Method for manufacturing high voltage equipment and high voltage equipment

Abstract

To provide high voltage equipment which exhibits high insulation performance and is less likely to degrade its insulation performance.SOLUTION: A method for manufacturing high voltage equipment (1) includes the steps of: providing resin moldings (13a and 13b) on the surface of a pair of electrodes (12a and 12b) that are insulated from one another, to which different potentials are applied; and coating the surface of at least a part of the resin moldings with resin insulators (17a and 17b) containing no filler.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing high voltage equipment. [Background technology]

[0002] In a pair of electrodes that are insulated from each other and to which different potentials are applied, the electric field between the electrodes increases, which can cause the insulation to break down and a flashover to occur. If a flashover occurs, abnormal heat will be generated at the flashover location, which is undesirable.

[0003] Patent Document 1 discloses an example in which an insulating coating layer made of resin is added to electrodes in a gas-insulated switchgear as a high-voltage device. The insulating coating layer enhances insulation and makes it difficult for flashover to occur. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-141794 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of Patent Document 1, there is a possibility that flashovers may occur in a concentrated manner at a specific location. When flashovers occur in a specific location, the specific location deteriorates. This reduces the insulation performance, making the flashover more likely to occur.

[0006] An object of one aspect of the present invention is to provide a method for manufacturing high-voltage equipment that exhibits high insulation performance and is resistant to deterioration of the insulation performance. [Means for solving the problem]

[0007] In order to solve the above problems, a manufacturing method according to one embodiment of the present invention is a manufacturing method for a high-voltage device having a pair of electrodes insulated from each other and to which different potentials are applied, the manufacturing method including the steps of providing a resin molding on a surface of the electrodes and covering at least a portion of the surface of the resin molding with a resin insulator that does not contain a filler.

[0008] In order to solve the above problems, a manufacturing method according to one embodiment of the present invention is a method for manufacturing a high-voltage device having a pair of electrodes insulated from each other and to which different potentials are applied, comprising the steps of providing a resin molding on a surface of the electrodes, and roughening the surface of the resin molding so that the coefficient of variation of a maximum height Rz of the surface of the resin molding after roughening is lower than the coefficient of variation of a maximum height Rz of the surface before roughening.

[0009] In order to solve the above problems, a high-voltage device according to one embodiment of the present invention comprises a pair of electrodes insulated from each other and to which different potentials are applied, a resin molding provided on the surfaces of the electrodes, and a filler-free resin insulator covering at least a portion of the surface of the resin molding.

[0010] In order to solve the above problems, a high-voltage device according to one embodiment of the present invention comprises a pair of electrodes insulated from each other and to which different potentials are applied, and a resin molding provided on a surface of the electrodes, wherein the coefficient of variation of the maximum height Rz of the surface of the resin molding is 0.4 or less. Effect of the Invention

[0011] According to one aspect of the present invention, it is possible to achieve an effect of exhibiting high insulating performance and preventing the insulating performance from deteriorating. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a high-voltage device according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a cross-sectional view showing another high-voltage device according to an embodiment of the present invention. [Diagram 3]1 is a graph showing a voltage change when a flashover occurs. [Figure 4] 1 is a graph showing the ratio of minimum voltage to maximum voltage when a flashover occurs. [Diagram 5] 1 shows images of test specimens before and after testing with an untreated surface, a roughened surface, and a resin-coated surface. [Figure 6] FIG. 1 is a diagram showing the distribution of flashover sites on untreated, roughened, and resin-coated surfaces. [Figure 7] 1 is a bar graph showing the measured maximum height Rz of each test piece. [Figure 8] 1 is a bar graph showing the coefficient of variation of the maximum height Rz of each test specimen. [Figure 9] The standard deviation of the electric field at which a flashover occurs is plotted against the coefficient of variation of the maximum height Rz. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Embodiment] (High voltage equipment configuration) FIG. 1 is a cross-sectional view showing a high-voltage device 1 according to this embodiment. The high-voltage device 1 is an evaluation device for insulation performance at high voltage. The high-voltage device 1 is not limited to the evaluation device, and may be a high-voltage device such as a gas-insulated switchgear. In the high-voltage device 1, a first electrode 12a and a second electrode 12b are fixed to a first conductor 11a and a second conductor 11b, respectively. The first electrode 12a is covered with a first resin molded body 13a. The second electrode 12b is covered with a second resin molded body 13b. That is, a resin molded body is provided on the surface of the electrode. The first resin molded body 13a and the second resin molded body 13b face each other with a distance therebetween. The distance between them is, for example, about 7 mm, but this value is an example and is not limited thereto.

[0014] The first electrode 12a and the second electrode 12b have a cylindrical shape, and one of the two circular surfaces of the cylindrical shape is closed facing the first conductor 11a and the second conductor 11b, and the other is open.

[0015] The first resin molding 13a and the second resin molding 13b have a cylindrical shape with an outer diameter smaller than the inner diameter of the first electrode 12a and the second electrode 12b. A flange is formed on one side of the cylindrical shape, and the opening side end faces of the first electrode 12a and the second electrode 12b are closed by the flange. Note that the first resin molding 13a and the second resin molding 13b are molded using a metal mold, and are prone to sink marks due to hardening shrinkage during molding, resulting in unevenness.

[0016] Here, different potentials are applied to the first electrode 12a and the second electrode 12b, which are a pair of electrodes, and they are insulated from each other. That is, a first potential is applied to the first electrode 12a. A second potential is applied to the second electrode 12b. The first potential and the second potential are different potentials, and a high voltage is generated between them. For example, the first potential is a high potential, and the second potential is a ground potential.

[0017] The installation environment of the high-voltage equipment 1 was a test tube pressurized to 5 atmospheres with dry air (Taiyo Nippon Sanso pure air G3), but is not limited to this.

[0018] (Electric Fields and Flashovers) An electric field is generated between objects where a potential difference occurs, such as the first electrode 12a and the second electrode 12b. It is known that when this electric field exceeds the dielectric strength of something (e.g., resin or air) located between the objects, a dielectric breakdown occurs and a flashover occurs between the objects.

[0019] The surface of an object is burned by the arc generated by the flashover, and the surface condition changes due to the local high temperature. For example, the resin on the surface of an object may melt due to the high temperature of the arc, exposing the filler contained in the resin. In addition, the material deteriorates in the area where the flashover occurred.

[0020] The inventors of the present application have discovered that when the resin surface is uneven due to fillers or the like, the electric field concentrates at those locations, making flashovers more likely to occur at those locations. In addition, the concentration of flashover locations causes significant localized material deterioration at those locations. As a result, the more flashovers occur, the more likely they are to occur. Below, we disclose a method for manufacturing high-voltage equipment that can prevent material deterioration even if flashovers occur.

[0021] (Test Procedure) The second potential of the high-voltage equipment 1 was grounded, and the first potential was variable. The absolute value of the first potential was increased by 10 kV from a negative polarity of 50 kV, and the first flashover when the voltage was applied was counted as the first time. After that, if a flashover occurred the previous time the voltage was applied, the absolute value of the voltage was decreased by 10 kV, and if no flashover occurred the previous time the voltage was applied, the absolute value of the voltage was increased by 10 kV, and the voltage was applied up to 40 times.

[0022] After that, the absolute value of the first potential was increased by 10 kV from 50 kV of positive polarity, and the first flashover was counted as the first time the voltage was applied. After that, if a flashover occurred the previous time the voltage was applied, the absolute value of the voltage was decreased by 10 kV, and if no flashover occurred the previous time the voltage was applied, the absolute value of the voltage was increased by 10 kV, and the voltage was applied up to 40 times.

[0023] In other words, after the first flashover, voltage was applied a total of 80 times. During this time, the voltage change, the presence or absence of flashover, and the value of the electric field were measured.

[0024] (Test piece) The first resin molded body 13a and the second resin molded body 13b were prepared as test pieces in the following three ways, and comparative tests were conducted. The test pieces of the first resin molded body 13a and the second resin molded body 13b used in the comparative tests were three types: a test piece with an untreated surface, a test piece with a roughened surface, and a test piece with a resin coating. The details of these and the manufacturing method will be explained first. Several pieces of each test piece were prepared, and comparative tests were conducted.

[0025] (untreated surface) The test pieces having untreated surfaces were first resin molded body 13a and second resin molded body 13b, which had not been subjected to any treatment.

[0026] The first resin molded body 13a and the second resin molded body 13b may be molded directly on the first electrode 12a and the second electrode 12b. Alternatively, only the first resin molded body 13a and the second resin molded body 13b may be molded separately, and then the first electrode 12a and the second electrode 12b may be fitted into the molded body. In other words, it is only necessary that the first resin molded body 13a and the second resin molded body 13b are provided for the first electrode 12a and the second electrode 12b.

[0027] The first resin molded body 13a and the second resin molded body 13b are insulating materials containing fillers. The insulating material is a mixture of Nagase ChemteX epoxy resin CT200, Nagase ChemteX hardener HT903, Nagase ChemteX colorant DW06, and Fumitec crystalline silica HHH (filler) in a mass ratio of 100:30:2:200. The first resin molded body 13a and the second resin molded body 13b used for surface roughening and resin coating are also similar to the first resin molded body 13a and the second resin molded body 13b.

[0028] As a result, the filler may be exposed on the surfaces of the first resin molded body 13a and the second resin molded body 13b in the surface-untreated test piece. The high-voltage device with the surface-untreated test piece to be evaluated is the high-voltage device 1 shown in FIG.

[0029] (Roughening) The test pieces for roughening are first resin molding 13a and second resin molding 13b, the surfaces of which are roughened in two stages.

[0030] First, the first resin molded body 13a and the second resin molded body 13b are molded in the same process as the surface-untreated test piece. Next, the surfaces of the first resin molded body 13a and the second resin molded body 13b are polished with sandpaper of No. 80. Thereafter, the surfaces of the first resin molded body 13a and the second resin molded body 13b are polished with sandpaper of No. 240. It is to be noted that the polishing may be performed in one step using only No. 240 instead of in two steps. The roughness of the sandpaper is not limited to this value, and any value may be used. That is, in the roughened test piece, the surfaces of the first resin molded body 13a and the second resin molded body 13b are roughened so that the coefficient of variation of the maximum height Rz of the surface of the first resin molded body 13a and the second resin molded body 13b after roughening is lower than the coefficient of variation of the maximum height Rz of the surface before roughening. In particular, the surface is roughened so that the coefficient of variation of the maximum height Rz of the surface is 0.4 or less.

[0031] As a result of the roughening, the irregularities on the surfaces of the first resin mold body 13a and the second resin mold body 13b are roughened almost uniformly. Note that in the roughened test pieces, the filler may be exposed on the surface.

[0032] In the roughened test piece, the surfaces of the first resin molded body 13a and the second resin molded body 13b to be polished are at least the opposing surfaces 14a and 14b where the first resin molded body 13a and the second resin molded body 13b face each other. The inner surfaces 15a and 15b of the cylinders of the first resin molded body 13a and the second resin molded body 13b may be polished. The outer surfaces 16a and 16b of the cylinders of the first resin molded body 13a and the second resin molded body 13b may be polished. In particular, it is particularly useful to polish the connection parts between the opposing surface 14a and the inner surface 15a and the outer surface 16a, and the connection parts between the opposing surface 14b and the inner surface 15b and the outer surface 16b, since electric fields tend to concentrate on these connection parts.

[0033] When polishing the surfaces of the first resin molded body 13a and the second resin molded body 13b, the first electrode 12a and the second electrode 12b may or may not have the first resin molded body 13a and the second resin molded body 13b. The high-voltage device with the roughened test piece to be evaluated is the high-voltage device 1 shown in FIG.

[0034] (Resin coating) For the resin-coated test pieces, at least a portion of the surfaces of the first resin molding 13a and the second resin molding 13b are coated (covered) with a resin that does not contain a filler. The coated layers are referred to as resin insulators 17a and 17b (not shown). Note that the surfaces of the first resin molding 13a and the second resin molding 13b may be roughened before coating in order to remove a release agent that adheres when the first resin molding 13a and the second resin molding 13b are molded.

[0035] First, the first resin molded body 13a and the second resin molded body 13b are made with the same process as the roughened test piece. Next, the resin insulators 17a and 17b are brushed on the surfaces of the first resin molded body 13a and the second resin molded body 13b with a resin that does not contain a filler. That is, in the resin-coated test piece, the surfaces of the resin insulators 17a and 17b are resin-coated so that the coefficient of variation of the maximum height Rz of the surfaces of the resin insulators 17a and 17b after resin coating is lower than the coefficient of variation of the maximum height Rz of the surfaces before resin coating. In particular, the resin is coated so that the coefficient of variation of the maximum height Rz of the surfaces is 0.4 or less.

[0036] In addition, the method is not limited to brush painting, but the first resin molding 13a and the second resin molding 13b may be immersed in a liquid resin bath, and layers of resin insulators 17a and 17b may be adhered to the surfaces of the first resin molding 13a and the second resin molding 13b and then cured.

[0037] Resin insulators 17a and 17b are made by mixing epoxy resin CY230 manufactured by Nagase Chemtex and amine-based hardener ST-12 manufactured by Mitsubishi Chemical in a mass ratio of 2:1.

[0038] In the resin-coated test piece, the surfaces of the first resin molded body 13a and the second resin molded body 13b to be coated are at least the opposing surfaces 14a and 14b where the first resin molded body 13a and the second resin molded body 13b face each other. The inner surfaces 15a and 15b of the cylinders of the first resin molded body 13a and the second resin molded body 13b may be resin-coated. The outer surfaces 16a and 16b of the cylinders of the first resin molded body 13a and the second resin molded body 13b may be resin-coated. In particular, the connection parts between the opposing surface 14a and the inner surface 15a and the outer surface 16a, and the connection parts between the opposing surface 14b and the inner surface 15b and the outer surface 16b are prone to electric field concentration, so it is particularly useful to resin-coat the connection parts.

[0039] When the surfaces of the first resin molded body 13a and the second resin molded body 13b are resin-coated, the first electrode 12a and the second electrode 12b may or may not be provided with the first resin molded body 13a and the second resin molded body 13b. The high-voltage device to be evaluated using the resin-coated test piece is the high-voltage device 2 shown in FIG.

[0040] (Discharge path) The discharge from the first electrode 12a to the second electrode 12b passes over the insulators (the first resin molding 13a, the second resin molding 13b, the resin insulators 17a and 17b, and the gas or air) that are located between the exposed portions of the electrodes and on the path of the flashover. In other words, the discharge passes over a surface (or a curved surface) that extends from one electrode to the other electrode.

[0041] Alternatively, at the location in first resin molding 13a where the electric field is strongest, insulation breaks down instantaneously at that location, and a discharge occurs from there, passing through second resin molding 13b and / or resin insulator 17b and gas or air, and then entering second electrode 12b.

[0042] In this embodiment, the location where the electrodes are exposed is one end face of the cylinder forming first electrode 12a to second electrode 12b that is not covered with first resin molded body 13a and second resin molded body 13b.

[0043] (Test Results) Figure 3 is a graph showing the voltage change when a flashover occurs, and Figure 4 is a graph showing the ratio of the minimum voltage to the maximum voltage when a flashover occurs.

[0044] As shown in Figure 3, in the case of the untreated test piece, the flashover voltage gradually decreases as the flashover is repeated. In other words, the dielectric strength is decreasing. In contrast, the flashover voltage of the roughened test piece and the resin-coated test piece decreases less than that of the untreated test piece. In fact, looking at Figure 4, the flashover voltage of the resin-coated test piece was about 93%, the roughened test piece was about 82%, and the untreated test piece was about 49%.

[0045] (Changes in surface properties) FIG. 5 shows images of the test pieces before and after the test for an untreated surface test piece, a roughened surface test piece, and a resin-coated test piece. Reference numeral 101 shows an image of the untreated surface test piece before the test. Reference numeral 102 shows an image of the flashover location of the untreated surface test piece after the test. Reference numeral 103 shows an image of the untreated surface test piece after the test. Reference numeral 111 shows an image of the roughened surface test piece before the test. Reference numeral 112 shows an image of the flashover location of the roughened surface test piece after the test. Reference numeral 113 shows an image of the untreated surface test piece after the test. Reference numeral 121 shows an image of the resin-coated test piece before the test. Reference numeral 122 shows an image of the flashover location of the resin-coated test piece after the test. Reference numeral 123 shows an image of the untreated surface test piece after the test.

[0046] As shown by reference numeral 101, in the case of the test piece without surface treatment, there are some places where the filler is exposed before the test. Also, unevenness is observed on the surface. It is considered that these unevennesses are caused by unevenness in the flow of the resin due to the use of resin mixed with filler. It is also considered that the unevenness is caused by sink marks due to hardening shrinkage during molding.

[0047] As shown by reference numeral 102, in the case of the test piece without surface treatment, the filler was entirely exposed at the flashover area after the test. This can be said to be because the surface melted due to the arc caused by the flashover, exposing the filler. It is also considered that the flashover was concentrated on the unevenness of the sink marks caused by the hardening shrinkage during molding, exposing the filler at that area.

[0048] As shown by reference numeral 103, after the test of the test piece without surface treatment, no exposed filler or surface irregularities were observed in the non-flashover areas, and it can be seen that the condition is similar to that of reference numeral 101. However, there are some areas where sink marks have occurred due to cure shrinkage during molding.

[0049] As shown by reference numeral 111, in the case of the roughened test piece, it can be seen that the surface has unevenness more uniformly overall than reference numeral 101 before the test.

[0050] As shown by reference numeral 112, after the test of the roughened test piece, it was found that the filler was exposed at the flashover point, which is similar to the state shown by reference numeral 102.

[0051] As shown by reference numeral 113, after the test of the roughened test piece, it can be seen that the non-flashover portion remains uneven in substantially the same manner as that shown by reference numeral 111 before the test.

[0052] As shown by reference numeral 121, the surface of the resin-coated test piece is smooth. This is because the resin does not contain fillers and the resin flows evenly and can be applied with a brush.

[0053] As shown by reference numeral 122, after testing the resin-coated test piece, unevenness was observed at the flashover location compared to reference numeral 121, but less unevenness was observed than in the other cases.

[0054] As shown by reference numeral 123, after the test of the resin-coated test piece, less unevenness was observed in the non-flashover area than in reference numeral 122.

[0055] 5, it can be seen that the unevenness at the flashover location after the test is larger than that before the test. This is because the periphery of the filler contained in the first resin molded body 13a and the second resin molded body 13b has melted, exposing the filler.

[0056] However, for the resin-coated test piece, the irregularities caused by the filler in first resin molding body 13a and second resin molding body 13b are covered by the resin coating, so the surface is essentially smooth and uneven. Therefore, even if resin insulating bodies 17a and 17b melt to some extent, they do not melt until they reach first resin molding body 13a and second resin molding body 13b.

[0057] (Distribution of flashover points) FIG. 6 is a diagram showing the distribution of flashover points in an untreated test piece, a roughened test piece, and a resin-coated test piece. Reference numeral 131 shows the distribution of flashover points in the untreated test piece. Reference numeral 132 shows the distribution of flashover points in the roughened test piece. Reference numeral 133 shows the distribution of flashover points in the resin-coated test piece. In FIG. 6, the points marked with "x" are the flashover points. The flashover points are located on the inner surfaces 15a and 15b of the cylinder.

[0058] As shown in Fig. 6, in the test piece with untreated surface (reference numeral 131), flashovers were found to be concentrated locally. This is believed to be because the electric field was concentrated in the area where the unevenness was large, making the flashover more likely to occur in that area. In addition, the more flashovers occurred, the more the surface properties of that area deteriorated, making the area more likely to experience flashovers.

[0059] It can be seen that the flashover points are more dispersed in the roughened test piece (reference numeral 132) than in the test piece reference numeral 131. This is thought to be because the roughening of the surface has made the surface unevenness uniform overall, and the susceptibility to flashover has become uniform overall.

[0060] It can be seen that the flashover points are more dispersed in the resin-coated test piece (reference number 133) than in the test piece reference number 131. This is thought to be because the resin coating evens out the surface irregularities overall, making the susceptibility to flashover uniform overall.

[0061] (Maximum height Rz) Next, we show the results of measuring the maximum height Rz (JIS B0601-2001), which is an index of surface roughness of each test piece before the test. Figure 7 is a bar graph showing the maximum height Rz of each test piece. The height of each bar graph represents the average value, and the error bars represent the maximum and minimum values.

[0062] As shown in Figure 7, for the untreated test pieces, the average value of maximum height Rz is small due to the flow of the resin, but the variation in the maximum and minimum values ​​is large. In contrast, for the resin-coated test pieces, the average value of maximum height Rz remains roughly the same as for the untreated test pieces, and the variation in the maximum and minimum values ​​has also been reduced. This indicates that because it does not contain filler, the resin flows well and can be applied uniformly.

[0063] In contrast, the maximum height Rz of the roughened test piece is naturally larger than that of the untreated test piece because the surface has been actively roughened. However, the variation in the maximum and minimum values ​​is smaller than that of the untreated test piece.

[0064] Here, if the maximum heights Rz were compared directly, it would be difficult to make a quantitative comparison due to the difference in absolute values, so we calculated the coefficient of variation for the maximum heights Rz. Figure 8 is a bar graph showing the coefficient of variation for the maximum heights Rz of each test piece. The coefficient of variation for the maximum heights Rz was calculated from the maximum heights Rz in at least four locations.

[0065] As shown in Figure 8, the coefficient of variation was small for the roughened and resin-coated surfaces, whereas the coefficient of variation was large for the untreated surface. Here, we investigated the correlation between the coefficient of variation and the flashover conditions.

[0066] Figure 9 is a scatter plot of the standard deviation of the electric field at which a flashover occurs versus the coefficient of variation of the maximum height Rz. As shown in Figure 9, when the coefficient of variation of the maximum height Rz is 0.4 or less, the standard deviation of the electric field at which a flashover occurs is small. In other words, the variation in the electric field when a flashover occurs is small, and the drop in the flashover voltage is small, meaning that the insulation performance is less likely to decrease.

[0067] On the other hand, when the coefficient of variation of the maximum height Rz is larger than 0.4, the standard deviation of the electric field at which the flashover occurs is large. In other words, the electric field varies greatly when the flashover occurs. In other words, the flashover voltage decreases with the number of flashovers, and the insulation performance decreases.

[0068] If the maximum height Rz is 30 μm or more, dust will easily adhere to the surface, and electric field concentration will easily occur.

[0069] (Action and effect) As described above, it was found that the roughened test pieces and the resin-coated test pieces exhibited higher insulating performance and were less susceptible to deterioration of their insulating performance than the untreated test pieces.

[0070] In particular, when roughening the surface, it is sufficient to roughen the surface so that the coefficient of variation of the maximum height Rz is 0.4 or less, and therefore the surface can be roughened based on a numerical index. Therefore, the high-voltage device 1 can be manufactured stably.

[0071] [Modifications] The manufacturers and types of epoxy resins, hardeners, etc. used in the resin moldings 13a and 13b and the resin insulators 17a and 17b are not limited to those given above, and any desired ones may be used. The compounding ratio is also not limited to those given above, and any desired compounding ratio may be selected.

[0072] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0073] 1, 2 High voltage equipment 11a First Conductor 11b Second conductor 12a 1st electrode 12b 2nd electrode 13a First resin molding 13b Second resin molded body 14a, 14b opposing surfaces 15a, 15b inner surface 16a, 16b external surface 17a, 17b Resin insulator

Claims

1. A method for manufacturing a high-voltage device having a pair of electrodes insulated from each other and to which different potentials are applied, comprising the steps of: providing a resin molded body on a surface of the electrode; and covering at least a portion of the surface of the resin molded body with a resin insulating material that does not contain a filler.

2. A method for manufacturing a high-voltage device having a pair of electrodes insulated from each other and to which different potentials are applied, comprising the steps of: providing a resin molded body on a surface of the electrode; and roughening the surface of the resin molded body so that a coefficient of variation of a maximum height Rz of the surface of the resin molded body after roughening is lower than a coefficient of variation of a maximum height Rz of the surface before roughening.

3. The method according to claim 2 , wherein in the surface roughening step, the surface is roughened so that a coefficient of variation of a maximum height Rz of the surface is 0.4 or less.

4. A pair of electrodes insulated from each other to which different potentials are applied; A resin molded body provided on a surface of the electrode; and a resin insulator containing no filler, covering at least a portion of the surface of the resin molded body.

5. A pair of electrodes insulated from each other to which different potentials are applied; A resin molded body provided on a surface of the electrode, The high-voltage device, wherein the coefficient of variation of the maximum height Rz of the surface of the resin molded body is 0.4 or less.

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