Transformer and partial discharge determination method

Abstract

To provide a transformer capable of properly measuring physical quantities for detecting partial discharge and a partial discharge determination method.SOLUTION: The transformer includes a gas-tight enclosure with insulating properties, a coil device, a cooling unit, a fan, and a sensor. The coil device is located inside the enclosure. The cooling unit is located in the enclosure and removes heat from gas. The fan is located between the coil device and the cooling unit and pumps the gas. The sensor is located in a part of the enclosure different from a part where the fan is located and measures physical quantities related to partial discharges produced by the coil device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a transformer and a partial discharge determination method.

Background Art

[0002] As a precursor to the insulation breakdown of electrical equipment, partial discharge may occur from the electrical equipment. A technique is known in which, by utilizing such characteristics and measuring a physical quantity that changes due to partial discharge using a sensor, the insulation breakdown of electrical equipment is predicted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a specific example of electrical equipment, there is a transformer in which a coil is stored in a tank that seals a gas having insulating properties, thereby ensuring insulation between the winding and the tank. For such a transformer, it is desirable to detect partial discharge. The problem to be solved by the present invention is to provide a transformer and a partial discharge determination method capable of appropriately measuring a physical quantity for detecting partial discharge.

Means for Solving the Problems

[0005] The transformer according to the embodiment includes a housing that seals a gas having insulating properties, a coil device, a cooling unit, a fan, and a sensor. The coil device is located inside the housing. The cooling unit is located on the housing and takes heat from the gas. The fan is located between the coil device and the cooling unit and pumps the gas. The sensor is located at a location different from the location of the fan on the housing and measures a physical quantity related to partial discharge generated from the coil device.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

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Figure 4

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Figure 6

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0007] Hereinafter, the transformer and the partial discharge determination method of the embodiments will be described with reference to the drawings. 〈First Embodiment〉 《Configuration of Transformer 10》 Hereinafter, the embodiments will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the transformer 10 according to the first embodiment. FIG. 2 is a cross-sectional view of the transformer 10 according to the first embodiment. The transformer 10 according to the first embodiment is a three-phase three-winding transformer. As shown in Fig. 1, the transformer 10 includes three coil devices 11, a coil tank 13, a heat exchanger 15, a connecting pipe 17, and a sensor 19.

[0008] The three coil devices 11 are housed in the coil tank 13. The coil tank 13 seals the pressurized air. The pressurized air is pressurized at at least 1 atmosphere or more. The coil tank 13 is made of, for example, a steel plate. The heat exchanger 15 extracts heat from the pressurized air filled in the coil tank 13 and releases it into the atmosphere. The connecting pipe 17 connects the coil tank 13 and the heat exchanger 15 and allows the pressurized air to flow through. The sensor 19 measures the TEV (Transient Earth Voltage) of the coil tank 13. Specifically, the sensor 19 detects the surface potential of the coil tank 13 detected through the stray capacitance formed between the coil device 11. When partial discharge occurs in the coil device 11, the ground voltage of the coil tank 13 changes transiently. Therefore, by measuring the TEV with the sensor 19, partial discharge can be detected. That is, TEV is an example of a physical quantity related to partial discharge.

[0009] The pressurized air is sealed by the coil tank 13, the heat exchanger 15, and the connecting pipe 17. That is, the coil tank 13, the heat exchanger 15, and the connecting pipe 17 constitute the housing of the transformer 10.

[0010] 《Configuration of Coil Device 11》 As shown in Fig. 1, the three coil devices 11 are installed side by side in a row in the coil tank 13 respectively. That is, the coil tank 13 is an example of a first housing that houses the coil device 11. The three coil devices 11 correspond to the U phase, V phase, and W phase respectively. Each coil device 11 includes an iron core 111, a coil 112, and a lead wire 113 as shown in Fig. 2.

[0011] The coil 112 has a high-voltage side winding 112a, a low-voltage side winding 112b, a gap portion 112c, and a covering portion 112d. The high-voltage side winding 112a and the low-voltage side winding 112b are wound around the iron core 111. The high-voltage side winding 112a functions as the primary side winding to which high-voltage power is input when the transformer 10 is applied to the power system. The low-voltage side winding 112b functions as the secondary side winding that outputs low-voltage power when the transformer is applied to the power system. The high-voltage side winding 112a is provided outside the low-voltage side winding 112b. The gap portion 112c is formed between the high-voltage side winding 112a and the low-voltage side winding 112b. The coating portion 112d is formed of a highly insulating insulating member such as an epoxy resin. The high-voltage side winding 112a and the low-voltage side winding 112b are coated. The coating portion 112d is formed, for example, by immersing the high-voltage side winding 112a and the low-voltage side winding 112b in an insulating member and curing the insulating member. The lead-out wire 113 includes a high-voltage side lead-out wire 113a drawn from the high-voltage side winding 112a and a low-voltage side lead-out wire 113b drawn from the low-voltage side winding 112b.

[0012] 《Configuration of the coil tank 13》 The coil tank 13 includes legs 131, a bottom plate 132, side walls 133, a cover plate 134, a high-voltage side terminal 135, a low-voltage side terminal 136, an upper clamp 137, a lower clamp 138, and a ground electrode 139.

[0013] The legs 131 support the coil tank 13 from below. The bottom plate 132 is provided on the legs 131. The coil device 11 is installed on the bottom plate 132. The side walls 133 are provided so as to rise upward from the edge of the bottom plate 132. The cover plate 134 is provided so as to cover the upper part of the side walls 133. The bottom plate 132, the side walls 133, and the cover plate 134 are made of steel plates.

[0014] A plurality of reinforcing portions 133a for reinforcing the coil tank 13 in the circumferential direction of the coil tank 13 are provided on the side walls 133. The reinforcing portions 133a are portions that extend in the horizontal direction protruding outward from the side walls 133. That is, the outer surface of the side walls 133 is formed with concave and convex portions extending in one direction by the reinforcing portions 133a. The reinforcing part 133a may be, for example, a channel member (lip groove steel) or a square steel pipe having a C-shaped cross section formed by bending a steel plate. In this case, the lip of the reinforcing part 133a is adhered or welded to the side wall 133. Further, the reinforcing part 133a may be, for example, a convex part generated by bending the side wall 133 into a corrugated shape.

[0015] The high-voltage side terminal 135 and the low-voltage side terminal 136 are provided so as to penetrate the cover plate 134 in the vertical direction. The high-voltage side terminal 135 and the low-voltage side terminal 136 are constituted by, for example, a T-shaped bushing or a direct mold bushing. The inner end of the high-voltage side terminal 135 inside the coil tank 13 is connected to the high-voltage side winding 112a via the high-voltage side lead-out wire 113a. The inner end of the low-voltage side terminal 136 inside the coil tank 13 is connected to the low-voltage side winding 112b via the low-voltage side lead-out wire 113b. The high-voltage side terminal 135 and the low-voltage side terminal 136 are extraction terminals electrically connected to the coil device 11.

[0016] The upper clamp 137 is provided across the three coil devices 11 and is fixed in a state of sandwiching the upper end portions of the cores 111 of the respective coil devices 11. The lower clamp 138 is provided across the three coil devices 11 and is fixed in a state of sandwiching the lower end portions of the cores 111 of the respective coil devices 11. The lower clamp 138 is fixed to the bottom plate 132. The upper clamp 137 and the lower clamp 138 may be constituted by, for example, a channel member (groove steel) or an angle member (angle steel) formed by bending a steel plate. The ground electrode 139 is buried in the ground and is connected to the outer wall (for example, the side wall 133) of the coil tank 13 via a ground wire. Thereby, the bottom plate 132, the side wall 133, and the cover plate 134 of the coil tank 13, and the connection pipe 17 and the heat exchanger 15 connected to the coil tank 13 are grounded.

[0017] 《Configuration of the heat exchanger 15》 The heat exchanger 15 is provided in a direction intersecting the arrangement direction of the coil devices 11 with respect to the coil tank 13. For example, if the arrangement direction of the coil devices 11 is defined as the left - right direction of the coil tank 13, the heat exchanger 15 is provided behind the coil tank 13. The heat exchanger 15 has a heat exchange part composed of, for example, a plurality of tubes through which pressurized air passes and fins that increase the surface area with the atmosphere. That is, the heat exchanger 15 is an example of the second housing having a cooling part (heat exchange part). The connection pipe 17 has an upper connection pipe 171 that connects the upper part of the heat exchanger 15 and the upper part of the coil tank 13, and a lower connection pipe 172 that connects the lower part of the heat exchanger 15 and the lower part of the coil tank 13. The upper connection pipe 171 allows the pressurized air heated by the coil device 11 to flow into the heat exchanger 15. The lower connection pipe 172 allows the pressurized air cooled by the heat exchanger 15 to flow into the coil tank 13. A fan 172a for pumping the pressurized air from the heat exchanger 15 to the coil tank 13 is provided in the lower connection pipe 172. The fan 172a does not necessarily have to be a blower, and it may be a blower or the like with a high pressure ratio. Also, in other embodiments, a fan for pumping the pressurized air from the coil tank 13 to the heat exchanger 15 may be provided in the upper connection pipe 171.

[0018] 《Arrangement of Sensor 19》 The sensor 19 is attached to the outer surface of the side wall 133 of the coil tank 13. Specifically, the sensor 19 is attached to a surface of the side wall 133 that is on the opposite side of the surface facing the heat exchanger 15 and that faces the central coil device 11 among the three coil devices 11 arranged side by side. That is, the sensor 19 is provided on the front surface of the coil tank 13. Also, the sensor 19 is attached to a concave plane without the reinforcing part 133a, avoiding the reinforcing part 133a of the side wall 133. In the first embodiment, the position on the side wall 133 that faces the central coil device 11 among the three coil devices 11 is the location where the distance from the outer peripheral surface of the coil device 11 is the shortest.

[0019] That is, the sensor 19 according to the first embodiment is attached at a position different from the lower connecting pipe 172 provided with the fan 172a. Thereby, it is possible to prevent noise generated by driving the fan 172a from being mixed into the measured value of the sensor 19. Also, the sensor 19 is attached while avoiding the reinforcing portion 133a, the high-voltage side terminal 135, and the low-voltage side terminal 136. Thereby, the distance between the sensor 19 and the coil device 11 can be shortened. The shorter the distance between the sensor 19 and the coil device 11, the more sensitively the sensor 19 can detect the TEV emitted from the coil device 11.

[0020] 《Method for Detecting Partial Discharge of Transformer 10》 The presence or absence of partial discharge of the transformer 10 according to the first embodiment is determined by an inspection device 30 provided outside the transformer 10. The inspection device 30 is a computer such as a PC (Personal Computer). The inspection device 30 includes an arithmetic unit 31 and a display 32.

[0021] FIG. 3 is a schematic block diagram showing the configuration of the inspection device 30 according to the first embodiment. The inspection device 30 includes an acquisition unit 311, a determination unit 312, and an output unit 313. The acquisition unit 311 acquires a measured value from the sensor 19. The determination unit 312 determines the presence or absence of the occurrence of partial discharge based on the measured value acquired by the acquisition unit 311. The output unit 313 outputs the determination result by the determination unit 312 to the display 32.

[0022] The determination unit 312 detects partial discharge by, for example, the following method. The determination unit 312 extracts a voltage waveform related to a predetermined center frequency from the measured values acquired by the acquisition unit 311 from the sensor 19. The center frequency is determined, for example, by measuring the frequency related to the TEV of the coil device 11 through experiments or the like. The determination unit 312 observes the extracted waveform and determines the presence or absence of partial discharge. The presence or absence of partial discharge is determined, for example, by the duration of the state where the magnitude of the voltage waveform exceeds a predetermined threshold value, the frequency at which the voltage exceeds the threshold value, and the like. The threshold value is determined, for example, by measuring the TEV value of the one farthest from the sensor 19 among the three coil devices 11 through experiments or the like. Since partial discharge often appears as intermittent discharge, the determination unit 312 determines that partial discharge has occurred, for example, when the number of times the voltage exceeds a predetermined threshold value exceeds a predetermined number of times.

[0023] Note that the determination unit 312 may detect partial discharge by, for example, the following method. The acquisition unit 311 further acquires the measured values by a sensor (not shown) connected to the ground electrode 139, and the determination unit 312 calculates the difference between the measured value related to the ground electrode 139 and the measured value of the sensor 19. The determination unit 312 observes the current waveform related to the difference and determines the presence or absence of pulse current. When the noise superimposed on the measured value by the sensor is strong, the determination unit 312 can cancel the noise by taking the difference between the measured value at the location where there may be partial discharge and the measured value at the location where there is no partial discharge.

[0024] That is, the inspector who inspects the partial discharge of the transformer 10 attaches the sensor 19 at a position facing the central coil device 11 among the three coil devices 11 arranged side by side on the surface of the side wall 133 of the coil tank 13 opposite to the surface facing the heat exchanger 15. Then, the sensor 19 and the inspection device 30 are connected, and the inspection device 30 is made to execute a partial discharge inspection program. Thereby, the inspection device 30 determines the presence or absence of partial discharge of the coil device 11 based on the measured value of the sensor 19. The inspection device 30 outputs the determination result to the display 32.

[0025] 《Function and Effect》 As described above, the sensor 19 of the transformer 10 according to the first embodiment is attached to a position different from the position where the fan 172a is disposed in the coil tank 13. Thereby, the transformer 10 can prevent noise caused by driving of the fan 172a from being superimposed on the measurement value of the sensor 19. Therefore, the inspection apparatus 30 according to the first embodiment can accurately determine the presence or absence of partial discharge based on the measurement value of the sensor 19.

[0026] Further, the sensor 19 of the transformer 10 according to the first embodiment is attached to a surface of the coil tank 13 that does not face the heat exchanger 15. Since the space between the heat exchanger 15 and the coil tank 13 is narrow, the sensor 19 is attached to a surface of the coil tank 13 that does not face the heat exchanger 15, so that an inspector can easily access the sensor 19.

[0027] Also, the sensor 19 according to the first embodiment is attached to a position facing the central coil device 11 among the three coil devices 11. Thereby, the TEV of the three coil devices 11 can be detected by one sensor 19. In other embodiments, when the number of coil devices 11 is even, the sensor 19 may be attached to a location corresponding to between the two central coil devices 11.

[0028] <Second Embodiment> FIG. 4 is a perspective view showing the configuration of the transformer 10 according to the second embodiment. The sensor 19 according to the first embodiment is attached to the front surface of the coil tank 13. In contrast, the sensor 19 according to the second embodiment is attached to the cover plate 134 of the coil tank 13.

[0029] <<Arrangement of Sensor 19>> The configuration of the transformer 10 according to the second embodiment is different from that of the first embodiment only in the attachment position of the sensor 19. The sensor 19 according to the second embodiment is attached to a position on the cover plate 134 of the coil tank 13 that faces the central coil device 11 among the three coil devices 11 arranged side by side. Further, the sensor 19 is attached to a plane without terminals, avoiding the high-voltage side terminal 135 and the low-voltage side terminal 136 of the cover plate 134. As a result, the distance between the sensor 19 and the coil device 11 is shortened, and the sensor 19 can measure the TEV of the coil device 11 with high sensitivity.

[0030] <Third Embodiment> FIG. 5 is a perspective view showing the configuration of the transformer 10 according to the third embodiment. The transformer 10 according to the first embodiment detects the TEV generated from any one of the three coil devices 11 by one sensor 19. In contrast, the transformer 10 according to the second embodiment detects the TEV by two sensors 19 to identify which coil device 11 the inspection device 30 has partial discharge occurring in.

[0031] <<Arrangement of Sensor 19>> The transformer 10 according to the third embodiment includes a first sensor 19a and a second sensor 19b instead of the sensor 19. The first sensor 19a is attached to a position on the surface of the side wall 133 opposite to the surface facing the heat exchanger 15, and faces the coil device 11 located at the end on the first side in the arrangement direction among the three coil devices 11 arranged side by side. For example, the first sensor 19a is attached to a position facing the coil device 11 located on the leftmost side. The second sensor 19b is attached to a position on the surface of the side wall 133 opposite to the surface facing the heat exchanger 15, and faces the coil device 11 located at the end on the second side in the arrangement direction among the three coil devices 11 arranged side by side. For example, the second sensor 19b is attached to a position facing the coil device 11 located on the rightmost side. The first sensor 19a and the second sensor 19b are attached to the recessed plane without the reinforcing portion 133a, avoiding the reinforcing portion 133a of the side wall 133.

[0032] 《Configuration of the Inspection Device 30》 FIG. 6 is a schematic block diagram showing the configuration of the inspection device 30 according to the third embodiment. The inspection device 30 according to the third embodiment further includes a specifying unit 314 in addition to the configuration of the first embodiment. The acquisition unit 311 is connected to the first sensor 19a and the second sensor 19b by wire or wirelessly, and acquires measurement values from the first sensor 19a and the second sensor 19b respectively. The determination unit 312 determines the presence or absence of partial discharge based on the measurement values of the first sensor 19a and the second sensor 19b respectively. The specifying unit 314 specifies which of the three coil devices 11 has a partial discharge based on the measurement values of the first sensor 19a and the second sensor 19b respectively. The output unit 313 outputs the determination results by the determination unit 312 and the specifying unit 314 to the display 32.

[0033] 《Method for Detecting Partial Discharge of the Transformer 10》 The inspection device 30 according to the third embodiment detects partial discharge by, for example, the following method. FIG. 7 is a flowchart showing a method for determining partial discharge by the inspection device 30 according to the third embodiment. The determination unit 312 of the inspection device 30 determines the presence or absence of partial discharge for each of the first sensor 19a and the second sensor 19b by the same method as in the first embodiment (step S1). When the determination unit 312 determines that no partial discharge has occurred for the measurement values of both the first sensor 19a and the second sensor 19b (step S1: NO), the output unit 313 outputs a determination result indicating that no partial discharge has occurred in the transformer 10 (step S2).

[0034] On the other hand, when the determination unit 312 determines that partial discharge has occurred in at least one of the measured values of the first sensor 19a and the second sensor 19b (step S1: YES), the specifying unit 314 determines whether the difference between the TEV measured by the first sensor 19a and the TEV measured by the second sensor 19b is equal to or greater than a predetermined value (step S3). When the difference between the TEV measured by the first sensor 19a and the TEV measured by the second sensor 19b is less than the predetermined value (step S3: NO), the output unit 313 outputs a determination result indicating that partial discharge has occurred in the one installed in the center among the three coil devices 11 (step S4).

[0035] When the difference between the TEV measured by the first sensor 19a and the TEV measured by the second sensor 19b is equal to or greater than the predetermined value (step S3: NO), the specifying unit 314 determines whether the TEV measured by the first sensor 19a is greater than the TEV measured by the second sensor 19b (step S5). When the TEV measured by the first sensor 19a is greater than the TEV measured by the second sensor 19b (step S5: YES), the output unit 313 outputs a determination result indicating that partial discharge has occurred in the one of the three coil devices 11 that faces the first sensor 19a, that is, the coil device 11 located on the leftmost side (step S6). On the other hand, when the TEV measured by the first sensor 19a is less than the TEV measured by the second sensor 19b (step S5: NO), the output unit 313 outputs a determination result indicating that partial discharge has occurred in the one of the three coil devices 11 that faces the second sensor 19b, that is, the coil device 11 located on the rightmost side (step S7).

[0036] As described above, according to the third embodiment, the inspection device 30 can specify which of the three coil devices 11 partial discharge has occurred in by the first sensor 19a and the second sensor 19b.

[0037] <Fourth Embodiment> FIG. 8 is a perspective view showing the configuration of the transformer 10 according to the fourth embodiment. The first sensor 19a and the second sensor 19b according to the third embodiment are attached to the front surface of the coil tank 13. In contrast, the first sensor 19a and the second sensor 19b according to the fourth embodiment are attached to the side surface of the coil tank 13.

[0038] 《Arrangement of Sensor 19》 The configuration of the transformer 10 according to the fourth embodiment is different from that of the third embodiment only in the attachment positions of the first sensor 19a and the second sensor 19b. The first sensor 19a according to the fourth embodiment is attached to a position facing the coil device 11 located at the end on the first side in the arrangement direction of the coil device 11 among the side walls 133 on the first side in the arrangement direction. For example, the first sensor 19a is attached to a position facing the coil device 11 located at the leftmost side among the left side surfaces of the coil tank 13. The second sensor 19b according to the fourth embodiment is attached to a position facing the coil device 11 located at the end on the second side in the arrangement direction of the coil device 11 among the side walls 133 on the second side in the arrangement direction. For example, the first sensor 19a is attached to a position facing the coil device 11 located at the rightmost side among the right side surfaces of the coil tank 13. The first sensor 19a and the second sensor 19b are attached to the recessed plane without the reinforcing portion 133a, avoiding the reinforcing portion 133a of the side wall 133.

[0039] 〈Fifth Embodiment〉 FIG. 9 is a perspective view showing the configuration of the transformer 10 according to the fifth embodiment. The first sensor 19a and the second sensor 19b according to the third embodiment are attached to the front surface of the coil tank 13. In contrast, the first sensor 19a and the second sensor 19b according to the fifth embodiment are attached to the back surface of the coil tank 13.

[0040] 《Arrangement of Sensor 19》 The configuration of the transformer 10 according to the fifth embodiment is different from that of the third embodiment only in the attachment positions of the first sensor 19a and the second sensor 19b. The first sensor 19a according to the fifth embodiment is attached to a position on the surface of the side wall 133 facing the heat exchanger 15 and opposite to the coil device 11 located at the end on the first side in the arrangement direction among the three coil devices 11 provided side by side. For example, the first sensor 19a is attached to a position opposite to the coil device 11 located on the leftmost side. The second sensor 19b according to the fifth embodiment is attached to a position on the surface of the side wall 133 facing the heat exchanger 15 and opposite to the coil device 11 located at the end on the second side in the arrangement direction among the three coil devices 11 provided side by side. For example, the second sensor 19b is attached to a position opposite to the coil device 11 located on the rightmost side. The first sensor 19a and the second sensor 19b are attached to the recessed plane without the reinforcing portion 133a, avoiding the reinforcing portion 133a of the side wall 133. Further, the first sensor 19a and the second sensor 19b are attached to positions different from the position where the lower connecting pipe 172 having the fan 172a is arranged. Thereby, it is possible to prevent noise generated by driving the fan 172a from being mixed into the measured values of the sensor 19.

[0041] 〈Sixth Embodiment〉 FIG. 10 is a perspective view showing the configuration of the transformer 10 according to the sixth embodiment. The first sensor 19a and the second sensor 19b according to the third embodiment are attached to the front surface of the coil tank 13. On the other hand, the first sensor 19a and the second sensor 19b according to the sixth embodiment are attached to the bottom surface of the coil tank 13.

[0042] 《Arrangement of Sensor 19》 The configuration of the transformer 10 according to the sixth embodiment is different only in the attachment positions of the first sensor 19a and the second sensor 19b from the third embodiment. The first sensor 19a according to the sixth embodiment is attached to a position outside the position opposite to the coil device 11 located at the end on the first side in the arrangement direction of the side wall 133. For example, the first sensor 19a is attached further to the left of the position opposite to the coil device 11 located on the leftmost side. The second sensor 19b according to the sixth embodiment is attached outside the position facing the coil device 11 located at the end on the second side in the arrangement direction among the side walls 133. For example, the second sensor 19b is attached further to the right of the position facing the coil device 11 located on the rightmost side.

[0043] The first sensor 19a and the second sensor 19b of the transformer 10 according to the sixth embodiment are attached to the bottom surface of the coil tank 13. Since the height of the bottom surface of the coil tank 13 is low, by attaching the first sensor 19a and the second sensor 19b to the surface of the coil tank 13 that does not face the heat exchanger 15, an inspector can easily access the first sensor 19a and the second sensor 19b.

[0044] <Seventh Embodiment> FIG. 11 is a perspective view showing the configuration of the transformer 10 according to the seventh embodiment. The heat exchanger 15 according to the first embodiment is provided behind the coil tank 13. In contrast, the heat exchanger 15 according to the seventh embodiment is provided on the coil tank 13. That is, in the seventh embodiment, the heat exchanger 15 and the coil device 11 are provided at positions with different heights from each other.

[0045] <<Arrangement of Sensor 19>> The sensor 19 is attached to the surface of the side wall 133 that is opposite to the surface facing the heat exchanger 15 and at a position facing the central coil device 11 among the three coil devices 11 arranged side by side. Also, the sensor 19 is attached to the concave plane without the reinforcing portion 133a, avoiding the reinforcing portion 133a of the side wall 133.

[0046] <Eighth Embodiment> FIG. 12 is a perspective view showing the configuration of the transformer 10 according to the eighth embodiment. The inspection device 30 according to the first embodiment is provided separately from the transformer 10. In contrast, in the transformer 10 according to the eighth embodiment, the control device 21 provided in the transformer 10 functions as an inspection device.

[0047] For example, in the example shown in FIG. 12, the control device 21 is provided on the cover plate 134 of the transformer 10. While controlling the behavior of the transformer 10, the control device 21 periodically detects partial discharge based on the measured values of the sensor 19.

[0048] <Other Embodiments> As described above, several embodiments have been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like are possible. That is, in other embodiments, the order of the above-described processes may be appropriately changed. Also, some processes may be executed in parallel. The inspection device 30 according to the above-described embodiment may be configured by a single computer, or the configuration of the inspection device 30 may be divided and arranged among a plurality of computers, and the plurality of computers may function as the inspection device 30 by cooperating with each other. At this time, some of the computers constituting the inspection device 30 may be mounted on the transformer 10, and other computers may be provided outside the transformer 10.

[0049] The sensor 19 according to the above-described embodiment measures the TEV of the coil device 11, but is not limited thereto. For example, the sensor 19 according to other embodiments may be any sensor that can measure current, electromagnetic waves, sound waves, or vibrations resulting from partial discharge in the coil device 11.

[0050] The transformer 10 according to the above-described embodiment includes three coil devices 11, but is not limited thereto. For example, the transformer 10 according to other embodiments may include two or fewer coil devices 11, or may include four or more coil devices 11.

[0051] In the above-described embodiment, the heat exchanger 15 using a radiator is provided as the cooling unit, but is not limited thereto. For example, the cooling unit according to other embodiments may cool pressurized air by a heat pump.

[0052] In the above-described embodiments, the transformer 10 seals the pressurized air, but it is not limited thereto. For example, in other embodiments, the transformer 10 may seal other insulating gases such as SF6 gas. Further, in other embodiments, the coil 112 does not necessarily have to be molded.

[0053] In the above-described embodiments, the housing of the transformer 10 is composed of the coil tank 13, the heat exchanger 15, and the connecting pipe 17, but it is not limited thereto. For example, the transformer 10 according to other embodiments may have a housing in which the coil tank 13 and the heat exchanger 15 are integrated.

[0054] 〈Computer Configuration〉 The inspection device 30 and the control device 21 include a processor, a memory, an auxiliary storage device, etc. connected by a bus, and function as a device including an acquisition unit 311, a determination unit 312, and an output unit 313 by executing a partial discharge detection program. Examples of the processor include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), a microprocessor, etc. The partial discharge detection program may be recorded on a computer-readable recording medium. A computer-readable recording medium is, for example, a storage device such as a magnetic disk, a magneto-optical disk, an optical disk, a semiconductor memory, etc. The partial discharge detection program may be transmitted via a telecommunication line. Note that all or part of each function of the inspection device 30 or the control device 21 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 PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). Such integrated circuits are also included as an example of a processor.

[0055] According to at least one embodiment described above, the transformer 10 has a sensor for measuring a physical quantity related to partial discharge at a location different from the location where the fan 172a is disposed in the housing, so that the physical quantity for detecting partial discharge can be appropriately measured. Although some embodiments of the present invention have been described, these embodiments are presented by way of example 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, as well as in the invention described in the claims and its equivalent scope.

Description of Reference Numerals

[0056] 10... transformer, 11... coil device, 13... coil tank, 15... heat exchanger, 17... connecting pipe, 171... upper connecting pipe, 172... lower connecting pipe, 172a... fan, 19... sensor, 30... inspection device, 311... acquisition unit, 312... determination unit, 313... output unit, 314... specifying unit

Claims

1. A housing that seals a gas having insulating properties, a coil device located within the housing, a cooling unit located on the housing that extracts heat from the gas, a fan that pumps the gas and circulates the gas between the coil device and the cooling unit, and a sensor located at a location different from the location where the fan is located on the housing that measures the transient ground voltage of the housing and includes: The housing includes a first housing that houses the coil device, a second housing that has the cooling unit, and a connecting pipe that connects the first housing and the second housing, the fan is located within the connecting pipe, and the sensor is located at a location different from the location where the connecting pipe is disposed on a surface of the first housing that faces the second housing. Transformer.

2. A housing that seals a gas having insulating properties, a coil device located within the housing, a cooling unit located on the housing that extracts heat from the gas, a fan that pumps the gas and circulates the gas between the coil device and the cooling unit, and a sensor located at a location different from the location where the fan is located on the housing that measures the transient ground voltage of the housing, and includes: the cooling unit and the coil device are located at locations having different heights from each other, and the sensor is located on a surface of the housing that faces the coil device. Transformer.

3. A housing that seals a gas having insulating properties, a coil device located within the housing, a cooling unit located on the housing that extracts heat from the gas, a fan that pumps the gas and circulates the gas between the coil device and the cooling unit, and a sensor located at a location different from the location where the fan is located on the housing that measures the transient ground voltage of the housing and includes: the housing includes a plurality of coil devices arranged in one direction within the housing including the coil device, and the sensor is located on a surface of the housing that faces the central portion of the plurality of coil devices. Transformer.

4. A housing that seals a gas having insulating properties, a coil device located within the housing, a cooling unit located on the housing that extracts heat from the gas, a fan that pumps the gas and circulates the gas between the coil device and the cooling unit, and a sensor located at a location different from the location where the fan is located on the housing that measures the transient ground voltage of the housing, and the housing includes a plurality of coil devices arranged in one direction within the housing including the coil device, and includes: The sensor includes a first sensor and a second sensor that measure the transient ground voltage. The first sensor is located on a surface of the housing that faces a surface provided at the first end in the one direction among the plurality of coil devices. The second sensor is located on a surface of the housing that faces a surface provided at the second end in the one direction among the plurality of coil devices. Transformer.

5. The first sensor is located on the surface of the first end side of the housing. The second sensor is located on the surface of the second end side of the housing. The transformer according to claim 4.

6. A housing that seals a gas having insulating properties, A coil device located inside the housing, A cooling unit located on the housing that takes heat from the gas, A fan that pumps the gas and circulates the gas between the coil device and the cooling unit, A sensor that is located at a location different from the location where the fan is located on the housing and measures the transient ground voltage of the housing and includes. The sensor is located at a location on the surface of the housing where the distance from the outer peripheral surface of the coil device is the shortest. Transformer.

7. A housing that seals a gas having insulating properties, A coil device located inside the housing, A cooling unit located on the housing that takes heat from the gas, A fan that pumps the gas and circulates the gas between the coil device and the cooling unit, A sensor that is located at a location different from the location where the fan is located on the housing and measures the transient ground voltage of the housing and includes. The outer surface of the housing has a concave portion and a convex portion extending in one direction. The sensor is located in the concave portion. Transformer.

8. An extraction terminal electrically connected to the coil device is located on the outer surface of the housing. The sensor is located at a location different from the location where the extraction terminal is arranged. The transformer according to any one of claims 1 to 7.

9. A housing that seals a gas having insulating properties, A coil device located inside the housing, A cooling unit located on the housing that takes heat from the gas, A fan that pumps the gas and circulates the gas between the coil device and the cooling unit, A sensor that is located at a location different from the location where the fan is located on the housing and measures the transient ground voltage of the housing and includes. The sensor is a transformer located on the lower surface of the housing and not facing the coil device.

10. The housing seals the gas at 1 atm or more. The surface of the coil device is covered with an insulating member. The transformer according to any one of claims 1 to 9.

11. The sensor is located on the outer surface of the housing The transformer according to any one of claims 1 to 10.

12. Comprising a determination unit that determines the presence or absence of partial discharge in the coil device based on the measured value of the sensor The transformer according to any one of claims 1 to 11.

13. Comprising an identification unit that identifies the coil device in which partial discharge is occurring among the plurality of coil devices based on the measured value of the first sensor and the measured value of the second sensor The transformer according to claim 4 or claim 5.

14. A step of attaching a sensor for measuring the transient ground voltage of the housing to a surface of the housing that faces the coil device, at a location different from the location where the fan is located, in the housing of a transformer comprising a housing that seals a gas having insulating properties, a coil device located in the housing, a cooling unit located at a location having a different height from the coil device in the housing and taking heat from the gas, and a fan that pumps the gas and circulates the gas between the coil device and the cooling unit; A step of determining the presence or absence of partial discharge in the coil device based on the measured value of the sensor And a partial discharge determination method having the above.

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