A high voltage cable partial discharge tester and method of use thereof

Abstract

The application discloses a kind of high-voltage cable partial discharge tester and its using method, it is related to on-line cable partial discharge detection technical field, and its technical solution key points include, movable arm assembly one, movable arm assembly one includes first half circular shell, first magnetic core half ring fixed therein and secondary induction coil wound on first magnetic core half ring, movable arm assembly two, movable arm assembly two includes second half circular shell, second magnetic core half ring fixed therein, movable arm assembly one, movable arm assembly two are connected by locking piece, locking piece can swing, it is used to control the connection state of movable arm assembly one, movable arm assembly two, splicing interface one, splicing interface two, when being in closed position, first magnetic core half ring and second magnetic core half ring are connected to form complete annular magnetic circuit.The application effectively prevents dust and moisture from invading by glue injection sealing structure, improves the detection stability and reliability, and is convenient for disassembly maintenance and reuse.

Description

Technical Field

[0001] This invention relates to the field of online cable partial discharge detection technology, specifically to a high-voltage cable partial discharge tester and its usage method. Background Technology

[0002] In the operation and maintenance of high-voltage cables, partial discharge detection is a key means of assessing their insulation condition.

[0003] Traditional high-voltage cable partial discharge testers typically employ an open-and-close structure, where two semi-circular housings are fastened together by bolts or clips to form a closed magnetic circuit to sense discharge signals.

[0004] Patent CN112051492B discloses a partial discharge monitoring assembly and device for high-voltage cables. The partial discharge monitoring assembly includes: a first assembly, a second assembly, and a current transformer; the first assembly and the second assembly are detachably connected; a first ring is provided on the first assembly, and a second ring is provided on the second assembly; the radial cross-sections of both the first and second rings are semi-circular; the first and second rings are arranged opposite each other and positioned by insertion to form a channel allowing the high-voltage cable to pass through; the current transformer is fixed to the inner wall of the first ring. This design can reduce the weight of the partial discharge monitoring assembly. While reducing the complexity of the partial discharge monitoring system and shortening its construction cycle, the complex on-site environment makes it easy for impurities such as moisture and dust in the air to penetrate through the joint between the two semi-circular shells, adhering to the surface of the magnetic core or entering the gap in the magnetic circuit. This not only leads to a decrease in the magnetic permeability of the magnetic core and generates measurement errors, but also interferes with the signal acquisition of the induction coil, reducing the signal-to-noise ratio of the detection. Secondly, simple mechanical fastening methods cannot guarantee the long-term sealing and stability of the joint surface. Under equipment vibration or environmental temperature changes, the joint is prone to slight displacement or loosening, resulting in poor magnetic circuit contact, which in turn affects the repeatability and accuracy of the test data, and cannot meet the high reliability requirements of long-term online monitoring. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a high-voltage cable partial discharge tester and its usage method, solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-voltage cable partial discharge tester, comprising:

[0007] The movable arm assembly one includes a first semi-circular shell, a first magnetic core half-ring fixed therein, and a secondary induction coil wound on the first magnetic core half-ring;

[0008] The second movable arm assembly includes a second semi-circular shell and a second magnetic core semi-ring fixed therein. The first movable arm assembly and the second movable arm assembly are connected by a locking member. The locking member can swing and is used to control the connection state of the first movable arm assembly and the second movable arm assembly.

[0009] When in the closed position, the first magnetic core half-ring and the second magnetic core half-ring are connected to form a complete annular magnetic circuit, and the contact surface between the second semi-circular shell and the second splicing interface forms a splicing gap.

[0010] The glue injection locking mechanism is installed on both sides of the first semi-circular shell, and the glue injection locking mechanism includes a glue storage cavity and a fluid channel;

[0011] The gel storage cavity is pre-set with a first sub-cavity and a second sub-cavity;

[0012] One end of the fluid channel is connected to the glue storage cavity, and the other end is connected to the splicing seam;

[0013] When the locking member is in the closed state of movable arm assembly one and movable arm assembly two, it squeezes the glue storage cavity, so that the sealant is injected through the fluid channel and fills the splicing gap.

[0014] The signal processing unit is coupled to the movable arm assembly and is used to amplify and digitize the analog signals collected by the first magnetic core half-ring and the secondary induction coil.

[0015] The main control analysis unit is used to perform time-frequency domain analysis on the digital signals from the receiving signal processing unit, generate PRPD spectra, and identify the discharge type.

[0016] According to the above technical solution, the gel storage cavity includes a sandwich membrane, and a first compartment and a second compartment are provided on the sandwich membrane. A gap is provided between the first compartment and the second compartment, and the first compartment and the second compartment are independent compartments.

[0017] A static mixing tube is provided at the inlet of the fluid channel to mix the components in the first compartment and the second compartment when the sealant is extruded;

[0018] A sealing part is provided between the first compartment and the second compartment and the fluid channel. The sealing part is used to guide the components in the first compartment and the second compartment into the fluid channel. The sealing part is normally closed when not in operation.

[0019] The channel of the sealing part is heat-fused and glued. When the first cavity and the second cavity are compressed, and the channel is subjected to pressure exceeding the threshold, the channel is squeezed open.

[0020] According to the above technical solution, the locking member is hinged to one side of the first semi-circular shell, and the side of the locking member near the glue injection locking mechanism is an elastic extrusion surface. When the locking member sways and fits against the side wall of the first semi-circular shell, it extrudes the glue storage cavity of the glue injection locking mechanism.

[0021] A guide rod is fixedly connected to the side of the locking member away from the movable arm assembly. A limit rod is slidably connected to the guide rod. A nut is threaded to the end of the guide rod. A spring is sleeved between the nut and the limit rod.

[0022] According to the above technical solution, the top of the first magnetic core half ring and the centering screw are respectively provided with an assembly cover plate. The assembly cover plate includes a first semi-circular cover plate and a second semi-circular cover plate. The splicing end of the first semi-circular cover plate and the second semi-circular cover plate are provided with a splicing interface three. The splicing interface three is connected to the splicing gap. The top of the splicing interface three is provided with a micro exhaust hole.

[0023] A sealing ring is fixedly connected to the splicing end of the first semicircular cover plate and the second semicircular cover plate. The sealing ring is located outside the second magnetic core half ring and the first magnetic core half ring. The sealing ring is composed of two protrusions, one concave and one convex. The sealing ring is used to prevent the sealant from contacting the first magnetic core half ring and the second magnetic core half ring.

[0024] The first magnetic core half-ring protrudes from the end of the movable arm assembly, and the flat interface of the sealing ring is misaligned with the splicing interface of the first magnetic core half-ring and the second magnetic core half-ring.

[0025] According to the above technical solution, the middle part of the movable arm assembly one and the movable arm assembly two is provided with an annular groove, and a filling device is engaged in the groove. The filling device is used to fix the partial discharge tester to the cable. The filling device includes an elastic band, and multiple rows of spirally arranged rubber sheets are distributed at equal intervals on the side of the elastic band near the cable. The rubber sheets are sheet-shaped and are used to fill the diameter difference between the partial discharge tester and the cable.

[0026] The two ends of the elastic band overlap and engage, and after the elastic band overlaps and engages, it is adapted to the annular groove. The overlapping area is the overlapping area, and a U-shaped groove and a protrusion are provided in the overlapping area.

[0027] The U-shaped groove is formed at one end of the elastic band, and the protrusion is fixedly connected to the other end of the elastic band. The protrusion is slidably connected to the U-shaped groove.

[0028] According to the above technical solution, at least three centering screws are threaded to the bottom of the movable arm assembly one and movable arm assembly two, and a rubber head is provided at the end of the centering screw near the cable;

[0029] By rotating each centering screw, the partial discharge tester is aligned with the cable axis.

[0030] According to the above technical solution, a positioning device is provided in the splicing interface 2. The positioning device is used to guide the movable arm assembly 1 and the movable arm assembly 2. The positioning device includes a guide pin. The guide pin is fixed in the splicing interface 2. The splicing interface 1 is provided with mutually compatible grooves at the position corresponding to the guide pin.

[0031] The number of guide pins is two;

[0032] Cutting slots are provided on adjacent sides of the two guide pins, and a support strip is fixedly connected in the cutting slots. A cutting blade is provided on the top of the support strip.

[0033] The fluid channel is located between the two cutting slots when the movable arm assembly 2 and movable arm assembly 1 are spliced ​​together.

[0034] The cutting blade is used to cut the fluid channel, and the support bar is used to support the fluid channel.

[0035] According to the above technical solution, the signal processing unit includes a low-noise preamplifier module, an adaptive digital filter module, an analog-to-digital converter module, and a peak hold circuit connected in sequence.

[0036] The low-noise preamplifier module is used to convert weak pulse current signals into voltage signals and perform preliminary amplification.

[0037] The adaptive digital filtering module is used to monitor the field noise spectrum in real time and dynamically adjust the filtering center frequency to suppress narrowband interference.

[0038] The peak hold circuit is used to capture and hold the peak amplitude of the discharge pulse for sampling by the analog-to-digital conversion module.

[0039] A method for using a high-voltage cable partial discharge tester includes the following steps:

[0040] S1: Wrap the filling device around the outside of the cable and splice the two ends of the filling device together;

[0041] S2: Snap the movable arm assembly one and movable arm assembly two onto the outside of the filling device, and align them on the grounding wire of the cable being tested;

[0042] S3: Move the locking part to squeeze the glue storage cavity of the glue injection locking mechanism, push the first and second sub-cavities to open the sealing part, so that the sealant is mixed through the static mixing tube in the fluid channel and injected into the magnetic core splicing gap, and cured to form an elastic sealing layer, while realizing the splicing and fixing of the movable arm assembly one.

[0043] S4: Turn on the tester. The sensor captures the signal, which is amplified by the low-noise preamplifier module and then suppressed by the adaptive digital filter module.

[0044] S5: The main control analysis unit performs time-frequency domain analysis and PRPD spectrum generation on the processed signal, and uses the built-in algorithm to identify the discharge type and severity.

[0045] S6: Display the discharge spectrum and diagnostic results on the human-computer interaction interface, and save the data;

[0046] S7: Periodic cycle from S4 to S6.

[0047] This invention provides a high-voltage cable partial discharge tester and its usage method. It has the following beneficial effects:

[0048] This invention uses a locking component to compress the glue storage cavity of the glue injection locking mechanism, allowing two-component sealant to be injected and filled into the joint gap between movable arm assembly one and movable arm assembly two. After curing, it forms an elastic sealing layer, which not only achieves a reliable seal at the joint, effectively preventing moisture and dust from entering and affecting the detection accuracy, but also simultaneously completes the firm splicing and fixing of the two movable arm assemblies, ensuring the stability of the overall structure.

[0049] In terms of signal processing and analysis, this invention utilizes a low-noise preamplifier module, an adaptive digital filter module, and a peak hold circuit in the signal processing unit to effectively amplify, suppress noise, and capture the weak pulse signal acquired by the magnetic core half-ring. The signal is then analyzed in the time and frequency domain and generated by the main control analysis unit. The built-in algorithm accurately identifies the discharge type and severity, thereby achieving online monitoring of partial discharge in high-voltage cables with high sensitivity, high anti-interference capability, and high diagnostic accuracy.

[0050] This invention provides a high-voltage cable partial discharge tester that achieves stable clamping and precise positioning of cables of different diameters through the coordinated operation of a filling device and centering screws. The rubber sheet spirally arranged inside the elastic band effectively fills the diameter difference between the partial discharge tester and the cable, and ensures the stability of the equipment installation by increasing contact friction, preventing slippage. At the same time, by rotating at least three centering screws, the relative position of the partial discharge tester and the cable can be finely adjusted to align their axes, significantly improving the symmetry and consistency of the detection signal, thereby improving the accuracy and repeatability of partial discharge detection. It is especially suitable for rapid adaptation and high-precision testing of multi-specification cables in complex field environments. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0052] Figure 2This is a schematic diagram of the overall structure of the first explosion of the present invention;

[0053] Figure 3 This is a schematic diagram of the overall second explosion structure of the present invention;

[0054] Figure 4 This is a schematic diagram of the overall positioning device of the present invention;

[0055] Figure 5 This is a schematic diagram of the overall top cross-section of the present invention;

[0056] Figure 6 This invention as a whole Figure 3 A structural diagram of area C;

[0057] Figure 7 This invention as a whole Figure 3 A structural diagram of area B;

[0058] Figure 8 This invention as a whole Figure 5 A schematic diagram of the structure of region D;

[0059] Figure 9 This is a schematic diagram of the overall filling device structure of the present invention;

[0060] Figure 10 This is a schematic diagram of the overall electronic control structure of the present invention.

[0061] In the diagram: 1. Locking component;

[0062] 2. Movable arm assembly one; 201. First semi-circular shell; 202. Splicing interface one; 3. Movable arm assembly two; 301. Second semi-circular shell; 302. Splicing interface two;

[0063] 5. Assemble the cover plate; 501. First semi-circular cover plate; 502. Splicing interface three; 503. Sealing ring; 504. Second semi-circular cover plate;

[0064] 6. Positioning device; 601. Guide pin; 602. Cutting slot; 603. Cutting blade; 604. Support bar;

[0065] 7. First magnetic core half-ring;

[0066] 8. Filling device; 801. Elastic band; 802. Rubber sheet; 803. Overlapping area; 804. U-shaped groove; 805. Plug;

[0067] 9. Glue injection locking mechanism; 901. First cavity; 902. Second cavity; 903. Sealing part; 904. Fluid channel; 905. Interlayer membrane;

[0068] 10. Centering screw; 11. Limiting rod; 12. Guide rod; 13. Spring; 14. Nut; 15. Second magnetic core half ring. Detailed Implementation

[0069] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0070] Please see Figure 1-10 A high-voltage cable partial discharge tester includes a movable arm assembly 2, which includes a first semi-circular shell 201, a first magnetic core half-ring 7 fixed therein, and a secondary induction coil wound on the first magnetic core half-ring 7.

[0071] The second movable arm assembly 3 includes a second semi-circular housing 301 and a second magnetic core semi-ring 15 fixed therein. The first movable arm assembly 2 and the second movable arm assembly 3 are connected by a locking member 1. The locking member 1 can swing and is used to control the connection state of the first movable arm assembly 2 and the second movable arm assembly 3.

[0072] When splicing interface 1 202 and splicing interface 2 302 are in the closed position, the first magnetic core half ring 7 and the second magnetic core half ring 15 are connected to form a complete annular magnetic circuit, and the contact surface between the second semi-circular shell 301 and splicing interface 2 302 forms a splicing gap.

[0073] The glue injection locking mechanism 9 is installed on both sides of the first semi-circular housing 201. The glue injection locking mechanism 9 includes a glue storage cavity and a fluid channel 904.

[0074] The glue storage cavity is pre-installed with a first sub-cavity 901 and a second sub-cavity 902;

[0075] One end of the fluid channel 904 is connected to the glue storage cavity, and the other end is connected to the splicing seam;

[0076] When the locking component 1 is in the closed state of movable arm assembly 1 2 and movable arm assembly 2 3, it squeezes the glue storage cavity, so that the sealant is injected through the fluid channel 904 and fills the splicing gap.

[0077] The signal processing unit is coupled to the movable arm assembly 2 and is used to amplify and digitize the analog signals collected by the first magnetic core half-ring 7 and the secondary induction coil.

[0078] The main control analysis unit is used to perform time-frequency domain analysis on the digital signals from the receiving signal processing unit, generate PRPD spectra, and identify the discharge type.

[0079] Furthermore, the signal processing unit and the main control analysis unit are built into the terminal body, and the main control analysis unit includes a microprocessor and a memory.

[0080] Furthermore, the two-component sealant for the first cavity 901 and the second cavity 902 is an addition-type liquid silicone rubber with a Shore hardness of A20-A50 after curing.

[0081] In use, the movable arm assembly 1 2 and movable arm assembly 2 3 are fitted onto the outside of the cable. Then, the locking piece 1 on one side of the movable arm assembly 1 2 is moved to squeeze the glue storage cavity. This allows the components in the first compartment 901 and the second compartment 902 on that side to be transported into the splicing gap through the fluid channel 904 and fill the splicing gap. This achieves a better sealing effect and prevents moisture and dust from entering between the first magnetic core half ring 7 and the second magnetic core half ring 15 through the gap, thereby affecting the detection effect of the partial discharge tester.

[0082] When the partial discharge tester malfunctions and needs to be replaced or repaired, release the locking part 1, then use a blade to insert into the gap between movable arm assembly 1 2 and movable arm assembly 2 3 to cut the solidified adhesive, or pry it open directly. After repair, the sealant can be softened by heating to remove the residual adhesive. After replacing the new adhesive injection locking mechanism 9, it can continue to be used.

[0083] The adhesive storage cavity includes a sandwich membrane 905, on which a first sub-cavity 901 and a second sub-cavity 902 are provided, with a gap between the first sub-cavity 901 and the second sub-cavity 902, and the first sub-cavity 901 and the second sub-cavity 902 are independent cavities;

[0084] A static mixing tube is provided at the inlet of the fluid channel 904 to mix the components in the first compartment 901 and the second compartment 902 when the sealant is extruded;

[0085] A sealing part 903 is provided between the first compartment 901 and the second compartment 902 and the fluid channel 904. The sealing part 903 is used to guide the components in the first compartment 901 and the second compartment 902 into the fluid channel 904. The sealing part 903 is normally closed when not in operation.

[0086] The channel of the sealing part 903 is heat-fused and glued. When the first cavity 901 and the second cavity 902 are compressed, and the channel is subjected to pressure exceeding the threshold, the channel is squeezed open.

[0087] Furthermore, the interlayer membrane 905 is formed by hot-melting and stacking two plastic sheets, and the first cavity 901 and the second cavity 902 are hollow areas, which store components sequentially;

[0088] The channel of the sealing part 903 is a point-melting area, which will be opened when subjected to greater pressure.

[0089] The locking member 1 is hinged to one side of the first semi-circular housing 201. The side of the locking member 1 near the glue injection locking mechanism 9 is an elastic extrusion surface. When the locking member 1 swings and fits against the side wall of the first semi-circular housing 201, it extrudes the glue storage cavity of the glue injection locking mechanism 9.

[0090] A guide rod 12 is fixedly connected to the side of the locking component 1 away from the movable arm assembly 2. A limit rod 11 is slidably connected to the guide rod 12. A nut 14 is threadedly connected to the end of the guide rod 12. A spring 13 is sleeved between the nut 14 and the limit rod 11.

[0091] Furthermore, the two ends of the second semi-circular shell 301 are provided with arc-shaped slots that are adapted to the limiting rod 11.

[0092] Furthermore, the number of locking components 1 is two.

[0093] In use, by moving the guide rod 12 at the end of the locking part 1, the sliding limit rod 11 on the guide rod 12 is placed in the arc-shaped slot on the movable arm assembly 2 3. Then, the nut 14 is rotated to compress the spring 13 and the limit rod 11, and the force is applied to the splice of the movable arm assembly 1 2 and the movable arm assembly 2 3, thereby fixing the movable arm assembly 1 2 and the movable arm assembly 2 3.

[0094] The top of the first magnetic core semi-ring 7 and the centering screw 10 are respectively provided with an assembly cover plate 5. The assembly cover plate 5 includes a first semi-circular cover plate 501 and a second semi-circular cover plate 504. The splicing ends of the first semi-circular cover plate 501 and the second semi-circular cover plate 504 are provided with a splicing interface 3 502. The splicing interface 3 502 communicates with the splicing gap. The top of the splicing interface 3 502 is provided with a micro exhaust hole.

[0095] A sealing ring 503 is fixedly connected to the splicing end of the first semicircular cover plate 501 and the second semicircular cover plate 504. The sealing ring 503 is located on the outside of the second magnetic core semi-ring 15 and the first magnetic core semi-ring 7. The sealing ring 503 is composed of two protrusions, one concave and one convex. The sealing ring 503 is used to prevent the sealant from contacting the first magnetic core semi-ring 7 and the second magnetic core semi-ring 15.

[0096] The first magnetic core half-ring 7 protrudes from the end of the movable arm assembly 2, and the flat interface of the sealing ring 503 is misaligned with the splicing interface of the first magnetic core half-ring 7 and the second magnetic core half-ring 15.

[0097] Furthermore, the sealing ring 503 separates the splicing gap from the first magnetic core half-ring 7 and the second magnetic core half-ring 15, preventing the sealant from affecting the operation of the first magnetic core half-ring 7 and the second magnetic core half-ring 15.

[0098] The middle of the movable arm assembly 1 2 and movable arm assembly 2 3 is provided with an annular groove, and a filling device 8 is engaged in the groove. The filling device 8 is used to fix the partial discharge tester to the cable. The filling device 8 includes an elastic band 801. Multiple rows of spirally arranged rubber sheets 802 are distributed at equal intervals on the side of the elastic band 801 near the cable. The rubber sheets 802 are sheet-shaped and are used to fill the diameter difference between the partial discharge tester and the cable.

[0099] The two ends of the elastic band 801 overlap and engage. After the elastic band 801 overlaps and engages, it is adapted to the annular groove. The overlapping area is the overlapping area 803. A U-shaped groove 804 and a protrusion 805 are provided in the overlapping area 803.

[0100] A U-shaped groove 804 is formed at one end of the elastic band 801, and a protrusion 805 is fixedly connected to the other end of the elastic band 801. The protrusion 805 and the U-shaped groove 804 are slidably connected.

[0101] Furthermore, rubber sheet 802 is also used to increase friction in contact with the cable.

[0102] Furthermore, in the area where the rubber sheet 802 is installed with the cable, a rough-surfaced tape can be wrapped around the outside of the cable to increase the stability of the connection.

[0103] At least three centering screws 10 are threaded at the bottom of the movable arm assembly 12 and movable arm assembly 23, and a rubber head is provided at the end of the centering screw 10 near the cable.

[0104] By rotating each centering screw 10, the partial discharge tester is aligned with the cable axis.

[0105] Furthermore, the centering screw 10 is located on the bottom side of the first magnetic core half-ring 7 and the second magnetic core half-ring 15.

[0106] Furthermore, both the filling device 8 and the centering screw 10 are made of non-conductive materials.

[0107] Furthermore, the rubber head is used to prevent the centering screw 10 from damaging the cable surface, and also to reduce the impact of vibration on the partial discharge tester.

[0108] In use, the elastic band 801 is unfolded and wrapped around the outside of the cable. Then, the two ends of the elastic band 801 are tightened so that the locking protrusion 805 is locked along the U-shaped locking groove 804. At this time, the rubber sheet 802 on the inner side of the elastic band 801 is inclined to fit against the surface of the cable, and under the compression of the elastic band 801 after locking, a frictional force sufficient to support the partial discharge tester is generated between it and the cable.

[0109] After the movable arm assembly 1 2, movable arm assembly 2 3 and filling device 8 are fully adapted, the axis of the partial discharge tester is roughly aligned with the axis of the cable by rotating the centering screw 10, thereby improving the detection effect of the partial discharge tester and achieving a better fixing effect.

[0110] A positioning device 6 is provided inside the splicing interface 2 302. The positioning device 6 is used to guide the movable arm assembly 1 2 and the movable arm assembly 2 3. The positioning device 6 includes a guide pin 601, which is fixed inside the splicing interface 2 302. The splicing interface 1 202 is provided with mutually compatible grooves at the positions corresponding to the guide pin 601.

[0111] The quantity of guide pin 601 is two;

[0112] Two guide pins 601 are provided with cutting slots 602 on adjacent sides, and a support bar 604 is fixedly connected in the cutting slots 602. A cutting blade 603 is provided on the top of the support bar 604.

[0113] The fluid channel 904 is located between the two cutting slots 602 when the movable arm assembly 2 and movable arm assembly 3 are spliced ​​together.

[0114] The cutting blade 603 is used to cut the fluid channel 904, and the support bar 604 is used to support the fluid channel 904.

[0115] Furthermore, the fluid channel 904 cut by the cutting blade 603 is in an adhered state and is not cut off.

[0116] In use, when the movable arm assembly 1 2 and movable arm assembly 2 3 are inserted and engaged with each other under the guidance of the positioning device 6, the V-shaped openings of the cutting blade 603 and the support bar 604 between the guide pins 601 limit the fluid channel 904 to the cutting area of ​​the cutting blade 603. The fluid channel 904 is disengaged from the cutting blade 603 under the support of the support bar 604, thereby forming an injection port on the fluid channel 904, which facilitates the entry of the sealing film into the splicing gap.

[0117] The signal processing unit includes a low-noise preamplifier module, an adaptive digital filter module, an analog-to-digital converter module, and a peak hold circuit connected in sequence.

[0118] The low-noise preamplifier module is used to convert weak pulse current signals into voltage signals and perform preliminary amplification.

[0119] The adaptive digital filtering module is used to monitor the field noise spectrum in real time and dynamically adjust the filter center frequency to suppress narrowband interference;

[0120] The peak hold circuit is used to capture and hold the peak amplitude of the discharge pulse for sampling by the analog-to-digital converter module.

[0121] A method for using a high-voltage cable partial discharge tester includes the following steps:

[0122] S1: Wrap the filling device 8 around the outside of the cable and splice the two ends of the filling device 8 together;

[0123] S2: Attach movable arm assembly 1 2 and movable arm assembly 2 3 to the outside of filling device 8, and align them on the grounding wire of the cable being tested.

[0124] S3: Move the locking part 1 to squeeze the glue storage cavity of the glue injection locking mechanism 9, push the first cavity 901 and the second cavity 902 to open the sealing part 903, so that the sealant is mixed through the static mixing tube in the fluid channel 904 and injected into the magnetic core splicing gap, and solidified to form an elastic sealing layer, while realizing the splicing and fixing of the movable arm assembly 2.

[0125] S4: Turn on the tester. The sensor captures the signal, which is amplified by the low-noise preamplifier module and then suppressed by the adaptive digital filter module.

[0126] S5: The main control analysis unit performs time-frequency domain analysis and PRPD spectrum generation on the processed signal, and uses the built-in algorithm to identify the discharge type and severity.

[0127] S6: Display the discharge spectrum and diagnostic results on the human-computer interaction interface, and save the data;

[0128] S7: Periodic cycle from S4 to S6.

[0129] Working principle: When in use, first wrap the filling device 8 around the outside of the cable and fix it in place. Then, attach the movable arm assembly 1 2 and movable arm assembly 2 3 to the cable through the filling device 8 and put them on the grounding wire of the cable under test.

[0130] Next, the locking member 1 is moved so that it swings and fits against the side wall of the first semi-circular shell 201, thereby squeezing the glue storage cavity of the glue injection locking mechanism 9, pushing the two-component sealant in the first cavity 901 and the second cavity 902 to open the sealing part 903. The sealant is mixed through the static mixing tube in the fluid channel 904 and then injected into the splicing gap formed by the splicing interface 1 202 and the splicing interface 2 302. After curing, it forms an elastic sealing layer, and at the same time realizes the splicing and fixing of the movable arm assembly 1 2 and the movable arm assembly 2 3.

[0131] At this time, the first magnetic core half-ring 7 and the second magnetic core half-ring 15 are connected to form a complete ring magnetic circuit. The secondary induction coil collects the analog signal generated by the partial discharge of the cable. The signal processing unit amplifies and digitizes it. After receiving the digital signal, the main control analysis unit performs time-frequency domain analysis and generates PRPD spectrum. It uses the built-in algorithm to identify the discharge type and severity and displays the diagnostic results on the human-machine interface. The monitoring task is executed periodically, thereby realizing high-precision and high-reliability online detection of partial discharge of high-voltage cables.

[0132] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-voltage cable partial discharge tester, characterized in that, include: The movable arm assembly (2) includes a first semi-circular shell (201), a first magnetic core half ring (7) fixed therein, and a secondary induction coil wound on the first magnetic core half ring (7); The second movable arm assembly (3) includes a second semi-circular shell (301) and a second magnetic core half ring (15) fixed therein. The first movable arm assembly (2) and the second movable arm assembly (3) are connected by a locking member (1). The locking member (1) can swing and is used to control the connection state of the first movable arm assembly (2) and the second movable arm assembly (3). When splicing interface one (202) and splicing interface two (302) are in the closed position, the first magnetic core half ring (7) and the second magnetic core half ring (15) are connected to form a complete annular magnetic circuit, and the contact surface of the second semi-circular shell (301) and splicing interface two (302) forms a splicing gap. The glue injection locking mechanism (9) is installed on both sides of the first semi-circular shell (201). The glue injection locking mechanism (9) includes a glue storage cavity and a fluid channel (904). The gel storage cavity is pre-set with a first sub-cavity (901) and a second sub-cavity (902). One end of the fluid channel (904) is connected to the glue storage cavity, and the other end is connected to the splicing gap; When the locking member (1) is in the closed state of the movable arm assembly one (2) and the movable arm assembly two (3), it squeezes the glue storage cavity, so that the sealant is injected through the fluid channel (904) and fills the splicing gap. The signal processing unit is coupled to the movable arm assembly (2) and is used to amplify and digitize the analog signals collected by the first magnetic core half ring (7) and the secondary induction coil. The main control analysis unit is used to perform time-frequency domain analysis on the digital signals from the receiving signal processing unit, generate PRPD spectra, and identify the discharge type.

2. The high-voltage cable partial discharge tester according to claim 1, characterized in that: The gel storage cavity includes a sandwich membrane (905), on which a first compartment (901) and a second compartment (902) are provided. A gap is provided between the first compartment (901) and the second compartment (902), and the first compartment (901) and the second compartment (902) are independent compartments. A static mixing tube is provided at the inlet of the fluid channel (904) for mixing the components in the first compartment (901) and the second compartment (902) when the sealant is extruded; A sealing part (903) is provided between the first compartment (901) and the second compartment (902) and the fluid channel (904). The sealing part (903) is used to guide the components in the first compartment (901) and the second compartment (902) into the fluid channel (904). The sealing part (903) is normally closed when not in operation. The channel of the sealing part (903) is heat-fused and glued. When the first cavity (901) and the second cavity (902) are compressed and the channel is subjected to pressure exceeding the threshold, the channel is squeezed open.

3. The high-voltage cable partial discharge tester according to claim 1, characterized in that: The locking member (1) is hinged to one side of the first semi-circular shell (201). The side of the locking member (1) near the glue injection locking mechanism (9) is an elastic extrusion surface. When the locking member (1) swings and fits against the side wall of the first semi-circular shell (201), it extrudes the glue storage cavity of the glue injection locking mechanism (9). The locking member (1) is fixedly connected to a guide rod (12) on the side away from the movable arm assembly (2). A limit rod (11) is slidably connected on the guide rod (12). A nut (14) is threaded to the end of the guide rod (12). A spring (13) is sleeved between the nut (14) and the limit rod (11).

4. A high-voltage cable partial discharge tester according to claim 3, characterized in that: The top of the first magnetic core half ring (7) and the centering screw (10) are respectively provided with an assembly cover plate (5). The assembly cover plate (5) includes a first semi-circular cover plate (501) and a second semi-circular cover plate (504). The splicing ends of the first semi-circular cover plate (501) and the second semi-circular cover plate (504) are provided with a splicing interface three (502). The splicing interface three (502) is connected to the splicing gap. The top of the splicing interface three (502) is provided with a micro exhaust hole. A sealing ring (503) is fixedly connected to the splicing end of the first semicircular cover plate (501) and the second semicircular cover plate (504). The sealing ring (503) is located outside the second magnetic core half ring (15) and the first magnetic core half ring (7). The sealing ring (503) is composed of two protrusions, one concave and one convex. The sealing ring (503) is used to prevent the sealant from contacting the first magnetic core half ring (7) and the second magnetic core half ring (15). The first magnetic core half ring (7) protrudes from the end of the movable arm assembly (2), and the flat interface of the sealing ring (503) is misaligned with the splicing interface of the first magnetic core half ring (7) and the second magnetic core half ring (15).

5. A high-voltage cable partial discharge tester according to claim 1, characterized in that: The movable arm assembly 1 (2) and movable arm assembly 2 (3) are provided with annular slots in the middle, and a filling device (8) is engaged in the slots. The filling device (8) is used to fix the partial discharge tester to the cable. The filling device (8) includes an elastic band (801). The elastic band (801) has multiple rows of spirally arranged rubber sheets (802) evenly distributed on the side near the cable. The rubber sheets (802) are sheet-shaped and are used to fill the diameter difference between the partial discharge tester and the cable. The two ends of the elastic band (801) overlap and engage. After the elastic band (801) overlaps and engages, it is adapted to the annular groove. The overlapping area is the overlapping area (803). The overlapping area (803) is provided with a U-shaped groove (804) and a protrusion (805). The U-shaped groove (804) is formed at one end of the elastic band (801), and the protrusion (805) is fixedly connected to the other end of the elastic band (801). The protrusion (805) is slidably connected to the U-shaped groove (804).

6. A high-voltage cable partial discharge tester according to claim 5, characterized in that: The bottom of the movable arm assembly one (2) and movable arm assembly two (3) are threaded with at least three centering screws (10), and the centering screws (10) are provided with rubber heads at one end near the cable. By rotating each centering screw (10), the partial discharge tester is aligned with the cable axis.

7. A high-voltage cable partial discharge tester according to claim 1, characterized in that: The second splicing interface (302) is provided with a positioning device (6), which is used to guide the first movable arm assembly (2) and the second movable arm assembly (3). The positioning device (6) includes a guide pin (601), which is fixed in the second splicing interface (302). The first splicing interface (202) is provided with a groove that is compatible with each other at the position corresponding to the guide pin (601). The number of guide pins (601) is two; Cutting slots (602) are provided on adjacent sides of the two guide pins (601), and a support strip (604) is fixedly connected in the cutting slots (602). A cutting blade (603) is provided on the top of the support strip (604). The fluid channel (904) is located between the two cutting slots (602) when the movable arm assembly 2 (3) and the movable arm assembly 1 (2) are spliced ​​together; The cutting blade (603) is used to cut the fluid channel (904), and the support bar (604) is used to support the fluid channel (904).

8. A high-voltage cable partial discharge tester according to claim 6, characterized in that: The signal processing unit includes a low-noise preamplifier module, an adaptive digital filter module, an analog-to-digital converter module, and a peak hold circuit connected in sequence. The low-noise preamplifier module is used to convert weak pulse current signals into voltage signals and perform preliminary amplification. The adaptive digital filtering module is used to monitor the field noise spectrum in real time and dynamically adjust the filtering center frequency to suppress narrowband interference. The peak hold circuit is used to capture and hold the peak amplitude of the discharge pulse for sampling by the analog-to-digital conversion module.

9. The method of using a high-voltage cable partial discharge tester as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Wrap the filling device (8) around the outside of the cable and splice the two ends of the filling device (8); S2: Snap the movable arm assembly one (2) and movable arm assembly two (3) onto the outside of the filling device (8) and align them on the grounding wire of the cable to be tested; S3: Move the locking part (1) to squeeze the glue storage cavity of the glue injection locking mechanism (9), push the first cavity (901) and the second cavity (902) to open the sealing part (903), so that the sealant is mixed through the static mixing tube in the fluid channel (904) and injected into the magnetic core splicing gap, and solidified to form an elastic sealing layer, while realizing the splicing and fixing of the movable arm assembly (2); S4: Turn on the tester. The sensor captures the signal, which is amplified by the low-noise preamplifier module and then suppressed by the adaptive digital filter module. S5: The main control analysis unit performs time-frequency domain analysis and PRPD spectrum generation on the processed signal, and uses the built-in algorithm to identify the discharge type and severity. S6: Display the discharge spectrum and diagnostic results on the human-computer interaction interface, and save the data; S7: Periodic cycle from S4 to S6.

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