Composite sleeve and method thereof

Abstract

The invention discloses a composite bushing and a method thereof, and belongs to the technical field of transformer bushings. The composite bushing comprises a bushing body filled with insulating oil, a piezoelectric conversion device communicated with the inside of the bushing body and used for converting hydraulic pressure of the insulating oil in the bushing body into an electric signal, and a far-end controller connected with the piezoelectric conversion device and used for controlling the piezoelectric conversion device and the far-end controller. Detecting an electric signal generated by the piezoelectric conversion device through the far-end controller, and judging whether the sleeve body leaks oil or not; a method of compositing a casing; the oil leakage detection device has the advantages that whether the sleeve body leaks oil or not can be conveniently found in time, and the oil leakage judgment accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer bushings, and in particular to a composite bushing and a method thereof. Background Art

[0002] Composite bushing is a type of high-voltage transformer bushing and is the main insulating device outside the transformer box. The lead wires of the transformer winding must pass through the insulating bushing to insulate the lead wires from each other and from the transformer casing, and it also serves to fix the lead wires.

[0003] The bushing is filled with insulating oil, which is mainly sealed by rubber seals. During long-term use, rubber seals are not only naturally aged, but also affected by factors such as their own material, environment (acidic gas, liquid), and high temperature accelerated aging, which may cause damage and lead to leakage of insulating oil.

[0004] Insulating oil leakage will reduce the insulation strength of the transformer bushing and may even cause flashover discharge, leading to major power outages. Therefore, it is very important to detect oil leakage in oil-immersed transformer bushings.

[0005] At present, the detection of oil-immersed transformer bushings relies on manual detection, that is, it relies on visual observation by operation and maintenance personnel in combination with the operation and maintenance strategy of the equipment in the station. However, since the oil storage capacity of the oil-immersed transformer bushing is less than that of the main transformer body, once the oil-immersed transformer bushing leaks oil, the oil level of the oil-immersed transformer bushing will drop significantly in a short period of time. In addition, the observation window of the oil-immersed transformer bushing is set at a high height. Manual detection of the oil-immersed transformer bushing has the problem of high detection difficulty and difficulty in timely detection of oil leakage of the oil-immersed transformer bushing. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that it is difficult to timely detect leakage of insulating oil during use of the current transformer bushing, and to propose a composite bushing and a method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A composite casing, comprising A bushing body, the interior of which is filled with insulating oil; A piezoelectric conversion device, the piezoelectric conversion device is connected to the interior of the bushing body, and the piezoelectric conversion device converts the hydraulic pressure of the insulating oil in the bushing body into an electrical signal; The remote controller detects the electrical signal generated by the piezoelectric conversion device to determine whether the sleeve body is leaking oil.

[0008] Furthermore, the piezoelectric conversion device includes an insulating shell located on the side of the sleeve body, the insulating shell and the sleeve body are connected through a piston cylinder, a piston is arranged inside the piston cylinder, and the piston is connected to the remote controller through an electrical conversion mechanism, and the linear reciprocating motion of the piston is converted into an electrical signal through the electrical conversion mechanism and sent to the remote controller.

[0009] Furthermore, the power transfer mechanism includes a conductive rod and a resistor, the conductive rod is rotatably mounted on the inner side of the insulating housing through a first pin shaft, a reset torsion spring is mounted on the first pin shaft, one end of the conductive rod is hinged to the piston, and the other end is slidably connected to the resistor; The access end of the remote controller is connected to the conductive rod and the resistor sheet respectively.

[0010] Furthermore, the first pin shaft is located at an eccentric position of the conductive rod, the end of the conductive rod close to the first pin shaft is hinged to the piston, and the end far away is slidably connected to the resistor, and the resistor is arranged along the swinging trajectory of the end of the conductive rod away from the first pin shaft.

[0011] Further, the power transfer mechanism includes a rotating disk, a conductive block, and a resistance ring. The rotating disk is drivingly connected to the first pin shaft. A conductive block is radially slidably arranged on the end surface of the rotating disk. A resistance ring corresponding to the conductive block is arranged on the side wall of the insulating housing close to the conductive block. The input end of the remote controller is connected to the conductive block and the resistance ring respectively.

[0012] Furthermore, a plurality of speed gears are arranged between the first pin shaft and the rotating disk, and the speed gears are composed of a large gear and a small gear arranged coaxially, and the large gear and the small gear on two adjacent speed gears are meshed.

[0013] Furthermore, the resistance ring is a spiral structure coaxial with the turntable, the end surface of the resistance ring close to the conductive block is a groove structure, and the end surface of the conductive block close to the resistance ring is provided with a ball corresponding to the groove structure.

[0014] Furthermore, at least two sets of sleeve bodies and piezoelectric conversion devices are connected to the same remote controller.

[0015] A method for composite casing, the steps are as follows: S1. During the initial installation, record the parameter value representing the oil pressure detected on each remote controller as the initial parameter value; S2. During use, the change of the actual parameter value is observed through the remote controller. When the actual pressure represented by the actual parameter value becomes smaller than the initial pressure represented by the initial parameter value, it is determined that the corresponding casing body has a leak.

[0016] A method for composite casing, the steps are as follows: S1. During the initial installation, record the corresponding parameter values ​​of the insulating oil in all bushing bodies on the remote controller and record them as initial parameter values; S2, taking the initial parameter value of any one of the casing bodies as a reference value, calculating and recording the ratio between the initial parameter values ​​of other casing bodies and the reference value as a reference ratio, and forming a reference ratio sequence; S3. During use, the change in the actual ratio of each casing body is observed through the remote controller. When the actual ratio of one casing body does not match the reference ratio, it is determined that the casing body is leaking.

[0017] Compared with the prior art, the present invention provides a composite casing having the following beneficial effects: The composite bushing of the present invention is used by installing a remote controller in a monitoring room of an electric power device. The pressure value of the insulating oil in the bushing body is converted into an electrical signal through a piezoelectric conversion device and sent to the remote controller. Since the change of the pressure value of the insulating oil corresponds to the electrical signal, when the pressure value of the insulating oil decreases, the change of the corresponding electrical signal can be observed through the remote controller, thereby judging that the insulating oil in the bushing body is leaking, and discovering the oil leakage problem in time.

[0018] A method for composite bushings has the following beneficial effects: when in use, by comparing the hydraulic pressure values ​​of the insulating oils in different bushing bodies, it is possible to judge whether the hydraulic pressure value of the insulating oil in each bushing body is normal in different temperature environments, thereby reducing misjudgments caused by the influence of temperature environments, improving the accuracy of judgment, and improving practicality.

[0019] Other advantages, objectives and features of the present invention will be described in part in the following description; and in part, will be apparent to those skilled in the art based on an examination of the following; or, may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 It is a three-dimensional schematic diagram of the internal structure of the insulating housing of Example 1 of the present invention; Figure 4 It is a schematic front view of the internal structure of the insulating housing of Example 1 of the present invention; Figure 5 It is a three-dimensional schematic diagram of the internal structure of the insulating housing of Example 2 of the present invention; Figure 6 It is a schematic diagram of a three-dimensional right front view of the speed change gear structure of the present invention; Figure 7 It is a three-dimensional right rear perspective schematic diagram of the speed change gear structure of the present invention; Figure 8 It is a schematic diagram of the chute structure of the present invention; Fig. 9 For the present invention Figure 8 A schematic diagram of the structure enlargement of part A; Fig.10 It is a schematic side view of the speed change gear structure of the present invention; Fig.11 For the present invention Fig.10 A schematic diagram of the structure of part B in the middle is enlarged; Fig.12 It is a schematic diagram of the installation effect of the present invention.

[0021] In the figure: 1. Sleeve body; 2. Piezoelectric conversion device; 201. Insulating shell; 202. Piston cylinder; 203. Piston; 204. Piston rod; 205. First pin shaft; 206. Rocker arm; 3. Remote controller; 301. Wire; 302. Controller body; 4. Power transfer mechanism; 401. Conductive rod; 402. Resistor; 403. Large gear; 404. Speed ​​change gear; 405. Small gear; 406. Second pin shaft; 407. Turntable; 408. Conductive block; 409. Resistor ring; 410. Slide; 411. Ball; 5. Transformer. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] Example 1 Reference Figure 1-4 The present invention provides a composite bushing, comprising a bushing body 1, wherein the bushing body 1 is filled with insulating oil; A piezoelectric converter 2, the piezoelectric converter 2 is connected to the inside of the bushing body 1, the oil pressure of the insulating oil drives the piezoelectric converter 2, and the piezoelectric converter 2 converts the hydraulic pressure of the insulating oil in the bushing body 1 into an electrical signal; The remote controller 3 is installed at a location far away from the transformer and the substation, such as in the power equipment monitoring room, when in use. The remote controller 3 detects the electrical signal generated by the piezoelectric conversion device 2, and determines whether the oil pressure of the insulating oil in the bushing body 1 is normal and whether there is oil leakage in the bushing body 1 through the electrical signal.

[0024] Since the pressure of the insulating oil at a certain point in the bushing body 1 is mainly related to the depth of the insulating oil at that position, according to the liquid pressure calculation formula P = ρgh, ρ is the liquid density, g is the gravitational acceleration, and h is the liquid depth, therefore, by testing the pressure of the insulating oil at a certain depth in the bushing body 1 by the piezoelectric conversion device 2, the oil pressure at that position can be determined to be P0, and the electrical signal value converted from P0 can be expressed as a resistance value R, a current value I, or a voltage value U, which can be recorded as R0, I0, or U0.

[0025] When using, follow the steps below (taking resistance value as an example): S1. During the initial installation, the parameter value representing the oil pressure detected by the remote controller 3 corresponding to each bushing body 1 in the state where the insulating oil has not leaked is recorded as the initial parameter value R0; S2. During use, the change of the actual parameter value R1 is observed through the remote controller 3. When the actual oil pressure P1 represented by the actual parameter value R1 is smaller than the initial oil pressure P0 represented by the initial parameter value R0, it can be seen from P = ρgh that, when ρ and g remain unchanged, h decreases, that is, the oil level decreases. It is inferred that the insulating oil in the bushing body 1 is reduced, and it can be judged that the corresponding bushing body 1 is leaking.

[0026] The piezoelectric conversion device 2 includes an insulating shell 201 located on the side of the sleeve body 1. The insulating shell 201 is connected to the sleeve body 1 through a piston cylinder 202. The end of the piston cylinder 202 close to the sleeve body 1 is connected to the inside of the sleeve body 1. The insulating oil submerges the end of the piston cylinder 202. A piston 203 is installed inside the piston cylinder 202. The pressure of the insulating oil acts on the piston 203, causing the piston 203 to move linearly in the piston cylinder 202.

[0027] The piston 203 is connected to the remote controller 3 through a power transfer mechanism 4. When the liquid level of the insulating oil changes, the pressure and pressure of the insulating oil also change accordingly, and the effects produced when acting on the power transfer mechanism 4 are also different. Therefore, the different effects of the linear reciprocating motion of the piston 203 are converted into electrical signals through the power transfer mechanism 4 and sent to the remote controller 3. The remote controller 3 displays the parameter value represented by the electrical signal, which is used to represent the pressure and pressure of the insulating oil at the corresponding position, as well as the depth or liquid level of the insulating oil in the bushing body 1.

[0028] The power transfer mechanism 4 includes a conductive rod 401 and a resistor 402. The conductive rod 401 is rotatably mounted on the inner side of the insulating housing 201 through a first pin shaft 205. A reset torsion spring is mounted on the first pin shaft 205. One end of the conductive rod 401 is hinged to the piston 203 through a piston rod 204. Both ends of the piston rod 204 are hinged to the piston 203 and the conductive rod 401, respectively, so that the linear reciprocating motion of the piston 203 is converted into a circular reciprocating swing of the conductive rod 401. The other end of the conductive rod 401 is slidably connected to the resistor 402. When the conductive rod 401 swings, the contact point between the conductive rod 401 and the resistor 402 also changes accordingly. The remote controller 3 includes wires 301 and a controller body 302. The access ends of the two wires 301 are connected to the conductive rod 401 and the resistor 402 respectively, and the other ends are connected to the controller body 302, so that the resistance value of the part where the resistor 402 is connected to the two wires 301 is detected by the controller body 302.

[0029] Specifically, when the insulating oil leaks, the liquid level of the insulating oil is lower than the initial state. At this time, the pressure acting on the piston 203 is also reduced. Under the elastic action of the torsion spring, the conductive rod 401 swings accordingly, and the resistance value between the resistor 402 and the two wires 301 also changes accordingly (depending on the different connection positions of the wires 301 on the resistor 402, it can be increased or decreased. Here, in order to be more in line with usage habits, this application takes the example that the resistance value decreases when the liquid level decreases and the resistance value increases when the liquid level rises). When the staff observes that the resistance value representing the liquid level height decreases through the controller body 302, it is determined that the insulating oil has leaked.

[0030] In the actual process, generally speaking, the leakage of insulating oil is mainly seepage, the leakage speed is very slow, and the leakage amount in a short period of time is very small. Therefore, in order to be able to detect whether the insulating oil is leaking more promptly, in the present application, a set of signal amplification mechanisms is also provided, which is used to amplify the electrical signal emitted by the power transfer mechanism 4, so that when the power transfer mechanism 4 is subjected to the same magnitude of pressure from the insulating oil, a larger range of resistance value changes can occur, thereby improving the sensitivity of the power transfer mechanism 4 to the pressure change of the insulating oil, so as to be able to detect whether the insulating oil is leaking more promptly.

[0031] Here, the first pin 205 is located at an eccentric position of the conductive rod 401, as shown in FIG. Figure 3-4As shown, the end of the conductive rod 401 close to the first pin shaft 205 is hinged to the piston 203, and the end far from the first pin shaft 205 is slidably connected to the resistor 402. The resistor 402 is arranged along the swinging track of the end of the conductive rod 401 away from the first pin shaft 205, so that when the conductive rod 401 swings, the resistor 402 and the end of the conductive rod 401 always keep in contact and conduct electricity. At this time, the conductive rod 401 is equivalent to a labor-saving lever driven by the piston 203. When the insulating oil leaks, even if only a small amount of leakage occurs, a small pressure value change is generated, which acts on the piston 203, and can also drive the conductive rod 401 to slide over a larger end distance on the resistor 402 (compared with the case where the conductive rod 401 is used as a labor-saving lever or a labor-intensive lever), thereby generating a larger value change, which is convenient for the staff to detect the change in time.

[0032] In the present application, the influence of other factors on the above-mentioned structure and force is not considered. For example, the conductive rod 401 itself is in a vertical position, and the influence of the gravity of the conductive rod 401 itself is not considered here. If gravity is taken into consideration, the conductive rod 401 is selected to be in a horizontal position, that is, the axial direction of the first pin shaft 205 is in the up and down direction, and the conductive rod 401 rotates in the horizontal direction.

[0033] Example 2 Reference Figure 5-12 The present invention provides a composite casing. The difference between this embodiment and embodiment 1 is that the power transfer mechanism 4 has a different implementation scheme. Specifically, the power transfer mechanism 4 includes a turntable 407, a conductive block 408, and a resistance ring 409. The first pin shaft 205 is fixedly connected with the rocker arm 206 and the large gear 403. The rocker arm 206 and the piston 203 are hinged together through the piston rod 204.

[0034] The rotating disk 407 is in transmission connection with the first pin shaft 205. When the piston 203 drives the first pin shaft 205 to rotate, the first pin shaft 205 is transmitted to the rotating disk 407. A slide groove 410 is processed radially on the end surface of the rotating disk 407. A conductive block 408 is slidably installed in the slide groove 410. A resistance ring 409 corresponding to the conductive block 408 is arranged on the side wall of the insulating housing 201 close to the conductive block 408. When the rotating disk 407 rotates, the conductive block 408 is driven to rotate, thereby changing the contact position between the conductive block 408 and the resistance ring 409. The input end of the remote controller 3 is connected to the conductive block 408 and the resistance ring 409 respectively. Similarly, the two wires 301 are connected to the conductive block 408 and the resistance ring 409 respectively. When the contact position between the conductive block 408 and the resistance ring 409 changes, the resistance value connected between the two wires 301 also changes accordingly, which is used to judge the change of the liquid level of the insulating oil.

[0035] The turntable 407 is mounted on the second pin shaft 406, and a reset torsion spring is also mounted on the first pin shaft 205 for resetting when the pressure from the insulating oil decreases.

[0036] The advantage of using the turntable 407 over the conductive rod 401 is that the structural size can be effectively reduced. For example, when the electrical signal needs to be further amplified, the conductive rod 401 needs to be significantly longer, while the length, width and height of the resistance ring 409 do not increase significantly.

[0037] In this embodiment, there is also a signal amplification structure. Specifically, a plurality of speed gears 404 are installed between the first pin shaft 205 and the turntable 407. The speed gears 404 are composed of a large gear 403 and a small gear 405 arranged coaxially. The large gears 403 on two adjacent speed gears 404 mesh with the small gears 405. One of the large gears 403 is installed on the first pin shaft 205 and meshes with the small gear 405 on the adjacent speed gear 404. One of the small gears 405 is installed on the second pin shaft 406 and meshes with the large gear 403 on the adjacent speed gear 404. When the pressure of the insulating oil acts on the piston 203, the piston 203 drives the first pin shaft 205 to rotate. The rotation angle of the first pin shaft 205, after the gear matching transmission, causes the turntable 407 to rotate a larger angle, thereby displaying a larger resistance value change on the resistance ring 409.

[0038] As described above, the signal amplification structure formed by the acceleration gear set composed of the speed change gear combination can effectively control the structural size of the power transfer mechanism 4 while having a more obvious amplification effect.

[0039] The resistance ring 409 is a spiral structure coaxial with the turntable 407. The end face of the resistance ring 409 close to the conductive block 408 is a spiral groove structure. The end face of the conductive block 408 close to the resistance ring 409 is semi-embedded with a ball 411 corresponding to the groove structure. When the turntable 407 rotates, the turntable 407 drives the conductive block 408 to move on the resistance ring 409. The conductive block 408 and the resistance ring 409 are rollingly connected in the groove structure through the ball 411, and the conductive block 408 and the resistance ring 409 are electrically connected through the ball 411.

[0040] During use of the solution of the present application, considering that the insulating oil is affected by temperature changes, the volume expansion and contraction effect of the insulating oil is obvious. In order to avoid confusion between the volume change caused by thermal expansion and contraction of the insulating oil and the volume change caused by oil leakage, when using the solution of the present application, at least two sets of bushing bodies 1 and piezoelectric conversion devices 2 can be connected to the same remote controller 3, and then a comparison method is used to determine whether there is leakage of the insulating oil in each bushing body 1.

[0041] Specifically, the steps are as follows: S1. During initial installation, the corresponding parameter values ​​of the insulating oil in all bushing bodies 1 on the remote controller 3 are recorded as initial parameter values; S2, taking the parameter value of any one of the casing bodies 1 as a reference value, calculating and recording the ratio between the initial parameter values ​​of the other casing bodies 1 and the reference value as a reference ratio, and forming a reference ratio sequence; S3. During use, the change of the actual ratio of each cannula body 1 is observed through the remote controller 3. When the actual ratio of one cannula body 1 does not match the reference ratio, it is determined that the cannula body 1 is leaking.

[0042] During the use of transformer bushing, the insulating oil is affected by temperature changes and produces obvious thermal expansion and contraction effects. Therefore, a corresponding oil pillow is often installed on the transformer bushing. One function of the oil pillow is to provide expansion space for the insulating oil when it expands due to heat, and the other function is to replenish oil when the insulating oil shrinks or leaks.

[0043] The volume expansion calculation formula here is V2=V1[1+α(t2-t1)], where V1 is the volume at t1°C, V2 is the volume at t2°C, and α is the expansion coefficient.

[0044] Or the volume expansion calculation formula is ΔV=V0×β×ΔT, where ΔV is the volume change, V0 is the initial volume, β is the volume expansion coefficient, and ΔT is the temperature change.

[0045] Furthermore, when the internal structures of bushing bodies 1 of the same specification are the same and the internal contour of the bushing body 1 is similar to a cylindrical structure as a whole, the volume formula of the insulating oil in the bushing body 1 can be applied to the volume calculation formula of the cylinder, which is V=S×h.

[0046] At the same time, since the amount of insulating oil filled in each transformer bushing meets the requirements during production, the amount of insulating oil in each transformer is similar but not exactly the same, so the height of the liquid level of the insulating oil in the oil pillow of each transformer is also close.

[0047] In this case, taking three bushings as an example, the liquid levels of the insulating oil in the three bushing bodies 1 are h1, h2, and h3 respectively. When the insulating oil expands and contracts due to temperature changes, the volume changes of the insulating oil in the three bushing bodies 1 are ΔV1, ΔV2, and ΔV3. The relationship between ΔV1, ΔV2, and ΔV3 changes simultaneously under the influence of temperature, and the changes among the three are positively correlated.

[0048] In the solution of the present application, the changes of ΔV1, ΔV2 and ΔV3 are reflected on the remote controller 3 after conversion by the piezoelectric conversion device 2 and the power transfer mechanism 4, and the actual parameter value and the actual ratio formed will all change accordingly. If the insulating oil in a certain bushing body 1 leaks, resulting in changes in the observed actual parameter value or actual ratio, when the above comparison is performed, it will be found that the actual ratio does not correspond to the reference ratio and does not match.

[0049] Therefore, considering that in a real environment (temperature is affected by season and weather), if the remote controller 3 detects that the oil level in the bushing body 1 is lowered, in order to determine whether the level reduction is caused by temperature or leakage, the parameter values ​​detected by the remote controller 3 in multiple bushings and the calculated ratios can be compared. This comparison method can effectively ignore the interference of the thermal expansion and contraction effect of the insulating oil due to temperature in the present application on the parameter value judgment, thereby improving the accuracy of the judgment.

[0050] In the present application, in order to facilitate observation and calculation, at least two sets of sleeve bodies 1 and piezoelectric conversion devices 2 are connected to the same remote controller 3, and the same remote controller 3 performs calculations and displays the results for observation and use by staff. Specifically, the same controller body 302 is connected to multiple power transfer mechanisms 4.

[0051] Working principle: In the present application, when the contour shape of the insulating oil in the internal chamber of the bushing body 1 is approximately cylindrical, and the contour shape of the insulating oil in the oil pillow on the bushing body 1 is a standard cylinder, the volume change caused by the thermal expansion and contraction of the insulating oil and the volume change caused by the leakage of the insulating oil will form corresponding changes in the oil pillow, ΔV=ΔS×Δh. The pressure change on the piston 203 located on the side of the bushing body 1 caused by Δh is displayed on the remote controller 3 after conversion by the piezoelectric conversion device 2 and the power conversion mechanism 4. During daily work, the staff judges whether the corresponding bushing body 1 has oil leakage according to the parameter values ​​and ratios displayed on the remote controller 3, so as to timely discover the oil leakage problem.

[0052] The electronic product used in the solution of the present application is only the controller body 302, and the controller body 302 is far away from the transformer 5. Compared with the prior art in which various sensor detection devices and other electronic equipment are installed on the transformer 5, firstly, in the solution of the present application, only the wire 301 is a live device, which is less affected by the strong electromagnetic environment of the high-voltage transformer; secondly, in the prior art, sensors and electronic equipment installed near the high-voltage transformer need to use products with anti-electromagnetic interference, and the cost of such products is significantly higher than other common types of similar products. Therefore, the cost of the solution of the present application is also significantly lower than the above-mentioned traditional solution.

[0053] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0055] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A composite casing, characterized in that: include A bushing body (1), the interior of the bushing body (1) being filled with insulating oil; a piezoelectric conversion device (2), the piezoelectric conversion device (2) being in communication with the interior of the bushing body (1), the piezoelectric conversion device (2) converting the hydraulic pressure of the insulating oil in the bushing body (1) into an electrical signal; A remote controller (3) detects the electrical signal generated by the piezoelectric conversion device (2) through the remote controller (3) to determine whether the sleeve body (1) is leaking oil.

2. A composite casing according to claim 1, characterized in that: The piezoelectric conversion device (2) comprises an insulating shell (201) located on the side of the sleeve body (1); the insulating shell (201) and the sleeve body (1) are connected via a piston cylinder (202); a piston (203) is arranged inside the piston cylinder (202); the piston (203) and the remote controller (3) are connected via an electric conversion mechanism (4); the electric conversion mechanism (4) converts the linear reciprocating motion of the piston (203) into an electric signal and sends it to the remote controller (3).

3. A composite casing according to claim 2, characterized in that: The power transfer mechanism (4) comprises a conductive rod (401) and a resistor (402); the conductive rod (401) is rotatably mounted on the inner side of the insulating housing (201) via a first pin shaft (205); a return torsion spring is mounted on the first pin shaft (205); one end of the conductive rod (401) is hinged to the piston (203), and the other end is slidably connected to the resistor (402); The access end of the remote controller (3) is respectively connected to the conductive rod (401) and the resistor sheet (402).

4. A composite casing according to claim 3, characterized in that: The first pin shaft (205) is located at an eccentric position of the conductive rod (401); an end of the conductive rod (401) closer to the first pin shaft (205) is hinged to the piston (203), and an end farther away from the first pin shaft (205) is slidably connected to the resistor sheet (402); and the resistor sheet (402) is arranged along a swinging track of an end of the conductive rod (401) farther away from the first pin shaft (205).

5. A composite casing according to claim 2, characterized in that: The power transfer mechanism (4) comprises a rotating disk (407), a conductive block (408), and a resistance ring (409); the rotating disk (407) is drivingly connected to the first pin shaft (205); a conductive block (408) is radially slidably arranged on the end surface of the rotating disk (407); and a resistance ring (409) corresponding to the conductive block (408) is arranged on a side wall of the insulating housing (201) close to the conductive block (408); The input end of the remote controller (3) is respectively connected to the conductive block (408) and the resistance ring (409).

6. A composite casing according to claim 5, characterized in that: A plurality of speed gears (404) are arranged between the first pin shaft (205) and the rotating disk (407), the speed gears (404) comprising a large gear (403) and a small gear (405) arranged coaxially, and the large gear (403) and the small gear (405) on two adjacent speed gears (404) are meshed.

7. A composite casing according to claim 5, characterized in that: The resistance ring (409) is a spiral structure coaxial with the rotating disk (407); the end surface of the resistance ring (409) close to the conductive block (408) is a groove structure; and a ball (411) corresponding to the groove structure is arranged on the end surface of the conductive block (408) close to the resistance ring (409).

8. The composite casing according to claim 1, characterized in that: At least two sets of sleeve bodies (1) and piezoelectric conversion devices (2) are connected to the same remote controller (3).

9. A method for preparing a composite casing according to any one of claims 1 to 8, characterized in that: Here are the steps: S1. During initial installation, record the parameter value representing the oil pressure intensity detected on each remote controller (3) as the initial parameter value; S2. During use, the change of the actual parameter value is observed through the remote controller (3). When the actual pressure represented by the actual parameter value becomes smaller than the initial pressure represented by the initial parameter value, it is determined that the corresponding sleeve body (1) has leaked.

10. A method for preparing a composite casing according to any one of claims 1 to 8, characterized in that: Here are the steps: S1. During initial installation, the corresponding parameter values ​​of the insulating oil in all bushing bodies (1) on the remote controller (3) are recorded as initial parameter values; S2, taking the initial parameter value of any one of the casing bodies (1) as a reference value, calculating and recording the ratio between the parameter values ​​of the other casing bodies (1) and the reference value as a reference ratio, and forming a reference ratio sequence; S3. During use, the change in the actual ratio of each sleeve body (1) is observed through the remote controller (3). When the actual ratio of one of the sleeve bodies (1) does not match the reference ratio, it is determined that the sleeve body (1) is leaking.

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