JP7852126B2 - Transformer and method for determining partial discharge - Google Patents

Description

Embodiments of the present invention relate to a transformer and a method for determining partial discharge.

Partial discharge can occur in power equipment as a precursor to dielectric breakdown. A technique is known that utilizes this characteristic to predict dielectric breakdown by measuring the physical quantities that change due to partial discharge using sensors.

Patent No. 6588781

One specific example of power equipment is a transformer in which the coil is housed in a tank sealed with an insulating gas, thereby ensuring insulation between the winding and the tank. For such transformers, it is desirable to detect partial discharge.
The problem that this invention aims to solve is to provide a transformer and a method for determining partial discharge that can appropriately measure the physical quantities necessary for detecting partial discharge.

The transformer of this embodiment comprises a housing that seals an insulating gas, a coil device, a cooling unit, a fan, and a sensor. The coil device is located within the housing. The cooling unit is located within the housing and removes heat from the gas. The fan is located between the coil device and the cooling unit and pumps the gas. The sensor is located within the housing at a location different from where the fan is situated and measures physical quantities related to the partial discharge generated by the coil device.

This is a perspective view showing the configuration of a transformer according to the first embodiment. This is a cross-sectional view of a transformer according to the first embodiment. This is a schematic block diagram showing the configuration of the inspection apparatus according to the first embodiment. This is a perspective view showing the configuration of a transformer according to the second embodiment. This is a perspective view showing the configuration of a transformer according to the third embodiment. This is a schematic block diagram showing the configuration of the inspection device according to the third embodiment. This is a flowchart showing a method for determining partial discharge using an inspection device according to the third embodiment. This is a perspective view showing the configuration of a transformer according to the fourth embodiment. This is a perspective view showing the configuration of a transformer according to the fifth embodiment. This is a perspective view showing the configuration of a transformer according to the sixth embodiment. This is a perspective view showing the configuration of a transformer according to the seventh embodiment. This is a perspective view showing the configuration of a transformer according to the eighth embodiment.

The transformer and partial discharge determination method of the embodiment will be described below with reference to the drawings.
<First Embodiment>
Configuration of transformer 10
The embodiments will be described in detail below with reference to the drawings.
Figure 1 is a perspective view showing the configuration of the transformer 10 according to the first embodiment. Figure 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 Figure 1, the transformer 10 comprises three coil devices 11, a coil tank 13, a heat exchanger 15, connecting pipes 17, and a sensor 19.

The three coil devices 11 are housed within the coil tank 13. The coil tank 13 seals in pressurized air. The pressurized air is pressurized to at least 1 atmosphere. The coil tank 13 is constructed, for example, from steel plate. The heat exchanger 15 removes heat from the pressurized air filling the coil tank 13 and releases it into the atmosphere. The connecting pipe 17 connects the coil tank 13 and the heat exchanger 15, allowing the pressurized air to circulate. 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, which is detected via the stray capacitance formed between it and the coil devices 11. When a partial discharge occurs in the coil devices 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. In other words, TEV is an example of a physical quantity related to partial discharge.

The pressurized air is sealed by the coil tank 13, the heat exchanger 15, and the connecting pipe 17. In other words, the coil tank 13, the heat exchanger 15, and the connecting pipe 17 constitute the housing of the transformer 10.

Configuration of the coil device 11
As shown in Figure 1, the three coil devices 11 are installed in a row within the coil tank 13. That is, the coil tank 13 is an example of a first housing that accommodates the coil devices 11. The three coil devices 11 correspond to the U phase, V phase, and W phase, respectively. As shown in Figure 2, each coil device 11 comprises an iron core 111, a coil 112, and lead wires 113.

The coil 112 has a high-voltage side winding 112a, a low-voltage side winding 112b, an air gap 112c, and a covering portion 112d.
The high-voltage side winding 112a and the low-voltage side winding 112b are formed by winding them 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 a power system. The low-voltage side winding 112b functions as the secondary side winding to which low-voltage power is output when the transformer is applied to a power system. The high-voltage side winding 112a is provided on the outside of the low-voltage side winding 112b.
The gap 112c is formed between the high-voltage side winding 112a and the low-voltage side winding 112b. The covering portion 112d is made of a highly insulating material such as epoxy resin. It covers the high-voltage side winding 112a and the low-voltage side winding 112b. The covering portion 112d is formed, for example, by immersing the high-voltage side winding 112a and the low-voltage side winding 112b in the insulating material and curing the insulating material.
The lead wire 113 includes a high-voltage side lead wire 113a drawn from the high-voltage side winding 112a and a low-voltage side lead wire 113b drawn from the low-voltage side winding 112b.

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

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

The side wall 133 is provided with a plurality of reinforcing portions 133a in the circumferential direction of the coil tank 13 to reinforce the coil tank 13. The reinforcing portions 133a are horizontally extending portions that protrude outward from the side wall 133. In other words, the outer surface of the side wall 133 is formed by the reinforcing portions 133a, creating recesses and protrusions that extend in one direction.
The reinforcing portion 133a may be, for example, a channel member with a C-shaped cross-section (lip channel steel) formed by bending a steel plate, or a rectangular steel pipe. In this case, the lip of the reinforcing portion 133a is bonded or welded to the side wall 133. Alternatively, the reinforcing portion 133a may be a protrusion created by bending the side wall 133 into a corrugated shape.

The high-voltage terminal 135 and low-voltage terminal 136 are provided, penetrating the cover plate 134 in the vertical direction. The high-voltage terminal 135 and low-voltage terminal 136 are constructed, for example, by T-type bushings or direct-molded bushings. The inner end of the high-voltage terminal 135 in the coil tank 13 is connected to the high-voltage winding 112a via the high-voltage lead wire 113a. The inner end of the low-voltage terminal 136 in the coil tank 13 is connected to the low-voltage winding 112b via the low-voltage lead wire 113b. The high-voltage terminal 135 and low-voltage terminal 136 are output terminals electrically connected to the coil device 11.

The upper clamp 137 is provided across the three coil devices 11 and is fixed in place by clamping the upper end of the iron core 111 of each coil device 11.
The lower clamp 138 is provided across the three coil devices 11 and is fixed in place by clamping the lower end of the iron core 111 of each coil device 11. The lower clamp 138 is fixed to the bottom plate 132.
The upper clamp 137 and the lower clamp 138 may be made of, for example, channel members (channel steel) or angle members (angle steel) formed by bending steel plates.
The grounding electrode 139 is buried in the ground and connected to the outer wall (for example, the side wall 133) of the coil tank 13 via a grounding wire. This grounds the bottom plate 132, side walls 133 and lid plate 134 of the coil tank 13, as well as the connecting pipe 17 and heat exchanger 15 connected to the coil tank 13.

Configuration of the heat exchanger 15
The heat exchanger 15 is installed in a direction that intersects the direction in which the coil devices 11 are arranged relative to the coil tank 13. For example, if the direction in which the coil devices 11 are arranged is defined as the left-right direction of the coil tank 13, the heat exchanger 15 is installed behind the coil tank 13. The heat exchanger 15 has a heat exchange section consisting 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 a second housing having a cooling section (heat exchange section). The connecting pipe 17 has an upper connecting pipe 171 that connects the upper part of the heat exchanger 15 to the upper part of the coil tank 13, and a lower connecting pipe 172 that connects the lower part of the heat exchanger 15 to the lower part of the coil tank 13. The upper connecting pipe 171 allows pressurized air heated by the coil devices 11 to flow through to the heat exchanger 15. The lower connecting pipe 172 allows pressurized air cooled by the heat exchanger 15 to flow through to the coil tank 13. A fan 172a is provided in the lower connecting pipe 172 to pump pressurized air from the heat exchanger 15 to the coil tank 13. The fan 172a does not necessarily have to be a blower; it may be a blower with a high pressure ratio or the like. In another embodiment, a fan for pumping pressurized air from the coil tank 13 to the heat exchanger 15 may be provided in the upper connecting pipe 171.

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 mounted on the side wall 133 on the side opposite to the side facing the heat exchanger 15, and at a position facing the central coil device 11 of the three coil devices 11 arranged side by side. In other words, the sensor 19 is mounted on the front surface of the coil tank 13. Furthermore, the sensor 19 is mounted on a recessed surface without the reinforcing portion 133a of the side wall 133, avoiding the reinforcing portion 133a. In the first embodiment, the position on the side wall 133 facing the central coil device 11 of the three coil devices 11 is the point with the shortest distance from the outer surface of the coil device 11.

In other words, the sensor 19 according to the first embodiment is mounted at a different position from the lower connecting pipe 172 on which the fan 172a is provided. This prevents noise generated by the operation of the fan 172a from being mixed into the measurement values of the sensor 19.
Furthermore, the sensor 19 is mounted so as to avoid the reinforcing portion 133a, the high-voltage terminal 135, and the low-voltage terminal 136. This allows the distance between the sensor 19 and the coil device 11 to 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.

Method for detecting partial discharge of transformer 10
The presence or absence of partial discharge in 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 comprises an arithmetic unit 31 and a display 32.

Figure 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 measured values from the sensor 19.
The determination unit 312 determines whether or not a partial discharge has occurred based on the measured values acquired by the acquisition unit 311.
The output unit 313 outputs the determination result from the determination unit 312 to the display 32.

The determination unit 312 detects partial discharge, for example, by the following method.
The determination unit 312 extracts a voltage waveform related to a predetermined center frequency from the measurement values acquired by the acquisition unit 311 from the sensor 19. The center frequency is determined by measuring the frequency related to the TEV of the coil device 11 through experiments, etc. The determination unit 312 observes the extracted waveform and determines whether or not a partial discharge has occurred. Whether or not a partial discharge has occurred is determined, for example, by the duration of the state in which the magnitude of the voltage waveform exceeds a predetermined threshold, the frequency with which the voltage exceeds the threshold, etc. The threshold is determined by measuring the TEV value of the coil device 11 furthest from the sensor 19 through experiments, etc. Since partial discharge often appears as intermittent discharge, the determination unit 312 determines that a partial discharge has occurred, for example, when the number of times the voltage exceeds a predetermined threshold exceeds a predetermined number of times.

Furthermore, the determination unit 312 may detect partial discharge using, for example, the following method. The acquisition unit 311 further acquires measurement values from a sensor (not shown) connected to the grounding electrode 139, and the determination unit 312 calculates the difference between the measurement value related to the grounding electrode 139 and the measurement value from the sensor 19. The determination unit 312 observes the current waveform related to this difference and determines whether or not a pulse current is generated. If the noise superimposed on the sensor measurement value is strong, the determination unit 312 can cancel out the noise by taking the difference between the measurement value at a location where partial discharge is possible and the measurement value at a location where partial discharge is not present.

Specifically, the inspector performing the partial discharge test on the transformer 10 attaches the sensor 19 to the side wall 133 of the coil tank 13, on the side opposite to the side facing the heat exchanger 15, and at a position facing the central coil device 11 of the three coil devices 11 arranged side by side. The sensor 19 is then connected to the inspection device 30, and the inspection device 30 is instructed to run the partial discharge test program. Based on the measurement value from the sensor 19, the inspection device 30 determines whether or not there is a partial discharge in the coil device 11. The inspection device 30 outputs the determination result to the display 32.

Action/Effect
Thus, in the first embodiment, the sensor 19 of the transformer 10 is mounted in a position different from the position where the fan 172a is located in the coil tank 13. This prevents noise from the fan 172a from superimposing on the measurement value of the sensor 19. Therefore, the inspection device 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.

Furthermore, in the first embodiment, the sensor 19 of the transformer 10 is mounted on the side of the coil tank 13 that does not face the heat exchanger 15. Because the space between the heat exchanger 15 and the coil tank 13 is narrow, mounting the sensor 19 on the side of the coil tank 13 that does not face the heat exchanger 15 allows inspectors to easily access the sensor 19.

Furthermore, in the first embodiment, the sensor 19 is mounted at a position opposite the central coil device 11 among the three coil devices 11. This allows one sensor 19 to detect the TEV of all three coil devices 11. In other embodiments, if there is an even number of coil devices 11, the sensor 19 may be mounted at a corresponding location between the two central coil devices 11.

<Second Embodiment>
Figure 4 is a perspective view showing the configuration of the transformer 10 according to the second embodiment.
In the first embodiment, the sensor 19 is mounted on the front of the coil tank 13. In contrast, in the second embodiment, the sensor 19 is mounted on the lid plate 134 of the coil tank 13.

Arrangement of sensor 19
The configuration of the transformer 10 according to the second embodiment differs from that of the first embodiment only in the mounting position of the sensor 19.
In the second embodiment, the sensor 19 is mounted on the lid plate 134 of the coil tank 13, at a position facing the central coil device 11 of the three coil devices 11 arranged side by side. Furthermore, the sensor 19 is mounted on a flat surface without terminals, avoiding the high-voltage side terminals 135 and low-voltage side terminals 136 of the lid plate 134. This shortens the distance between the sensor 19 and the coil device 11, allowing the sensor 19 to measure the TEV of the coil device 11 with high sensitivity.

<Third Embodiment>
Figure 5 is a perspective view showing the configuration of the transformer 10 according to the third embodiment.
In the first embodiment, the transformer 10 detects the TEV generated from any of the three coil devices 11 using one sensor 19. In contrast, in the second embodiment, the transformer 10 detects the TEV using two sensors 19, allowing the inspection device 30 to identify which coil device 11 is experiencing partial discharge.

Arrangement of sensor 19
The transformer 10 according to the third embodiment is equipped with a first sensor 19a and a second sensor 19b instead of the sensor 19.
The first sensor 19a is mounted on the side wall 133, on the side opposite to the side facing the heat exchanger 15, and in a position opposite the coil device 11 located at the first end in the direction of alignment of the three coil devices 11 that are arranged side by side. For example, the first sensor 19a is mounted in a position opposite the leftmost coil device 11.
The second sensor 19b is mounted on the side wall 133 opposite to the side facing the heat exchanger 15, and is positioned opposite the coil device 11 located at the second end in the direction of alignment of the three coil devices 11 that are arranged side by side. For example, the second sensor 19b is mounted opposite the coil device 11 located on the far right.
The first sensor 19a and the second sensor 19b are mounted on a recessed surface without the reinforcing portion 133a of the side wall 133, avoiding the reinforcing portion 133a.

Configuration of the inspection device 30
Figure 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 specific 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 wireless connection, and acquires measured values from the first sensor 19a and the second sensor 19b, respectively.
The determination unit 312 determines whether or not there is a partial discharge based on the measured values of the first sensor 19a and the second sensor 19b.
The identification unit 314 identifies which of the three coil devices 11 is experiencing partial discharge based on the measured values of the first sensor 19a and the second sensor 19b.
The output unit 313 outputs the determination results from the determination unit 312 and the identification unit 314 to the display 32.

Method for detecting partial discharge of transformer 10
In the third embodiment, the inspection device 30 detects partial discharge by, for example, the following method.
Figure 7 is a flowchart showing the method for determining partial discharge using the inspection device 30 according to the third embodiment.
The determination unit 312 of the inspection device 30 determines whether or not partial discharge occurs for each of the first sensor 19a and the second sensor 19b in the same manner as in the first embodiment (step S1). If the determination unit 312 determines that no partial discharge has occurred for the measured 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).

On the other hand, if the determination unit 312 determines that partial discharge is occurring in at least one of the measured values of the first sensor 19a and the second sensor 19b (Step S1: YES), the identification 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 greater than or equal to a predetermined value (Step S3). If 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 is occurring in the centrally located of the three coil devices 11 (Step S4).

If the difference between the TEV measured by the first sensor 19a and the TEV measured by the second sensor 19b is greater than or equal to a predetermined value (Step S3: NO), the identification 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). If 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 a partial discharge is occurring in the coil device 11 that is opposite the first sensor 19a among the three coil devices 11, i.e., the leftmost coil device 11 (Step S6).
On the other hand, if the TEV measured by the first sensor 19a is smaller than the TEV measured by the second sensor 19b (step S5: NO), the output unit 313 outputs a determination result indicating that partial discharge is occurring in the coil device 11 that is opposite the second sensor 19b, i.e., the rightmost coil device 11 (step S7).

Thus, according to the third embodiment, the inspection device 30 can identify which of the three coil devices 11 is experiencing partial discharge using the first sensor 19a and the second sensor 19b.

<Fourth Embodiment>
Figure 8 is a perspective view showing the configuration of the transformer 10 according to the fourth embodiment.
In the third embodiment, the first sensor 19a and the second sensor 19b are mounted on the front of the coil tank 13. In contrast, in the fourth embodiment, the first sensor 19a and the second sensor 19b are mounted on the side of the coil tank 13.

Arrangement of sensor 19
The configuration of the transformer 10 according to the fourth embodiment differs from that of the third embodiment only in the mounting positions of the first sensor 19a and the second sensor 19b.
In the fourth embodiment, the first sensor 19a is mounted on the first side wall 133 of the coil device 11 in the direction of alignment, at a position facing the coil device 11 located at the first end in the direction of alignment. For example, the first sensor 19a is mounted on the left side surface of the coil tank 13, at a position facing the leftmost coil device 11.
In the fourth embodiment, the second sensor 19b is mounted on the second side wall 133 of the coil device 11 in the direction of alignment, at a position facing the coil device 11 located at the second end in the direction of alignment. For example, the first sensor 19a is mounted on the right side of the coil tank 13, at a position facing the coil device 11 located on the far right.
The first sensor 19a and the second sensor 19b are mounted on a recessed surface without the reinforcing portion 133a of the side wall 133, avoiding the reinforcing portion 133a.

<Fifth Embodiment>
Figure 9 is a perspective view showing the configuration of the transformer 10 according to the fifth embodiment.
In the third embodiment, the first sensor 19a and the second sensor 19b are mounted on the front of the coil tank 13. In contrast, in the fifth embodiment, the first sensor 19a and the second sensor 19b are mounted on the rear of the coil tank 13.

Arrangement of sensor 19
The configuration of the transformer 10 according to the fifth embodiment differs from that of the third embodiment only in the mounting positions of the first sensor 19a and the second sensor 19b.
In the fifth embodiment, the first sensor 19a is mounted on the side wall 133 facing the heat exchanger 15, and is positioned opposite the coil device 11 located at the first end in the direction of alignment of the three coil devices 11 that are arranged side by side. For example, the first sensor 19a is mounted opposite the leftmost coil device 11.
In the fifth embodiment, the second sensor 19b is mounted on the side wall 133 facing the heat exchanger 15, and is positioned opposite the coil device 11 located at the second end in the direction of alignment of the three coil devices 11 arranged side by side. For example, the second sensor 19b is mounted opposite the coil device 11 located on the far right.
The first sensor 19a and the second sensor 19b are mounted on a recessed surface without the reinforcing portion 133a of the side wall 133, avoiding the reinforcing portion 133a. Furthermore, the first sensor 19a and the second sensor 19b are mounted at a position different from the position where the lower connecting pipe 172 having the fan 172a is located. This prevents noise generated by the operation of the fan 172a from being mixed into the measurement values of the sensor 19.

<Sixth Embodiment>
Figure 10 is a perspective view showing the configuration of the transformer 10 according to the sixth embodiment.
In the third embodiment, the first sensor 19a and the second sensor 19b are mounted on the front of the coil tank 13. In contrast, in the sixth embodiment, the first sensor 19a and the second sensor 19b are mounted on the bottom of the coil tank 13.

Arrangement of sensor 19
The configuration of the transformer 10 according to the sixth embodiment differs from that of the third embodiment only in the mounting positions of the first sensor 19a and the second sensor 19b.
In the sixth embodiment, the first sensor 19a is mounted on the side wall 133 at a position further outward than the position facing the coil device 11 located at the first end in the alignment direction. For example, the first sensor 19a is mounted to the left of the position facing the leftmost coil device 11.
In the sixth embodiment, the second sensor 19b is mounted on the side wall 133 at a position further outward than the position facing the coil device 11 located at the second end in the alignment direction. For example, the second sensor 19b is mounted to the right of the position facing the rightmost coil device 11.

In the sixth embodiment, the first sensor 19a and the second sensor 19b of the transformer 10 are mounted on the bottom surface of the coil tank 13. Because the bottom surface of the coil tank 13 is low, the first sensor 19a and the second sensor 19b are mounted on the side of the coil tank 13 that does not face the heat exchanger 15, allowing inspectors to easily access the first sensor 19a and the second sensor 19b.

<Seventh Embodiment>
Figure 11 is a perspective view showing the configuration of the transformer 10 according to the seventh embodiment.
In the first embodiment, the heat exchanger 15 is located behind the coil tank 13. In contrast, in the seventh embodiment, the heat exchanger 15 is located above the coil tank 13. That is, in the seventh embodiment, the heat exchanger 15 and the coil device 11 are located at different heights from each other.

Arrangement of sensor 19
The sensor 19 is mounted on the side wall 133, on the side opposite to the side facing the heat exchanger 15, and in a position facing the central coil device 11 of the three coil devices 11 arranged side by side. Furthermore, the sensor 19 is mounted on a recessed surface of the side wall 133 that does not have a reinforcing portion 133a, avoiding the reinforcing portion 133a.

<Eighth Embodiment>
Figure 12 is a perspective view showing the configuration of the transformer 10 according to the eighth embodiment.
In the first embodiment, the inspection device 30 is provided separately from the transformer 10. In contrast, in the eighth embodiment, the transformer 10 has a control device 21 that functions as the inspection device.

For example, in the example shown in Figure 12, the control device 21 is mounted on the cover plate 134 of the transformer 10. The control device 21 controls the behavior of the transformer 10 and periodically detects partial discharge based on the measurements of the sensor 19.

<Other Embodiments>
Although several embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to those described above, and various design changes are possible. In other embodiments, the order of the processes described above may be changed as appropriate. Also, some processes may be executed in parallel.
The inspection device 30 according to the above embodiment may be composed of a single computer, or the configuration of the inspection device 30 may be divided among multiple computers, and the multiple computers may cooperate with each other to function as the inspection device 30. In this case, some of the computers constituting the inspection device 30 may be mounted on the transformer 10, and the other computers may be provided outside the transformer 10.

The sensor 19 according to the above embodiment measures the TEV of the coil device 11, but is not limited to this. For example, the sensor 19 according to another embodiment may be any sensor capable of measuring current, electromagnetic waves, sound waves, or vibrations originating from the partial discharge of the coil device 11.

The transformer 10 according to the above embodiment comprises three coil devices 11, but is not limited to this. For example, the transformer 10 according to other embodiments may comprise two or fewer coil devices 11, or four or more coil devices 11.

In the above-described embodiment, a heat exchanger 15 using a radiator is provided as the cooling unit, but the system is not limited to this. For example, the cooling unit in other embodiments may cool pressurized air using a heat pump.

In the embodiment described above, the transformer 10 seals in pressurized air, but this is not limited to this. For example, in another embodiment, the transformer 10 may seal in another insulating gas, such as SF6 gas. Also, in another embodiment, the coil 112 does not necessarily have to be molded.

In the embodiment described above, the housing of the transformer 10 is composed of a coil tank 13, a heat exchanger 15, and connecting pipes 17, but it is not limited to this. For example, the transformer 10 in another embodiment may have a housing in which the coil tank 13 and the heat exchanger 15 are integrated.

<Computer Configuration>
The inspection device 30 and control device 21 are equipped with a processor, memory, auxiliary storage device, etc., connected by a bus, and function as a device comprising an acquisition unit 311, a determination unit 312, and an output unit 313 by executing a partial discharge detection program. Examples of processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), and microprocessors.
The partial discharge detection program may be recorded on a computer-readable recording medium. Computer-readable recording media include, for example, magnetic disks, magneto-optical disks, optical disks, and semiconductor memory. The partial discharge detection program may also be transmitted via a telecommunications line.
Furthermore, all or part of the functions of the inspection device 30 or the control device 21 may be implemented using custom LSIs (Large Scale Integrated Circuits) such as ASICs (Application Specific Integrated Circuits) or PLDs (Programmable Logic Devices). Examples of PLDs include PALs (Programmable Array Logic), GALs (Generic Array Logic), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays). Such integrated circuits are also included as examples of processors.

According to at least one embodiment described above, the transformer 10 has a sensor for measuring physical quantities related to partial discharge located in a different location within the housing from where the fan 172a is positioned, thereby enabling the appropriate measurement of physical quantities for detecting partial discharge.
While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

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... Judgment unit, 313... Output unit, 314... Identification unit

Claims (17)

A housing that seals an insulating fluid,
A coil device located inside the aforementioned housing,
A cooling unit located in the aforementioned housing, which removes heat from the fluid,
A pumping device that pumps the fluid and circulates the fluid between the coil device and the cooling unit,
A transformer equipped with a sensor for measuring the transient ground voltage of the housing, which is mounted on a location in the housing different from the location where the pressure feeding device is located. The housing comprises a first housing for housing the coil device, a second housing having the cooling section, and a connecting pipe connecting the first housing and the second housing.
The pumping device is located inside the connecting pipe,
The transformer according to claim 1, wherein the sensor is mounted on the first housing. The transformer according to claim 2, wherein the sensor is mounted on the side of the first housing that does not face the second housing. The transformer according to claim 2, wherein the sensor is mounted on the surface of the first housing facing the second housing, at a location different from the location where the connecting pipe is arranged. The cooling unit and the coil device are located at different heights from each other.
The transformer according to any one of claims 1 to 4, wherein the sensor is mounted on the surface of the housing facing the coil device. The housing includes a plurality of coil devices arranged in one direction, including the aforementioned coil device.
The transformer according to any one of claims 1 to 5, wherein the sensor is mounted on a surface of the housing facing the central portion of the plurality of coil devices. The housing includes a plurality of coil devices arranged in one direction, including the aforementioned coil device.
The sensor comprises a first sensor and a second sensor for measuring the transient ground voltage.
The first sensor is mounted on the surface of the housing facing the coil device provided at the first end in one direction among the plurality of coil devices.
The transformer according to any one of claims 1 to 5, wherein the second sensor is mounted on the surface of the housing facing the coil device provided at the second end in one direction of the plurality of coil devices. The first sensor is mounted on the first end surface of the housing.
The transformer according to claim 7, wherein the second sensor is attached to the second end surface of the housing. The transformer according to any one of claims 1 to 8, wherein the sensor is mounted on the surface of the housing at the location where it is closest to the outer surface of the coil device. The outer surface of the housing has a recess and a protrusion extending in one direction.
The transformer according to any one of claims 1 to 9, wherein the sensor is mounted in the recess. On the outer surface of the housing, there is an outlet terminal that is electrically connected to the coil device.
The transformer according to any one of claims 1 to 10, wherein the sensor is mounted at a location different from the location where the output terminal is located. The transformer according to claim 1 or 2, wherein the sensor is mounted on the lower surface of the housing at a location not facing the coil device. The housing seals the fluid at 1 atmosphere or more.
The transformer according to any one of claims 1 to 12, wherein the surface of the coil device is covered with an insulating material. The transformer according to any one of claims 1 to 13, wherein the sensor is attached to the outer surface of the housing. A transformer according to any one of claims 1 to 14, further comprising a determination unit that determines whether or not there is a partial discharge in the coil device based on the measured value of the sensor. The transformer according to claim 7 or claim 8, further comprising a identifying unit that identifies a coil device among the plurality of coil devices that is causing partial discharge, based on the measured value of the first sensor and the measured value of the second sensor. A transformer comprising a housing for sealing an insulating fluid, a coil device located inside the housing, a cooling unit located inside the housing for removing heat from the fluid, and a pumping device for pumping the fluid and circulating the fluid between the coil device and the cooling unit, wherein a sensor for measuring the transient ground voltage of the housing is attached to a location in the housing different from the location where the pumping device is located.
A method for determining partial discharge, comprising the step of determining whether or not there is a partial discharge in the coil device based on the measured value of the sensor.