Digital protective relay and its test system and test method

Abstract

To conduct an operation test for a digital protection relay easier than conventional tests.SOLUTION: In a digital protection relay 1, a protection relay calculation unit 60 executes various kinds of protection relay calculations for a test signal 66 converted in digital. A signal state table 61 constantly updates and stores each of an on / off state or numerical values of input signals, intermediate signals in the middle of calculation, and output signals of the protection relay calculation unit 60. An oscillograph output processing unit 62 reads the on / off state or the numerical values of a plurality of signals selected by a user among the stored signal in the signal state table at every first cycle from the signal state table 61 and then outputs it to an oscillograph recording device 4. An WEB-API server 63 reads the selected on / off state or numerical values of the plurality of signals from the signal state table 61 at every second cycle and outputs it to a maintenance computer 2 in response to a request from the external maintenance computer 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a digital protection relay and a test system and test method thereof. [Background technology]

[0002] Some digital protective relays have a data output section for an oscilloscope recorder (such as an electromagnetic oscillograph or digital data recorder) for use in operational tests (see, for example, Japanese Patent Laid-Open Publication No. 8-98388 (Patent Document 1)). During operational tests, a test current or test voltage is input to the digital protective relay to operate it, and the calculation process within the protective relay and the digital output signal are recorded on the oscilloscope recorder. Based on the waveform data recorded on the oscilloscope recorder, it is determined whether the protective relay is operating properly.

[0003] Some digital protective relays are also equipped with Internet protocol communication means and web server functions, which make it possible to operate and view internal information of the digital protective relay, such as setting values, from a maintenance personal computer equipped with a browser (see, for example, Japanese Patent Laid-Open Publication No. 2001-333549 (Patent Document 2)). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-98388 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-333549 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the above-described configuration of the digital protection relay, the settings for the operation test, such as the type of signal to be output from the data output section for the oscilloscope recorder, can be easily performed while checking the screen of the maintenance computer.

[0006] However, to perform an operational test and check the results, an oscilloscope recorder capable of recording multiple high-speed signals must be used. Unlike a maintenance computer, an oscilloscope recorder does not have the function of displaying the type of input signal for each channel, and so it cannot be said to have excellent usability. In addition, to check the results of the operational test, it is necessary to output the waveform data recorded on the oscilloscope recorder, which requires time and effort.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and one of its objectives is to provide a function for performing an operational test more efficiently than conventionally in a digital protective relay equipped with a data output unit for an oscilloscope recorder and an interface for connecting a maintenance computer. [Means for solving the problem]

[0008] In one embodiment, the digital protective relay includes an analog-to-digital converter, a protective relay calculation unit, a signal status table, an oscilloscope output processor, and a WEB-API (Application Program Interface) server. The analog-to-digital converter receives a signal representing an electrical quantity acquired from a power system during normal operation and a test signal during an operational test, and digitally converts the input signal representing the electrical quantity and the test signal. The protective relay calculation unit performs various protective relay calculations on the digitally converted signal representing the electrical quantity and the test signal. The signal status table stores, while constantly updating, the on / off states or numerical values ​​of the input signals, intermediate signals during the calculation, and output signals of the protective relay calculation unit for various protective relay calculations performed on the digitally converted test signals during the operational test. The oscilloscope output processor reads, from the signal status table for each first period, the on / off states or numerical values ​​of multiple signals selected by a user from the signals stored in the signal status table and outputs them to an oscilloscope recorder. In response to a request from an external maintenance computer, the WEB-API server reads the on / off states or numerical values ​​of the above-mentioned selected multiple signals from the signal state table every second period, which is longer than the first period, and transmits them to the maintenance computer. [Effects of the Invention]

[0009] According to the above embodiment, the oscilloscope output processing unit reads the on / off states or numerical values ​​of the selected multiple signals from the signal state table for each first period and outputs them to the oscilloscope recording device, and the WEB-API server reads the on / off states or numerical values ​​of the selected multiple signals from the signal state table for each second period and sends them to the maintenance computer, thereby enabling operational tests to be performed more efficiently than before. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of a hardware configuration of a test system for a digital protection relay. [Figure 2]FIG. 2 is a block diagram illustrating an example of a hardware configuration of a maintenance PC. [Figure 3] 2 is a block diagram showing an example of the functional configuration of the digital protection relay, the maintenance PC, and the oscilloscope recorder of FIG. 1. FIG. [Figure 4] 10 is a flowchart showing the operation of the HMI tool during an operation test of a digital protective relay. [Figure 5] FIG. 10 is a diagram showing an example of an oscilloscope setting / test start screen displayed on the display unit of the maintenance PC by the HMI tool. [Figure 6] FIG. 10 is a diagram showing an example of an editing screen for an oscilloscope output pattern displayed on the display unit of the maintenance PC by the HMI tool. [Figure 7] FIG. 10 is a diagram showing an example of an oscilloscope setting / test start screen display during an operation test of a digital protection relay. [Figure 8] 10 is a flowchart showing the operation of an HMI tool during an operation test of a digital protective relay in the test system of the second embodiment. [Figure 9] FIG. 10 is a diagram showing another example of the display of the oscilloscope setting / test start screen during an operation test of a digital protection relay. [Figure 10] 1 is a flowchart illustrating a method for testing a digital protection relay. [Figure 11] FIG. 6 is a simplified diagram of the display area of ​​the output signal list in FIG. 5. [Figure 12] FIG. 2 is a diagram for explaining input to the learning device. [Figure 13] FIG. 10 is a diagram illustrating the configuration of a learning device for rearranging selection signals. [Figure 14] FIG. 10 is a diagram illustrating learning in a model generation unit. [Figure 15] 10 is a flowchart relating to a learning process of the learning device. [Figure 16] FIG. 1 is a diagram illustrating the configuration of an inference device for determining the optimal order of selection signals. [Figure 17] 10 is a flowchart relating to an inference process of the inference device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Each embodiment will be described in detail below with reference to the drawings. The same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

[0012] Embodiment 1 [Example of hardware configuration for test system 8] Fig. 1 is a block diagram showing an example of the hardware configuration of a test system 8 for a digital protective relay 1. As shown in Fig. 1, the test system 8 includes the digital protective relay 1, a maintenance personal computer (PC) 2, a test signal input device 3, and an oscilloscope recording device 4. The oscilloscope recording device 4 is an electromagnetic oscillograph or a digital data recorder, etc., and records a plurality of input high-speed digital signals.

[0013] The digital protection relay 1 includes an input conversion unit 10, an A / D (Analog-to-Digital) conversion unit 20, an arithmetic processing unit 30, and an I / O (Input and Output) unit 40. These components will be described in order below.

[0014] The input conversion unit 10 is for receiving high voltage and high current from electrical facilities in a power station via a voltage transformer (VT) and a current transformer (CT), respectively. The input conversion unit 10 includes input converters 11_1, 11_2, 11_3, ... (collectively referred to as input converters 11) for each input channel to adjust the signal levels of input signals IN1, IN2, IN3, ... of multiple input channels. The input converters are, for example, auxiliary transformers.

[0015] During an operation test, each input channel of the input conversion unit 10 is connected to a test signal input device 3. The test signal input device 3 is equipped with a plurality of current sources and a plurality of voltage sources, and during an operation test, a test current or a test voltage (hereinafter collectively referred to as a test signal) is input to each input channel of the digital protection relay 1. In one embodiment, the test current and test voltage output from the test signal input device 3 and the timing at which the test current and test voltage are output are controlled by a maintenance PC 2.

[0016] The A / D conversion unit 20 includes analog filters 21_1, 21_2, 21_3, ... (collectively referred to as analog filters 21) provided for each input channel, a multiplexer 22, and an A / D converter 23. Furthermore, a sample-and-hold circuit may be provided after the analog filter 21 and before the multiplexer 22 for each input channel.

[0017] The analog filter 21 prevents aliasing during A / D conversion by passing low-frequency components, including the fundamental components, of the input signals IN1, IN2, IN3, ... The multiplexer 22 sequentially takes in the multi-channel input signals and inputs them as a single signal to the A / D converter 23. The A / D converter 23 converts the input signal into a digital value.

[0018] The arithmetic processing unit 30 is configured based on a microcomputer including a CPU (Central Processing Unit) 31, a RAM (Random Access Memory) 32, a ROM (Read Only Memory) 33, and a bus 34. Alternatively, at least a part of the arithmetic processing unit 30 may be configured by at least one of a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) or a dedicated integrated circuit such as an ASIC (Application Specific Integrated Circuit).

[0019] The CPU 31 controls the digital protection relay 1 and executes various protection relay calculations using the time-series digital data output from the A / D converter 23. The RAM 32 and ROM 33 are used as work memories for the CPU 31. The ROM 33 is configured as an electrically rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or flash memory. The ROM 33 stores operation programs, various data, and the like.

[0020] The I / O unit 40 includes a LAN (Local Area Network) interface (I / F) 41, an oscilloscope output interface (I / F) 42, a plurality of digital output circuits (D / O) 43, and a plurality of digital input circuits (D / I) 44.

[0021] The LAN interface 41 connects to the maintenance PC 2 via Internet Protocol communication. The oscilloscope output interface 42 is connected to the oscilloscope recorder 4, and outputs multiple digital signals selected by the user in parallel and at high speed to the oscilloscope recorder 4. The digital output circuit 43 outputs digital signals to power equipment (such as a circuit breaker or switch) external to the digital protection relay 1. The digital input circuit 44 receives digital signals from power equipment external to the digital protection relay 1.

[0022] [Example of hardware configuration for maintenance PC] Fig. 2 is a block diagram showing an example of the hardware configuration of the maintenance PC 2. As shown in Fig. 2, the maintenance PC 2 includes a CPU 50, a RAM 51, a ROM 52, a display unit 53, an input unit 54, a LAN interface (I / F) 55, and a bus 56 connecting these components.

[0023] The CPU 50 executes an HMI (Human Machine Interface) tool (reference numeral 70 in FIG. 3 ), which is a program for performing maintenance, management, testing, etc. of the digital protection relay 1. The RAM 51 and ROM 52 are used as work memories for the CPU 50. The ROM 52 is configured as an electrically rewritable non-volatile memory such as an EEPROM or flash memory. The ROM 52 stores programs executed by the CPU 50 and various data. The display unit 53 is a display for displaying information to the user. The input unit 54 is a user interface, such as a keyboard and mouse, for accepting input from the user. The LAN interface 55 is connected to the digital protection relay 1 and the test signal input device 3 via Internet Protocol communication.

[0024] [Functional configuration of test system 8] FIG. 3 is a block diagram showing an example of the functional configuration of the digital protection relay 1, the maintenance PC 2, and the oscilloscope recorder 4 shown in FIG.

[0025] As shown in Fig. 3, the digital protection relay 1 includes the input conversion unit 10, A / D conversion unit 20, LAN interface 41, and oscilloscope output interface 42 described in Fig. 1, as well as a protection relay calculation unit 60, a signal status table 61, an oscilloscope output processing unit 62, a WEB-API (Application Programming Interface) server 63, an oscilloscope output pattern storage area 64, and a selected signal storage area 65. The protection relay calculation unit 60, the oscilloscope output processing unit 62, and the WEB-API server 63 may be realized by the CPU 31 in Fig. 1 executing a program, or at least a portion of them may be realized by a PLD or ASIC. The signal status table 61, the oscilloscope output pattern storage area 64, and the selected signal storage area 65 are realized by the RAM 32 and ROM 33 in Fig. 1.

[0026] Specifically, the protection relay calculation unit 60 performs various protection relay calculations on the test signal 66 A / D converted by the A / D conversion unit 20 during an operation test of the digital protection relay 1.

[0027] The signal state table 61 stores, while constantly updating, the states or numerical values ​​(on / off states for binary signals, or numerical values ​​for numerical signals) of input signals, intermediate signals during the operation, and output signals for various protection relay calculations. The update cycle of the signal state table 61 is shorter than the output cycle to the oscilloscope recorder 4. The on / off states or numerical values ​​of each signal stored in the signal state table 61 can be accessed by specifying a cell address (also simply referred to as an address). The number of signals stored in the signal state table 61 may be, for example, 1,000 or more. One of the on state (also referred to as an active state) and off state (also referred to as an inactive state) of a binary signal corresponds to a high level of the signal, and the other corresponds to a low level of the signal.

[0028] The oscilloscope output processing unit 62 extracts the state or numerical value of a signal (hereinafter referred to as a selected signal) selected by the user from the states or numerical values ​​of over 1000 signals stored in the signal state table 61, and outputs the state or numerical value at regular intervals (for example, every few milliseconds) to the oscilloscope recorder 4 via the oscilloscope output interface 42. The number of signals that can be output to the oscilloscope recorder 4 is limited by the data processing speed, and is, for example, about 32.

[0029] The WEB-API server 63 responds to requests from the maintenance PC 2 by communicating with the maintenance PC 2 via the LAN interface 41. For example, it becomes possible to check and change setting values ​​from the maintenance PC 2. Furthermore, during an operational test of the digital protective relay 1, the maintenance PC 2 retrieves the signal status or numerical values ​​stored in the signal status table 61 via the WEB-API server 63 at regular intervals (for example, every few hundred milliseconds).

[0030] The oscilloscope output pattern storage area 64 is a memory area for storing combinations of signals (i.e., oscilloscope output patterns) selected to be output to the oscilloscope recorder 4. That is, the oscilloscope output pattern storage area 64 stores identifiers of multiple oscilloscope output patterns and addresses in the signal state table 61 corresponding to multiple signals selected for each oscilloscope output pattern. By predetermining multiple oscilloscope output patterns, the signal selection process when conducting an operational test can be simplified.

[0031] The selected signal storage area 65 is a memory area for storing the identifier of the oscilloscope output pattern to be actually output to the oscilloscope recorder 4 and the address in the signal state table 61 corresponding to the signal selected as the oscilloscope output pattern. During an operation test of the digital protection relay 1, the data at the address specified by the selected signal storage area 65 is output to the oscilloscope output processing unit 62 from among the data of many signals stored in the signal state table 61.

[0032] The HMI tool 70 executed by the maintenance PC 2 displays a menu on the display unit 53 of the maintenance PC 2, executes a menu selected by the user, and accepts input from the user. The HMI tool 70 also communicates with the WEB-API server 63 of the digital protective relay 1 to read or rewrite various settings of the digital protective relay 1 in accordance with a request from the user.

[0033] Furthermore, during an operational test of the digital protection relay 1, the HMI tool 70 reads the state or numerical value of the selected signal (on / off state in the case of a binary signal, or numerical value in the case of a numerical signal) from the signal state table 61 at regular intervals (for example, every few hundred milliseconds) via the WEB-API server 63 and displays it on the display unit 53.

[0034] The oscilloscope recorder 4 includes a recording unit 75, an output unit 76, and a simple display unit 77. The recording unit 75 is a memory for recording multiple pieces of time-series data output from the digital protection relay 1 via the oscilloscope output interface 42. The output unit 76 outputs the time-series data recorded in the recording unit 75 to a printer or display. The simple display unit 77 displays the on / off state of binary signals among the signals currently being output from the digital protection relay 1. The simple display unit 77 includes, for example, a number of light-emitting diodes corresponding to the number of signals.

[0035] [HMI tool features for testing digital protective relays] 4 is a flowchart showing the operation of the HMI tool 70 during an operation test of the digital protective relay 1. The function of the HMI tool 70 for the operation test of the digital protective relay 1 will be described in detail below.

[0036] 4, the HMI tool 70 displays a menu on the display unit 53. This menu displays items such as confirmation and change of various setting values ​​and control of operation tests, which can be selected by the user.

[0037] When the user selects control of the operation test of the digital protection relay 1 (YES in step S20), the HMI tool 70 displays an "Oscilloscope setting / Test start" screen on the display unit 53 of the maintenance PC 2 (step S30).

[0038] 5 is a diagram showing an example of an oscilloscope setting / test start screen 80 displayed on the display unit 53 of the maintenance PC 2 by the HMI tool 70. The oscilloscope setting / test start screen 80 includes an area 82 displaying the oscilloscope output pattern name, an oscilloscope output pattern selection area 81, an area 84 displaying a list of output signals corresponding to the selected oscilloscope output pattern, a number 83 indicating the display order of the output signals, an oscilloscope edit button 85, a test start button 86, and an end button 87.

[0039] When the HMI tool 70 displays the oscilloscope setting / test start screen 80, it requests the WEB-API server 63 to send the address information of all selected signals stored in the selected signal storage area 65 to the HMI tool 70. The HMI tool 70 converts the address information of the selected signals into signal names and displays them in the output signal list display area 84. For example, in the case of FIG. 5, the 32 signal names set as the No. 3 oscilloscope output pattern (i.e., "▽▽▽ test") selected by the selection unit 81 are displayed in the output signal list display area 84.

[0040] The display order of the signal names when displayed in the output signal list display area 84 follows the order of the data stored in the oscilloscope output pattern storage area 64 and the selected signal storage area 65. Alternatively, an identifier indicating the display order (for example, the number 83 indicating the display order in FIG. 5) may be stored in the oscilloscope output pattern storage area 64 and the selected signal storage area 65, and the signal names may be displayed in the order according to this identifier.

[0041] Furthermore, the ROM 52 of the maintenance PC 2 stores in advance a data table that indicates the correspondence between the signal names of all signals stored in the signal status table 61 of the digital protection relay 1 and the addresses of the signal status table 61. The HMI tool 70 converts the signal names and addresses based on this data table.

[0042] When the user changes the oscilloscope output pattern by operating the oscilloscope output pattern selection unit 81 in Fig. 5, the HMI tool 70 requests the WEB-API server 63 to change the identification number of the oscilloscope output pattern stored in the selected signal storage area 65 and the address information of the corresponding selected signal. After the WEB-API server 63 has completed changing the contents stored in the selected signal storage area 65, it transmits the address information of all the selected signals newly stored in the selected signal storage area 65 to the HMI tool 70. The HMI tool 70 converts the address information of the selected signals into signal names and displays them in the output signal list display area 84.

[0043] When the user selects the oscilloscope edit button 85 (YES in step S40 of FIG. 4), the HMI tool 70 displays an "Edit Oscilloscope Output Pattern" screen on the display unit 53 of the maintenance PC 2.

[0044] 6 is a diagram showing an example of an oscilloscope output pattern editing screen displayed on the display unit 53 of the maintenance PC 2 by the HMI tool 70. The oscilloscope output pattern editing screen includes an input area 90 for an oscilloscope output pattern name, an input area 91 for a keyword for signal search, a display area 93 for the searched signal name, and a display area 97 for the selected signal name.

[0045] When entering keywords for signal search, a selection unit 92 allows the user to select "contains," "starts with," or "ends with." When the user enters a keyword in the keyword input area 91, the HMI tool 70 searches the data table for the corresponding signal name and displays it in the display area 93. If there are many searched signal names, the screen can be scrolled to display them by moving the scroll bar knob (slider) 94 up and down.

[0046] When the user selects one of the signals displayed in the searched signal name display area 93 and clicks a move button 95, the signal is displayed in a selected signal name display area 97. At this time, the selected signals are displayed in the selected signal name display area 97 in order from top to bottom. When the user selects one of the signals displayed in the selected signal name display area 97 and clicks a move button 96, the signal is removed from the selected signal name display area 97. When the user selects one of the signals displayed in the selected signal name display area 97 and clicks a move button 98, the order in which the signal is displayed (i.e., the number corresponding to the signal) changes up by one. When the user selects one of the signals displayed in the selected signal name display area 97 and clicks a move button 99, the order in which the signal is displayed (i.e., the number corresponding to the signal) changes down by one.

[0047] When the user selects the all cancel button 100, the selection of all signals displayed in the selected signal name display area 97 is cancelled. As a result, nothing is displayed in the selected signal name display area 97.

[0048] When the user selects the automatic sorting button 101, all signals displayed in the selected signal name display area 97 are automatically sorted into an order that is considered appropriate by the HMI tool 70. Details of this function will be described in the third embodiment.

[0049] When the user clicks the cancel button 102, the HMI tool 70 ends editing of the oscilloscope output pattern without storing the user setting information of the oscilloscope output pattern in the RAM 32 and ROM 33 (specifically, the oscilloscope output pattern storage area 64 and the selection signal storage area 65) of the digital protection relay 1. As a result, the process returns to step S30 in FIG.

[0050] On the other hand, when the user clicks the save button 103, the HMI tool 70 stores the user setting information of the oscilloscope output pattern in the RAM 32 and ROM 33 (specifically, the oscilloscope output pattern storage area 64 and the selection signal storage area 65) of the digital protection relay 1, and then ends editing of the oscilloscope output pattern. As a result, the process returns to step S30 in FIG. 4.

[0051] Next, when the user selects the test start button 86 on the oscilloscope setting / test start screen 80 in Fig. 5 (YES in step S60), the test signal input device 3 inputs the test signal 66 to the digital protection relay 1. As a result, the oscilloscope output processing unit 62 outputs data related to the multiple selected signals set as the currently selected oscilloscope output pattern from the signal status table 61 to the oscilloscope recording device 4 via the oscilloscope output interface 42 at regular intervals (referred to as the first period, on the order of several milliseconds).

[0052] Furthermore, the HMI tool 70 of the maintenance PC 2 requests the WEB-API server 63 to read data regarding the multiple selected signals from the signal status table 61 and send it to the maintenance PC 2 at regular intervals (referred to as the second period, approximately several hundred milliseconds).

[0053] More specifically, the HMI tool 70 converts the signal names of all selected signals displayed in the output signal list display area 84 into the addresses of the corresponding signal status table 61 and transmits them to the WEB-API server 63. The WEB-API server 63 accesses the signal status table 61 based on the received addresses, collects the on / off states or numerical values ​​of the signals stored in the corresponding addresses at regular intervals (second intervals), and transmits them to the HMI tool 70. Alternatively, the WEB-API server 63 may access the signal status table 61 based on the addresses stored in the selected signal storage area 65, collect the on / off states or numerical values ​​of the signals stored in the corresponding addresses at regular intervals (second intervals), and transmit them to the HMI tool 70.

[0054] During the first transmission during an operational test, the WEB-API server 63 transmits the on / off states or numerical values ​​of all selection signals to the HMI tool 70, but from the second transmission onwards, it may transmit only the selection signals whose on / off states or numerical values ​​have changed to the HMI tool 70.

[0055] The HMI tool 70 of the maintenance PC 2 displays the on / off states of the binary signals among the received data relating to the plurality of selection signals on the display unit 53 in association with the signal names (step S70).

[0056] The on / off state of the output signal as described above will continue to be displayed until the oscilloscope output pattern is changed by operating the selection unit 81 on the oscilloscope setting / test start screen 80 in FIG. 5, or until a different screen is displayed by selecting the oscilloscope edit button 85 or the end button 87.

[0057] The first cycle, during which the selected output signals are read from the signal status table 61 and transmitted to the oscilloscope recorder 4, is as fast as several milliseconds. In contrast, the second cycle, during which the HMI tool 70 of the maintenance PC 2 retrieves the selected output signals from the signal status table 61 via the WEB-API server 63, is as fast as several hundred milliseconds. Therefore, the on / off states of the binary signals displayed on the display unit 53 of the maintenance PC 2 by the HMI tool 70 do not accurately reflect the state changes of the binary signals. However, checking the final state of a binary signal or checking the state changes of a binary signal that change relatively slowly, on a second-by-second basis, is easier than checking the contents recorded on the oscilloscope recorder 4. Furthermore, unlike the simplified display unit 77 of the oscilloscope recorder 4, the signal names are displayed in association with each other, making it easier for users to identify the signal names. These features enhance user convenience.

[0058] Fig. 7 is a diagram showing an example of the display of the oscilloscope setting / test start screen 80 during an operation test of the digital protection relay 1. As shown in Fig. 7, among the signals displayed in the display area 84 of the output signal list, the binary signal names in the ON state are displayed with a background color 110. Note that the background color 110 is not the only option, and the binary signal names in the ON state and the binary signal names in the OFF state may be displayed in different modes. This allows the user to easily check the ON / OFF states of the binary signals.

[0059] When the user selects the end button 87 on the oscilloscope setting / test start screen 80 in FIG. 5 (YES in step S80), the HMI tool 70 returns the screen display to the initial screen (step S10).

[0060] [Effects of the First Embodiment] According to the test system 8 for the digital protective relay 1 of the first embodiment, during an operation test, the state or value of the signal output from the digital protective relay 1 to the oscilloscope recorder 4 is also output to the maintenance PC 2 via the WEB-API server 63 and the LAN interface 41. The HMI tool 70 of the maintenance PC 2 displays the on / off state of the binary signal acquired from the digital protective relay 1 on the display unit 53 of the maintenance PC 2 in association with the signal name. This allows the user to easily check the on / off state of the binary signal.

[0061] Embodiment 2 In the test system 8 of the second embodiment, during an operation test of the digital protective relay 1, the HMI tool 70 of the maintenance PC 2 displays the on / off states of the binary signals in association with the signal names on the display unit 53, and also displays the numerical values ​​of the numeric signals in association with the signal names on the display unit 53. This further improves user convenience.

[0062] FIG. 8 is a flowchart showing the operation of the HMI tool 70 during an operation test of the digital protective relay 1 in the test system 8 of the second embodiment.

[0063] The flowchart in Fig. 8 differs from the flowchart in Fig. 4 in that step S70 is changed to step S70A. Specifically, when the user selects the test start button 86 on the oscilloscope setting / test start screen 80 in Fig. 5 (YES in step S60), the test signal input device 3 inputs a test signal 66 to the digital protection relay 1. As a result, the oscilloscope output processing unit 62 outputs data representing a plurality of selected signals set as the currently selected oscilloscope output pattern from the signal status table 61 to the oscilloscope recorder 4 via the oscilloscope output interface 42 at regular intervals (first intervals). Furthermore, the maintenance PC 2 requests the WEB-API server 63 at regular intervals (second intervals) to read the data representing the plurality of selected signals from the signal status table 61 and transmit it to the maintenance PC 2. The HMI tool 70 of the maintenance PC 2 displays the on / off state of the binary signal among the received data of the multiple selection signals on the display unit 53, corresponding to the signal name, and also displays the numerical value of the numeric signal on the display unit 53, corresponding to the signal name (step S70A).

[0064] Here, the first period is relatively fast, on the order of several milliseconds, while the second period is relatively slow, on the order of several hundred milliseconds. Therefore, the on / off states of binary signals and the values ​​of numeric signals displayed on the display unit 53 of the maintenance PC 2 by the HMI tool 70 do not accurately reflect the state and value changes of the binary signals. However, when checking the final state of a binary signal and the final value of a numeric signal, or when checking the state changes of a binary signal and the value changes of a numeric signal that change relatively slowly, on the order of seconds, it is easier to check them than when checking the contents recorded on the oscilloscope recorder 4. Furthermore, the signal states and values ​​are displayed on the display unit 53 in association with the signal names, making it easy for the user to check the signal names. These features further enhance user convenience.

[0065] FIG. 9 shows another example of the display of the oscilloscope setting / test start screen 80 during an operation test of the digital protection relay 1. The display area 84 of the output signal list on the oscilloscope setting / test start screen 80 switches every 2 to 3 seconds between a screen displaying the signal names as shown in FIG. 4 and a screen displaying the on / off states of binary signals and the numerical values ​​of numeric signals as shown in FIG. 9, without changing the display position of the signals. For binary signals, on (ON), off (OFF), and lock (Lock, a type of ON) are displayed. Binary signals in the on state are displayed with a background color 110. Note that the background color 110 is not limited to this, and the binary signal names in the on state and the off state may be displayed in different ways. For numerical signals, the numerical values ​​are displayed with units and with a background color 111 that is different from the binary signal. This allows the user to easily confirm the on / off states of binary signals and the numerical signal values ​​in the steady state by associating them with the signal names.

[0066] [Test method for digital protective relays] 10 is a flowchart for explaining a method for testing the digital protective relay 1. Hereinafter, the method for testing the digital protective relay described in the first and second embodiments will be summarized with reference to FIG.

[0067] In step S100 of FIG. 10, first, the test signal input device 3 inputs the test signal 66 to the digital protection relay 1.

[0068] In the next step S110, the input conversion unit 10 of the digital protection relay 1 adjusts the magnitude of the test signal 66, and the A / D conversion unit 20 A / D converts the test signal 66.

[0069] In the next step S120, the calculation processing unit 30 executes various protection relay calculations on the A / D converted test signal 66.

[0070] In the next step S130, the calculation processing unit 30 stores in the signal state table 61, updating from time to time, the on / off states or numerical values ​​of the input signals, intermediate signals during calculation, and output signals of the calculation processing unit 30 for various protective relay calculations.

[0071] In the next step S140, the calculation processing unit 30 reads out the on / off states or numerical values ​​of multiple signals selected by the user from the signals stored in the signal state table 61 from the signal state table 61 for each first period and outputs them to the oscilloscope recording device 4.

[0072] In the next step S150, the calculation processing unit 30 functions as a WEB-API server 63, and in response to a request from the maintenance computer 2, reads the on / off states or numerical values ​​of the selected multiple signals from the signal status table 61 for each second period (>first period) and transmits them to the maintenance computer 2.

[0073] In the next step S160, the maintenance computer 2 displays the on / off states or numerical values ​​of the selected multiple signals received from the digital protection relay 1 on the display (display unit 53) in correspondence with the signal names of the selected multiple signals.

[0074] [Effects of the second embodiment] According to the test system 8 for the digital protective relay 1 of the second embodiment, during an operation test, the signals output from the digital protective relay 1 to the oscilloscope recorder 4 are also output to the maintenance PC 2 via the WEB-API server 63 and the LAN interface 41. The HMI tool 70 of the maintenance PC 2 displays the on / off states of the binary signals among the signals output from the digital protective relay 1 on the display unit 53 of the maintenance PC 2 in association with the signal names, and also displays the values ​​of the numeric signals in association with the signal names on the display unit 53 of the maintenance PC 2. This allows the user to easily check the on / off states of the binary signals and the values ​​of the numeric signals.

[0075] Embodiment 3 In the third embodiment, the operation of the HMI tool 70 when the automatic sorting button 101 is selected on the oscilloscope output pattern editing screen of FIG. 6 will be described.

[0076] The order in which signals are displayed as oscilloscope output patterns requires the know-how of experienced testers and designers / developers to ensure that the signals are easy to check. For example, related binary and numeric signals are displayed side by side. Once the purpose of the work is determined, the order in which such signals are displayed will tend to be similar, although there will be some individual differences between testers and designers / developers.

[0077] Therefore, the display order of the selected signals set by many experienced testers and designers / developers is used as correct answer data to train the learning device using supervised learning. In this case, although the correct answer data is not limited to one, because they are mutually similar, the output of the trained model is an average of the correct answer data. The trained model obtained in this way is used to automatically rearrange multiple signals selected by the user. The learning phase and utilization phase will be explained below with reference to the drawings.

[0078] [Learning Phase] Fig. 11 is a simplified diagram of the display area 84 of the output signal list in Fig. 5. For ease of explanation, this embodiment will describe a case where four signals are selected and displayed out of eleven signals from signal A to signal K. In Fig. 11, signal J is displayed in the first display position, signal D is displayed in the second display position, signal A is displayed in the third display position, and signal K is displayed in the fourth display position.

[0079] 12 is a diagram for explaining input to the learning device. Referring to FIG. 12(A), a signal selected by the user from among signals A to K is assigned a value of 1, and unselected signals are assigned a value of 0. Therefore, the input in this case is [1, 0, 0, 1, 0, 0, 0, 0, 1, 1].

[0080] Referring to Fig. 12(B), when the four selected signal names are associated with 1, 2, 3, and 4, there are 24 patterns, P1 to P24, for the arrangement of the four signals. Therefore, one of these 24 patterns becomes the correct data corresponding to the input in Fig. 12(A). In the case of Fig. 11, the correct data is created by setting the value corresponding to pattern P15 to "1" and the other patterns to "0."

[0081] 13 is a configuration diagram of a learning device for rearrangement of selection signals. As shown in FIG. 13, learning device 120 includes data acquisition unit 121, model generation unit 122, and trained model storage unit .

[0082] The data acquisition unit 121 acquires information indicating whether or not each signal is selected as shown in Fig. 12(A) as input 1. As input 2 (correct answer data), it acquires a pattern indicating the order of the selected signals as shown in Fig. 12(B).

[0083] The model generation unit 122 learns the optimal order of selection signals as output based on the learning data created based on the combination of input 1 and input 2 (correct answer data) output from the data acquisition unit. That is, it generates a trained model that infers the appropriate order of selection signals as output from input 1 and input 2 (correct answer data) related to the rearrangement of selection signals. Here, the learning data is data in which input 1 and input 2 (correct answer) are associated with each other.

[0084] The learning device 120 and the inference device 140, which will be described later, are used to learn the optimal sequence of selection signals, but may be devices connected to a maintenance PC 2 of the test system 8 via a network and separate from the maintenance PC 2. The learning device 120 and the inference device 140 may also be built into the maintenance PC 2. Furthermore, the learning device 120 and the inference device 140 may reside on a cloud server.

[0085] 14 is a diagram illustrating learning in the model generation unit. Referring to FIG. 14, the model generation unit 122 learns an appropriate sequence of selection signals by so-called supervised learning, for example, according to a neural network model. Here, supervised learning refers to a technique in which a learning device is provided with pairs of input and result (label) data, and the device learns features of the learning data and infers a result from the input.

[0086] A neural network consists of an input layer consisting of multiple neurons, an intermediate layer (hidden layer) consisting of multiple neurons, and an output layer consisting of multiple neurons. The intermediate layer may be one layer, or two or more layers.

[0087] For example, in a three-layer neural network as shown in Figure 14, when multiple inputs are input to the input layer (X1 to X3), the values ​​are multiplied by weight W1 (w11 to w16) and input to the middle layer (Y1 to Y2), and the result is further multiplied by weight W2 (w21 to w26) and output from the output layer (Z1 to Z3). This output result changes depending on the values ​​of weights W1 and W2.

[0088] In the present disclosure, the neural network learns the output (i.e., the optimal order of selection signals) by so-called supervised learning in accordance with learning data created based on a combination of input 1 and input 2 (correct answer) acquired by data acquisition unit 121. That is, the neural network learns by inputting input 1 to the input layer and adjusting weights W1 and W2 so that the result output from the output layer approaches input 2 (correct answer).

[0089] By performing the above-described learning, the model generation unit 122 generates and outputs the trained model 123. The trained model storage unit 130 stores the trained model 123 output from the model generation unit 122.

[0090] Next, the learning process performed by the learning device 120 will be described with reference to Fig. 15. Fig. 15 is a flowchart showing the learning process performed by the learning device.

[0091] In step S200, the data acquisition unit 121 acquires information indicating whether or not each signal is to be used as input 1, and acquires a pattern indicating the order of the signals selected as input 2 (correct answer). Note that although input 1 and input 2 (correct answer) are acquired simultaneously, it is sufficient that input 1 and input 2 (correct answer) are input in association with each other, and the data for input 1 and input 2 (correct answer) may be acquired at different times.

[0092] In step S210, the model generation unit 122 learns the optimal order of the selection signals as output by so-called supervised learning in accordance with the learning data created based on the combination of input 1 and input 2 (correct answer) acquired by the data acquisition unit 121, and generates a learned model 123.

[0093] In step S220, the trained model storage unit 130 stores the trained model 123 generated by the model generation unit 122.

[0094] [Utilization phase] 16 is a configuration diagram of an inference device 140 for determining the optimum order of selection signals. Referring to FIG. 16, inference device 140 includes a data acquisition unit 141 and an inference unit 142.

[0095] The data acquisition unit 141 acquires information indicating whether or not each signal is to be selected as the input 1. More specifically, in accordance with the first and second embodiments, the data acquisition unit 141 acquires information on a plurality of selected signals selected by the user to be output to the oscilloscope recorder 4 from the signals to be stored in the signal state table 61.

[0096] The inference unit 142 infers as an output a pattern representing the optimal order of the selection signals obtained using the trained model 123. That is, by inputting the information acquired by the data acquisition unit 141, i.e., information representing whether or not each signal is to be used, as input 1 to this trained model 123, it is possible to output a pattern representing the optimal order of the selection signals, which is an output inferred from input 1.

[0097] For example, assume that signals A, E, J, and K are selected as selected signals as shown in Figure 12. Compared with the learning data shown in Figures 11 and 12, signal D has changed to signal E. In this case, trained model 123 outputs pattern P15 as the inference result, and the order shown in Figure 16 is determined as the final order of selected signals.

[0098] In this embodiment, it has been described that a pattern representing the optimal order of the selection signals is output using the trained model 123 trained by the model generation unit 122 of the maintenance PC 2, but it is also possible to obtain the trained model 123 from outside the maintenance PC 2 and output a pattern representing the optimal order of the selection signals based on this trained model 123.

[0099] Next, a process for obtaining a pattern representing the optimum sequence of selection signals as an output using inference device 140 will be described with reference to Fig. 17. Fig. 17 is a flowchart showing the inference process of inference device 140.

[0100] In step S300, the data acquiring unit 141 acquires information indicating whether or not each signal is to be used as the input 1. More specifically, in accordance with the first and second embodiments, the data acquiring unit 141 acquires information on a plurality of selected signals selected by the user to be output to the oscilloscope recorder 4 from the signals to be stored in the signal state table 61.

[0101] In step S310, the inference unit 142 inputs the above-mentioned input 1 to the learned model 123 stored in the learned model storage unit 130, and obtains as an output a pattern representing the optimal order of a plurality of selection signals.

[0102] In step S320, the inference unit 142 outputs a pattern representing the optimal arrangement order of the multiple selection signals obtained by the trained model 123 to the maintenance PC 2.

[0103] In step S330, the HMI tool 70 of the maintenance PC 2 rearranges the signal names displayed in the display area 97 for selected signal names on the oscilloscope output pattern editing screen in Fig. 6 according to a pattern that represents the optimal order of the output selected signals. This allows related signals to be arranged close to each other, making it possible to rearrange the selected signals in an order that makes it easy to check the test results.

[0104] In this embodiment, the case where supervised learning is applied to the learning algorithm used by the model generation unit has been described, but the present invention is not limited to this. As for the learning algorithm, reinforcement learning, unsupervised learning, semi-supervised learning, etc. can also be applied in addition to supervised learning.

[0105] Furthermore, the learning algorithm used in the model generation unit 122 can be deep learning, which learns to extract the features themselves, or machine learning can be performed according to other known methods, such as genetic programming, functional logic programming, or support vector machines.

[0106] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of this application is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0107] 1 Digital protection relay, 2 Maintenance computer, 3 Test signal input device, 4 Oscilloscope recording device, 8 Test system, 10 Input conversion section, 11 Input converter, 20 A / D conversion section, 21 Analog filter, 22 Multiplexer, 23 A / D converter, 30 Processing section, 31, 50 CPU, 32, 51 RAM, 33, 52 ROM, 34, 56 Bus, 40 I / O section, 41, 55 LAN interface, 42 Oscilloscope output interface, 43 Digital output circuit, 44 Digital input circuit, 53 Display section, 54 Input section, 60 Protection calculation section, 61 Signal status table, 62 Oscilloscope output processing section, 63 WEB-API server, 64 Oscilloscope output pattern storage area, 65 Selected signal storage area, 66 Test signal, 70 HMI tool, 75 Recording section, 76 Output section, 77 Simple display section, 80 Oscilloscope setting / test start screen, 120 learning device, 121, 141 data acquisition unit, 122 model generation unit, 123 trained model, 130 trained model memory unit, 140 inference device, 142 inference unit.

Claims

1. an analog-to-digital converter that receives a signal representing an amount of electricity acquired from the power grid during normal operation and a test signal during an operation test, and that digitally converts the input signal representing the amount of electricity and the test signal; a protection relay calculation unit that performs various protection relay calculations on the digitally converted signal representing the electrical quantity and the test signal; a signal state table that stores, while constantly updating, the on / off states or numerical values ​​of the input signals, intermediate signals during calculation, and output signals of the protection relay calculation unit for the various protection relay calculations performed on the digitally converted test signals during the operation test; an oscilloscope output processing unit that reads out from the signal state table, for each first period, on / off states or numerical values ​​of a plurality of signals selected by a user from among the signals stored in the signal state table, and outputs the read on / off states or numerical values ​​to an oscilloscope recorder; a WEB-API (Application Program Interface) server that, in response to a request from an external maintenance computer, reads the on / off states or numerical values ​​of the selected plurality of signals from the signal state table every second period that is longer than the first period and transmits the read information to the maintenance computer.

2. The on / off state or the numerical value of each signal stored in the signal state table can be accessed by specifying the address of the signal state table; 2. The digital protection relay of claim 1, further comprising a first memory area for storing a plurality of addresses of the signal state table corresponding to the selected plurality of signals.

3. The digital protection relay according to claim 2; an oscilloscope recorder that receives and records the states or values ​​of the selected signals from the oscilloscope output processor for each of the first periods; a maintenance computer that communicates with the WEB-API server according to an Internet protocol; the maintenance computer reads out the addresses from the first memory area via the WEB-API server, and displays signal names of the selected signals corresponding to the addresses on a display; A digital protection relay test system in which, during the operational test, the maintenance computer displays on the display the on / off states or numerical values ​​of the selected multiple signals read from the signal status table via the WEB-API server, in association with each signal name.

4. 4. The digital protection relay test system according to claim 3, wherein the maintenance computer displays on the display the signal names of binary signals among the selected plurality of signals in different forms depending on whether the signal is in an on state or an off state, thereby associating the on / off states of the binary signals with the respective signal names.

5. 4. The digital protection relay test system according to claim 3, wherein the maintenance computer associates the on / off states or numerical values ​​of the selected signals with the respective signal names by alternately displaying the signal names of the selected signals and the corresponding on / off states or numerical values ​​at the same position on the display.

6. The maintenance computer further an acquisition unit that acquires information on a plurality of signals selected by a user from the signals to be stored in the signal status table to be output to the oscilloscope recorder; an inference unit that infers, from the signal names of the selected plurality of signals, an order of the signal names of the selected plurality of signals when the signal names of the selected plurality of signals are to be displayed on the display, using a trained model for inferring, from the signal names of the selected plurality of signals, an order of the signal names of the selected plurality of signals when the signal names of the selected plurality of signals are to be displayed on the display; The digital protection relay test system according to any one of claims 3 to 5, wherein the maintenance computer displays the signal names of the selected plurality of signals on the display in the inferred order.

7. 7. The digital protection relay testing system of claim 6, wherein the trained model is generated by supervised learning using an arrangement created by an experienced user as correct answer data.

8. A test method for a digital protective relay, comprising: inputting a test signal to the digital protection relay; The digital protection relay performs analog-to-digital conversion of the test signal; A step in which an arithmetic processing unit of the digital protection relay performs various protection relay operations on the analog / digital converted test signal; The calculation processing unit stores, in a signal state table while constantly updating, the on / off states or numerical values ​​of the input signals, intermediate signals during calculation, and output signals of the calculation processing unit for the various protective relay calculations; the calculation processing unit reading out from the signal state table, for each first period, on / off states or numerical values ​​of a plurality of signals selected by a user from among the signals stored in the signal state table, and outputting the read out states or numerical values ​​to an oscilloscope recorder; the calculation processing unit functions as a WEB-API (Application Program Interface) server, and in response to a request from an external maintenance computer, reads out the on / off states or numerical values ​​of the selected plurality of signals from the signal state table for each second period longer than the first period, and transmits the read out signals to the maintenance computer; and displaying, by the maintenance computer, on a display, the on / off states or numerical values ​​of the selected plurality of signals received from the digital protection relay in association with the signal names of the selected plurality of signals.

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