Evaluation device, evaluation method and program

Abstract

To provide an evaluation device, an evaluation method and a program that can estimate a deterioration state of a polymeric material such as an insulation material.SOLUTION: An evaluation device according to an embodiment is an evaluation device that evaluates a polymeric material comprising an organic resin and an inorganic filler. The evaluation device comprises: an acquisition unit; and a strength estimation unit. The acquisition unit is an evaluation device that evaluates a polymeric material comprising an organic resin and an inorganic filler, and acquires a measured value associated with a surface state of the polymeric material. The strength estimation unit estimates a mechanical strength of the polymeric material on the basis of the measured value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to an evaluation device, an evaluation method, and a program.

Background Art

[0002] Electrical equipment such as transformers, switches, motors, and inverters is known. These electrical equipment are subjected to insulation treatment to prevent electric leakage. The insulating material used for electrical equipment mainly consists of a polymer insulating material such as epoxy resin. An inorganic filler may be blended into the insulating material for the purpose of improving mechanical strength, heat resistance, and reducing the overall cost of the resin. Silica, alumina, glass, etc. are used as the inorganic filler.

[0003] The insulating material deteriorates as the electrical equipment is used. When the deterioration of the insulating material progresses, voids and cracks that cause dielectric breakdown are generated inside. In order to prevent the occurrence of dielectric breakdown, it is required to appropriately estimate the deterioration state of the insulating material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an evaluation device, an evaluation method, and a program capable of estimating the deterioration state of polymer materials such as insulating materials.

Means for Solving the Problems

[0006] The evaluation device of the embodiment is an evaluation device that evaluates a polymer material in which an organic resin and an inorganic filler are blended. The evaluation device has an acquisition unit and a strength estimation unit. The acquisition unit is an evaluation device that evaluates a polymer material in which an organic resin and an inorganic filler are blended, and acquires a measurement value related to the surface state of the polymer material. The strength estimation unit estimates the mechanical strength of the polymer material based on the measurement value.

Brief Description of Drawings

[0007]

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Modes for Carrying Out the Invention

[0008] Hereinafter, the evaluation device, evaluation method, and program of the embodiment will be described with reference to the drawings.

[0009] (First Embodiment) FIG. 1 is a diagram showing the configuration of an evaluation system 1 according to the first embodiment. The evaluation system 1 according to the first embodiment evaluates the deterioration state of the insulating material of the electrical equipment 10 to be measured. Examples of the electrical equipment 10 include a transformer, a switchgear, a motor, an inverter, and the like. The insulating material of the electrical equipment 10 is a polymer material in which an organic resin and an inorganic filler are blended. The organic resin constituting the insulating material may be, for example, an epoxy resin. The inorganic filler constituting the insulating material may be, for example, silica, alumina, glass, or the like.

[0010] The evaluation system 1 includes a measuring device 30 and an evaluation device 50.

[0011] The measuring device 30 measures the surface roughness (average surface roughness (Ra)) of the insulating material of the electrical equipment 10. Examples of the measuring device 30 may be a non-contact measuring device such as a laser microscope or a white interferometer, or a contact measuring device having a stylus. In other embodiments, the maximum surface roughness (Rz) or the ten-point average roughness (Rzjis) may be obtained as the surface roughness. The surface roughness is an example of a state quantity representing the surface state of the insulating material.

[0012] The evaluation device 50 evaluates the deterioration state of the insulating material based on the surface roughness measured by the measuring device 30. The reason why the deterioration state of the insulating material can be evaluated by the surface roughness will be described. FIG. 2 is an example of the change in the surface of the insulating material accompanying deterioration according to the first embodiment. The surface of the insulating material of the electrical equipment 10 is smoothly formed when it is new (unused). That is, the surface roughness of the insulating material when it is new is a low value. When the electrical equipment 10 is used, the electric wire generates heat due to energization, and the insulating material is heated. When the insulating material is heated, the organic resin constituting the insulating material scatters. At this time, the internal inorganic filler is exposed on the surface as the organic resin scatters. Since the particle size of the inorganic filler is larger than that of the organic resin, the surface roughness of the insulating material increases as the organic resin scatters. Therefore, since the degree of thermal deterioration appears in the surface roughness, the evaluation device 50 can evaluate the deterioration state of the insulating material based on the surface roughness.

[0013] FIG. 3 is a diagram showing the configuration of the evaluation apparatus 50 according to the first embodiment. The evaluation apparatus 50 includes an acquisition unit 51, a storage unit 52, a strength estimation unit 53, a degradation prediction unit 54, a lifetime estimation unit 55, and an output unit 56.

[0014] The acquisition unit 51 acquires the measured value of the surface roughness from the measuring apparatus 30. The acquisition unit 51 records the acquired measured value in the storage unit 52 in association with the measurement time.

[0015] The storage unit 52 stores the measured value of the surface roughness acquired by the acquisition unit 51 in association with the measurement time. Further, the storage unit 52 stores a strength function indicating the relationship between the surface roughness and the mechanical strength of the insulating material in advance.

[0016] FIG. 4 is a diagram showing the relationship between the surface roughness and the mechanical strength according to the first embodiment. The strength function is obtained, for example, by the following procedure. 1. Prepare a plurality of bending test pieces made of the same material as the insulating material. 2. Thermally degrade the plurality of bending test pieces under different temperature conditions. 3. Determine the bending strength by performing a bending test on the plurality of bending test pieces. The bending strength is the stress at which the test piece is broken in the bending test. The bending strength is an example of an index representing the mechanical strength of the insulating material. 4. Normalize the bending strength. The normalization of the bending strength is performed by obtaining the ratio of the bending strength to the bending strength of the test piece before thermal degradation. That is, the normalized bending strength of the test piece before thermal degradation is 1. 5. Plot the relationship between the normalized bending strength and the surface roughness on a graph. 6. Generate a strength function by fitting a linear function based on the plot.

[0017] Note that through experiments, it was found that the relationship between surface roughness and bending strength changes in two stages as shown in Fig. 3. That is, when the surface roughness is less than a certain roughness P, the change in bending strength is gentle, and when the surface roughness exceeds a certain roughness P, it was found that the change in bending strength becomes steep. This is explained as follows. Generally, thermosetting resins are shipped with some unreacted groups for manufacturing rationality. Therefore, in the initial stage of deterioration, while the cross-links are broken by the heat generated during the use of the electrical equipment 10, new cross-links are formed from the unreacted groups. At this stage, the cross-link density in the thermosetting resin hardly changes, and the mechanical strength also does not change significantly. However, as the reaction progresses over time and the unreacted groups are exhausted, only the cross-link breakage due to the heat generated during the use of the electrical equipment 10 occurs, so the cross-link density decreases and the mechanical strength also decreases. On the other hand, regarding the surface roughness, it increases at a certain rate with deterioration regardless of the presence or absence of unreacted groups. From the above, it is presumed that when the surface roughness reaches a certain roughness P, the unreacted groups in the resin are almost exhausted, so the decrease in mechanical strength is accelerated. Therefore, the strength function according to the first embodiment is represented by two linear functions. Also, as a result of the experiment, it was found that the relationship between surface roughness and mechanical strength does not depend on the deterioration temperature conditions of the insulating material. Therefore, the strength function according to the first embodiment does not need to be prepared for each temperature.

[0018] The strength estimation unit 53 estimates the mechanical strength of the insulating material based on the measured value of the surface roughness acquired by the acquisition unit 51 and the strength function stored in the storage unit 52.

[0019] The deterioration prediction unit 54 generates a deterioration function showing the relationship between surface roughness and time based on the mechanical strength at different times estimated by the strength estimation unit 53. The deterioration function according to the first embodiment is a linear function representing the relationship between surface roughness and the logarithm of the usage time (deterioration time) of the electrical equipment 10.

[0020] The remaining service life (remaining life) until the mechanical strength falls below a threshold value Th (for example, 0.5) is estimated by the remaining life estimation unit 55 based on the degradation function generated by the degradation prediction unit 54 and the mechanical strength estimated by the strength estimation unit 53.

[0021] The output unit 56 outputs the estimation results of the strength estimation unit 53 and the remaining life estimation unit 55. The output unit 56 may, for example, display the estimation results on a display, transmit the estimation results by e-mail, or write the estimation results to a recording medium.

[0022] FIG. 5 is a flowchart showing a method for evaluating the degradation state by the evaluation system 1 according to the first embodiment. First, the acquisition unit 51 acquires the measured value of the surface roughness from the measuring device 30 at the first time (step S1). The acquisition unit 51 records the acquired measured value in the storage unit 52 in association with the first time. The strength estimation unit 53 estimates the mechanical strength of the insulating material at the first time based on the measured value of the surface roughness acquired in step S1 and the strength function stored in the storage unit 52 (step S2). The strength estimation unit 53 records the estimated mechanical strength in the storage unit 52 in association with the first time. The output unit 56 outputs the estimation result of the mechanical strength estimated in step S2 (step S3). Thereby, the user can recognize the degree of degradation of the insulating material of the electrical equipment 10 at the first time.

[0023] The acquisition unit 51 acquires the measured value of the surface roughness from the measuring device 30 at the second time after the first time (step S4). The acquisition unit 51 records the acquired measured value in the storage unit 52 in association with the second time. The strength estimation unit 53 estimates the mechanical strength of the insulating material at the second time based on the measured value of the surface roughness acquired in step S4 and the strength function stored in the storage unit 52 (step S5). The strength estimation unit 53 records the estimated mechanical strength in the storage unit 52 in association with the second time.

[0024] The degradation prediction unit 54 generates a degradation function based on the mechanical strength at each time (the first time and the second time) recorded in the storage unit 52 (step S6). The remaining life estimation unit 55 estimates the remaining usage time until the mechanical strength falls below the threshold Th based on the degradation function generated by the degradation prediction unit 54 and the mechanical strength estimated in step S5 (step S7). The output unit 56 outputs the estimation result of the mechanical strength at the second time estimated in step S2 and the estimation result of the remaining usage time estimated in step S7 (step S8). As a result, the user can recognize the degree of degradation of the insulating material of the electrical equipment 10 and the remaining life of the electrical equipment 10 at the second time.

[0025] Thereafter, the evaluation device 50 repeats the processes after step S4 to estimate the degree of degradation and the remaining life. Note that the accuracy of the degradation function increases as the mechanical strength at each time estimated in step S5 is accumulated in the storage unit 52.

[0026] As described above, the evaluation system 1 according to the first embodiment acquires the measured value of the surface roughness of the insulating material and estimates the mechanical strength of the insulating material based on the measured value. Since the mechanical strength of the insulating material represents the degradation state of the insulating material, the evaluation system 1 according to the first embodiment can estimate the degradation state of the insulating material. Further, the evaluation system 1 according to the first embodiment predicts the temporal change of the mechanical strength based on the mechanical strengths estimated at different times. As a result, the evaluation system 1 can make the user recognize the progress of the degradation of the insulating material. Further, the evaluation system 1 according to the first embodiment estimates the time when the mechanical strength of the insulating material falls below a predetermined strength based on the predicted temporal change of the mechanical strength. As a result, the evaluation system 1 can make the user recognize the maintenance time and replacement time of the electrical equipment 10.

[0027] The experimental results of the evaluation system 1 according to the first embodiment are shown below. The inventor created a plurality of bending test pieces of epoxy resin and thermally degraded each of them under different degradation times at three temperature conditions. The three temperature conditions are, in descending order of temperature, Condition 1 (225°C), Condition 2 (205°C), and Condition 3 (190°C). The inventor measured the surface roughness and bending strength of the thermally degraded bending test pieces respectively. The inventor obtained the average surface roughness of the bending test pieces using a 3D laser microscope. FIG. 6 is a diagram showing the relationship between the surface roughness and the bending strength in the experiment according to the first embodiment. FIG. 7 is a diagram showing the relationship between the surface roughness and the degradation time in the experiment according to the first embodiment. As a result of the experiment, it was found that the relationship between the surface roughness and the bending strength, that is, the strength function, does not depend on the temperature condition. Also, in this experiment, it was found that when the surface roughness is 1 micrometer or less, the bending strength does not change significantly. On the other hand, it was found that the rate of increase in the surface roughness varies depending on the degradation conditions.

[0028] From these experimental results, it can be seen that, as in the first embodiment, the mechanical strength of the insulating material can be estimated from the surface roughness. Note that the change in the surface roughness is caused by the exposure of the inorganic filler on the surface of the insulating material due to degradation. Therefore, the magnitude of the change in the surface roughness varies depending on the particle size of the inorganic filler. On the other hand, even if the particle size and content rate of the inorganic filler are different, the relationship that the mechanical strength decreases as the surface roughness increases always holds.

[0029] (Second Embodiment) The evaluation system 1 according to the second embodiment evaluates the degradation state of the insulating material based on the color difference of the insulating material. The measuring device 30 according to the second embodiment may be a color difference meter. The measured value of the color difference (color tone) may be, for example, the a* value or the b* value representing the color in the L*a*b* color system. Note that which of the a* value and the b* value is used may be determined by the original color of the resin. For example, when the original color of the resin is close to red or green, that is, when the a* value of the original color of the resin is larger than the b* value, the a* value may be used, and when the original color of the resin is close to yellow or blue, that is, when the a* value of the original color of the resin is smaller than the b* value, the b* value may be used.

[0030] The reason why the deterioration state of the insulating material can be evaluated by the color difference will be described. The surface of the insulating material of the electrical equipment 10 has the original color of the resin when it is new (unused). Generally, since the original color of the resin when it is new has a relatively high chroma, the absolute values of the a* value and the b* value are high. When the electrical equipment 10 is used, the electric wire generates heat due to energization, and the insulating material is heated. When the insulating material is heated, the carbonization of the resin constituting the insulating material progresses. That is, since the color of the resin fades in the insulating material, the a* value and the b* value approach 0. Thereafter, as the use of the electrical equipment 10 progresses, scattering of the organic resin occurs due to overheating of the insulator, and the internal inorganic filler is exposed on the surface. Since the powder of the inorganic filler appears white, as the organic resin scatters, the color of the insulating material becomes white, and the absolute values of the a* value and the b* value increase. Note that the powder of the inorganic filler appears white because the color of the powder is white and the powder is transparent and scattering of incident light occurs. Therefore, since the degree of thermal deterioration appears in the color difference, the evaluation device 50 can evaluate the deterioration state of the insulating material based on the color difference. In particular, by using the color difference instead of the surface roughness, the mechanical strength of the resin can be estimated in the same manner as in the first embodiment.

[0031] The experimental results of the evaluation system 1 according to the second embodiment will be shown below. The inventor created a plurality of bending test pieces of an epoxy resin and thermally deteriorated each of them under different deterioration times under three temperature conditions. The three temperature conditions are Condition 1, Condition 2, and Condition 3 in descending order of temperature. The inventor measured the a* value and the bending strength of the thermally deteriorated bending test pieces, respectively. FIG. 8 is a diagram showing the relationship between the a* value and the bending strength in the experiment according to the second embodiment. FIG. 9 is a diagram showing the relationship between the a* value and the deterioration time in the experiment according to the second embodiment. As a result of the experiment, it was found that the relationship between the a* value and the bending strength, that is, the strength function, does not depend on the temperature condition. On the other hand, it was found that the increasing rate of the a* value differs depending on the deterioration condition. It was also found that the a* value shows a very high value when not in use. From this, when the a* value related to the measured value is sufficiently high, the strength estimation unit 53 may estimate that it has a sufficiently high strength.

[0032] From the results of this experiment, it can be seen that the mechanical strength of the insulating material can be estimated from the a* value as in the second embodiment. Also, although the results of the a* value were presented in this experimental example, it is also possible to estimate the mechanical strength in the same manner using the b* value.

[0033] Note that the evaluation system 1 according to other embodiments can also evaluate the deterioration state using, instead of the color difference, the brightness R·G·B in the RGB color system, the luminance Y in the XYZ color system, the luminance L* in the L*a*b* color system, the glossiness, etc. That is, the evaluation system 1 may evaluate the deterioration state based on the reflected light of the insulating material.

[0034] Note that in other embodiments, the measuring device 30 may measure the surface roughness of the insulating material and values representing surface states other than the values related to the reflected light. For example, the measuring device 30 according to other embodiments may measure wettability, ion content on the surface, etc. The surface roughness, reflected light, wettability, and ion content on the surface are all values representing the surface state. Also, these values can be said to be values indicating the degree of exposure of the inorganic filler.

[0035] According to at least one of the embodiments described above, the evaluation device 50 has the following characteristics. That is, the evaluation device has an acquisition unit and a strength estimation unit. The acquisition unit is an evaluation device that evaluates a polymer material in which an organic resin and an inorganic filler are blended, and acquires a measurement value related to the surface state of the polymer material. The strength estimation unit estimates the mechanical strength of the polymer material based on the measurement value. Thereby, the evaluation device 50 can estimate the deterioration state of a polymer material such as an insulating material.

[0036] 〈Computer Configuration〉 The evaluation device 50 includes a processor, a memory, an auxiliary storage device, etc. connected by a bus, and functions as a device including an acquisition unit 51, a storage unit 52, a strength estimation unit 53, a deterioration prediction unit 54, a lifespan estimation unit 55, and an output unit 56 by executing an evaluation program. Examples of the processor include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), a microprocessor, etc. The evaluation program may be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include storage devices such as magnetic disks, magneto-optical disks, optical disks, and semiconductor memories. The evaluation program may be transmitted via an electric communication line. Note that all or part of each function of the evaluation device 50 may be realized using a custom LSI (Large Scale Integrated Circuit) such as an ASIC (Application Specific Integrated Circuit) or a PLD (Programmable Logic Device). Examples of the PLD include a PAL (Programmable Array Logic), a GAL (Generic Array Logic), a CPLD (Complex Programmable Logic Device), and an FPGA (Field Programmable Gate Array). Such an integrated circuit is also included as an example of the processor.

[0037] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0038] 1…Evaluation system 10…Electrical equipment 30…Measuring device 50…Evaluation device 51…Acquisition unit 52…Memory unit 53…Strength estimation unit 54…Deterioration prediction unit 55…Lifetime estimation unit 56…Output unit

Claims

1. An evaluation apparatus for evaluating a polymer material in which an organic resin and an inorganic filler are compounded, comprising: an acquisition unit that acquires a measurement value related to the surface state of the polymer material; a strength estimation unit that estimates the mechanical strength of the polymer material based on the measurement value The evaluation apparatus comprising the above.

2. The measurement value is a value related to the surface roughness of the polymer material The evaluation apparatus according to claim 1.

3. The measurement value is a value related to the reflected light of the polymer material The evaluation apparatus according to claim 1.

4. The measurement value is at least one measurement value of the color difference, glossiness, wettability, and ion content of the polymer material The evaluation apparatus according to claim 1.

5. A deterioration prediction unit that predicts the time change of the mechanical strength based on the mechanical strength estimated at different times The evaluation apparatus according to any one of claims 1 to 4, comprising the above.

6. A life estimation unit that estimates the time when the mechanical strength of the polymer material falls below a predetermined strength based on the predicted time change of the mechanical strength The evaluation apparatus according to claim 5, comprising the above.

7. An evaluation method for evaluating a polymer material in which an organic resin and an inorganic filler are compounded, comprising: a step of acquiring a measurement value related to the surface state of the polymer material; a step of estimating the mechanical strength of the polymer material based on the measurement value The evaluation method having the above.

8. A program for causing a computer to execute a step of acquiring a measurement value related to the surface state of a polymer material in which an organic resin and an inorganic filler are compounded; a step of estimating the mechanical strength of the polymer material based on the measurement value The program for the above.

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