figure, the substation data has items of transformer capacity and transformer %Z. The transformer capacity is the capacity (unit: MW (megawatts)) of the transformer installed in the distribution substation 10. The transformer %Z is the reactance component L of the percent impedance of the transformer installed in the distribution substation 10. T1 (The unit is % (percent)). If there is a measuring device that measures the earth capacitance of the entire distribution substation 10, the substation data may include the earth capacitance (the unit is uF (microfarad)) measured by the measuring device. The substation data may also include location information of the distribution substation 10.

[0029] <<Information processing device 2>> The information processing device 2 is a device that locates a fault point P when a fault occurs in the power system 1 due to an accident or the like. Hereinafter, the hardware configuration and functional blocks of the information processing device 2 will be described in that order.

[0030] <Hardware configuration of information processing device 2> 7 is a diagram illustrating a hardware configuration of an information processing device 2 according to an embodiment of the present invention. The information processing device 2 is a computer having a CPU (Central Processing Unit) 21, a memory 22, an input unit 23, an output unit 24, a storage unit 25, a recording medium drive unit 26, and a network connection unit 27.

[0031] [CPU21] The CPU 21 executes information processing programs stored in the memory 22 or the storage unit 25 to realize various functions of the information processing device 2.

[0032] [Memory 22] The memory 22 is, for example, a RAM (Random-Access Memory) and is used as a temporary storage area for various programs, data, and the like.

[0033] [Input section 23] The input unit 23 is a device that accepts commands and data input by a user, and includes an input interface such as a keyboard and a touch sensor that detects a touch position on a touch panel display.

[0034] [Output section 24] The output unit 24 is, for example, a device such as a display or a printer.

[0035] [Storage section 25] The storage unit 25 is a non-transitory (eg, non-volatile) storage device that stores various data to be executed or processed by the CPU 21.

[0036] [Recording medium drive unit 26] The recording medium driving unit 26 reads various data such as information processing programs recorded on a recording medium such as an SD card, a DVD, or a CD-ROM, and stores the data in the storage unit 25.

[0037] [Network connection part 27] The network connection unit 27 exchanges various programs and data with other computers via the network.

[0038] <Function blocks of information processing device 2> 8 is a diagram showing functional blocks of the information processing device 2. The information processing device 2 includes an acquisition unit 211, a determination unit 212, a location unit 213, and an output unit 214. The information processing device 2 realizes each function of the acquisition unit 211, the determination unit 212, the location unit 213, and the output unit 214 by the CPU 21 reading out a program stored in the storage unit 25 into the memory 22 and executing it.

[0039] Each of these will be explained below, but first an overview will be given, and then each will be explained in detail later with specific examples using flow charts.

[0040] [Acquisition unit 211] The acquisition unit 211 acquires, from the database DB, a measurement value D1 before the fault and a measurement value D2 after the fault, which are measured by the sensor of the measuring device 13. The measurement values ​​here include the voltage of the distribution line 11 at the installation point of the measuring device 13 and the current flowing through the distribution line 11.

[0041] [Determination unit 212] The determining unit 212 determines whether or not the resonant frequency of the power system 1 can be identified based on the post-fault measured value D2 acquired by the acquiring unit 211.

[0042] [Orientation section 213] The locating unit 213 executes a plurality of methods for locating a fault point when a fault occurs in the power system 1. Specifically, the locating unit 213 executes an effective value method (corresponding to a "first method") and a resonant frequency method (corresponding to a "second method").

[0043] The effective value method includes a process of estimating the fault point resistance of the fault point P while locating the fault point P based on a calculated value C corresponding to a measured value D2 after the fault when one of a plurality of nodes N provided in the power system 1 is assumed to be the fault point P and one of a plurality of fault point resistances is assumed to be the fault point resistance of the fault point, and the measured value D2 after the fault.

[0044] In addition, the "calculated value C corresponding to the measured value D2 after the fault" is a calculated value of the voltage of the distribution line 11 and the current flowing through the distribution line 11 at the installation point of the measuring instrument 13, and is a calculated value obtained by a calculation simulating a fault.

[0045] The resonant frequency method includes a process of identifying a resonant frequency of the power system 1 based on a result of a frequency analysis of the power system 1 obtained using a post-fault measurement value D2, and locating a fault point P based on the identified resonant frequency. The resonant frequency method also includes a process of locating a fault point using a fault point resistance of the fault point P estimated by the effective value method.

[0046] Here, "executing the resonant frequency method" means performing at least a frequency analysis (Fast Fourier Transform (FFT) to be described later) of the power system 1. The frequency analysis of the power system 1 will be described in detail later.

[0047] Here, if the location unit 213 determines that the resonant frequency can be identified, it executes the effective value method and the resonant frequency method, and if it determines that the resonant frequency cannot be identified, it executes the effective value method.

[0048] [Output section 214] The output unit 214 outputs information about the fault point P based on the execution results of each of the multiple methods. For example, when the output unit 214 determines that the resonant frequency can be identified, it outputs information about the fault point P based on the execution result of the effective value method and the execution result of the resonant frequency method. Specifically, the output unit 214 outputs the power outage section due to the fault, and the range in which the fault occurred based on the execution result of the effective value method and the execution result of the resonant frequency method.

[0049] In addition, if the output unit 214 determines that the resonant frequency cannot be identified, it outputs information about the fault point P based on the result of executing the effective value method (for example, the located fault point P and the fault point resistance of the estimated fault point P).

[0050] <<Processing Executed by Information Processing Device 2>> The process executed by the information processing device 2 will be described with reference to a flowchart in FIG.

[0051] First, in step S10, the acquisition unit 211 reads input data (node ​​data, branch data, measurement data, and substation data) from the database DB. At this time, the acquisition unit 211 acquires a measurement value D1 before the fault and a measurement value D2 after the fault from the measurement data.

[0052] Next, in step S20, the determination unit 212 performs a frequency analysis of the power system 1 based on the post-fault measurement value D2 (analyzes the waveform data). Specifically, the determination unit 212 first calculates a zero-phase voltage V0, a ​​positive-phase voltage V1, and a negative-phase voltage V2 by the following formula (1).

[0053]

number

[0054] Here, E' a is the a-phase voltage after the fault, and E' b is the b-phase voltage after the fault, and E' c is the c-phase voltage after the fault. Also, a=cos120°+jsin120°.

[0055] Moreover, the determining unit 212 calculates the zero-phase current I0, the positive-phase current I1, and the negative-phase current I2 by the following equation (2).

[0056]

number

[0057] Here, I' a is the a-phase current after the fault, and I' b is the b-phase current after the fault, and I' c is the c-phase current after the fault. The determination unit 212 calculates the zero-phase voltage V0, the positive-phase voltage V1, the negative-phase voltage V2, the zero-phase current I0, the positive-phase current I1, and the negative-phase current I2 for each measurement time after the fault, and generates converted measurement data that represents the calculated voltages and currents in a time series.

[0058] <Measurement data after conversion> 10 is a schematic diagram showing a data structure and an example of the converted measurement data. As shown in the figure, the converted measurement data includes items such as a measuring device ID, a measurement time, a positive-phase voltage, a positive-phase current, a negative-phase voltage, a negative-phase current, a zero-phase voltage, and a zero-phase current.

[0059] Next, in step S30, the determining unit 212 determines whether or not the resonant frequency can be identified from the time-series waveform data of the zero-phase current.

[0060] FIG. 11 is a diagram for explaining a process for determining whether or not a resonant frequency can be identified. In the illustrated graph 1010, the vertical axis is the zero-phase current and the horizontal axis is time, and represents the time-series waveform data of the zero-phase current. The determination unit 212 performs a fast Fourier transform (FFT) on the waveform data of the zero-phase current shown in the graph 1010 as shown in the graph 1020. In the illustrated graph 1020, the vertical axis is the power spectrum and the horizontal axis is the frequency. The determination unit 212 determines that the resonant frequency can be identified when there is a frequency that exceeds a preset power spectrum threshold value α. In the illustrated example, the power spectrum shown by the reference numeral 1021 exceeds the threshold value α. On the other hand, in a case where the fault point resistance is large and the vibration component of the waveform of the zero-phase current is quickly attenuated, there is no frequency that exceeds the threshold value α. Therefore, the determination unit 212 determines that the resonant frequency cannot be identified when there is no frequency that exceeds the power spectrum threshold value α.

[0061] If the determination unit 212 determines that the resonant frequency can be identified, it identifies the resonant frequency of the power system 1, and proceeds to processing in step S40. Specifically, the determination unit 212 determines that the frequency at which the power spectrum has a peak is the resonant frequency f0. On the other hand, if the determination unit 212 determines that the resonant frequency cannot be identified, it proceeds to processing in step S41.

[0062] In this embodiment, the determination unit 212 specifies the resonant frequency based on the waveform data of the zero-phase current, but the method is not limited to this and the resonant frequency may be specified based on the waveform data of the zero-phase voltage. Also, the method of specifying the resonant frequency is not limited to the above, and may be based on the analysis results of frequency analysis (Fourier transform) performed based on the waveform data of the zero-phase current or the zero-phase voltage.

[0063] Next, in step S40 or S41, the locating unit 213 executes an effective value method location process to locate the fault point P by the effective value method. Location by the effective value method can find the fault point P even if the fault point resistance is large. Therefore, even if the resonant frequency cannot be identified, by executing step S41, it is possible to support the worker in searching for the fault point. Also, when the resonant frequency can be identified, the fault point resistance R obtained by executing step S40 is used as the fault point location process. f By utilizing the results of fault point P in subsequent processing, it is possible to improve the location accuracy.

[0064] <Actual value method location processing> 12 is a flowchart illustrating the effective value method location process executed by the information processing device 2. Note that, in the following, a case where a single-line ground fault occurs in the power system 1 will be described as an example.

[0065] First, in step S401, the location unit 213 estimates the pre-fault state of the power system 1 based on the equipment information (node ​​data, branch data, and substation data) of the power system 1 and the measurement value D1 before the fault.

[0066] Specifically, the location unit 213 determines whether a plurality of nodes N i The voltage and current values ​​at each of (1≦i≦N) are estimated.

[0067] Next, in step S402, the location unit 213 generates an impedance matrix Z. When the current injected into each of the multiple nodes N is I and the voltage of each of the multiple nodes N is V, the impedance Z is expressed by the following equation (3).

[0068]

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[0069] In the following description, the power system 1 includes N nodes (nodes N1 to N NIn this case, the voltage V is expressed by the following equation (4), the current I by the following equation (5), and the impedance Z by the following equation (6).

[0070]

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[0071]

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[0072]

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[0073] That is, the voltage V and the current I are a matrix with N rows and 1 column, and the impedance Z is a matrix with N rows and N columns. Hereinafter, the impedance Z in equation (6) will be particularly referred to as the "impedance matrix Z."

[0074] In equation (4), the component V of the voltage V i (1≦i≦N) is node N i In addition, in equation (5), the component I of the current I i (1≦i≦N) is node N i is the injection current into the

[0075] In equation (6), the component Z of the impedance matrix Z ij (1≦i≠j≦N) is the node N i and node N j is the impedance between

[0076] In addition, in equation (6), the diagonal components Z of the impedance matrix Z ii is the node N i This corresponds to the impedance of the entire power system 1 when the reference voltage is 1.

[0077] Next, in step S403, the location unit 213 executes a calculation to simulate the power system 1 when a predetermined fault condition is imposed on the power system 1, and calculates a calculated value C corresponding to the post-fault measurement value D2 acquired by the acquisition unit 211 in step S10. At this time, the location unit 213 performs the calculation by imposing one of a plurality of predetermined fault conditions on the power system 1.

[0078] The fault condition is a node corresponding to the fault point P and a fault point resistance of the fault point P. Specifically, the "node corresponding to the fault point P" is the node N i (1≦i≦N). In addition, the "fault point resistance of the fault point P" is one of the multiple pre-set candidate values ​​of fault point resistance R fk (1≦k≦M) (k and M are natural numbers). Candidate value R fk may be M values ​​extracted from a range assumed to include the actual fault point resistance value of the fault point P.

[0079] In step S403, the location unit 213 determines the state of node N i Assuming that the fault point is P, the candidate value R fk to node N i The fault point resistance is assumed to be P. Hereinafter, the node N i is called the "simulated fault point", and the candidate value R fk is called the "simulated fault point resistance."

[0080] The calculations performed by the location unit 213 in step S403 are described in detail below. The calculations performed by the location unit 213 in step S403 specifically include a step of calculating the voltage and current at the fault point P, and a step of calculating the voltage and current after the fault at the installation point of the measuring device 13. The calculations are described in detail below.

[0081] [Step to calculate voltage and current at fault point P] First, the node N assumed to be the fault point P i As mentioned above, in this example, the type of fault that has occurred is a line-to-ground fault. In this case, the following formula is used to calculate the current and voltage.

[0082]

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[0083]

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[0084] As described above, the orientation unit 213 performs calculations using a symmetric coordinate system. Therefore, the components of the current I, voltage V, and impedance matrix Z are given superscripts to indicate that they are expressed using a symmetric coordinate system. The superscript "0" means zero phase, the superscript "1" means positive phase, and the superscript "2" means negative phase. The same applies in the following explanation.

[0085] In equations (7) and (8), "F" indicates after a failure. Also, the R in the denominator on the right side of equation (7) fk is one of multiple candidate values ​​of the fault point resistance of the fault point P.

[0086] Node N assumed to be fault point P i The voltage can be expressed by the following equations (9) to (11).

[0087]

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[0088]

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[0089]

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[0090] V on the right hand side of equation (10) i 1 is the node N iThe positive-phase voltage before the fault, and the value estimated in step S401 can be substituted therein. The currents in the right-hand sides of the equations (9) to (11) can be substituted with the currents in the equations (7) and (8). The location unit 213 uses the equations (7) to (11) to determine the node N assumed to be the fault point P. i Calculate the voltage.

[0091] [Step of calculating the voltage and current after a fault at the installation point of the measuring instrument 13] Next, the voltage and current after the fault at the installation point of the measuring instrument 13 are formulated. As described above, the installation point of the measuring instrument 13 is a position corresponding to any one of the multiple nodes, and the node is referred to as node N. k Let us assume that.

[0092] Node N corresponding to the installation point of the measuring instrument 13 k The voltage is calculated using the following equations (12) to (14) using equations (9) to (11) and Ohm's law.

[0093]

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[0094]

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[0095]

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[0096] Furthermore, a node N corresponding to the installation point of the measuring instrument 13 k The current is calculated using the following equations (15) to (17) using equations (12) to (14) and Ohm's law.

[0097]

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[0098]

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[0099]

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[0100] Here, each of the formulas (15) to (17) is k and node N k Node N adjacent to j The denominator of the right hand side of the second equal sign in each of equations (15) to (17) is the current between node N k and node N j is the impedance between

[0101] The location unit 213 can calculate the voltage and current (calculated value C) after a fault occurs at the installation point of the measuring device 13 using the formulas (12) to (17).

[0102] Next, in step S404, the location unit 213 detects the simulated fault point (node ​​N i ), simulated fault point resistance (candidate value R fk ), and the calculated value C are stored in the database DB in correspondence with each other.

[0103] The location unit 213 further calculates the calculated value C corresponding to the post-fault measurement value D2 for all fault conditions in the above-mentioned procedure, and stores the calculated value C in the database DB.

[0104] In other words, the location unit 213 calculates the calculated value C corresponding to the measured value D2 after the fault in this case at the node N i For each (1≦i≦N), multiple candidate fault point resistance values ​​R fk The calculation is performed in correspondence with (1≦k≦M). Therefore, the orientation unit 213 obtains N×M calculated values ​​C.

[0105] In addition, the preset candidate value R fk There is no particular limit to the number M. Candidate value R fkmay be M values ​​extracted from a range assumed to include the actual fault point resistance value of the fault point P.

[0106] For example, it is sufficient to set M values ​​that equally divide a range that is assumed to include the actual fault point resistance value of the fault point P into M-1 values.

[0107] Next, in step S405, the location unit 213 locates the fault point P based on the similarity between the measured value D2 after the fault and the N×M calculated values ​​C calculated in step S403, and calculates the fault point resistance R f Among the multiple assumed fault conditions, the fault condition whose corresponding calculated value C is similar to the measured value D2 after the fault is considered to be closer to the state of the power system 1 after the fault. Using this, the locating unit 213 locates the fault point P while estimating the fault point resistance R f Estimate.

[0108] Specifically, the locating unit 213 uses an evaluation function indicating the degree of similarity to locate the fault point P. The evaluation function used is a function that changes according to the difference between the measured value and the calculated value C for the voltage and current of each phase in a symmetrical coordinate system expressed by the zero phase, the positive phase, and the negative phase.

[0109] In this embodiment, the orientation unit 213 uses an evaluation function F shown in the following equation (18).

[0110]

number

[0111]

number

[0112] p in equation (18) is a variable shown in equation (19), and the node N assumed to be the fault point P i and the candidate value R of the fault point resistance of the fault point P fkThis is a summary of some of the above.

[0113] The evaluation function of equation (18) is a weighted sum obtained by multiplying the absolute value of the difference between the post-fault measurement value D2 and the calculated value C for the voltage of each phase in the symmetric coordinate system and the difference between the post-fault measurement value D2 and the calculated value C for the current of each phase by predetermined weights w1 to w6.

[0114] The location unit 213 uses predetermined weights w1 to w6 set according to the type of fault. For example, if the type of fault is a ground fault, the weight w1 related to the zero-phase voltage and the weight w4 related to the zero-phase current may be set to 1, and the other weights may be set to 0. Alternatively, if the type of fault is not a ground fault, the weight w1 related to the zero-phase voltage and the weight w4 related to the zero-phase current may be set to 0, and the other weights may be set to 1.

[0115] The evaluation function is not limited to the example of formula (18). As another example, instead of the absolute value of the difference between the measured value D2 after the failure and the calculated value C in formula (18), another function that increases as the absolute value of the difference between the measured value D2 after the failure and the calculated value C increases may be used.

[0116] The location unit 213 calculates an evaluation value F(p) using an evaluation function for each of all fault conditions (combinations of simulated fault points and simulated fault point resistances), generates data for effective value analysis indicating the calculated evaluation values, and stores the generated data for effective value analysis in a database DB.

[0117] <Data for effective value analysis> 13 is a schematic diagram showing a data structure and an example of effective value analysis data. As shown in the figure, the effective value analysis data includes an evaluation value and a simulated fault point resistance (candidate value R fk ) and the simulated fault point (node ​​N i The orientation unit 213 sorts the calculated evaluation values ​​in ascending order, for example, to generate effective value analysis data.

[0118] Next, in step S406, the location unit 213 selects the fault condition (simulated fault point (node ​​N i ) and simulated fault point resistance (candidate value R fk ) combination) and extract the extracted simulated fault point (node ​​N i ) and simulated fault point resistance (candidate value R fk ) is the orientation result (fault point P and fault point resistance R f For example, in the data example shown in FIG. 13, the location unit 213 outputs node N as the fault point P. 100 The node name "NO100" is the fault point resistor R f Then, the RMS method location process ends.

[0119] 9, following step S40, in step S50, the locating unit 213 executes a resonant frequency method locating process for locating the fault point P by the resonant frequency method. The locating unit 213 uses the input data read in step S10 and the fault point resistance R calculated in step S40 to f Using this, the resonance frequency f is calculated using the following equations (20) to (23).

[0120]

number

[0121]

number

[0122]

number

[0123]

number

[0124] Here, R f is the fault point resistance, R u1is the total resistance (positive sequence component) of the distribution line 11 where the fault occurred, and l fu is the distance from the distribution substation 10 to the fault point P, R T1 is the resistance (positive sequence component) of the transformer installed in the distribution substation 10, R u0 is the total resistance (zero-phase component) of the distribution line 11 where the fault occurred, L u1 is the total inductance (positive sequence component) of the distribution line 11 where the fault occurred, L T1 is the inductance (positive sequence component) of the transformer installed in the distribution substation 10, L u0 is the total inductance (zero-phase component) of the distribution line 11 where the fault occurred, C u0 is the capacitance to earth (zero-phase component) of each distribution line 11 of the power system 1, l Σ is the total length of the substation.

[0125] The location unit 213 is a distance l from the distribution substation 10 to the fault point P. fu Change each distance l fu For example, the location unit 213 calculates the resonant frequency f at each of the nodes N i The distance to each fu Then, for each node N i The locating unit 213 calculates the resonant frequency f assuming each of the fault points P as the fault point resistance R f , the distance l from the distribution substation 10 to the fault point P fu , and the calculated resonant frequency f are associated with each other and stored as resonant frequency data in the database DB.

[0126] <Resonant frequency data> FIG. 14 is a schematic diagram showing the data structure and an example of the resonant frequency data. The resonant frequency data is obtained by calculating the result of FFT and the fault point resistance R f and the distance l from distribution substation 10 fu and resonance frequency f. The result of the FFT is the resonance frequency f0 ("1200" in the example shown in the figure) (unit: Hz (Hertz)) identified by frequency analysis in S30.

[0127] Next, the locating unit 213 locates the fault point P by comparing the resonant frequency data with the resonant frequency f0 obtained in step S30.

[0128] 15 is a diagram for explaining the resonant frequency analysis. The resonant frequency data has characteristics as shown in a graph 1030. The vertical axis of the graph 1030 is the resonant frequency f, and the horizontal axis is the distance l from the distribution substation 10. fu The location unit 213 extracts the resonance frequency f that has the smallest difference from the resonance frequency f0 obtained in step S30 from the resonance frequency data, and calculates the distance l corresponding to the extracted resonance frequency f. fu Node N in i is located at the fault point P.

[0129] For example, in the data example shown in FIG. 12, the location unit 213 identifies the node N with the node name "NO102" at a distance "7.5" corresponding to the resonance frequency f "1205" that has the smallest difference from the resonance frequency f0 "1200". 102 is located at the fault point P.

[0130] Next, in step S60, the location unit 213 identifies the location range PA (corresponding to "information on the fault point P") of the fault point P using the first fault point P1 located by the effective value location method processing and the second fault point P2 located by the resonant frequency method processing. The location range PA of the fault point P corresponds to the "range in which the fault has occurred."

[0131] Fig. 16 is a diagram for explaining the process of identifying the fault point location range. In this figure, x1 and x2 are the first fault point P1 located by the effective value location method process or the second fault point P2 located by the resonant frequency method process. In addition, y1 is the automatic switch 14a installed on the upstream side of the power outage section SC (the automatic switch 14a on the upstream side that is open) and y2 is the automatic switch 14b installed on the downstream side of the power outage section SC (the automatic switch 14b on the downstream side that is open).

[0132] 16, both x1 and x2 are in the power outage section SC. Therefore, the location unit 213 specifies the section from x1 to x2 as the location range PA of the fault point P.

[0133] 16, x1 is located upstream of y1 (outside the power outage section SC), and x2 is inside the power outage section SC. Therefore, the location unit 213 specifies the section from y1 to x2 as the location range PA of the fault point P. This is because there is no fault point P upstream of y1 (outside the power outage section SC).

[0134] 16, x1 is in the power outage section SC, and x2 is downstream of y2 (outside the power outage section SC). Therefore, the location unit 213 specifies the section from x1 to y2 as the location range PA of the fault point P. This is because there is no fault point P downstream of y2 (outside the power outage section SC).

[0135] 16, both x1 and x2 are outside the power outage section SC. Therefore, the locating unit 213 identifies the power outage section SC from y1 to y2 as the location range PA of the fault point P.

[0136] Next, in step S70, the output unit 214 outputs the location result. The location result is the fault point P and the fault point resistance R located by the location unit 213 in step S41 using the effective value method location process. f , or the location range PA of the fault point P identified by the locating unit 213 in step S60. After that, this fault point locating process is terminated.

[0137] According to the procedure described above, the location accuracy can be improved by combining different location methods. Even if a ground fault occurs for which the resonant frequency cannot be calculated, the fault point can be located by switching to the effective value method, and the operator can be supported in searching for the fault point. In the case of a ground fault for which the resonant frequency can be calculated, the location accuracy can be improved by combining the effective value method and the resonant frequency method.

[0138] ==Summary== As described above, the information processing device 2 of the embodiment includes a location unit 213 that executes multiple methods to locate a fault point P when a fault occurs in the power system 1, and an output unit 214 that outputs information regarding the fault point P based on the execution results of each of the multiple methods.

[0139] With this configuration, it is possible to assist the worker in locating the fault point with higher accuracy.

[0140] The information processing device 2 also includes an acquisition unit 211 that acquires a measurement value D2 including a post-fault voltage and current from a measuring instrument 13 installed in the power system 1, and the location unit 213 executes an effective value method for locating the fault point P based on a calculated value C corresponding to the post-fault measurement value D2 when any one of a plurality of nodes installed in the power system 1 is assumed to be the fault point P and the post-fault measurement value D2, and a resonant frequency method for identifying a resonant frequency of the power system based on a result of a frequency analysis of the power system 1 obtained using the post-fault measurement value D2, and locating the fault point based on the identified resonant frequency.

[0141] According to such a configuration, by combining the effective value method and the resonant frequency method, it is possible to output information regarding the fault point with higher accuracy.

[0142] The information processing device 2 also includes a determination unit 212 that determines whether or not the resonant frequency of the power system 1 can be identified based on the measurement value D2 after the failure, and if the location unit 213 determines that the resonant frequency can be identified, it executes the effective value method and the resonant frequency method, and if it determines that the resonant frequency cannot be identified, it executes the effective value method.

[0143] With this configuration, even if a ground fault occurs where the fault point resistance is large and the resonant frequency cannot be identified, the fault point can be located using the effective value method, making it possible to assist workers in locating the fault point.

[0144] In addition, in the information processing device 2, when the output unit 214 determines that the resonant frequency can be identified, it outputs information about the fault point P based on the execution result of the effective value method and the execution result of the resonant frequency method, and when it determines that the resonant frequency cannot be identified, it outputs information about the fault point P based on the execution result of the effective value method.

[0145] With this configuration, even if a ground fault occurs where the fault point resistance is large and the resonant frequency cannot be identified, the location results can be output using the effective value method, making it possible to assist workers in locating the fault point.

[0146] In addition, the effective value method includes a process of estimating the fault point resistance of the fault point P based on a calculated value C assuming that one of a plurality of nodes is the fault point P and one of a plurality of fault point resistances is the fault point resistance of the fault point P, and a measured value D2 after the failure, and the resonant frequency method includes a process of locating the fault point P using the fault point resistance of the fault point P estimated by the effective value method.

[0147] According to such a configuration, the fault point P is located by the resonant frequency method using the fault point resistance estimated by the effective value method, so that the accuracy of locating the fault point P can be improved.

[0148] In the information processing device 2, the output unit 214 outputs the power outage section SC due to the failure and the range in which the failure occurred based on the execution results of the multiple methods.

[0149] According to this configuration, the range in which the failure has occurred can be presented to the worker with greater accuracy, making it easier for the worker to search for the point of failure.

[0150] The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. Furthermore, the present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

[0151] For example, in the above-described embodiment, the information processing device 2 outputs the location range PA of the fault point P as the "information on the fault point P", but is not limited thereto, and the "information on the fault point P" may be a range, a point (position in the power system 1), or a probability distribution. For example, the information processing device 2 may output the first fault point P1 and the second fault point P2 as candidate points for the fault point P, may output the midpoint between the first fault point P1 and the second fault point P2 as the fault point P, or may output a probability distribution of the fault point P based on the first fault point P1 and the second fault point P2.

[0152] In addition, in the above-described embodiment, the effective value method and the resonant frequency method are given as examples of multiple methods, but the information processing device 2 may output information regarding the fault point P by combining multiple other methods, such as, for example, a capacitor addition method or a method of locating the fault position on the power transmission and distribution line from the difference in surge detection time at two sub-stations on either side of the fault point.

[0153] In addition, the data stored in the above-mentioned database DB may be read by the CPU 21 via the recording medium drive unit 26, or may be obtained from an external computer or server via the network connection unit 27.

[0154] In addition, various data generated by each function of the information processing device 2, such as the above-mentioned converted measurement data, data for effective value analysis, or resonant frequency data, may be stored in the memory unit 25 by the CPU 21, may be written to a recording medium via the recording medium driving unit 26, may be stored as a structure on the memory 22, or may be output to the output unit 24 together with the positioning results. [Explanation of symbols]

[0155] power system 1 Distribution Substation 10 Power Lines 11 Circuit breaker 12 Measuring instrument 13 Automatic switch 14a, 14b Electric pole 15 Data processing device 2 CPU 21 Memory 22 Input section 23 Output section 24 Memory section 25 Recording medium drive unit 26 Network connection 27 Acquisition Department 211 Judgment section 212 Orientation section 213 Output section 214 Database DB

Claims

1. A location unit that executes a plurality of methods for locating a fault point when a fault occurs in the power system; an output unit that outputs information about the fault point based on the execution results of each of the plurality of methods; Including, Information processing device.

2. 2. The information processing device according to claim 1, An acquisition unit that acquires measured values ​​including voltage and current after a fault from a sensor installed in the power system, The orientation unit includes: A first method for locating the fault point based on a calculated value corresponding to the measurement value when any one of a plurality of nodes provided in the power system is assumed to be the fault point and the measurement value; A second method of identifying a resonant frequency of the power system based on a result of a frequency analysis of the power system obtained using the measured values, and locating the fault point based on the identified resonant frequency. Information processing device.

3. 3. The information processing device according to claim 2, a determination unit that determines whether or not a resonant frequency of the power system can be identified based on the measurement value, The orientation unit includes: When it is determined that the resonant frequency can be identified, the first method and the second method are executed; When it is determined that the resonant frequency cannot be identified, the first method is executed. Information processing device.

4. 4. The information processing device according to claim 3, The output unit is When it is determined that the resonant frequency can be identified, information regarding the fault point based on the execution result of the first method and the execution result of the second method is output; When it is determined that the resonant frequency cannot be identified, information regarding the fault point based on the execution result of the first method is output. Information processing device.

5. 3. The information processing device according to claim 2, The first method is A process of estimating a fault point resistance of the fault point based on the calculated value and the measured value when one of a plurality of fault point resistances is assumed to be the fault point while assuming one of the plurality of nodes to be the fault point, The second method is A process of locating the fault point using the fault point resistance of the fault point estimated by the first method, Information processing device.

6. 6. The information processing device according to claim 1, The output unit is Outputting a power outage section due to the fault and a range in which the fault occurred based on the execution results of the multiple methods. Information processing device.

7. An information processing device, Executing a plurality of methods for locating a fault when a fault occurs in the power system; outputting information about the fault point based on the execution results of each of the plurality of methods; Including, Information processing methods.

8. On the computer, A location unit that executes a plurality of methods for locating a fault point when a fault occurs in the power system; an output unit that outputs information about the fault point based on the execution results of each of the plurality of methods; To achieve this, Information processing program.

Images