Partial discharge tester

Abstract

The invention relates to a partial discharge tester, which relates to the technical field of power distribution switch control equipment and comprises a long-strip-shaped host, a soft probe rod and a detection mechanism. The detection mechanism is arranged at the second end of the soft probe rod and comprises a hollow shell, a detachably-connected detection end, a transducer installed in the installation frame and a sound absorption piece arranged in an annular gap between the shell and the installation frame. The sound absorption part can be switched between a first state and a second state, and in the first state, the sound absorption part avoids the mounting frame in the radial direction, so that the mounting frame can move in the axial direction and is mounted at a preset position of the shell; in the second state, a sound absorption area is formed in the annular gap, and standing waves in the shell are reduced by absorbing and dissipating sound energy, so that standing wave interference is reduced, and the signal receiving stability and test precision of the transducer are improved. According to the technical scheme, installation convenience and test reliability are both considered to a certain extent, the working state of the sound absorption part can be flexibly adjusted according to the test working condition, and the adaptability of the instrument is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution switch control equipment, and particularly relates to a partial discharge tester. BACKGROUND

[0002] At present, in the fields of partial discharge detection of power distribution switch control equipment, non-destructive testing of materials and mechanical structure state monitoring, a non-contact ultrasonic sensor is widely used because it does not need to be in direct contact with the measured object and can realize acoustic signal collection at a certain distance. Such a sensor usually includes a piezoelectric transducer, an acoustic front cavity and a shell structure, receives ultrasonic signals radiated or reflected by the measured target through an acoustic window, and converts the ultrasonic signals into an electric signal for processing.

[0003] However, in actual application, due to the limitations of the front cavity space, support structure and shell shape of the non-contact ultrasonic sensor, ultrasonic waves often reflect multiple times inside the probe, forming a standing wave field. The standing wave not only may form local energy superposition on the sensitive surface of the piezoelectric transducer, but also may interfere with the effective signal from the measured object, resulting in phenomena such as mixing of false peaks, noise enhancement and spectrum distortion in the received signal. This interference is particularly obvious in high-sensitivity detection and wideband signal collection, especially when detecting weak partial discharge ultrasonic signals, the standing wave noise often covers the characteristics of the real discharge signal, thereby affecting the accurate identification and quantitative analysis of the signal. SUMMARY

[0004] Embodiments of the present application provide a partial discharge tester to at least partially solve the above technical problems.

[0005] In order to achieve the above purpose, a partial discharge tester is provided, which comprises: an elongated host; a flexible probe rod, the elongated host being arranged at a first end of the flexible probe rod; a detection mechanism arranged at a second end of the flexible probe rod, the detection mechanism comprising a shell, a detection end head, a transducer and a mounting bracket, the shell being hollow inside and having an open end, the detection end head being detachably connected to the open end of the shell, the mounting bracket being arranged in the shell and forming an annular gap with the inner wall of the shell and a rear cavity gap with the end wall of the shell away from the detection end head, the transducer being mounted in the mounting bracket and electrically connected to the elongated host; a sound-absorbing member arranged in the annular gap, and the sound-absorbing member having at least a first state and a second state which can be switched, wherein, The sound absorption member is configured to avoid the mounting frame in the radial direction of the shell when in the first state, so that the mounting frame can be moved in the axial direction and mounted at a preset position in the shell; and configured to form a sound absorption area in the annular gap when in the second state, so as to reduce the standing wave in the shell.

[0006] Optionally, the mounting frame comprises a cylindrical tube coaxially arranged in the shell and opposite to the probe head, and the annular gap is formed between the outer wall of the cylindrical tube and the inner wall of the shell. The cylindrical tube is made of sound-absorbing material, and a plurality of sound-absorbing portions are arranged on the outer wall of the cylindrical tube. After the mounting frame is configured to be mounted at a preset position in the shell, the plurality of sound-absorbing portions are distributed in the axial direction of the annular gap with the sound absorption member in the second state, and the projection of the sound-absorbing portions in the axial direction of the annular gap overlaps with the sound absorption member in the second state.

[0007] Optionally, a plurality of through holes are radially arranged on the wall of the cylindrical tube, and the diameter of the through holes gradually increases from the side close to the annular gap to the side in the cylindrical tube in the radial direction of the cylindrical tube.

[0008] Optionally, the mounting frame further comprises a support portion arranged at the pipe opening end of the cylindrical tube away from the probe head, and the transducer is mounted in the cylindrical tube and located on the inner surface of the support portion. The surface of the support portion is provided with a plurality of heat dissipation holes, and the rear cavity gap is formed between the support portion and the inner end wall of the shell away from the probe head.

[0009] Optionally, the transducer and the long strip-shaped host are electrically connected through a wire, and the wire extends into the long strip-shaped host after sequentially passing through the end wall of the shell and the inner cavity of the flexible probe rod from the shell. The mounting frame further comprises a limiting tube, a first end of the limiting tube is coaxially connected with the inner end wall of the shell and communicates with the inner cavity of the cylindrical tube, a second end of the limiting tube is coaxially connected with the support portion and communicates with the inner cavity of the cylindrical tube, and part of the wire is located in the limiting tube.

[0010] Optionally, the sound absorption member comprises a fluorosilicone rubber film, the shell has a first ring shell wall and a second ring shell wall, an air cavity is arranged between the first ring shell wall and the second ring wall, the first ring shell wall is close to the mounting frame, the second ring shell wall is located on the side of the first ring shell wall away from the mounting frame, a plurality of air holes are arranged on the first ring shell wall, and the fluorosilicone rubber film is sleeved on the air holes and located in the annular gap. When the external gas charging device charges gas into the air cavity, the fluorosilicone rubber membrane expands in the annular gap and is in the second state; When the external gas charging device discharges gas from the air cavity, the fluorosilicone rubber membrane shrinks in the annular gap and is in the first state.

[0011] Optionally, the shell is provided with a connecting piece in communication with the air cavity, and the connecting piece is configured to be connected with the external gas charging device.

[0012] Optionally, the connecting piece comprises a first gas pipe, a second gas pipe and a cap, the first gas pipe is arranged on an end wall of the shell away from the probe head, the length direction of the first gas pipe is consistent with the length direction of the shell, the first gas pipe is in communication with the air cavity, the second gas pipe is vertically communicated at one end of the first gas pipe away from the air cavity, and the second gas pipe extends towards a side away from the soft probe rod, and the cap is detachably connected with the first gas pipe.

[0013] Optionally, an inner thread is arranged on an inner wall of the cap, an outer thread is arranged on an outer wall of the second gas pipe close to a pipe opening, and the cap is threadedly sleeved at the pipe opening end of the second gas pipe.

[0014] Optionally, the rear cavity gap is filled with a damping material layer.

[0015] In summary, the present application has at least one of the following beneficial technical effects: 1、The sound absorbing piece arranged between the shell and the mounting frame of the detection mechanism can be switched between the first state and the second state, so that the partial discharge tester takes into account the installation convenience and the standing wave interference reduction effect to some extent. When the sound absorbing piece is in the first state, it avoids the mounting frame in the radial direction, so that it does not block the mounting frame during the assembly of the mounting frame to the shell in the axial direction, which is beneficial to shorten the assembly time and reduce the installation wear of the parts. When the sound absorbing piece is in the second state, it forms a sound absorbing area in the annular gap, so that the standing wave in the shell interior contacts the sound absorbing piece multiple times and dissipates sound energy during propagation, which can weaken the interference problem caused by the concentration of standing wave energy to some extent, thereby improving the signal-to-noise ratio of the effective signal received by the transducer. In addition, this structure can switch the state of the sound absorbing piece without additional disassembly of the shell, which can be flexibly adjusted when the working conditions such as detection environment and standing wave intensity change, and is beneficial to improve the adaptability and measurement stability of the whole machine in various test environments; 2、The partial discharge tester provided by the application can reduce the interference of standing waves generated in the internal structure of the probe on effective signals to a certain extent by introducing a fluorosilicone rubber film combined with an air cavity into the partial discharge tester. The fluorosilicone rubber film expands in the annular gap in the inflated state to form a bulging shape, can produce a rebounding effect on the standing waves entering the gap, and through the synergistic cooperation with the sound absorbing part, the standing waves are weakened to a certain extent. At the same time, part of the standing waves will be reflected and energy dissipated multiple times inside the air cavity after penetrating the fluorosilicone rubber film into the air cavity, thereby further reducing the intensity of the standing waves. The inflatable and exhaustable characteristics of the structure enable the fluorosilicone rubber film to freely switch between different states, which can not only provide good sound wave attenuation effect during detection, but also shrink to a shape that does not affect other components during installation or maintenance, thereby improving the adaptability of the whole machine under different working conditions. 3、The shell structure design of the application takes into account the standing wave reduction performance and acoustic absorption performance, the air cavity is arranged between the first ring shell wall and the second ring shell wall, and a plurality of air holes are formed in the first ring shell wall, so that the fluorosilicone rubber film can be directly sleeved at the air holes and in the annular gap, forming an adjustable state acoustic damping unit. In the inflated state of the fluorosilicone rubber film, the standing waves are reflected, interfered and energy attenuated multiple times in the annular gap, and when the fluorosilicone rubber film shrinks, the sound absorbing part on the cylindrical pipe and the film body do not interfere with each other, facilitating the rapid disassembly and maintenance of the equipment. In addition, the first ring shell wall and the second ring shell wall can be made of a material with certain sound absorption capacity, so that the air cavity not only has a structural reflection effect, but also provides an additional sound energy absorption path to a certain extent, thereby achieving a comprehensive effect of multi-path reduction of standing wave energy and improving the accuracy and stability of the test results. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating laborious work.

[0017] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0018] Figure 1 is the overall structure schematic diagram of the partial discharge tester provided in the embodiments of the present application; Figure 2 is the partial sectional view of the partial discharge tester provided in the embodiments of the present application; Figure 3 is the partial sectional view of the sound absorbing part in the detection mechanism in the first state provided in the embodiments of the present application; Figure 4 is a partial sectional view of the sound absorption member in the detection mechanism in the embodiment of the present application in a second state.

[0019] Reference signs: 1. long strip-shaped host; 2. soft probe rod; 3. detection mechanism; 31, shell; 311, first ring shell wall; 3111, air hole; 312, second ring shell wall; 313, air cavity; 32, detection end head; 33, transducer; 34, mounting bracket; 341, cylindrical tube; 3411, sound attenuation part; 3412, through hole; 342, support part; 3421, heat dissipation hole; 343, limiting tube; 4. annular gap; 5. rear cavity gap; 6. sound absorption member; 61, fluorosilicone rubber film; 7. wire; 8. butt joint; 81, first air pipe; 82, second air pipe; 83, cap; 9. damping material layer. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0021] The present application provides a partial discharge tester, please refer to Figure 1 , Figure 2 and Figure 3 , the partial discharge tester includes a long strip-shaped host 1, a soft probe rod 2 and a detection mechanism 3. The long strip-shaped host 1 is located at the first end of the soft probe rod 2, and the detection mechanism 3 includes a shell 31, a detection end head 32, a transducer 33 and a mounting bracket 34. The long strip-shaped host 1 is electrically connected with the transducer 33 in the detection mechanism 3 through the internal signal processing circuit, for receiving and analyzing the ultrasonic signal output by the transducer 33. The soft probe rod 2 adopts a flexible connection mode, so that the operator can adjust the spatial position of the detection mechanism 3 during the test process to adapt to the test requirements of different equipment or different angles. The detection mechanism 3 is located at the second end of the soft probe rod 2.

[0022] Exemplarily, the shell 31 is a hollow cylindrical structure, one end of which is open, and the other end is a closed end wall. The probe head 32 is mounted at the open end of the shell 31 through a detachable connection structure. Such detachable structure can be a threaded connection, a buckle connection or other mechanical locking structure, which facilitates the probe head 32 to be taken out separately when maintaining or replacing. The mounting bracket 34 is installed inside the shell 31 and forms an annular gap 4 between the inner wall of the shell 31, and at the same time, the mounting bracket 34 forms a rear cavity gap 5 between the closed end wall of the shell 31. The transducer 33 is fixed on the mounting bracket 34 and electrically connected with the long strip-shaped host 1, which is used to convert ultrasonic signals into electrical signals or convert electrical signals into ultrasonic signals. It can be understood that the mounting bracket 34 plays a role in supporting the transducer 33 and keeping its position stable, and its structure size is designed to balance the annular gap 4 between acoustic performance and mechanical strength.

[0023] Exemplarily, the sound absorbing member 6 is arranged in the annular gap 4, which adopts a flexible deformable structure, for example, is made of fluorosilicone rubber, silicone rubber base material, polyurethane elastomer or other high-damping polymers, and attenuates the sound wave energy to a certain extent through the internal friction of the material molecules and air damping effect. The sound absorbing member 6 can be switched between the first state and the second state. In the first state, the sound absorbing member 6 retracts or avoids the mounting bracket 34 in the radial direction, so that the mounting bracket 34 can be smoothly loaded into the preset position of the shell 31, and in this state, there is enough gap between the outer wall of the mounting bracket 34 and the sound absorbing member 6 to reduce friction and interference during installation, and to a certain extent, it can avoid component damage. In the second state, the sound absorbing member 6 returns to the designed deformation, so that it forms a sound absorbing area in the annular gap 4. The existence of the sound absorbing area is beneficial to introducing the standing wave inside the shell 31 around the sound absorbing material, so as to gradually dissipate the sound energy in the multiple reflection process. The sound absorbing member 6 in the second state is optimized in geometric cooperation relationship with the annular gap 4, so that the sound wave encounters a damping interface in the radial direction, the sound energy is dispersed in the sound absorbing material and gradually reduced, thereby reducing the interference degree of the standing wave on the received signal of the transducer 33.

[0024] It can be understood that the reason why standing waves are prone to occur in such a structure is that, after the ultrasonic waves enter the inside of the shell 31 from the detection head 32, if the internal structure presents an axial through and lacks an energy dissipation path, the reflected waves will propagate back and forth between the end of the shell 31 and the detection head 32, forming interfering fixed nodes and loops. By forming an annular gap 4 between the shell 31 and the mounting frame 34 and arranging the sound-absorbing member 6 in the annular gap 4, the reflected sound waves will be attenuated to a certain extent due to the damping effect when they come into contact with the sound-absorbing area, and this attenuation effect will gradually accumulate during multiple back-and-forth propagation, so that the amplitude of the standing wave is significantly reduced. The annular gap 4 between the mounting frame 34 and the shell 31 not only provides space for accommodating the sound-absorbing member 6, but also provides a channel for the standing wave to enter the sound-absorbing area, thus providing a condition for the dissipation of standing wave energy from the acoustic path.

[0025] Through the above structural arrangement, the partial discharge tester can reduce the standing wave energy to a certain extent during operation, thereby helping to improve the signal-to-noise ratio of the received signal by the transducer 33 and enhance the stability and repeatability of the ultrasonic detection result. At the same time, the switchable state design of the sound-absorbing member 6 helps to simplify the assembly process of the detection mechanism 3, so that forced friction between the sound-absorbing member 6 and the mounting frame 34 is avoided during the installation stage, reducing the risk of structural damage, and the sound-absorbing function is restored through state switching after installation is completed. Overall, this structure provides a feasible solution in terms of acoustic performance and assembly convenience, and has applicability for partial discharge test equipment that requires high-precision detection and long-term stable operation.

[0026] In some embodiments, in combination with Figure 2 , Figure 3 and Figure 4 , the mounting frame 34 includes a cylindrical tube 341, which is arranged coaxially with the shell 31 along the axial direction, and one end of the cylindrical tube 341 is opposite to the detection head 32, so that the ultrasonic waves emitted or received by the detection head 32 can be transmitted to the inside of the cylindrical tube 341 along a straight path and perform signal transmission with the transducer 33 mounted inside the cylindrical tube 341.

[0027] Exemplarily, the annular gap 4 is formed between the cylindrical tube 341 and the inner wall of the shell 31 in the radial direction, and is used to arrange the sound-absorbing member 6 and the sound-absorbing portion 3411. The cylindrical tube 341 is made of sound-absorbing material, which can be porous sound-absorbing material, composite fiber material, or polymer material with certain elasticity and porosity, and can partially absorb the standing wave acoustic energy through the inner wall to reduce the reflection intensity of the standing wave. Further, the outer wall of the cylindrical tube 341 is provided with a plurality of sound-absorbing portions 3411, which can be protruding, recessed or embedded sound-absorbing components in structure. In this application, the sound-absorbing portion 3411 is selected as a protruding sound-absorbing component, and is made of fluorosilicone rubber, silicone rubber base material, polyurethane elastomer or other high-damping polymer material.

[0028] Exemplarily, a plurality of through holes 3412 are radially formed on the wall of the cylindrical tube 341, and the hole diameters of the through holes 3412 gradually increase from the side close to the annular gap 4 to the inside of the cylindrical tube 341 in the radial direction. This design helps to form an acoustic impedance gradient, so that the sound waves entering the through holes 3412 gradually release acoustic energy and attenuate during transmission, reducing the interference caused by direct transmission of sound waves. At the same time, it is also convenient for the standing wave to enter the annular gap 4 through the through holes 3412 after passing through the through holes 3412, and not to re-enter the cylindrical tube 341 from the annular gap 4. During ultrasonic detection, part of the standing wave will be directly absorbed by the inner wall of the cylindrical tube 341, and the other part will enter the annular gap 4 through the through holes 3412, and be absorbed again through the synergistic effect of the sound-absorbing member 6 and the sound-absorbing portion 3411. Since the axial projections of the sound-absorbing portion 3411 and the sound-absorbing member 6 overlap, if the sound-absorbing member 6 is in the second state during installation of the cylindrical tube 341, the sound-absorbing portion 3411 can contact the sound-absorbing member 6. At this time, by switching the sound-absorbing member 6 to the first state, the sound-absorbing member 6 is radially avoided from the mounting frame 34, which is beneficial to the smooth installation of the cylindrical tube 341 to the predetermined position inside the shell 31, and reduces the mechanical interference between materials during assembly.

[0029] It can be understood that in this structure, the cylindrical tube 341 serves as the main body of the mounting frame 34, not only providing the fixing and positioning function of the transducer 33, but also bearing part of the acoustic processing function, through material selection and surface structure design, the standing wave entering its internal and external annular gap 4 is absorbed and reduced in multiple paths, thereby reducing the influence of the standing wave on the ultrasonic signal detection accuracy to a certain extent. The aperture gradient design of the through hole 3412 combined with the staggered distribution of the sound absorbing piece 6 in the annular gap 4 and the sound absorbing part 3411 makes the standing wave attenuate step by step in different paths, and the multiple dispersion and consumption of sound energy helps to improve the uniformity of the internal sound field, so that the proportion of effective signals received by the transducer 33 increases and the degree of signal interference decreases. The combined structure takes into account the installation convenience and the sound absorption effect during use through the two-state switching function of the sound absorbing piece 6 during the assembly stage, improving the adaptability and maintainability of the overall structure in the actual detection environment.

[0030] In some examples, in combination with Figure 2 、 Figure 3 and Figure 4 , the mounting frame 34 further comprises a support part 342, which is arranged at the pipe opening position of the cylindrical tube 341 away from the detection head 32, so that an integrated mounting structure is formed between the cylindrical tube 341 and the support part 342.

[0031] Exemplarily, the support part 342 cooperates with the cylindrical tube 341 to form an internal groove accommodating the transducer 33, and the transducer 33 is fixed in the internal groove and located at the inner surface position of the support part 342, so that the transducer 33 can be stably positioned during the detection process and maintain the coaxial relationship with the axis of the cylindrical tube 341, thereby reducing the deviation phenomenon on the signal transmission path and ensuring the transmission directionality of the sound wave.

[0032] Exemplarily, a plurality of heat dissipation holes 3421 are provided through the surface of the support part 342, which not only facilitates the conduction of heat generated by the transducer 33 during operation to the outside of the shell 31 through natural convection or air flow, so that the transducer 33 can be maintained in a more suitable working temperature range, but also can be used as a discharge channel for excess standing waves in terms of acoustic function.

[0033] It can be understood that during the ultrasonic detection process, part of the standing wave may still remain after being absorbed by the inner wall of the cylindrical tube 341 and the secondary absorption of the sound absorption member 6 and the sound absorbing part 3411 in the annular gap 4. These residual standing waves can enter the rear cavity gap 5 through the heat dissipation holes 3421 on the surface of the support part 342. The rear cavity gap 5 is formed by the space between the support part 342 and the inner end wall of the shell 31 away from the detection head 32. The space can be arranged with sound absorption or sound absorbing structure, or rely on the geometric shape and material properties of the space itself to reflect multiple times to attenuate the incoming sound waves, so that the sound energy is further reduced, thereby reducing the influence of the standing wave on the signal receiving quality of the transducer 33 to a certain extent. Specifically, the rear cavity gap 5 is filled with a layer of damping material 9. Since the heat dissipation holes 3421 of the support part 342 are uniformly distributed along the surface thereof, and the hole diameter and arrangement are optimized, it is beneficial to form a uniform air flow path to enhance the heat dissipation efficiency of the transducer 33, and also beneficial to the dispersion and propagation of the standing wave, so that the sound energy is lost during transmission to the rear cavity gap 5.

[0034] Based on this, through the mounting bracket 34 structure integrated with the support part 342 and the cylindrical tube 341, the transducer 33 positioning function, heat dissipation function and standing wave reduction function are combined, and the mechanical stability and acoustic performance are considered under the premise of compact structure, which is beneficial to improve the stability of the partial discharge tester in long time operation and the effectiveness of the detection signal.

[0035] In some examples, as shown in Figure 2 , Figure 3 and Figure 4 , the transducer 33 and the long strip-shaped host 1 are electrically connected through the wire 7. The wire 7 extends into the interior of the long strip-shaped host 1 from the inside of the shell 31 through the end wall of the shell 31 and the inner cavity of the soft probe rod 2 in turn, thereby maintaining the stability of the signal transmission path in mechanical structure, and reducing the loosening phenomenon of the wire 7 caused by bending or external force impact during use.

[0036] Exemplarily, the mounting frame 34 is further provided with a limiting tube 343 between the cylindrical tube 341 and the support portion 342. The first end of the limiting tube 343 is coaxially connected with the end wall in the shell 31 and communicates with the inner cavity of the cylindrical tube 341. The second end of the limiting tube 343 is coaxially connected with the support portion 342 and also communicates with the inner cavity of the cylindrical tube 341, so that the limiting tube 343 forms a cylindrical passage consistent with the central axis of the cylindrical tube 341. The partial wire 7 close to the transducer 33 is accommodated in the limiting tube 343, which plays a physical supporting and protecting role on the partial wire 7 and isolates the wire 7 from the damping material layer 9 in the rear cavity gap 5 through the wall of the limiting tube 343. Since the rear cavity gap 5 can be filled with damping materials with certain flexibility and elasticity to absorb standing wave energy, these materials can be slightly displaced or deformed when subjected to sound pressure, thereby generating extrusion or friction on the wire 7 to a certain extent. The limiting tube 343 can effectively reduce such direct contact, which is beneficial to maintaining the integrity of the outer insulating layer of the wire 7 and prolonging the service life thereof.

[0037] Meanwhile, as an independent hollow component, the limiting tube 343 plays an axial guiding role inside the mounting frame 34, so that the wire 7 is kept in central arrangement when passing between the cylindrical tube 341 and the support portion 342, thereby reducing the risk of signal transmission stability reduction caused by deviation. In addition, the smooth inner wall of the internal passage of the limiting tube 343 can reduce the abrasion of the wire 7 during installation and use, thereby ensuring the reliability of signal transmission to a certain extent. By partially accommodating the wire 7 in the limiting tube 343 and isolating it from the damping material, this structural design takes into account mechanical protection, guiding support and stable signal transmission and other aspects of performance on the premise of compact layout, which is overall beneficial to improving the long-term working reliability of the partial discharge tester in complex environments and the stability of detection data.

[0038] In some embodiments, in combination with Figure 2 , Figure 3 and Figure 4 , the sound-absorbing member 6 includes a fluorosilicone rubber film 61, the shell 31 has a first annular shell wall 311 and a second annular shell wall 312, and the air cavity 313 is formed between the first annular shell wall 311 and the second annular shell wall 312. The first annular shell wall 311 is close to the mounting frame 34, and the second annular shell wall 312 is located on the side of the first annular shell wall 311 away from the mounting frame 34. A plurality of air holes 3111 are formed in the first annular shell wall 311. The fluorosilicone rubber film 61 is sleeved on the air holes 3111 and located in the annular gap 4. In the installed state, the fluorosilicone rubber film 61 covers the outer surface of the air holes 3111 and extends towards the annular gap 4.

[0039] It can be understood that when the external inflating device introduces gas into the air cavity 313, the air pressure in the air cavity 313 increases, the fluorosilicone rubber film 61 is expanded outward in the annular gap 4 under the action of the air pressure and enters the second state, so that the surface of the fluorosilicone rubber film 61 forms a bulging elastic blocking surface in the annular gap 4. In this structure, the fluorosilicone rubber film 61 in the expanded state can form a certain degree of reflection and scattering effect on the standing wave entering the annular gap 4 when cooperating with the sound-absorbing part 3411 on the cylindrical pipe 341, and part of the sound wave energy is dispersed or attenuated after contacting the surface of the fluorosilicone rubber film 61, which is beneficial to reducing the intensity of the standing wave. Further, since the fluorosilicone rubber film 61 has high flexibility and certain air tightness, under the impact of the standing wave, the surface of the fluorosilicone rubber film 61 will produce slight deformation and absorb part of the sound energy, thereby realizing multiple sound-absorbing paths.

[0040] In addition, when the standing wave contacts the fluorosilicone rubber film 61, part of the energy may be conducted into the air cavity 313 through the film surface. In the limited space of the air cavity 313, the sound wave will undergo multiple reflection and refraction processes, and the sound wave energy will be further weakened under the cooperation of the first ring shell wall 311 and the second ring shell wall 312 (which can be made of sound-absorbing material). This structure design enhances the reduction effect of the standing wave to a certain extent, that is, the first ring shell wall 311 and the second ring shell wall 312 can also be made of sound-absorbing material. Thus, after part of the standing wave contacts the expanded fluorosilicone rubber film 61, part of the standing wave may enter the air cavity 313 through the fluorosilicone rubber film 61, and this part of the standing wave can also repeatedly reflect and weaken in the air cavity 313, thereby improving the reduction effect of the standing wave.

[0041] At the same time, when the external inflating device extracts gas from the air cavity 313, the air pressure in the air cavity 313 decreases, the fluorosilicone rubber film 61 shrinks inward and is in the first state, the film surface of the fluorosilicone rubber film 61 is tightly attached to the position of the air hole 3111, at this time the space of the annular gap 4 is released, and the sound-absorbing part 3411 can be assembled or disassembled with the mounting frame 34 without interference of the fluorosilicone rubber film 61, which is beneficial to more convenient operation during equipment maintenance or replacement.

[0042] Further, in order to ensure the deformation stability of the fluorosilicone rubber film 61 under different air pressures, the thickness, elastic modulus and sleeve structure of the film can be reasonably designed to maintain good sealing performance and mechanical properties of the fluorosilicone rubber film 61 in multiple expansion and contraction cycles.

[0043] In addition, the width of the annular gap 4 and the volume of the air cavity 313 can be optimized according to the standing wave frequency and the sound pressure distribution, so that the fluorosilicone rubber film 61 in the expanded state forms a more favorable sound wave attenuation path between the sound attenuation part 3411. In the overall design, this deformable sound absorption part 6 not only can reduce energy in multiple paths and multiple media for the standing wave in the working state of the test instrument, but also can be retracted in the non-working state to facilitate equipment operation, taking into account the acoustic performance and the practicality of structural assembly, and can improve the adaptability and measurement accuracy of the partial discharge test instrument in a complex power field environment to a certain extent.

[0044] In some embodiments, as shown in Figure 2 , Figure 3 and Figure 4 , the shell 31 is provided with a connecting piece 8 communicating with the air cavity 313, which is used to connect with an external gas charging device, so as to be able to introduce gas into the air cavity 313 or exhaust the gas in the air cavity 313. Specifically, the connecting piece 8 includes a first gas pipe 81, a second gas pipe 82 and a cap 83, wherein the first gas pipe 81 is fixedly arranged on the end wall of the shell 31 away from the detection head 32, and the length direction of the first gas pipe 81 is consistent with the length direction of the shell 31. The inner cavity of the first gas pipe 81 directly communicates with the air cavity 313, so that the inside and outside of the air cavity 313 can exchange gas through the first gas pipe 81. The second gas pipe 82 is connected perpendicularly to one end of the first gas pipe 81 away from the air cavity 313, and the extension direction of the second gas pipe 82 is arranged towards the side away from the soft probe 2. This structure facilitates the quick docking of the gas charging pipe of the external gas charging device with the second gas pipe 82 in the case of limited installation space, and because the direction of the second gas pipe 82 is opposite to that of the soft probe 2, it can leave sufficient operating space for the hands of the installer during operation.

[0045] Exemplarily, the cap 83 is detachably connected with the second gas pipe 82. When it is necessary to charge or exhaust the air cavity 313, the installer can unscrew the cap 83, connect the interface of the external gas charging device with the second gas pipe 82; when no gas operation is performed, the cap 83 can be screwed to the pipe opening of the second gas pipe 82 to block the outside gas from entering the air cavity 313 or prevent the gas in the air cavity 313 from leaking. In order to enhance the sealing performance, the inner wall of the cap 83 is provided with an internal thread, and the outer wall of the second gas pipe 82 close to the pipe opening is provided with a matching external thread, and the two are stably connected through thread fitting. In addition, a rubber sealing ring can be added between the cap 83 and the second gas pipe 82 to improve the air tightness to a certain extent.

[0046] Through the arrangement of the adapter 8, a reliable gas passage is established between the gas cavity 313 and the external gas charging device, so that the fluorosilicone rubber film 61 can be inflated to form a bulging structure in the annular gap 4 in the inflated state, thereby combining the sound-absorbing part 3411 to reflect and reduce the standing wave entering the gap; in the deflated state, the fluorosilicone rubber film 61 is contracted to the first state, thereby not interfering with the sound-absorbing part 3411 on the cylindrical pipe 341 during the mounting or dismounting of the mounting frame 34. The above structure not only improves the reduction effect of the standing wave to a certain extent, but also takes into account the operation convenience and sealing performance, which is conducive to the flexible use of the partial discharge tester in different detection environments.

[0047] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0048] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0049] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0050] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment without departing from the technical solution of the present application and according to the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A partial discharge tester characterized by, The utility model relates to a long strip host (1); Flexible probe rod (2), the long strip host (1) is located at the first end of flexible probe rod (2); Detection mechanism (3) is located at the second end of flexible probe rod (2), and the detection mechanism (3) includes shell (31), detection end head (32), transducer (33) and mounting bracket (34), the inside of shell (31) is hollow and the end opening is arranged, detection end head (32) is detachably connected at the end opening of shell (31), mounting bracket (34) is arranged in shell (31) and forms annular gap (4) with the inner wall of shell (31), forms rear cavity gap (5) with the end wall of shell (31) away from detection end head (32), transducer (33) is installed in mounting bracket (34) and is electrically connected with long strip host (1); Sound absorption piece (6) is arranged in annular gap (4), and the sound absorption piece (6) has at least switchable first state and second state, wherein, The sound absorption piece (6) is configured to avoid the mounting bracket (34) in the radial direction of the shell (31) when in the first state, so that the mounting bracket (34) can be moved axially and installed in the preset position in the shell (31); And be configured to form a sound absorption area in the annular gap (4) when in the second state to reduce the standing wave in the shell (31). The mounting bracket (34) includes a cylindrical tube (341) coaxially arranged in the shell (31) and opposite to the detection end head (32), and the annular gap (4) is formed between the outer wall of the cylindrical tube (341) and the inner wall of the shell (31); 2. The partial discharge tester of claim 1, wherein, The cylindrical tube (341) is made of sound-absorbing material, and a plurality of sound-absorbing portions (3411) are provided on the outer wall of the cylindrical tube (341), and after the mounting bracket (34) is configured to be installed in the preset position in the shell (31), the plurality of sound-absorbing portions (3411) are distributed in the axial direction of the annular gap (4) with the sound absorption piece (6) in the second state, and the projection part of the sound-absorbing portion (3411) and the sound absorption piece (6) in the second state in the axial direction of the annular gap (4) overlaps. A plurality of through holes (3412) are radially provided on the tube wall of the cylindrical tube (341), and the hole diameter of the through hole (3412) gradually increases from the side close to the annular gap (4) to the side in the cylindrical tube (341) in the radial direction of the cylindrical tube (341).

3. The partial discharge tester of claim 2, wherein, The mounting bracket (34) further includes a support portion (342) arranged at the tube opening end of the cylindrical tube (341) away from the detection end head (32), and the transducer (33) is installed in the cylindrical tube (341) and located on the inner surface of the support portion (342).

4. The partial discharge tester of claim 2, wherein, ​ The surface of the support part (342) is provided with a plurality of heat dissipation holes (3421), and the rear cavity gap (5) is formed between the support part (342) and the inner end wall of the shell (31) away from the detection tip (32).

5. The partial discharge tester of claim 4, wherein, The transducer (33) and the long strip-shaped host (1) are electrically connected through a wire (7), the wire (7) extends to the long strip-shaped host (1) after sequentially passing through the end wall of the shell (31) and the inner cavity of the soft probe rod (2) from the shell (31). The mounting rack (34) further comprises a limiting tube (343), the first end of the limiting tube (343) is coaxially connected with the inner end wall of the shell (31) and communicates with the inner cavity of the cylindrical tube (341), the second end of the limiting tube (343) is coaxially connected with the support part (342) and communicates with the inner cavity of the cylindrical tube (341), and part of the wire (7) is located in the limiting tube (343).

6. The partial discharge tester of any one of claims 2 to 5, wherein, The sound absorption member (6) comprises a fluorosilicone rubber film (61), the shell (31) has a first ring shell wall (311) and a second ring shell wall (312), an air cavity (313) is formed between the first ring shell wall (311) and the second ring shell wall (312), the first ring shell wall (311) is close to the mounting rack (34), the second ring shell wall (312) is located on the side of the first ring shell wall (311) away from the mounting rack (34), a plurality of air holes (3111) are formed in the first ring shell wall (311), the fluorosilicone rubber film (61) is sleeved on the air hole (3111) and located in the annular gap (4), wherein, When the external inflation device introduces gas into the air cavity (313), the fluorosilicone rubber film (61) expands in the annular gap (4) and is in a second state; When the external inflation device extracts gas from the air cavity (313), the fluorosilicone rubber film (61) shrinks in the annular gap (4) and is in a first state.

7. The partial discharge tester of claim 6, wherein, The shell (31) is provided with a docking member (8) communicating with the air cavity (313), and the docking member (8) is configured to be connected with an external inflation device.

8. The partial discharge tester of claim 7, wherein, The docking member (8) comprises a first air tube (81), a second air tube (82) and a cap (83), the first air tube (81) is arranged on the end wall of the shell (31) away from the detection tip (32), the length direction of the first air tube (81) is consistent with the length direction of the shell (31), and the first air tube (81) communicates with the air cavity (313), the second air tube (82) is vertically communicated at one end of the first air tube (81) away from the air cavity (313), and the second air tube (82) extends towards the side away from the soft probe rod (2), and the cap (83) is detachably connected with the first air tube (81).

9. The partial discharge tester of claim 8, wherein, The inner wall of the cap (83) is provided with an internal thread, the outer wall of the second air tube (82) close to the tube opening is provided with an external thread, and the cap (83) is threadedly sleeved on the tube opening end of the second air tube (82).

10. The partial discharge tester of any one of claims 1 to 5, wherein, The rear cavity gap (5) is filled with a layer of damping material (9). The rear cavity gap (5) is filled with a layer of damping material (9).

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