Impulse test system and impulse test method

Abstract

To provide an impulse test system and an impulse test method that make it possible to appropriately grasp an electric discharge point.SOLUTION: An impulse test system 20 tests a test transformer 1 for impulses. The impulse test system 20 comprises: a high-speed camera control device 25 for outputting a recording start command on the basis of the test voltage application timing of an impulse test; a high-speed camera 26 for capturing an image beginning from a timing at which the recording start command is received and installed in the periphery of the test transformer 1 that is the object to be tested; a test data recording server 22 for recording the captured image; and a display unit 21a for displaying an electric discharge point included in the result that is recorded in the test data recording server 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to an impulse test system and an impulse test method. [Background technology]

[0002] Industrial molded static induction devices are checked for insulation defects by lightning impulse testing (see, for example, Patent Document 1). In the static induction device described in Patent Document 1, the coil clamp insulator interposed between the coil clamp metal and the upper end surface of the coil acts as an insulating spacer to provide insulation between them, and it has been confirmed that even when a lightning impulse test is performed, the occurrence of partial discharge between the coil clamp metal and the coil can be sufficiently suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-078194 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, if an impulse test results in a failure, a discharge may occur at the location of the poor insulation, and the location of this discharge can provide a clue to identifying the defective area. However, the discharge ends in an instant, making it difficult to confirm visually. Similarly, the sound generated during the impulse test can also provide a clue to detecting an abnormality, but it is difficult for the operator to remember and judge it by hearing it.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an impulse test system and an impulse test method that enable appropriate detection of discharge locations. [Means for solving the problem]

[0006] An impulse test system according to one aspect of the present embodiment performs an impulse test on a molded static induction device as a transformer under test. The impulse test system includes an output unit that outputs a recording start command based on the timing of application of a test voltage for the impulse test, a high-speed camera installed in the vicinity of the transformer under test and capturing images from the timing of receiving the recording start command, a recording unit that records the captured images, and a display unit that displays discharge locations included in the results recorded in the recording unit. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a system configuration diagram illustrating an impulse test system according to an embodiment. [Figure 2] FIG. 1 is a front view schematically illustrating the structure of a test transformer according to one embodiment. [Figure 3] FIG. 1 is a rear view schematically illustrating the structure of a test transformer according to one embodiment. [Figure 4] FIG. 1 is a side view schematically illustrating an installation state of a high-speed camera according to an embodiment. [Figure 5] 1 is a flowchart illustrating a flow of a lightning impulse test according to an embodiment. [Figure 6] 1 is a flowchart illustrating a test flow in an automatic mode according to an embodiment. [Figure 7] An example of image data captured during a lightning impulse test in one embodiment DETAILED DESCRIPTION OF THE INVENTION

[0008] An impulse test system 20 and an impulse test method according to an embodiment will be described below with reference to the drawings. The impulse test system 20 is a system for performing a lightning impulse test on a test transformer 1 as a stationary induction device.

[0009] 1, the impulse test system 20 is mainly composed of a test control PC 21 and a test data recording server 22, and also includes an impulse test device 23 (corresponding to an output unit), a high-speed camera control device 24, and a high-speed camera 26. The test data recording server 22 has an internal database as a recording unit for recording the test results of the impulse test.

[0010] The impulse test system 20 also includes a sound level meter 27 and a microphone 28. The sound level meter 27 and the microphone 28 are provided to acquire the sound emitted from the transformer under test 1 during the impulse test. The test control PC 21 is configured by a personal computer.

[0011] The impulse test equipment 23 is configured by a PLC (Programmable Logic Controller) that executes a lightning impulse test based on commands from the PC 21. The impulse test equipment 23 also includes a pulse generator that applies a lightning impulse to the transformer under test 1 on a trial basis.

[0012] The high-speed camera control device 25 is a device that controls the high-speed camera 26, and controls the imaging of the test transformer 1 to be tested by the high-speed camera 26. The high-speed camera 26 is a camera that is capable of high-speed imaging at approximately 1000 frames per second. The imaging results of the high-speed camera 26 are transmitted to the PC 21 via the high-speed camera control device 25. The PC 21 transmits the imaging results to the test data recording server 22, and the test data recording server 22 records the imaging results. The PC 21 is equipped with a display as a display unit 21a that displays the recorded imaging results.

[0013] Figure 2 shows a schematic diagram of the overall structure of test transformer 1, which is a molded static induction device. Test transformer 1 has three coils 3 attached to core 2. Coils 3 are molded coils. Core 2 is made by laminating multiple thin metal plates, for example, made of silicon steel, and is configured with upper yoke 4 and lower yoke 5, which extend left and right in Figure 1, and three leg portions 6 that extend up and down and are connected to them. A coil 3 is wound around each leg portion 6.

[0014] The upper yoke 4 is fastened and fixed by an upper clamp made of, for example, steel. Similarly, the lower yoke 5 is fastened and fixed by a lower clamp (not shown) serving as a fixing part. The lower yoke 5 and the lower clamp are fixedly installed on a base 9. The core 2, the upper and lower clamps, and the base 9 are connected to the ground potential.

[0015] Figure 3 shows the back side of the coil 3. The coil 3 is provided with tap leads 3a that protrude outward from the winding. The coil 3 also has terminals 3b for fixing the tap leads 3a, and crimp terminals 3c are crimped to the ends of the tap leads 3a, which are then fixed to the terminals 3b. Metal members 3d are provided between each coil 3.

[0016] The tap leads 3a are provided in multiple protruding positions on the outer surface of the coil 3, and when a lightning surge is applied to the test transformer 1, discharges are likely to occur between the core wires of the tap leads 3a or between the tap leads 3a and the metal members 3d installed around them. It has been confirmed that the tap leads 3a are prone to malfunction due to the generation of an uneven electric field at the end of the drain wire of their crimp terminals 3c.

[0017] Therefore, when conducting a lightning impulse test, it is desirable to install a high-speed camera 26 so that it can capture an image of at least a portion of the tap lead 3a emerging from the transformer under test 1, as shown in Figure 4. This allows the high-speed camera 26 to be installed facing an area of ​​the transformer under test 1 where malfunctions are likely to occur.

[0018] It is desirable to install multiple high-speed cameras 26 around the transformer under test 1. Specifically, as shown in Figure 4, high-speed cameras 26 may include high-speed camera 26UF, which captures images of the transformer under test 1 from an upper front diagonal downward angle, high-speed camera 26DF, which captures images of the transformer under test 1 from an upper front diagonal downward angle, high-speed camera 26UR, which captures images of the transformer under test 1 from an upper rear diagonal downward angle, and high-speed camera 26DR, which captures images of the transformer under test 1 from an upper rear diagonal downward angle. Furthermore, microphone 28 should also be installed so that it can clearly capture the popping sound generated by the application of a lightning impulse during the lightning impulse test; for example, it may be installed above coil 3 of transformer under test 1.

[0019] The flow of the lightning impulse test will be explained below with reference to Figures 5 and 6. First, in S1 of Figure 5, the test transformer 1 to be tested is registered on the operation panel and operation screen to start up the equipment, and then in S2 an operator performs setup procedures, such as connecting the impulse test device 23 to the test transformer 1. Then, each test item is performed in response to the operator's command to start the test.

[0020] An operator operates the operation panel of the impulse testing device 23 and selects a mode such as an automatic mode, a semi-automatic mode, or a manual mode in S3. The impulse testing device 23 is provided with various modes, such as an automatic mode, a semi-automatic mode, and a manual mode. In the automatic mode, the order of three-phase grounding conditions (U-phase grounded → V-phase grounded → W-phase grounded → three-phase ungrounded) or a single-phase grounding condition (U-phase grounded → V-phase grounded → single-phase ungrounded) is automatically set, and when an operator issues a test start command from the impulse testing device 23, the test items under the three-phase grounding conditions or the single-phase grounding conditions are automatically processed.

[0021] In semi-automatic mode, an operator operates the control panel to select the test item for each individual grounding condition, either the three-phase grounding condition or the single-phase grounding condition, and the test is performed under that individual condition. In semi-automatic mode, tests with special patterns can be performed. In manual mode, one of the three phases is grounded or the three phases are ungrounded, and discharge is performed by operating the control panel under the specified grounding condition.

[0022] When selecting the mode, the operator selects either automatic mode, semi-automatic mode, or manual mode. Once the mode is selected, the test is executed in S4 of Figure 5. For example, if automatic mode is selected in S3, the process shown in Figure 6 is executed. As shown in Figure 6, first, the ground contact conditions are established in S11.

[0023] Let us assume that a test is performed under three-phase grounding conditions in automatic mode (U-phase grounded → V-phase grounded → W-phase grounded → three-phase ungrounded). First, in the initial grounding conditions in automatic mode, a U-phase grounding condition is established in S11. When an operator operates the operation panel to instruct the impulse testing device 23 to start a test, the impulse testing device 23 charges the test voltage using the pulse generator in S12 and waits until charging is complete in S13.

[0024] When charging is complete, the impulse testing device 23 outputs a trigger to the high-speed camera control device 25, thereby outputting a recording start command to the high-speed camera control device 25. When the high-speed camera control device 25 receives the recording start command, it outputs a recording start command to the high-speed camera 26 in S14, causing the high-speed camera 26 to start recording the transformer 1 under test.

[0025] That is, the high-speed camera control device 25 may cause the high-speed camera 26 to record by inputting a trigger signal for recording in synchronization with the application of the test voltage to the transformer under test 1 by the impulse test equipment 23. At the same time as or before that timing, the impulse test equipment 23 outputs a trigger to the sound level meter 27, which serves as a sound acquisition unit, to start recording through the microphone 28. The sound level meter 27 can acquire the sound emitted from the transformer under test 1. As a result, video and audio can be recorded simultaneously in synchronization with the start of the impulse test. Alternatively, the PC 21 may instruct the sound level meter 27 to record and start recording through the microphone 28 before issuing a command to the high-speed camera 26 to start recording.

[0026] The high-speed camera 26 has an internal buffer for storing recorded data, but because it captures images at a high speed of 1000 frames per second, it consumes a large amount of buffer capacity for recording the recorded data. This limits the amount of recorded data that can be stored in the buffer. On the other hand, the sound level meter 27 also has an internal buffer for storing sound recording data, but the sound recording data recorded through the microphone 28 only requires sampling data of around several tens of kHz.

[0027] For this reason, there is often ample buffer storage capacity for storing recorded data. As a result, recording via microphone 28 can be performed prior to recording with high-speed camera 26. This ensures that both video and audio recordings, including the timing of application of the test voltage to transformer under test 1, can be reliably recorded in the buffer.

[0028] Furthermore, by inputting a trigger signal in synchronization with the application of the test voltage to the transformer under test 1, the PC 21 measures the voltage and current waveforms of the applied impulse using an oscilloscope and various measuring instruments, and records the measured waveform data internally.The measured waveform data is recorded in the internal database of the test data recording server 22, linked to the identification information of the transformer under test 1.

[0029] The impulse testing device 23 discharges the specified voltage that has been charged in S15. During this time, the high-speed camera 26 continues to record images for a predetermined period including the timing of the trigger described above. During this time, the PC 21 calculates waveform characteristics using the measured waveform data acquired in S16 and diagnoses whether the waveform is OK or NG. An operator may visually judge the waveform characteristics to determine whether the waveform is OK or NG.

[0030] The test data recording server 22 also receives the video data and audio data recorded via the PC 21 from the buffer, associates them with the identification information of the tested transformer 1, and records them in an internal database. The video data and audio data can be labeled with pass / fail information and recorded, and then trained by artificial intelligence (AI) as pass / fail samples. This can then be used to provide a supplementary judgment function for pass / fail judgment.

[0031] After the impulse testing device 23 has finished discharging the charged specified voltage, it outputs a recording stop command to the high-speed camera control device 25. Upon receiving this recording stop command, the high-speed camera control device 25 outputs a recording stop command to the high-speed camera 26, thereby causing the high-speed camera 26 to stop recording in S17. The high-speed camera 26 may also be configured to measure a predetermined time using a timer without receiving a recording stop command, and to automatically stop after the time has elapsed.

[0032] Then, in S18, the PC 21 determines whether the waveform diagnosis result, which is the result of calculating the waveform characteristics using the measured waveform data of S16, is OK (pass) or NG (fail). If the measured waveform data cannot be recorded in the first place or if the judgment defect cannot be identified, it is determined to be NG. If the result is NG, the PC 21 notifies the operator.

[0033] If the test result is NG, the operator displays the video data from the high-speed camera 26 on the display unit 21a. The PC 21 displays the discharge location included in the results recorded in the internal database of the test data recording server 22 on the display unit 21a. The PC 21 may search for and display the frame of the video data of the image captured at the time of the discharge. The operator visually plays back the video, frame by frame, starting from that frame, and determines whether the test is NG or not. This allows the operator to visually check the frames of the video data acquired in accordance with the discharge timing and confirm the details of the cause of the NG test. Specifically, the operator checks whether there is a discharge in the test transformer 1 that has been determined to be NG, and if there is a discharge, the discharge location can be identified. The operator may directly visually check the discharge marks occurring on the test transformer 1 to determine the details of the NG cause. Since the sound may differ from normal, the audio data may be played back and compared with the sound from normal (OK) conditions to provide a supplementary judgment.

[0034] If the result of the waveform diagnosis does not fall under NG, the result is determined to be OK in S18, and the PC 21 notifies this fact. Then, in S19, the grounding condition previously set by the operator (the U-phase grounding condition in the first case) is canceled, and in S20, it is confirmed whether or not there are other grounding conditions. In the automatic mode, after the U-phase grounding condition, the test is performed by establishing a V-phase grounding condition → a W-phase grounding condition → a three-phase non-grounding condition, so it is determined in S20 that there are other grounding conditions, and the next grounding condition is established in S21. After establishing the next grounding condition, the process returns to S12 and the test is repeated. In this way, in the automatic mode, the test is repeated under the following conditions: U-phase grounding condition → V-phase grounding condition → W-phase grounding condition → three-phase non-grounding condition. The test ends when all grounding conditions are passed.

[0035] As described above, the impulse voltage waveform and current waveform are measured using an oscilloscope or various measuring instruments. These waveforms may be linked to the identification information of the transformer under test 1 and recorded in the internal database of the test data recording server 22. The PC 21 may classify the characteristics of waveforms learned from past malfunction data into multiple patterns and accumulate them as learning data. The PC 21 may then determine whether a waveform is NG or whether an NG has been overlooked by determining which of the multiple patterns the waveform belongs to based on this learning data. Furthermore, video data captured by the high-speed camera 26 and audio data recorded using the sound level meter 27 may be recorded in the internal database of the test data recording server 22. Similarly to the above, the PC 21 may classify the video data and audio data learned from past malfunction data into multiple patterns and accumulate them as learning data. The PC 21 may then determine whether the video data and audio data are NG or whether an NG has been overlooked by determining which of the multiple patterns the waveform belongs to based on this learning data.

[0036] Figure 7 shows an image frame captured by high-speed camera 26 during a lightning impulse test. The image frame shown in Figure 7 shows light emitted from lead 3aa of a certain tap lead 3a toward a metal member 3d installed around it. See light-emitting portion H.

[0037] Conventionally, it has been confirmed that even if an image of the vicinity of the tap lead 3a is captured using a camera capable of capturing images at a normal rate of approximately 30 to 60 frames per second and a certain frame is observed, only an image frame in which light is emitted from not only the tap lead 3a that actually starts discharging but also an area including many surrounding tap leads 3a is obtained. For this reason, when a normal camera of approximately 30 to 60 frames per second is used as in the past, it has been difficult to observe which tap lead 3a is discharging and further which part of the tap lead 3a is discharging.

[0038] The impulse testing system 20 of this embodiment uses a high-speed camera 26, which makes it possible to capture images of the tap leads 3a at approximately 1000 frames per second, and by observing a certain frame, it is easy to observe which tap lead 3a is discharging from, and furthermore, which tap lead 3aa is discharging from. As a result, the discharge location can be properly identified.

[0039] The impulse testing device 23 outputs a recording start command based on the timing of application of the test voltage in the impulse test, and the high-speed camera 26 begins capturing images from the timing at which it receives the recording start command via the high-speed camera control device 25. This allows recording to start in time with the application of the test voltage, and allows recording data to be acquired in time with the application of the test voltage. Furthermore, the high-speed camera 26 can minimize the capacity of the memory buffer it uses.

[0040] Furthermore, the display unit 21a displays frames of images taken at the time of discharge based on the timing of the sound acquired by the sound level meter 27, making it easier for workers and analysts to analyze problems that occur during discharge.

[0041] The high-speed camera 26 is installed so as to capture images of at least some of the points where the tap leads 3a emerge from the transformer under test 1, so that images can be focused on the tap leads 3a, which are likely to cause NG during testing, thereby improving the convenience of the test.

[0042] (Other embodiments) Although the embodiments have been described above, the following modifications can be made. In each embodiment, the molded static induction device is described as a test transformer 1, but the present invention is not limited to this. For example, the present invention may be applied to a reactor. Also, the present invention is not limited to this. In addition, the present invention is described as having three coils 3, but the present invention is not limited to this.

[0043] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications 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 inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0044] In the drawing, 1 indicates a test transformer (molded static induction device), 20 indicates an impulse test system, 22 indicates a test data recording server (recording unit), and 26 indicates a high-speed camera.

Claims

1. An impulse test system for performing an impulse test on a molded static induction device as a transformer under test, comprising: an output unit that outputs a recording start command based on the timing of application of the test voltage in the impulse test; a high-speed camera installed in the vicinity of the test transformer to be tested and taking images from the timing when the recording start command is received; a recording unit that records the captured image; a display unit that displays the discharge location included in the results recorded in the recording unit; An impulse test system comprising:

2. a sound acquisition unit that acquires a sound emitted from the stationary induction device; The impulse testing system according to claim 1 , wherein the display unit displays frames of the captured image at the time of discharge based on the timing of the sound acquired by the sound acquisition unit.

3. 3. The impulse testing system according to claim 1, wherein the high-speed camera is installed so as to capture an image of at least a portion of the tap lead emerging from the transformer under test.

4. An impulse test method for performing an impulse test on a molded static induction device as a test transformer, comprising: an output unit outputs a recording start command based on the timing of application of the test voltage in the impulse test; A high-speed camera is installed around the test transformer to be tested and takes images from the timing when the recording start command is received, a recording unit that records the captured image; An impulse testing method, wherein a display unit displays a discharge location included in the results recorded in the recording unit.

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