State diagnosis device, state diagnosis method, and program

Abstract

To provide a state diagnosis device capable of improving accuracy of detecting abnormality of a circuit breaker.SOLUTION: A state diagnosis device according to an aspect of the present disclosure includes a measurement unit configured to measure a first command current value that is a value of a current flowing at a time of a closing command of a circuit breaker, and a determination unit configured to determine a state of the circuit breaker based on a time-series change of the first command current value and a time-series change of a second command current value that is a value of a current flowing at a time of a closing command during normal operation of the circuit breaker stored in advance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a condition diagnosis device, a condition diagnosis method, and a program. [Background technology]

[0002] There is a known technology for early and efficient detection of abnormalities in a circuit breaker. Patent Document 1 describes a technology that measures the closing operation time required for a vacuum circuit breaker to transition to a closing state and the breaking operation time required for the vacuum circuit breaker to transition to a breaking state, and determines whether the vacuum circuit breaker is abnormal based on a comparison with each reference operation time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-87593 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 determines abnormalities in a circuit breaker based on the delay time between the circuit breaker's closing and opening operations. Therefore, it is necessary to monitor the circuit breaker's closing operation time to capture changes in the time direction. Since the time change is, for example, on the order of a few milliseconds, it is difficult to accurately detect it.

[0005] The present disclosure provides a condition diagnosis device that can improve the accuracy of detecting abnormalities in a circuit breaker. [Means for solving the problem]

[0006] The condition diagnosis device according to the present disclosure includes a measurement unit that measures a first command current value, which is the value of the current that flows when a command to close a circuit breaker is issued, and a determination unit that determines the condition of the circuit breaker based on a time series change in the first command current value and a time series change in a second command current value, which is the value of the current that flows when a command to close a circuit breaker is issued during normal operation and is stored in advance. [Effects of the Invention]

[0007] According to the condition diagnosis device according to the present disclosure, it is possible to improve the accuracy of detecting abnormalities in a circuit breaker. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a functional block diagram of a condition diagnosis device according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a hardware configuration diagram of a condition diagnosis device according to an embodiment of the present disclosure. [Figure 3] 5A and 5B are diagrams illustrating an example of time series changes in a first command current value and a second command current value when an abnormality occurs in the condition diagnosis device according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a diagram for explaining a method for diagnosing the state of a circuit breaker in a state diagnosis device according to a modified example of an embodiment of the present disclosure. [Figure 5] FIG. 1 is a flow chart for explaining a condition diagnosis method according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the preferred embodiments of the present invention with reference to the accompanying drawings. In the drawings, the same components are designated by the same reference numerals, and redundant explanations may be omitted.

[0010] <Background of the study leading to the conception of the condition diagnosis device 10 according to the embodiment> Circuit breakers, such as vacuum circuit breakers, which are current interruption devices, can lead to serious accidents if they do not operate normally. Therefore, it is preferable to detect circuit breaker abnormalities early and efficiently. Detecting abnormalities based on current values, which are data that clearly represent the circuit breaker state, is effective in that it allows for early and accurate detection of abnormalities and enables prompt and appropriate countermeasures.

[0011] The technology disclosed in Patent Document 1 determines abnormalities in a circuit breaker based on the delay time between the circuit breaker's closing and opening operations. The fluctuations in this delay time are extremely short, on the order of a few milliseconds, making it difficult to accurately detect. In addition, multiple signal contacts that open and close in response to the opening and closing of the vacuum valve must be incorporated into the circuit breaker when it is assembled, so this must be addressed from the circuit breaker design stage. Furthermore, contact information is easily affected by noise such as chattering, making it difficult to accurately detect fluctuations in delay time.

[0012] Therefore, a condition diagnosis device 10 according to the following embodiment has been found that can solve such problems.

[0013] [Embodiment] <Configuration of condition diagnosis device 10> 1 is a functional block diagram of a condition diagnosis device 10 according to an embodiment of the present disclosure. The condition diagnosis device 10 diagnoses the condition of a circuit breaker 20. The circuit breaker 20 to be diagnosed by the condition diagnosis device 10 may be, for example, a vacuum circuit breaker, but is not limited to this.

[0014] The condition diagnosis device 10 includes a measurement unit 11 and a determination unit 12. The measurement unit 11 measures a first command current value, which is the value of a current that flows when a command to close the circuit breaker 20 is issued. The measurement unit 11 includes a current sensor for detecting a current that flows through the circuit breaker 20 (for example, an output current from an output terminal of the circuit breaker 20).

[0015] The determination unit 12 determines the state of the circuit breaker 20 based on the time series change in the first command current value and the time series change in the second command current value, which is the value of the current that flows when a closing command is issued during normal operation of the circuit breaker 20 and is stored in advance. Hereinafter, the time series change in the current value is also referred to as a "waveform."

[0016] The time series changes of the first command current value and the second command current value may be stored as waveforms of current values ​​from the start of the closing operation of the circuit breaker 20 until the current value becomes at least 0. Furthermore, multiple time series changes of the second command current value may be stored.

[0017] When it is determined that the circuit breaker 20 is abnormal, the command current value measured at the time of the determination may be stored as event log data in which the type of abnormality that occurred in the circuit breaker 20, the date and time of the occurrence, and the date and time of completion of the response are recorded as one record. When the determination unit 12 determines that the circuit breaker 20 is abnormal, the stored event log data may be used as a means for identifying the type of abnormality in the circuit breaker 20 by comparing it with the waveform of the measured command current value.

[0018] The time-series change in the second command current value may be stored in a device separate from the condition diagnosis device 10, or may be stored in a storage means included in the condition diagnosis device 10. The storage means includes, for example, at least one of a RAM (Random Access Memory), a main storage device such as a ROM (Read Only Memory), and an external storage device such as an HDD (Hard Disk Drive).

[0019] Furthermore, the determining unit 12 determines that the state of the circuit breaker 20 is abnormal if the difference between the first command current value and the second command current value at a predetermined time after the start of the closing operation of the circuit breaker 20 is equal to or greater than a predetermined threshold value.

[0020] More specifically, the judgment unit 12 may judge that the state of the circuit breaker is abnormal if, after a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20, the first command current value is greater than the second command current value by a predetermined threshold value or more.

[0021] Furthermore, the determination unit 12 may determine that the state of the circuit breaker is abnormal when the first command current value is smaller than the second command current value by a predetermined threshold or more when a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20. Note that when the first command current value is smaller than the second command current value by a predetermined threshold or more, it is considered that the cause is, for example, a failure of a switch included in the circuit breaker.

[0022] 2 is a hardware configuration diagram of a condition diagnosis device 10 according to the first embodiment of the present disclosure. The condition diagnosis device 10 includes an input device 101, a display device 102, an external I / F (Interface) 103, a RAM 104, a ROM 105, a CPU (Central Processing Unit) 106, a communication I / F 107, and an HDD 108, all of which are connected via a bus B.

[0023] The input device 101 and the display device 102 may be connected as needed. In the condition diagnosis device 10, the RAM 104, the ROM 105, and the CPU 106 realize the function of the determination unit 12 of the condition diagnosis device 10.

[0024] The input device 101 is a touch panel, operation keys or buttons, keyboard, mouse, etc. that are used by the user to input various signals. The display device 102 is composed of a display such as a liquid crystal or organic electroluminescence (EL) display for displaying a screen, a speaker for outputting sound data such as voice or music, etc. The communication I / F 107 is an interface that allows the condition diagnosis device 10 to perform data communication via an external network.

[0025] The HDD 108 is an example of a non-volatile storage device that stores programs and data. The stored programs and data include an OS, which is basic software that controls the entire condition diagnosis device 10, and applications that provide various functions on the OS. Note that the condition diagnosis device 10 may use a drive device that uses a flash memory as a storage medium instead of the HDD 108. The drive device may be, for example, an SSD.

[0026] The external I / F 103 is an interface with an external device. The external device may be a recording medium 103a. This allows the condition diagnostic device 10 to read from and write to the recording medium 103a via the external I / F 103. The recording medium 103a may be a flexible disk, a CD, a DVD, an SD memory card, a USB memory, or the like.

[0027] The RAM 104 is an example of a volatile semiconductor memory that temporarily stores programs and data. The ROM 105 is an example of a nonvolatile semiconductor memory that can store programs and data even when the power is turned off. The ROM 105 stores programs and data such as BIOS, OS settings, and network settings that are executed when the condition diagnostic device 10 is started up.

[0028] The CPU 106 is a computing device that reads programs and data from storage devices such as the ROM 105 and the HDD 108 onto the RAM 104 and executes processing to realize the overall control and functions of the condition diagnostic device 10 .

[0029] <Determining the state of the circuit breaker 20> The following describes the state determination of the circuit breaker 20 performed by the determination unit 12 of the state diagnosis device 10. Fig. 3 is a diagram showing an example of time series changes in the first command current value and the second command current value when an abnormality occurs in the state diagnosis device 10 according to an embodiment of the present disclosure. In the graph shown, the horizontal axis represents time, and the vertical axis represents the command current value.

[0030] In the figure, D indicates the difference between the first command current value and the second command current value when a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20. The illustrated example shows a case where the first command current value, which is the waveform during abnormal operation of the circuit breaker 20, is greater than the second command current value, which is the waveform during normal operation. If the difference D is equal to or greater than a predetermined threshold, the determination unit 12 determines that the state of the circuit breaker 20 is abnormal.

[0031] The condition diagnosis device 10 can diagnose the condition of the circuit breaker 20 based on a waveform that represents a time-series change in the command current of the circuit breaker 20, and the change in the waveform is caused by an abnormality in the circuit breaker 20. An example of an abnormal condition of the circuit breaker 20 could be a "vacuum leak" in a vacuum valve. In this case, a decrease in the self-closing force of the vacuum mechanism of the circuit breaker 20 causes a delay in the rear part of the peak-shaped waveform that represents a time-series change in the command current value. In other words, after a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20, the first command current value during abnormal operation becomes higher than the second command current value during normal operation.

[0032] Therefore, the determination unit 12 can determine the state of the circuit breaker 20 based on the difference between the first command current value and the second command current value at a predetermined time after the start of the closing operation of the circuit breaker 20. By using such a determination method, an abnormality in the circuit breaker 20 can be clearly detected.

[0033] Although the determination unit 12 determines the state of the circuit breaker 20 based on the change in the command current value when a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20, the state of the circuit breaker 20 may also be determined based on the change in time in the horizontal direction. In this case, the determination unit 12 may measure the time during which the first command current value and the second command current value show the same value, and determine that the circuit breaker 20 is abnormal if there is a difference of at least a predetermined time.

[0034] <Modification> The determination unit 12 may determine the state of the circuit breaker 20 using time-series changes in a plurality of second command current values. In this case, the determination unit 12 generates a reference waveform by averaging waveforms representing time-series changes in a plurality of second command current values. The determination unit 12 then calculates a current value in the reference waveform at a predetermined time after the start of the circuit breaker closing operation. Furthermore, if the difference between the calculated current value and the first command current value at a predetermined time after the start of the circuit breaker closing operation is equal to or greater than a predetermined threshold, the determination unit 12 determines that the state of the circuit breaker is abnormal.

[0035] In addition, the predetermined threshold value of the difference between the first command current value and the second command current value when determining the state of the circuit breaker 20 may be calculated based on the average and standard deviation between multiple second command current values ​​at a predetermined time after the start of the closing operation of the circuit breaker 20.

[0036] 4A and 4B are diagrams for explaining a method for diagnosing the state of a circuit breaker in a state diagnosis device 10 according to a modified example of an embodiment of the present disclosure. In Fig. 4A, the horizontal axis indicates time and the vertical axis indicates a command current value, similar to the example of Fig. 3. Also, Fig. 4B shows the number of measurements for each command current value at a predetermined time after the start of the closing operation of the circuit breaker 20.

[0037] The example in FIG. 4 includes time-series changes in a plurality of first command current values ​​and a plurality of second command current values. In the figure, W1 indicates a plurality of waveforms of a plurality of first command current values ​​when an abnormality occurs, and W2 indicates a plurality of waveforms of a plurality of second command current values. Furthermore, W indicates a reference waveform of the second command current value, and D indicates a difference between the reference waveform of the first command current value and the reference waveform of the second command current value at a predetermined time after the start of the closing operation of the circuit breaker 20. W1 in FIG. 4(b) shows how the first command current value changes beyond the variation of the second command current value, allowing the abnormality to be clearly detected.

[0038] The reference waveform W is a waveform generated by averaging waveforms representing time-series changes of a plurality of second command current values. The determination unit 12 may determine the state of the circuit breaker 20 based on a difference D between the reference waveform W and the first command current value, as shown in FIG. 4(a).

[0039] FIG. 4(b) shows an example in which the state of the circuit breaker 20 is determined based on a threshold calculated based on the average and standard deviation of multiple second command current values. The waveform that is the average of multiple second command current values ​​is the reference waveform W. In the illustrated example, the variation in the second command current value is defined as three times the standard deviation σ. In this case, the determination unit 12 may regard a waveform with a current value higher than 3σ in the figure (toward the arrow F in the figure) as the second command current value and determine that the state of the circuit breaker 20 is abnormal. Note that although the second command current value is defined as 3σ in the illustrated example, it is not limited to 3σ.

[0040] <Condition diagnosis method> 5 is a flow diagram illustrating a condition diagnosis method according to an embodiment of the present disclosure. The condition diagnosis method uses a condition diagnosis device 10.

[0041] The condition diagnosis device 10 stores in advance in a storage means a time series change in the second command current value, which is a current that flows when a closing command is issued during normal operation of the circuit breaker 20 (step S101). The storage means may be included in the condition diagnosis device 10 or may be provided in a separate device.

[0042] The measuring unit 11 measures a first command current value, which is a current that flows when a command to close the circuit breaker 20 is issued (step S102). The determining unit 12 compares a time series change in the first command current value with a time series change in a second command current value, which is a current that flows when a command to close the circuit breaker 20 is issued during normal operation (step S103).

[0043] If the difference between the first command current value and the second command current value after a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20 is greater than or equal to a predetermined threshold value (Yes in step S104), the judgment unit 12 judges that the state of the circuit breaker 20 is abnormal (step S105).

[0044] If the difference between the first command current value and the second command current value after a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20 is not greater than a predetermined threshold value (No in step S104), the judgment unit 12 judges that the state of the circuit breaker 20 is normal (step S106).

[0045] The condition diagnosis method according to one embodiment of the present invention is carried out through these steps. However, the condition diagnosis method according to one embodiment of the present invention may include other steps as appropriate depending on the measurement conditions, measurement environment, etc.

[0046] <Effects> The condition diagnosis device 10 according to this embodiment compares the measured first command current value with a time series change in a second command current value, which is a current that flows when a closing command is issued during normal operation of the circuit breaker 20 and is stored in advance. Then, the determination unit 12 determines that the condition of the circuit breaker 20 is abnormal if the difference between the respective command current values ​​at the time a predetermined time has elapsed since the start of the closing operation of the circuit breaker 20 is equal to or greater than a predetermined threshold value.

[0047] Because the determination unit 12 compares the waveforms of the command current value, it can accurately determine the state of the circuit breaker 20 even if the delay time in the closing operation due to an abnormality in the circuit breaker 20 is extremely short. Also, the command current value of the circuit breaker 20 can be easily measured and is less susceptible to the influence of noise such as chattering. Furthermore, because the measurement unit 11 measures the command current value, if the circuit breaker 20 is a vacuum circuit breaker, it does not need to be equipped with multiple signal contacts that open and close in response to the opening and closing of a vacuum valve.

[0048] Therefore, the condition diagnosis device 10 according to this embodiment can improve the accuracy of detecting an abnormality in the vacuum circuit breaker.

[0049] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims. [Explanation of symbols]

[0050] 10. Condition diagnostic device 11 Measurement section 12 Judgment section 20 Circuit Breaker

Claims

1. a measurement unit that measures a first command current value, which is a value of a current that flows when a command to close the circuit breaker is issued; a determination unit that determines a state of the circuit breaker based on a time series change in the first command current value and a time series change in a second command current value that is a value of a current that flows when a closing command is issued during normal operation of the circuit breaker and that is stored in advance; A condition diagnosis device comprising:

2. The determination unit If a difference between the first command current value and the second command current value after a predetermined time has elapsed since the start of the closing operation of the circuit breaker is equal to or greater than a predetermined threshold value, the state of the circuit breaker is determined to be abnormal. The condition diagnosis device according to claim 1 .

3. The determination unit When a predetermined time has elapsed since the start of the closing operation of the circuit breaker, if the first command current value is greater than the second command current value by the predetermined threshold value or more, the circuit breaker is determined to be in an abnormal state. The condition diagnosis device according to claim 2 .

4. The determination unit generating a reference waveform by averaging waveforms representing time-series changes of a plurality of second command current values; Calculating a current value at a predetermined time elapsed from the start of the closing operation of the circuit breaker in the reference waveform; If a difference between the calculated current value and the first command current value at a predetermined time after the start of the closing operation of the circuit breaker is equal to or greater than the predetermined threshold value, the state of the circuit breaker is determined to be abnormal. The condition diagnosis device according to claim 2 .

5. The predetermined threshold value is calculated based on an average and a standard deviation of the plurality of second command current values ​​at a predetermined time elapsed from the start of the closing operation of the circuit breaker. The condition diagnosis device according to claim 4.

6. A condition diagnosis method performed by a condition diagnosis device, measuring a first command current value which is a value of a current that flows when a command to close a circuit breaker is issued; determining a state of the circuit breaker based on a time series change in the first command current value and a time series change in a second command current value, which is a value of a current that flows when a closing command is issued during normal operation of the circuit breaker and is stored in advance; A condition diagnosis method including:

7. A program for causing a condition diagnosis device to function, a process of measuring a first command current value, which is a value of a current that flows when a command to close a circuit breaker is issued; a process of determining a state of the circuit breaker based on a time series change in the first command current value and a time series change in a second command current value, which is a value of a current that flows when a closing command is issued during normal operation of the circuit breaker and is stored in advance; A program to execute.

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