Degradation diagnosis device, degradation diagnosis system, and degradation diagnosis method

Abstract

A deterioration diagnosis device (1) comprises an antenna (11), a signal processing unit (12), a score determination unit (13), and a deterioration determination unit (14). The antenna (11) receives electromagnetic waves of a microwave frequency band and generates a reception signal, said electromagnetic waves being emitted due to partial discharge that occurs in an insulation member of an electric motor (41). The signal processing unit (12) samples the reception signal in each sampling period and generates sampling data indicating the signal strength of the reception signal. The score determination unit (13) calculates, from the sampling data generated by the signal processing unit (12) during a detection period including a plurality of sampling periods, a score indicating the strength of the signal strength over the detection period. The deterioration determination unit (14) determines whether there is deterioration in the insulating member from a comparison between the score and a score reference value.

Description

[Technical Field]

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

[0002] An electric motor mounted on a railway vehicle includes, for example, a rotor having a rotor core and rotor conductors inserted into slots formed on the outer circumferential surface of the rotor core, and a stator having a stator core and stator coils inserted into slots formed on the inner circumferential surface of the stator core. The electric motor also includes various insulating members, such as insulating members that insulate the stator core from the stator coils and insulating members that insulate the stator coils from each other. Deterioration of the insulating members can cause short circuits inside the electric motor, ground faults to the outside of the electric motor, and the like, so it is preferable to periodically check the degree of deterioration of the insulating members.

[0003] One example of a method for checking the degree of deterioration of insulating members is disclosed in Patent Document 1. The partial discharge measurement method disclosed in Patent Document 1 measures the circumferential electromagnetic wave signal spatial intensity distribution by moving multiple electromagnetic wave sensors, whose relative positions are fixed, at positions adjacent to the ends of the stator coil. This partial discharge measurement method detects the defect position from the peak position of the partial discharge signal obtained from the measured electromagnetic wave signal spatial intensity distribution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 029151 Summary of the Invention [Problem to be solved by the invention]

[0005] When determining the degree of deterioration of insulating materials using the partial discharge measurement method disclosed in Patent Document 1, workers must remove the electric motor from the vehicle and disassemble it, then move multiple electromagnetic wave sensors to positions adjacent to the ends of the stator coil to perform measurements. Because electric motors installed in railway vehicles are large and attached to bogies under the vehicle floor, maintenance work, including removing the motor from the bogie and disassembling the motor, is complicated. This makes it difficult to frequently monitor the deterioration of the insulating materials of the motor.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a degradation diagnosis device, a degradation diagnosis system, and a degradation diagnosis method that determine whether or not the insulating members of an electric motor have deteriorated when the electric motor is installed in a vehicle. [Means for solving the problem]

[0007] To achieve the above object, the degradation diagnosis device of the present disclosure includes an antenna, a signal processing unit, a score determination unit, and a degradation determination unit. The antenna receives electromagnetic waves in the microwave frequency band radiated due to partial discharge occurring in an insulating member of an electric motor and generates a received signal. The signal processing unit samples the received signal for each sampling period and generates sampling data indicating the signal strength of the received signal. The score determination unit calculates, from the sampling data generated by the signal processing unit during a detection period including multiple sampling periods, Using the sum of the products of the intensity reference values ​​set at regular intervals in the target intensity range, which is the target range of the signal intensity, and the number of sampling data having the signal intensity corresponding to the intensity reference values, The deterioration determination unit determines whether the insulating member has deteriorated by comparing the score with a reference score value determined according to the value that the signal strength of the received signal can take when the insulating member has deteriorated. [Effects of the Invention]

[0008] The degradation diagnosis device according to the present disclosure generates sampling data indicating the signal strength of the received signal by sampling a received signal based on electromagnetic waves radiated due to partial discharge occurring in insulating members of an electric motor, and determines whether the insulating members have deteriorated by comparing a score indicating the strength of the signal over a detection period with a score reference value. This makes it possible to determine whether the insulating members of an electric motor have deteriorated when the electric motor is installed in a vehicle. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a configuration of a degradation diagnosis system according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of an electric motor to be diagnosed by a degradation diagnosis device according to a first embodiment; [Figure 3] FIG. 1 is a diagram showing wires for forming a stator coil of an electric motor according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing how to bend wires to form a stator coil of the electric motor according to the first embodiment. [Figure 5] FIG. 10 is a diagram showing a method for manufacturing a stator coil of the electric motor according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing a method for manufacturing a stator coil of the electric motor according to the first embodiment. [Figure 7] FIG. 1 is a diagram showing how a stator coil is attached to a stator core of an electric motor according to a first embodiment. [Figure 8] 8 is a cross-sectional view of the electric motor according to the first embodiment taken along line VIII-VIII in FIG. 2 . [Figure 9] 1 is a cross-sectional view of an insulating member included in the electric motor according to the first embodiment; [Figure 10] FIG. 10 is a cross-sectional view showing an example of deterioration of an insulating member of the electric motor according to the first embodiment. [Figure 11] FIG. 1 is a diagram showing a hardware configuration of a degradation diagnosis device according to a first embodiment. [Figure 12] 1 is a flowchart showing an example of the operation of a degradation diagnosis process performed by a degradation diagnosis device according to Embodiment 1. [Figure 13]FIG. 1 is a diagram showing an example of a distribution of signal strength according to the first embodiment; [Figure 14] FIG. 10 is a diagram showing an example of the number of occurrences of signal strength according to the first embodiment. [Figure 15] FIG. 1 is a diagram showing an example of an intensity reference value used by the degradation diagnosis device according to the first embodiment; [Figure 16] FIG. 1 is a diagram showing an example of a score reference value used by the degradation diagnosis device according to the first embodiment. [Figure 17] FIG. 10 is a diagram showing an example of the score of each electric motor determined by the degradation diagnosis device according to the first embodiment; [Figure 18] FIG. 10 is a diagram showing an example of the relationship between the average value and the maximum value of the scores determined by the degradation diagnosis device according to the first embodiment. [Figure 19] FIG. 1 is a diagram showing an example of an appropriate score range used by the degradation diagnosis device according to the first embodiment. [Figure 20] FIG. 10 is a diagram showing the configuration of a degradation diagnosis device according to a second embodiment. [Figure 21] FIG. 10 is a diagram showing the configuration of an electric motor to be diagnosed by a degradation diagnosis device according to a second embodiment; [Figure 22] 22-XXII line cross-sectional view of the electric motor according to the second embodiment of the present invention. [Figure 23] FIG. 10 is a diagram showing a modification of the hardware configuration of the degradation diagnosis device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A degradation diagnostic device, a degradation diagnostic system, and a degradation diagnostic method according to embodiments of the present disclosure will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0011] (Embodiment 1) A degradation diagnosis device that determines whether or not an insulating member of an electric motor mounted on a railway vehicle has deteriorated, and a degradation diagnosis system that includes the degradation diagnosis device, will be described in embodiment 1. The degradation diagnosis system 100 shown in Fig. 1 includes a degradation diagnosis device 1 that determines whether or not an insulating member of an electric motor 41 driven by power supplied from a power conversion device 31 has deteriorated, and an output device 20 that acquires the determination result of the degradation diagnosis device 1 and outputs the acquired determination result.

[0012] The deterioration diagnosis device 1 includes an antenna 11 that receives electromagnetic waves in the microwave frequency band, a signal processing unit 12 that samples the received signal generated by the antenna 11 and generates sampling data indicating the signal strength of the received signal, a score determination unit 13 that determines a score indicating the strength of the signal strength, and a deterioration determination unit 14 that determines whether or not the insulating members of the electric motor 41 have deteriorated by comparing the score with a score reference value determined according to the value that the signal strength can take when the insulating members are deteriorated. The deterioration diagnosis device 1 operates by receiving power from a control power supply (not shown).

[0013] The power conversion device 31 that supplies power to the electric motor 41 that is the diagnosis target of the deterioration diagnosis device 1 having the above configuration is mounted on, for example, a railway vehicle that uses a DC power feed system, and receives DC power from a current collector (not shown) that acquires DC power from a substation via a power supply line. The power conversion device 31 converts the DC power into three-phase AC power and supplies the three-phase AC power to the electric motor 41. The power conversion device 31 and the electric motor 41 are electrically connected by electric wires 32a, 32b, and 32c. The electric motor 41 is a three-phase electric motor and is driven by the three-phase AC power supplied from the power conversion device 31.

[0014] A high voltage is applied from a current collector to the input terminal of the power converter 31. The high voltage is, for example, a direct current voltage of 400 V or more and 3000 V or less. When the power converter 31 is PWM (Pulse Width Modulation) controlled by a control device (not shown), a high pulse voltage output from the power converter 31 is applied to each of the stator coils 42 of the electric motor 41, specifically, the U-phase coil 42 a, the V-phase coil 42 b, and the W-phase coil 42 c. In the example of FIG. 1, the U-phase coil 42 a, the V-phase coil 42 b, and the W-phase coil 42 c are connected in a star connection.

[0015] As described above, the electric motor 41 that receives power from the power conversion device 31 includes, as shown in FIG. 2, a frame 40 attached to the underfloor of the railway vehicle, a shaft 43 connected to the axle via a joint, a gear device, etc. (not shown), a pair of bearings 44 that rotatably support the shaft 43, a rotor 45 that rotates integrally with the shaft 43, a stator 49 attached to the frame 40 and radially opposite the rotor 45, and a terminal box 51 attached to the frame 40 and inside which the electric wires 32a, 32b, 32c are arranged.

[0016] 2, the Z-axis direction indicates the vertical direction, the Y-axis direction indicates the width direction of the railway vehicle, and the X-axis direction indicates the direction of travel of the railway vehicle. In other words, the railway vehicle travels in the positive direction of the X-axis or the negative direction of the X-axis. The X-axis, Y-axis, and Z-axis are perpendicular to each other.

[0017] Frame 40 has a cylindrical shape with both ends closed, and houses shaft 43, a pair of bearings 44, rotor 45, and stator 49. The outer surface of frame 40 is attached to the underfloor of a railway vehicle by mounting members (not shown). An insertion hole 40a through which electric wires 32a, 32b, and 32c are routed is formed in the upper surface of frame 40. Insertion hole 40a is closed by terminal box 51, which prevents foreign matter such as dust and water droplets from entering the interior of frame 40.

[0018] Shaft 43 is supported by a pair of bearings 44 so as to be rotatable about a rotation axis AX indicated by a dashed line in Fig. 2. Rotation axis AX extends along the Y axis. One end of shaft 43 facing the positive Y axis is connected to an axle via a joint, a gear device, etc. The rotation of shaft 43 is transmitted to the axle, thereby generating propulsive force for the railway vehicle.

[0019] The pair of bearings 44 are held by the frame 40 and rotatably support the shaft 43. Specifically, the pair of bearings 44 are attached to opposite ends of the frame 40 in the Y-axis direction.

[0020] The rotor 45 has a rotor core 46 formed from laminated steel plates and fitted onto the shaft 43, conductor bars 47 inserted into slots formed on the outer circumferential surface of the rotor core 46, and a pair of short-circuit rings 48 attached to the conductor bars 47. The conductor bars 47 and the short-circuit rings 48 are made of a conductive material such as copper or aluminum. The rotor 45 having the above configuration rotates integrally with the shaft 43.

[0021] The stator 49 has a stator core 50 formed of laminated steel plates and attached to the inner peripheral surface of the frame 40 , and a stator coil 42 inserted into slots formed in the stator core 50 .

[0022] The stator coil 42 is formed by processing the wire 61 shown in Fig. 3 into a shape wound at least once in the direction indicated by the dashed arrow in Fig. 4. The wire 61 shown in Fig. 3 has a conductor 62 made of a conductive material such as copper or aluminum, and an insulating coating member 63 made of an insulating material such as vinyl or resin that coats the conductor 62. In the first embodiment, as shown in Fig. 4, the wire 61 is wound in a shape that can be considered partially hexagonal.

[0023] At the locations where the wires 61 are wound, the wires 61 are stacked in a bundle as shown in Fig. 5. The stator coil 42 is formed by stacking a plurality of wires 61, for example, three wires 61, as shown in Fig. 5, winding insulating tape 64 around the three stacked wires 61, and then stacking insulating tape 64 on top of another insulating tape 64 and winding the same around the other insulating tape as shown in Fig. 6. The insulating tape 64 is formed, for example, by laminating mica adhered with resin.

[0024] The stator coil 42 formed by the above-described processing is inserted into two slots 50a formed in a stator core 50, as shown in FIG. 7. In FIG. 7, to avoid complicating the drawing, the stator core 50 is depicted in a linear form. Two slots 50a are provided between the two slots 50a into which one stator coil 42 is inserted. In FIG. 7, the direction of current is shown in a cross section of the stator coil 42. The stator coils 42 arranged as shown in FIG. 7 are associated with the respective phases in the order of U phase, V phase, and W phase.

[0025] As shown in Figure 8, which is a cross-sectional view taken along line VIII-VIII in Figure 2, two stator coils 42 are inserted into one slot 50a. The stator coils 42 inserted into the same slot 50a are separated and electrically insulated by an inter-coil insulating member 52 made of an insulating material such as vinyl, resin, or mica. The two stator coils 42 inserted into the slot 50a are fixed in place by wedges 53. This prevents the stator coils 42 from coming off the slot 50a.

[0026] By performing a varnish impregnation process on the stator coil 42 before it is inserted into the slots 50a or on the stator 49 with the stator coil 42 inserted into the slots 50a, each component of the stator coil 42 is covered with an insulating material. More specifically, as shown in FIG. 9, which is a partially enlarged view of the area surrounded by the dotted line in FIG. 8, insulating varnish 65 is filled between the insulating tapes 64. As a result, the stator core 50 and the wires 61 that make up the stator coil 42 are electrically insulated by the insulating tapes 64 and the insulating varnish 65. By overlapping and winding the insulating tapes 64 around the multiple wires 61 that are stacked as described above, the creepage distance can be increased, as indicated by the dashed arrows in FIG. 9.

[0027] If the varnish impregnation is insufficient, voids 65a, which are air gaps, may occur inside the insulating varnish 65. If the voids 65a are small enough to ensure insulation between the wires 61 and the stator core 50, the wires 61 and the stator core 50 will remain electrically insulated.

[0028] When a high-voltage pulse voltage output from the power converter 31 is applied to the stator coil 42, the high voltage is applied to the insulating layer, which includes the insulating tape 64 and the insulating varnish 65. The application of a high voltage to the insulating layer can cause partial discharge, which can lead to electrical degradation, such as treeing, in the insulating layer. Furthermore, when the motor 41 is energized, the stator coil 42 generates heat, generating thermal stress, which can apply external forces, such as tensile, compressive, and bending stress, to the insulating layer, resulting in mechanical degradation, such as peeling and cracking of the insulating layer. Furthermore, environmental degradation, such as changes in humidity, contact with contaminants, or immersion, can occur. The electrical, mechanical, and environmental degradation, or a combination of these, can cause degradation of the insulating material, specifically, the expansion of voids 65a in the insulating layer, the formation of cracks 65b, and the expansion of cracks 65b.

[0029] If, for example, moisture seeps into the enlarged crack 65b, the insulation resistance between the wires 61 and the stator core 50 will decrease, possibly causing a short circuit between the wires 61 and the stator core 50 and resulting in dielectric breakdown.

[0030] When enlarged voids 65a and cracks 65b occur as shown in Figure 10, the amplitude of electromagnetic waves in the microwave frequency band generated by partial discharge increases compared to a state in which voids 65a are small and cracks 65b do not occur as shown in Figure 9.

[0031] Deterioration of the insulating members as described above necessitates the replacement of electric motor 41 itself. In other words, the lifespan of electric motor 41 is determined by the deterioration of the insulating members. Therefore, deterioration diagnosis device 1 according to embodiment 1 shown in FIG. 1 determines whether the insulating members of electric motor 41 have deteriorated based on electromagnetic waves in the microwave frequency band generated by partial discharge. The insulating members of electric motor 41 include inter-coil insulating member 52, insulating tape 64, and insulating varnish 65. When the insulating members of electric motor 41 deteriorate, electromagnetic waves in the microwave frequency band are emitted not only from the deteriorated portions but also from the ends of U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c, and from electric wires 32a, 32b, and 32c connected to U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c, respectively.

[0032] Partial discharges cause the emission of electromagnetic waves in the microwave frequency band, specifically, electromagnetic waves in the range of 300 MHz to 300 GHz, and therefore an antenna that receives electromagnetic waves in the microwave frequency band, such as a microstrip antenna, is used as antenna 11. Antenna 11 has a dielectric substrate, a radiating element provided on one surface of the dielectric substrate, and a ground conductor plate provided on the other surface of the dielectric substrate.

[0033] In order to reduce the effects of external noise, moisture, dust, ambient temperature, etc. on the received signal, it is preferable that the antenna 11 be provided inside the terminal box 51, as shown in Fig. 2. Providing the antenna 11 inside the terminal box 51 can prevent electromagnetic noise from outside the electric motor 41 from reaching the antenna 11. The terminal box 51 prevents moisture, dust, etc. contained in the air outside the electric motor 41 from coming into contact with the antenna 11. When the electric motor 41 is energized, the rotor 45 and the stator 49 generate heat, causing the air temperature inside the frame 40 to rise, but providing the antenna 11 inside the terminal box 51 suppresses fluctuations in the received signal generated by the antenna 11 due to an increase in the ambient temperature.

[0034] The antenna 11 is attached to the inner surface of the terminal box 51 with the surface of the dielectric substrate on which the radiating element is formed facing the stator coil 42, in other words, with the surface on which the antenna element is formed facing the negative direction of the Z axis. When the antenna 11 receives electromagnetic waves in the microwave frequency band generated by partial discharge, it generates a received signal and sends the received signal to the signal processing unit 12 shown in FIG.

[0035] The signal processing unit 12 performs signal processing such as noise removal using a BPF (Band Pass Filter), A / D (Analog / Digital) conversion, and detection on the received signal acquired from the antenna 11. Then, the signal processing unit 12 samples the processed received signal at a predetermined sampling period, for example, every 0.4 milliseconds, to generate sampling data indicating the signal strength of the received signal. The signal processing unit 12 sends the generated sampling data to the score determination unit 13.

[0036] The score determination unit 13 determines a score indicating the strength of the signal intensity over a detection period, which includes multiple sampling periods, from the sampling data generated by the signal processing unit 12. The length of the detection period is, for example, 5 seconds. The score determination unit 13 sends the determined score to the deterioration determination unit 14.

[0037] The deterioration determination unit 14 determines whether the insulating members of the electric motor 41 have deteriorated by comparing the score with a score reference value determined according to the value that the signal strength of the received signal can take when the insulating members of the electric motor 41 have deteriorated. The deterioration determination unit 14 transmits the determination result to the output device 20.

[0038] The output device 20 is provided, for example, in the driver's cab or in wayside equipment. The output device 20 provided in the driver's cab is a display device connected to the deterioration diagnosis device 1 via an in-vehicle network, and displays the determination result acquired from the deterioration determination unit 14 on a screen. The output device 20 provided in a control center, which is an example of wayside equipment, is connected to the deterioration diagnosis device 1 via an in-vehicle network and the Internet. The output device 20 displays the determination result acquired from the deterioration determination unit 14 on a screen, or transmits it to other equipment provided in the control center, for example, a condition monitoring and maintenance device that estimates signs of failure in on-board equipment.

[0039] FIG. 11 shows the hardware configuration of the control processing unit of the degradation diagnosis device 1 having the above configuration, specifically, the signal processing unit 12, score determination unit 13, and degradation determination unit 14. The degradation diagnosis device 1 includes a processor 91, a memory 92, and an interface 93. The processor 91, memory 92, and interface 93 are connected to each other via a bus 90. The functions of the signal processing unit 12, score determination unit 13, and degradation determination unit 14 are realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 92. The processor 91 reads and executes the programs stored in the memory 92 to realize the functions of the above-mentioned units. That is, the memory 92 stores programs for executing the processes of the signal processing unit 12, score determination unit 13, and degradation determination unit 14.

[0040] The memory 92 includes, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read-Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable and Programmable Read-Only Memory), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc), etc.

[0041] Deterioration diagnostic device 1 is connected to output device 20 via interface 93. Interface 93 has an interface module that complies with one or more standards depending on the connection destination.

[0042] The operation of the degradation diagnosis device 1 having the above configuration will be described below. When the power conversion device 31 starts operating, the degradation diagnosis device 1 starts the degradation diagnosis process shown in Fig. 12. For example, the degradation diagnosis device 1 acquires a U-phase voltage command value from a control device that controls the power conversion device 31, and starts the degradation diagnosis process when it detects a rise in the U-phase voltage command value.

[0043] The signal processing unit 12 samples the received signal at every predetermined sampling period to generate sampling data indicating the signal strength of the received signal (step S11). The signal strength indicated by the sampling data varies as shown in Figs. 13 and 14. Fig. 13 is a diagram showing the variation in signal strength for each phase. The horizontal axis of Fig. 13 indicates the phase (unit: degree), and the vertical axis indicates the signal strength (unit: dBm). The target strength range, which is the target range of the signal strength, for example, when the signal strength is 10 -9 More than mW and 10 -513, the range where the signal strength is less than -90 dBm and less than -50 dBm is shown. The target strength range may be determined according to the possible values ​​of the signal strength of the received signal generated by the antenna 11 when the insulating material of the electric motor 41 is degraded. The phase shown on the horizontal axis is the phase associated with the detected signal strength, based on the phase of the U-phase voltage.

[0044] Fig. 14 is a diagram showing the number of occurrences of signal strength. The vertical axis of Fig. 14 represents signal strength (unit: dBm), and the horizontal axis of Fig. 14 represents the number of sampling data having each signal strength. In the example of Fig. 14, the most frequent value of signal strength is -76 dBm.

[0045] As described above, the signal strength varies, but when the insulating member deteriorates, the signal strength indicated by each sampling data generated over the detection period tends to increase. Therefore, as shown in Fig. 12, the score determination unit 13 obtains a score indicating the strength of the signal strength from the sampling data generated by the signal processing unit 12 during the detection period (step S12).

[0046] For example, the score determination unit 13 uses the sum of the products of the intensity reference values ​​determined at regular intervals within the intensity target range and the number of sampling data whose signal intensity corresponds to the intensity reference values ​​as a score indicating the strength of the signal intensity.

[0047] In detail, as shown in FIG. 15, the score determination unit 13 stores in advance an intensity reference range and an intensity reference value corresponding to the intensity reference range. The intensity reference range is an intensity range having a width equivalent to, for example, 5 dBm and expressed in units of mW. The intensity reference value is expressed in mW. The score determination unit 13 counts the number of sampling data included in each intensity reference range. In the example of FIG. 15, the number of sampling data whose signal intensity S is greater than S1 and equal to or less than S2 is D2. The intensity reference value corresponding to the intensity reference range whose signal intensity S is greater than S1 and equal to or less than S2 is B2. The score determination unit 13 calculates a score Sc, which is the sum of the products of the intensity reference value and the number of sampling data whose signal intensity corresponds to the intensity reference value, as expressed by the following equation (1).

[0048]

number

[0049] Even if the received signal contains noise greater than -90 dBm and less than -82 dBm, the signal strength of the noise expressed in mW is sufficiently low that the impact on the score is small. By diagnosing the deterioration of insulating members based on the score calculated as described above, it is possible to perform the deterioration diagnosis with high accuracy.

[0050] In the first embodiment, the score determination unit 13 calculates the score for each detection period as described above. The score determination unit 13 further calculates the average value of the scores over multiple detection periods. The score determination unit 13 sends the score calculated for the most recent detection period and the average value of the scores over multiple detection periods prior to the detection period to the deterioration determination unit 14. The average value of the score is preferably a moving average value of the scores. For example, the average value of the scores calculated for the five detection periods immediately prior to the most recent detection period may be used as the average score.

[0051] 12, the deterioration determining unit 14 determines whether or not the insulating member has deteriorated by comparing the score reference value with the score acquired from the score determining unit 13 (step S13). The deterioration determining unit 14 transmits the determination result to the output device 20 (step S14).

[0052] Specifically, the deterioration determination unit 14 determines whether or not the insulating member has deteriorated by comparing the score with a reference score value. The deterioration determination unit 14 stores a reference score value in advance. The reference score value is determined according to the value that the signal strength of the received signal can take when the insulating member has deteriorated. Specifically, the reference score value can be determined by an accelerated deterioration test. The accelerated deterioration test is a test in which the motor 41 is subjected to higher heat, vibration, voltage, etc. than during normal operation to cause insulation breakdown of the motor 41 in a short period of time.

[0053] FIG. 16 shows the relationship between the usage period of the electric motor 41 and the score determined by the score determination unit 13 of the deterioration diagnosis device 1. The horizontal axis of FIG. 16 represents the usage period of the electric motor 41. The vertical axis of FIG. 16 represents the score. The score increases as the usage period of the electric motor 41 increases. In an accelerated aging test in which the electric motor 41 is intentionally and repeatedly thermally deteriorated, the score determination unit 13 determines the score of the electric motor 41 each time the heat deterioration is repeated. By plotting the cumulative deterioration time of the accelerated aging test on the horizontal axis and the score of the electric motor 41 on the vertical axis, an approximate line showing the relationship between the cumulative deterioration time in the accelerated aging test and the score can be obtained. By performing heat deterioration until dielectric breakdown occurs in the electric motor 41, a dielectric breakdown score, which is the score when dielectric breakdown occurs, can be obtained. The dielectric breakdown score is an index common to multiple electric motors 41 of the same design. It is preferable to perform an accelerated aging test on multiple electric motors 41 and use the average of the scores at which dielectric breakdown occurs for each electric motor 41 as the dielectric breakdown score. A value lower than this dielectric breakdown score, for example, a result obtained by multiplying the dielectric breakdown score obtained by the accelerated deterioration test by 0.8, is used as the score reference value. The deterioration determination unit 14 uses the same score reference value for multiple electric motors 41 of the same design.

[0054] While the electric motors 41 are in operation, the score determination unit 13 determines the score of each electric motor 41 as described above, and stores the score and usage period of each electric motor 41. An example of the relationship between the usage period of each electric motor 41 and its score is plotted in FIG. 16. From the plot results, an approximation line L1 is obtained, which indicates the relationship between the usage period of each electric motor 41 and its score, as shown by the dashed line in FIG. 16. From the approximation line L1, it is possible to determine the remaining lifespan Δt, which is the time remaining until insulation breakdown occurs in the electric motor 41, and the operational time Δt', which is the time remaining until the score of the electric motor 41 reaches the score reference value. If the operating pattern of the railway vehicle on which the electric motor 41 is mounted is constant, or if the usage period of the electric motor 41 is the net usage time, i.e., the running time of the railway vehicle, the remaining lifespan Δt and the operational time Δt' can be determined more accurately.

[0055] In order to improve the accuracy of deterioration determination, it is preferable that the deterioration determination unit 14 determines whether the score obtained from the score determination unit 13 is within the appropriate score range, and determines whether the insulating member has deteriorated or not when the score is within the appropriate score range.

[0056] When the scores are calculated for a plurality of electric motors 41 by the deterioration diagnosis device 1, the score value changes according to the degree of deterioration of the insulating members of each electric motor 41, as shown in Fig. 17. The vertical axis of Fig. 17 indicates the average, maximum, and minimum values ​​of the scores of each electric motor 41. The average score of the electric motor 41 whose insulating members are most deteriorated is Sc1. avg The maximum score of the motor 41 is Sc1 max The minimum score of the motor 41 is Sc1 min It is shown as follows.

[0057] 17, the ratio of the maximum or minimum score to the average score does not change significantly even if the degree of deterioration of the insulating materials of the motor differs. Therefore, the appropriate score range can be determined from the ratio of the maximum or minimum score to the average score, and the average score.

[0058] As shown in FIG. 18 , an approximation line L2 is obtained from the relationship between the average score and the maximum score of each electric motor 41. By using the approximation line L2, it is possible to estimate the maximum score from the average score calculated by the score determination unit 13. Similarly, by using the approximation line obtained from the relationship between the average score and the minimum score of each electric motor 41, it is possible to estimate the minimum score from the average score calculated by the score determination unit 13. The deterioration determination unit 14 estimates the maximum and minimum score values ​​as described above from the average score value acquired from the score determination unit 13, and calculates an appropriate score range that includes the estimated maximum and minimum score values. It is assumed that the deterioration determination unit 14 previously stores formulas, correspondence tables, etc. for calculating the appropriate score range from the average score value.

[0059] 19, the appropriate score range can be determined from an approximation line L2 obtained from the relationship between the average score and the maximum score for each electric motor 41, and an approximation line L3 obtained from the relationship between the average score and the minimum score for each electric motor 41. The deterioration determination unit 14 determines the appropriate score range from the average score obtained from the score determination unit 13 and the equation for the approximation lines L2 and L3. In detail, if the average score obtained from the score determination unit 13 is 30, the deterioration determination unit 14 uses the appropriate score range R1 shown in FIG. 19 as the appropriate score range.

[0060] The deterioration determination unit 14 determines whether the score obtained for the most recent detection period obtained from the score determination unit 13 is within the appropriate score range R1. In the example of Fig. 19, the scores Sc2 and Sc3 are not within the appropriate score range R1. Specifically, the score Sc2 is greater than the upper limit of the appropriate score range R1, and the score Sc3 is less than the lower limit of the appropriate score range R1.

[0061] If the score is not within the appropriate score range, it can be assumed that an abnormality has occurred in the received signal generated by the antenna 11 due to, for example, the influence of external noise, a poor power supply to the antenna 11, or a malfunction of the antenna 11. If the score acquired from the score determination unit 13 is not within the appropriate score range, the deterioration determination unit 14 does not perform deterioration determination.

[0062] 19, score Sc4 is included in score appropriate range R1. When the score acquired from score determination unit 13 is within the score appropriate range, deterioration determination unit 14 compares the score with a score reference value to determine whether or not the insulating member of electric motor 41 has deteriorated.

[0063] If the score is equal to or less than the score reference value, it can be assumed that there is no deterioration of the insulating members of the electric motor 41. If the score is greater than the score reference value, it can be assumed that there is deterioration of the insulating members of the electric motor 41. Since the score Sc4 is included in the score appropriate range R1 and is smaller than the score reference value, the deterioration determination unit 14 determines that there is no deterioration of the insulating members of the electric motor 41 and sends the determination result to the output device 20.

[0064] As the motor 41 continues to be used, the amplitude of the electromagnetic waves caused by partial discharge increases due to the expansion of voids 65a, the occurrence of cracks 65b, etc. As a result, the average score determined by the score determination unit 13 increases. As the average score increases, the upper and lower limits of the appropriate score range also increase. For example, if the average score obtained from the score determination unit 13 is 50, the deterioration determination unit 14 uses the appropriate score range R2 shown in FIG. 19 as the appropriate score range.

[0065] Since the score Sc5 is included in the appropriate score range R2 and is smaller than the score reference value, the deterioration determination unit 14 determines that the insulating members of the electric motor 41 have not deteriorated and sends the determination result to the output device 20.

[0066] The score Sc6 is included in the appropriate score range R2 but is greater than the score reference value. In this case, the deterioration determination unit 14 determines that the insulating member of the electric motor 41 has deteriorated because the score Sc6 is greater than the score reference value, and sends the determination result to the output device 20.

[0067] When the processing of step S14 is completed, the degradation diagnosis device 1 repeats the processing from step S11. While the power conversion device 31 is operating and power is being supplied to the electric motor 41, the degradation diagnosis device 1 repeats the degradation diagnosis processing.

[0068] When the output device 20 acquires the determination result from the deterioration determination unit 14 included in the deterioration diagnosis device 1, it displays the result on the display device in the driver's cab.

[0069] As described above, according to the degradation diagnosis device 1 of the first embodiment, the degradation determination unit 14 determines whether or not the insulating members of the electric motor 41 have deteriorated by comparing the score reference value with the score indicating the strength of the sampling data indicating the signal strength of the received signal generated by the antenna 11. This makes it possible to determine whether or not the insulating members of the electric motor 41 have deteriorated in a state in which the electric motor 41 is mounted on a vehicle.

[0070] The deterioration determination unit 14 determines whether or not the insulating material has deteriorated by comparing the score with a score reference value that is lower than the estimated score at the time of dielectric breakdown, thereby making it possible to detect deterioration of the insulating material before dielectric breakdown occurs. By detecting deterioration of the insulating material before dielectric breakdown occurs and outputting the determination result from the output device 20, the user can be prompted to perform maintenance work on the electric motor 41 before dielectric breakdown occurs. Dielectric breakdown in the stator coil 42 often accompanies destruction of the stator core 50, but if maintenance work can be performed before dielectric breakdown occurs, the stator core 50 can be reused.

[0071] (Embodiment 2) The number of antennas is not limited to the above example. As shown in Fig. 20, the degradation diagnosis device 2 included in the degradation diagnosis system 100 according to the second embodiment includes a plurality of antennas, specifically, antennas 11a, 11b, and 11c. The antennas 11a, 11b, and 11c are provided for each phase of the electric motor 41. For example, the antennas 11a, 11b, and 11c are provided corresponding to the U phase, V phase, and W phase, respectively. Specifically, the antennas 11a, 11b, and 11c are provided inside the terminal box 51 at positions adjacent to the electric wires 32a, 32b, and 32c, respectively. The structures of the antennas 11a, 11b, and 11c are similar to those of the antenna 11 included in the degradation diagnosis device 1 according to the first embodiment.

[0072] In addition to the configuration of electric motor 41 according to the first embodiment, electric motor 41 includes electrostatic shielding members 54a and 54b that separate antennas 11a, 11b, and 11c, as shown in Fig. 21 and Fig. 22, which is a cross-sectional view taken along line XXII-XXII in Fig. 21. Electrostatic shielding members 54a and 54b are made of a metal such as aluminum or iron.

[0073] The signal processing unit 12 samples the received signal for each phase corresponding to the antennas 11a, 11b, and 11c, and generates sampling data indicating the signal strength of the received signal. In other words, the signal processing unit 12 samples the received signal acquired from the antenna 11a and generates sampling data indicating the signal strength of the received signal generated by the antenna 11a. Similarly, the signal processing unit 12 samples the received signal acquired from the antenna 11b and generates sampling data indicating the signal strength of the received signal generated by the antenna 11b. Similarly, the signal processing unit 12 samples the received signal acquired from the antenna 11c and generates sampling data indicating the signal strength of the received signal generated by the antenna 11c.

[0074] The score determination unit 13 determines a score indicating the strength of the sampling data for each phase corresponding to the antennas 11a, 11b, and 11c. In other words, the score determination unit 13 determines a score corresponding to the U phase from the sampling data indicating the signal strength of the received signal generated by the antenna 11a. Similarly, the score determination unit 13 determines a score corresponding to the V phase from the sampling data indicating the signal strength of the received signal generated by the antenna 11b. Similarly, the score determination unit 13 determines a score corresponding to the W phase from the sampling data indicating the signal strength of the received signal generated by the antenna 11c.

[0075] The deterioration determiner 14 determines whether or not the insulating member has deteriorated for each phase corresponding to the antennas 11a, 11b, and 11c. In other words, the deterioration determiner 14 determines whether or not the insulating member of the U-phase coil 42a has deteriorated based on the score corresponding to the U-phase. Similarly, the deterioration determiner 14 determines whether or not the insulating member of the V-phase coil 42b has deteriorated based on the score corresponding to the V-phase. Similarly, the deterioration determiner 14 determines whether or not the insulating member of the W-phase coil 42c has deteriorated based on the score corresponding to the W-phase.

[0076] As described above, degradation diagnostic device 2 according to the second embodiment makes it possible to determine whether or not the insulating members have deteriorated for each phase corresponding to antennas 11a, 11b, and 11c.

[0077] The present disclosure is not limited to the above-described embodiment. The above-described hardware configuration and flowchart are merely examples, and can be changed and modified as desired.

[0078] The length of the sampling period can be determined arbitrarily. When the sampling period is not constant, in order to compensate for the difference in score due to the difference in sampling period, the score determination unit 13 may use the product of the signal strength indicated by the sampling data multiplied by a coefficient corresponding to the sampling period and the number of sampling data corresponding to the signal strength as the score.

[0079] The score determination unit 13 may calculate an average value of the scores over a plurality of detection periods including the most recent detection period, and send the average value of the scores to the deterioration determination unit 14. In this case, if the score calculated for the most recent detection period is within the appropriate score range, the deterioration determination unit 14 may compare the average value of the scores over a plurality of detection periods including the most recent detection period with a score reference value to determine whether or not the insulating member has deteriorated.

[0080] The method for determining the score reference value used by the deterioration determination unit 14 is not limited to the above example. As an example, the score determined by the score determination unit 13 when a dielectric breakdown occurs in the electric motor 41 during operation may be set as the dielectric breakdown score, and the score reference value may be determined based on the dielectric breakdown score.

[0081] The degradation determination unit 14 may use a warning threshold lower than the score reference value, and if the score is equal to or greater than the warning threshold value, transmit a determination result indicating signs of degradation of the insulating material to the output device 20. The degradation determination unit 14 may determine whether or not the insulating material has deteriorated or whether or not signs of deterioration of the insulating material have occurred based on the remaining life Δt or the operational life Δt'. The degradation determination unit 14 may calculate the remaining life Δt or the operational life Δt' from a line connecting a plot point and the origin shown in FIG. 16 and the score at the time of insulation breakdown or the score reference value. The degradation determination unit 14 may calculate the remaining life Δt or the operational life Δt' in the accelerated aging test from the relationship between a plot point shown in FIG. 16 and the cumulative deterioration time and score obtained in the accelerated aging test, and may calculate the remaining life Δt or the operational life Δt' by multiplying the remaining life or the operational life in the accelerated aging test by the deterioration factor Sr. The deterioration factor Sr is calculated based on the temperature T at which the life is halved, the vibration acceleration α, and the like according to the Arrhenius law.

[0082] The method of determining the appropriate score range used by the deterioration determiner 14 is not limited to the above example. In the above embodiment, the deterioration determiner 14 used the range from a point on the approximation line L3 to a point on the approximation line L2 as the appropriate score range, but the range may be defined by a lower limit value that is smaller than a point on the approximation line L3 and an upper limit value that is larger than the approximation line L2 as the appropriate score range.

[0083] The control portion of the degradation diagnosis devices 1 and 2 may be realized by a processing circuit 94 as shown in FIG. 23 . The processing circuit 94 is connected to the output device 20 via an interface circuit 95. When the processing circuit 94 is dedicated hardware, the processing circuit 94 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The signal processing unit 12, the score determination unit 13, and the degradation determination unit 14 may each be realized by a separate processing circuit 94, or the signal processing unit 12, the score determination unit 13, and the degradation determination unit 14 may be realized by a common processing circuit 94.

[0084] Some of the functions of the signal processing unit 12, score determination unit 13, and deterioration determination unit 14 may be realized by dedicated hardware, and other functions may be realized by software or firmware. For example, in the deterioration diagnosis device 1 according to the first embodiment, the signal processing unit 12 may be realized by a processing circuit 94 shown in Fig. 23, and the score determination unit 13 and deterioration determination unit 14 may be realized by the processor 91 shown in Fig. 11 reading and executing a program stored in a memory 92.

[0085] The mounting positions of antennas 11, 11a, 11b, and 11c are not limited to the above example and may be any positions that allow reception of electromagnetic waves generated by partial discharges. For example, antennas 11a, 11b, and 11c may be provided adjacent to U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c, respectively.

[0086] Deterioration diagnosis device 1 may determine whether or not motor 41 has deteriorated in a state in which in-phase voltages are applied to U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c from a test power supply device (not shown). When in-phase voltages are applied to U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c, the amplitude of the radio waves received by antenna 11 is larger than when out-of-phase voltages are applied to U-phase coil 42a, V-phase coil 42b, and W-phase coil 42c. The larger amplitude reduces the influence of noise, allowing deterioration diagnosis device 1 to more accurately determine whether or not the insulating members have deteriorated.

[0087] Deterioration diagnostic devices 1 and 2 may operate by receiving power from a current collector, similar to power conversion device 31.

[0088] The configuration of the electric motor 41 is not limited to the above example. As an example, the electric motor 41 may be a frameless motor. The electric motor 41, which is a frameless motor, is provided with a pair of brackets that sandwich the stator core 50 in the Y-axis direction. One of the brackets has insertion holes through which the electric wires 32a, 32b, and 32c are inserted. The antenna 11 is provided inside a terminal box 51 that covers the insertion holes formed in the brackets.

[0089] As another example, the electric motor 41 does not need to include the terminal box 51. In this case, the antenna 11 may be attached to the frame 40, the outer peripheral surface of a bracket that sandwiches the stator core 50 in the Y-axis direction, the outer peripheral surface of the stator core 50, the inner peripheral surface of the bracket, or the like.

[0090] The U-phase coil 42a, the V-phase coil 42b, and the W-phase coil 42c may be connected in a delta connection.

[0091] Antennas 11, 11a, 11b, and 11c are not limited to planar antennas, but may be any directional antenna that is capable of receiving electromagnetic waves radiated due to partial discharges occurring in insulating members of electric motor 41 and that can suppress interference with electromagnetic waves radiated from non-target electric motors 41.

[0092] The signal processing unit 12, score determination unit 13, and degradation discrimination unit 14 provided in the degradation diagnosis devices 1 and 2 may be realized as one function of a train information management system. Parts of the degradation diagnosis devices 1 and 2 may be mounted on the vehicle, and the other parts may be installed on the ground. As an example, the antenna 11 and signal processing unit 12 provided in the degradation diagnosis device 1 may be mounted on the vehicle, and the score determination unit 13 and degradation discrimination unit 14 provided in the degradation diagnosis device 1 may be provided in a control center. In this case, the signal processing unit 12 and the score determination unit 13 each have a communication function that allows them to communicate with each other.

[0093] A computer program for performing the above-described operations may be stored on a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disc - Read Only Memory), or a DVD-ROM (Digital Versatile Disc - Read Only Memory) and distributed, and the computer program may be installed on a computer to realize the degradation diagnosis devices 1 and 2 that perform the above-described operations. Alternatively, the degradation diagnosis devices 1 and 2 that perform the above-described operations may be realized by a dedicated system. The computer program may be provided via a communication network superimposed on a carrier wave.

[0094] The power conversion device 31 is not limited to being mounted on a DC-fed railway vehicle, but can be mounted on any vehicle such as an AC-fed railway vehicle or a railway vehicle equipped with an internal combustion engine.

[0095] The electric motor 41 may be either a three-phase induction motor or a three-phase synchronous motor. Furthermore, the electric motor 41 is not limited to a three-phase motor, and may be, for example, a single-phase motor or a DC motor. The electric motor 41 may be an inner rotor or an outer rotor. Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) an antenna that receives electromagnetic waves in the microwave frequency band radiated due to partial discharge occurring in an insulating member of the electric motor and generates a received signal; a signal processing unit that samples the received signal for each sampling period and generates sampling data that indicates the signal strength of the received signal; a score determination unit that determines a score indicating the strength of the signal intensity over a detection period from the sampling data generated by the signal processing unit during a detection period including a plurality of the sampling periods; a degradation determination unit that determines whether the insulating member has deteriorated by comparing the score with a score reference value that is determined according to a value that the signal strength can take when the insulating member has deteriorated; A deterioration diagnosis device comprising: (Appendix 2) the score determination unit uses, as the score, a sum of products of intensity reference values ​​determined at regular intervals within a target intensity range, which is a target range of the signal intensity, and the number of the sampling data having signal intensities corresponding to the intensity reference values. 2. The degradation diagnosis device according to claim 1. (Appendix 3) the deterioration determination unit determines whether the insulating member has deteriorated by comparing the reference score value with an average value of the scores over a plurality of the detection periods; 3. The degradation diagnosis device according to claim 1 or 2. (Appendix 4) the deterioration determination unit determines whether or not the insulating member has deteriorated by comparing the score with the reference score value when the score is within an appropriate score range, which is a range that the score can take, determined according to an average value of the scores over a plurality of detection periods prior to the detection period in which the score was calculated; 4. A degradation diagnosis device according to any one of appendices 1 to 3. (Appendix 5) The antenna is provided inside a terminal box of the electric motor, inside which an electric wire is arranged, the electric wire being passed from the outside of the electric motor to a stator coil inside the electric motor. 5. A degradation diagnosis device according to any one of appendices 1 to 4. (Appendix 6) The electric motor is a three-phase electric motor, the deterioration diagnosis device determines whether or not the insulating members of the electric motor have deteriorated when a voltage of the same phase is applied to coils of each phase of the electric motor; 6. A degradation diagnosis device according to any one of appendices 1 to 5. (Appendix 7) a plurality of the antennas provided at positions separated by electrostatic shielding members, the antennas corresponding to the phases of the three-phase motor, the signal processing unit generates the sampling data for each phase corresponding to the antenna; the score determination unit determines the score for each phase corresponding to the antenna; the deterioration determination unit determines whether or not the insulating member has deteriorated for each phase corresponding to the antenna; 6. A degradation diagnosis device according to any one of appendices 1 to 5. (Appendix 8) A deterioration diagnosis device according to any one of appendices 1 to 7, which determines whether or not an insulating member of the electric motor has deteriorated; an output device that acquires a determination result from the deterioration determination unit included in the deterioration diagnosis device and outputs the acquired determination result; A deterioration diagnosis system comprising: (Appendix 9) a receiving signal generated by an antenna that receives electromagnetic waves in a microwave frequency band radiated due to partial discharge occurring in an insulating member of the electric motor is sampled for each sampling period, and sampling data indicating the signal strength of the receiving signal is generated; determining a score indicating the strength of the signal intensity over a detection period from the sampling data during a detection period including a plurality of the sampling periods; determining whether the insulating member has deteriorated or not by comparing the score with a reference score value determined according to a value that the signal strength can take when the insulating member has deteriorated; Deterioration diagnosis method.

[0096] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of equivalent disclosures are considered to be within the scope of the present disclosure. [Explanation of symbols]

[0097] 1, 2 Deterioration diagnosis device, 11, 11a, 11b, 11c antenna, 12 signal processing unit, 13 score determination unit, 14 deterioration determination unit, 20 output device, 31 power conversion device, 32a, 32b, 32c electric wire, 40 frame, 40a insertion hole, 41 electric motor, 42 stator coil, 42a U-phase coil, 42b V-phase coil, 42c W-phase coil, 43 shaft, 44 bearing, 45 rotor, 46 rotor core, 47 conductor bar, 48 short-circuit ring, 49 stator, 50 stator core, 50a slot, 51 terminal box, 52 inter-coil insulating member, 53 wedge, 54a, 54b electrostatic shielding member, 61 strand, 62 conductor, 63 insulating coating member, 64 insulating tape, 65 insulating varnish, 65a Void, 65b crack, 90 bus, 91 processor, 92 memory, 93 interface, 94 processing circuit, 95 interface circuit, 100 deterioration diagnosis system, AX rotating axis, L1, L2, L3 approximation line, R1, R2 score appropriate range, Δt remaining life, Δt' operational time.

Claims

1. an antenna that receives electromagnetic waves in the microwave frequency band radiated due to partial discharge occurring in an insulating member of the electric motor and generates a received signal; a signal processing unit that samples the received signal for each sampling period and generates sampling data that indicates the signal strength of the received signal; a score determination unit that determines a score indicating the strength of the signal strength over the detection period from the sampling data generated by the signal processing unit during a detection period including a plurality of the sampling periods, using the sum of the products of strength reference values ​​determined at regular intervals within a target strength range that is a target range of the signal strength and the number of the sampling data having signal strengths corresponding to the strength reference values; and a degradation determination unit that determines whether the insulating member has deteriorated by comparing the score with a reference score value that is determined according to a value that the signal strength can take when the insulating member has deteriorated; A deterioration diagnosis device comprising:

2. the deterioration determination unit determines whether the insulating member has deteriorated by comparing the reference score value with an average value of the scores over a plurality of the detection periods; The deterioration diagnosis device according to claim 1 .

3. the deterioration determination unit determines whether or not the insulating member has deteriorated by comparing the score with the reference score value when the score is within an appropriate score range, which is a range that the score can take, determined according to an average value of the scores over a plurality of detection periods prior to the detection period in which the score was calculated; The deterioration diagnosis device according to claim 1 or 2.

4. The antenna is provided inside a terminal box of the electric motor, inside which an electric wire is arranged, the electric wire being passed from the outside of the electric motor to a stator coil inside the electric motor. The deterioration diagnosis device according to claim 1 or 2.

5. The electric motor is a three-phase electric motor, the deterioration diagnosis device determines whether or not the insulating members of the electric motor have deteriorated when a voltage of the same phase is applied to coils of each phase of the electric motor; The deterioration diagnosis device according to claim 1 or 2.

6. a plurality of the antennas provided at positions separated by electrostatic shielding members, the antennas corresponding to the phases of the three-phase motor, the signal processing unit generates the sampling data for each phase corresponding to the antenna; the score determination unit determines the score for each phase corresponding to the antenna; the deterioration determination unit determines whether or not the insulating member has deteriorated for each phase corresponding to the antenna; The deterioration diagnosis device according to claim 1 or 2.

7. a deterioration diagnosis device according to claim 1 or 2, which determines whether or not an insulating member of the electric motor has deteriorated; an output device that acquires a determination result from the deterioration determination unit included in the deterioration diagnosis device and outputs the acquired determination result; A deterioration diagnosis system comprising:

8. a receiving signal generated by an antenna that receives electromagnetic waves in a microwave frequency band radiated due to partial discharge occurring in an insulating member of the electric motor is sampled for each sampling period, and sampling data indicating the signal strength of the receiving signal is generated; a score indicating the strength of the signal strength over the detection period is calculated from the sampling data during a detection period including a plurality of the sampling periods by using the sum of the products of the strength reference values ​​determined at regular intervals within a target strength range, which is a target range of the signal strength, and the number of the sampling data having the signal strength corresponding to the strength reference values; determining whether the insulating member has deteriorated or not by comparing the score with a reference score value determined according to a value that the signal strength can take when the insulating member has deteriorated; Deterioration diagnosis method.

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