Partial discharge simulation and detection system for oil valve implanted transformer
By using an oil valve-embedded transformer partial discharge simulation device, a partial discharge defect model is implanted using a metal guide rod and combined with a test transformer and sensor detection. This solves the problem of transformer modification, realizes the simulation and detection of partial discharge inside the transformer, and ensures the insulation performance of the transformer.
Patent Information
- Application Number
- CN202511102814.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-12-12
AI Technical Summary
Existing technologies require modifications to the transformer to simulate partial discharge defects internally, making it impossible to achieve partial discharge detection that is reusable without modification and closely approximates real fault conditions.
A partial discharge simulation device for transformers with an oil valve is used. A partial discharge defect model is implanted inside the transformer through a metal guide rod inserted into the oil valve. The discharge signal is excited by applying voltage to the test transformer, without the need to apply voltage to the transformer body. The device is then used in conjunction with a UHF sensor and an oscilloscope for detection.
It enables the simulation and detection of partial discharge at different locations inside the transformer, protecting the insulation performance of the transformer body. It is simple to operate and reusable, avoiding the risks associated with transformer modification.
Smart Images
Figure CN121114674A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of transformer testing technology, and specifically relates to a partial discharge simulation and detection system for an oil valve-embedded transformer. Background Technology
[0002] Transformers are critical components in power systems, and their health directly impacts the stable operation of the power system. Partial discharge may occur inside a transformer due to design or manufacturing issues, or long-term insulation aging. As the degree of partial discharge deepens, the overall insulation strength of the transformer rapidly declines, potentially leading to serious failures. Partial discharge is a significant cause of transformer insulation degradation; timely detection of partial discharge within the transformer can effectively prevent further losses.
[0003] Research on partial discharge detection inside transformers requires simulating partial discharge defects of different discharge types within the transformer. However, existing technologies require modification of the transformer to create defects inside to simulate partial discharge. Therefore, this invention develops a partial discharge defect simulation method that requires no transformer modification, is reusable, and closely approximates real-world transformer fault conditions, and proposes a corresponding partial discharge detection system. Summary of the Invention
[0004] This invention provides a partial discharge simulation device for oil valve-implanted transformers. A defect implantation kit is used to insert a partial discharge defect into the transformer interior through the oil valve. The high-voltage electrode of the partial discharge defect is connected to the metal part of the implantation kit, and the ground electrode is connected to the transformer tank. A power frequency voltage is applied to the implantation kit through an external partial discharge-free test transformer. The partial discharge defect inside the transformer is excited, generating a partial discharge signal. By changing the insertion distance of the implantation kit, the simulation of partial discharge occurring at different locations inside the transformer can be achieved. A UHF sensor is installed on the side wall of the transformer tank, and the UHF partial discharge signal is acquired using an oscilloscope. This system can simulate and detect different types of discharges, such as tip discharges, floating discharges, surface discharges, and air gap discharges, at different locations inside the transformer.
[0005] The technical solution adopted by this invention to solve its technical problem is:
[0006] A partial discharge simulation and detection system for transformers with an oil valve implantation method is disclosed. The system uses a metal guide rod to implant a partial discharge defect model into the transformer through an oil valve. The system uses a test transformer to apply voltage to excite a discharge signal, and can generate a near-realistic partial discharge signal inside the transformer without applying voltage to the transformer body.
[0007] Preferably, the system includes: a transformer housing and a defect implantation kit; the defect implantation kit is installed on the side wall of the transformer housing and is used to implant a partial discharge defect model from the oil valve of the transformer housing into the interior of the transformer housing.
[0008] Preferably, the defect implantation kit includes: a metal guide rod, an insulating sleeve, and a ball valve; the metal guide rod extends into the transformer tank from inside the insulating sleeve through the ball valve.
[0009] Preferably, the defect implantation kit further includes: a partial discharge defect model; the partial discharge defect model is installed at the end of the metal guide rod, and the position of the partial discharge defect model inside the transformer tank can be changed by changing the length of the metal guide rod.
[0010] Preferably, the defect implantation kit further includes a valve; the valve remains closed when no partial discharge defect model is installed.
[0011] Preferably, the partial discharge defect model can be implanted without modification by changing the opening and closing state of the valve.
[0012] Preferably, when installing the partial discharge defect model, first install the partial discharge defect model at the bottom of the metal guide rod, then install the metal guide rod and insulating sleeve on the flange of the ball valve; open the valve, and then push the metal guide rod into the transformer tank to complete the implantation of the partial discharge defect model.
[0013] Preferably, the system further includes: a test transformer; the test transformer is connected to a metal conductor rod, and a voltage is applied to the partial discharge defect model at the end of the metal conductor rod to generate a partial discharge defect fault.
[0014] Preferably, the partial discharge defect model includes a tip discharge defect model, a floating discharge defect model, a surface discharge defect model, and an air gap discharge defect model.
[0015] Preferably, the system further includes: an ultra-high frequency sensor; the ultra-high frequency sensor is installed on the side of the transformer tank and is used to detect ultra-high frequency signals of partial discharge.
[0016] Preferably, the system further includes an oscilloscope; the oscilloscope is connected to the ultra-high frequency sensor, and the partial discharge ultra-high frequency signal is transmitted to the oscilloscope through a signal connection line.
[0017] The technical advantages of this invention are as follows:
[0018] This invention provides an oil valve-implanted transformer partial discharge simulation and detection system. A partial discharge defect model is implanted into the transformer via an oil valve using a metal guide rod. A voltage is applied to the test transformer to trigger a discharge signal. This system generates near-realistic partial discharge signals inside the transformer without applying voltage to the transformer itself, ensuring that the transformer's insulation performance is not degraded by partial discharge. Compared to existing partial discharge defect model implantation methods that require modification of the transformer or slinging, this invention allows for unmodified implantation of the partial discharge defect model by changing the valve's on / off state. Furthermore, by changing the length of the metal guide rod, partial discharge defects at different locations inside the transformer can be simulated. The partial discharge defect model can also be replaced entirely, making the operation convenient and simple. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of an unimplanted defect in one embodiment of the present invention;
[0020] Figure 2 This is a schematic diagram of implantation defects in one embodiment of the present invention;
[0021] Figure 3 This is a schematic diagram of a tip discharge defect model in one embodiment of the present invention;
[0022] Figure 4 This is a schematic diagram of a surface discharge defect model in one embodiment of the present invention;
[0023] Figure 5 This is a schematic diagram of a floating discharge defect model in one embodiment of the present invention;
[0024] Figure 6 This is a schematic diagram of an air gap discharge defect model in one embodiment of the present invention;
[0025] Figure 7 This is a PRPD spectrum of a tip discharge in one embodiment of the present invention;
[0026] Figure 8 This is a PRPD spectrum of surface discharge in one embodiment of the present invention;
[0027] Figure 9 This is a PRPD spectrum of suspended discharge in one embodiment of the present invention;
[0028] Figure 10 This is a PRPD spectrum of air gap discharge in one embodiment of the present invention. Detailed Implementation
[0029] The following will refer to the appendix. Figures 1 to 10Specific embodiments of the invention are described in detail below. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.
[0030] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.
[0031] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.
[0032] In one embodiment, the present invention provides an oil valve implanted transformer partial discharge simulation and detection system. The system uses a metal guide rod to implant a partial discharge defect model into the transformer through an oil valve, and uses a test transformer to apply voltage to excite a discharge signal. The system can generate a near-realistic partial discharge signal inside the transformer without applying voltage to the transformer body.
[0033] In another embodiment, the system includes: a transformer housing and a defect implantation kit; the defect implantation kit is installed on the side wall of the transformer housing and is used to implant a partial discharge defect model from the oil valve of the transformer housing into the interior of the transformer housing.
[0034] In another embodiment, the defect implantation kit includes: a metal guide rod, an insulating sleeve, and a ball valve; the metal guide rod extends from inside the insulating sleeve into the transformer tank through the ball valve.
[0035] In another embodiment, the defect implantation kit further includes: a partial discharge defect model; the partial discharge defect model is installed at the end of the metal guide rod, and the position of the partial discharge defect model inside the transformer tank can be changed by changing the length of the metal guide rod.
[0036] In another embodiment, the defect implantation kit further includes a valve; the valve remains closed when the partial discharge defect model is not installed.
[0037] In another embodiment, the partial discharge defect model can be implanted without modification by changing the on / off state of the valve.
[0038] In another embodiment, when installing the partial discharge defect model, the partial discharge defect model is first installed at the bottom of the metal guide rod, and then the metal guide rod and insulating sleeve are installed on the flange of the ball valve; the valve is opened, and then the metal guide rod is pushed into the transformer tank to complete the implantation of the partial discharge defect model.
[0039] In another embodiment, the system further includes: a test transformer; the test transformer is connected to a metal conductor rod, and a voltage is applied to a partial discharge defect model at the end of the metal conductor rod to generate a partial discharge defect fault.
[0040] In another embodiment, the partial discharge defect model includes a tip discharge defect model, a floating discharge defect model, a surface discharge defect model, and an air gap discharge defect model.
[0041] In another embodiment, the system further includes: an ultra-high frequency sensor; the ultra-high frequency sensor is mounted on the side of the transformer tank and is used to detect ultra-high frequency signals of partial discharge.
[0042] In another embodiment, the system further includes an oscilloscope; the oscilloscope is connected to the ultra-high frequency sensor, and the partial discharge ultra-high frequency signal is transmitted to the oscilloscope via a signal connection line.
[0043] In another embodiment, the present invention provides a partial discharge simulation and detection system for an oil valve-embedded transformer, referring to... Figure 1 The system includes a transformer housing 1, an iron core 2, windings 3, an ultra-high frequency sensor 4, an oscilloscope 5, a test transformer 6, a metal guide rod 7, an insulating bushing 8, a ball valve 9, a partial discharge defect model 10, and a valve 11.
[0044] A metal guide rod 7 extends into the transformer from inside the insulating bushing 8 through a ball valve 9. A partial discharge defect model 10 is installed at the end of the metal guide rod 7. The position of the partial discharge defect model 10 inside the transformer can be changed by altering the length of the metal guide rod 7. When the partial discharge defect model 10 is not installed, the valve 11 remains closed.
[0045] In another embodiment, refer to Figure 2 At this point, the partial discharge defect model is being implanted. When installing the partial discharge defect model 10, first install the partial discharge defect model 10 at the bottom of the metal guide rod 7, then install the metal guide rod 7 and the insulating sleeve 8 onto the flange of the ball valve 9. Open the valve 11, and then push the metal guide rod 7 into the transformer to complete the implantation of the partial discharge defect model.
[0046] By connecting the metal conductor rod 7 to the test transformer 6, a voltage is applied to the partial discharge defect model 10 at the end of the metal conductor rod to generate a partial discharge defect fault. The partial discharge defect models include a tip discharge defect model, a floating discharge defect model, a surface discharge defect model, and an air gap discharge defect model.
[0047] A UHF sensor 4 is installed on the side of the transformer housing. The detected UHF partial discharge signal is transmitted to the oscilloscope 5 through the signal connection line.
[0048] Oscilloscope 5 is used to acquire the output signals of the UHF sensors. By analyzing the signals detected by different sensors, the time delay of the partial discharge signal reaching different UHF sensors is analyzed, and the distance from the partial discharge source to different sensors is calculated to locate the partial discharge. Simultaneously, the partial discharge time-domain signal and the test transformer voltage signal are converted into PRPD spectra. The phase of the discharge is determined using the voltage signal, and the PRPD spectra are plotted. Figure 7 As shown. Statistical spectral characteristics used to study different forms of discharge.
[0049] In another embodiment, refer to Figure 3 The partial discharge defect model includes a screw hole 31, a high-voltage electrode holder 32, a high-voltage electrode 33, an oil-paper insulating medium 34, a low-voltage electrode 35, and an epoxy resin shell 36. The screw hole 31 is used to connect to the metal guide rod 7. The high-voltage electrode 33 is connected to the high-voltage electrode holder 32 via threads. The oil-paper insulating medium 34 is bonded to the low-voltage electrode 35 using polyvinyl alcohol. The low-voltage electrode 35, the high-voltage electrode holder 32, and the epoxy resin shell 36 are connected by threads to ensure the stability of the overall structure. Preferably, the screw hole 31 has a diameter of 12 mm, the high-voltage electrode holder and the low-voltage electrode have diameters of 40 mm, the high-voltage electrode has a diameter of 5 mm, and the epoxy resin shell has a diameter of 55 mm. The high-voltage electrode holder 32 is fixedly connected to the bottom end of the metal guide rod 7 via the screw hole 31, used to fix the partial discharge defect and provide a high-voltage potential. The high-voltage electrode 33 is made of tungsten carbide needle tip and is welded to the high-voltage electrode holder 32. The oil-paper insulating medium 34 is transformer insulating oil paper, the low-voltage electrode 35 is used to house the oil-paper insulating medium 34, and the epoxy resin shell 36 is used to fix and connect the high-voltage electrode holder 32 and the low-voltage electrode 35. The PRPD spectrum of the tip discharge is shown below. Figure 7 As shown, a clear polarity effect is observed, which mainly occurs at the voltage peak position, and the discharge amplitude of the negative half-cycle is higher than that of the positive half-cycle.
[0050] In another embodiment, refer to Figure 4The surface discharge defect model includes a screw hole 41, a high-voltage electrode base 42, a surface high-voltage electrode 43, an oil-paper insulating medium 44, a low-voltage electrode 45, and an epoxy resin shell 46. The screw hole 41 is used to connect to the metal guide rod 7. The surface high-voltage electrode 43 is connected to the high-voltage electrode base 42 by threads. The oil-paper insulating medium 44 is bonded to the low-voltage electrode 45 using polyvinyl alcohol. The low-voltage electrode 45, the high-voltage electrode base 42, and the epoxy resin shell 46 are connected by threads to ensure the stability of the overall structure. Preferably, the screw hole 41 has a diameter of 12 mm, the high-voltage electrode base 42 and the low-voltage electrode 45 have a diameter of 40 mm, the surface high-voltage electrode 43 has a diameter of 10 mm, and the epoxy resin shell has a diameter of 55 mm. The surface high-voltage electrode 43 is a brass cylinder with rounded edges to prevent sharp discharge at the edges of the surface discharge electrode. The PRPD spectrum of the surface discharge is shown below. Figure 8 As shown, during the voltage amplitude decrease, charge accumulates on the surface of the oil-paper insulating medium 44, forming surface charge, which reduces the local electric field strength on the high-voltage electrode side. Therefore, surface discharge is mainly concentrated on the positive half-cycle voltage rising edge and the negative half-cycle voltage falling edge.
[0051] In another embodiment, refer to Figure 5 The levitation discharge defect model includes a screw hole 51, a high-voltage electrode holder 52, a levitation high-voltage electrode 53, a levitation discharge kit 54, a low-voltage electrode 55, a metal disc 56, and an epoxy resin shell 57. The screw hole 51 is used to connect to the metal guide rod 7. The levitation high-voltage electrode 53 is connected to the high-voltage electrode holder 52 via threads. The levitation discharge kit 54 is directly pressed and fixed by the levitation high-voltage electrode 53 and the low-voltage electrode 55. The low-voltage electrode 55 is connected to the high-voltage electrode holder 52 and the epoxy resin shell 57 via threads, ensuring the stability of the overall structure. Preferably, the diameter of the screw hole 51 is 12 mm, the diameters of the high-voltage electrode holder 52 and the low-voltage electrode 55 are 40 mm, and the diameter of the epoxy resin shell is 55 mm. The levitation discharge kit consists of three layers of oil-paper insulating medium and a metal disc. The middle layer of oil-paper insulating medium has a central open hole structure, where a metal disc with a diameter of 3 mm is placed. The PRPD spectrum of the levitation discharge is shown below. Figure 9 As shown, the suspended defect spectrum has a flat shape, a wide phase coverage, and a large discharge amplitude.
[0052] In another embodiment, refer to Figure 6The air gap discharge defect model includes a screw hole 61, a high-voltage electrode holder 62, an air gap high-voltage electrode 63, an air gap discharge kit 64, a low-voltage electrode 65, and an epoxy resin shell 66. The screw hole 61 is used to connect to the metal guide rod 7. The air gap high-voltage electrode 63 is connected to the high-voltage electrode holder 62 via threads. The air gap discharge kit 64 is directly pressed and fixed by the air gap high-voltage electrode 63 and the low-voltage electrode 65. The low-voltage electrode 65 is threadedly connected to the high-voltage electrode holder 62 and the epoxy resin shell 66, ensuring the stability of the overall structure. Preferably, the diameter of the screw hole 61 is 12mm, the diameters of the high-voltage electrode holder 62 and the low-voltage electrode 65 are 40mm, and the diameter of the epoxy resin shell is 55mm. The air gap discharge kit consists of three layers of oil-paper insulating medium, wherein the middle layer of oil-paper insulating medium has a central open hole structure with a pore diameter of 5mm, containing air. The PRPD spectrum of the air gap discharge is shown below. Figure 10 As shown, the initial discharge voltage of the air gap defect is low, and the spectrum at the start of discharge is "turtle back" shaped, with the phase mainly distributed at the rising edge of the positive half-cycle and the falling edge of the negative half-cycle of the applied voltage.
[0053] This invention also provides a method for simulating and detecting partial discharge in an oil valve-embedded transformer, comprising:
[0054] The partial discharge defect model is mounted on the bottom of the metal guide rod;
[0055] Install the metal guide rod and insulating sleeve on the flange of the ball valve;
[0056] Open the valve and push the metal guide rod into the transformer to complete the implantation of the partial discharge defect model;
[0057] By connecting a metal conductor rod to a test transformer, a voltage is applied to the partial discharge defect model at the end of the metal conductor rod to generate a partial discharge defect fault.
[0058] The transformer housing is equipped with an ultra-high frequency sensor on its side to detect ultra-high frequency signals of partial discharge;
[0059] The detected partial discharge UHF signal is transmitted to an oscilloscope via a signal connection line. By analyzing the signals detected by different sensors, the partial discharge localization algorithm is studied. At the same time, the partial discharge time-domain signal and the test transformer voltage signal are converted into PRPD spectra to study the statistical spectrum characteristics of different forms of discharge.
[0060] The foregoing general description of the invention and its specific embodiments should not be construed as limiting the technical solution of the invention. Those skilled in the art, based on the disclosure of this invention, can add, reduce, or combine the inventive technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the invention, to form other technical solutions within the scope of protection of this invention.
Claims
1. A partial discharge simulation and detection system for an oil valve-embedded transformer, characterized in that, The system uses a metal guide rod to implant a partial discharge defect model into the transformer through an oil valve. It uses the test transformer to apply voltage to excite the discharge signal, and can generate a near-realistic partial discharge signal inside the transformer without applying voltage to the transformer body.
2. The system according to claim 1, characterized in that, Preferably, the system includes: a transformer housing and a defect implantation kit; The defect implantation kit is installed on the side wall of the transformer tank and is used to implant the partial discharge defect model from the oil valve of the transformer tank into the inside of the transformer tank.
3. The system according to claim 1, characterized in that, The defect implantation kit includes: a metal guide rod, an insulating sleeve, and a ball valve; The metal guide rod extends from inside the insulating bushing into the transformer tank through a ball valve.
4. The system according to claim 3, characterized in that, The defect implantation kit also includes: a partial discharge defect model; A partial discharge defect model is installed at the end of the metal guide rod. The position of the partial discharge defect model inside the transformer tank can be changed by changing the length of the metal guide rod.
5. The system according to claim 4, characterized in that, The defect implantation kit also includes a valve; the valve remains closed when no partial discharge defect model is installed.
6. The system according to claim 5, characterized in that, The partial discharge defect model can be implanted without modification by changing the opening and closing state of the valve.
7. The system according to claim 4, characterized in that, The system also includes: a test transformer; A test transformer is connected to a metal conductor rod. A voltage is applied to the partial discharge defect model at the end of the metal conductor rod to generate a partial discharge defect fault.
8. The system according to claim 4, characterized in that, The partial discharge defect models include the tip discharge defect model, the floating discharge defect model, the surface discharge defect model, and the air gap discharge defect model.
9. The system according to claim 1, characterized in that, The system also includes: an ultra-high frequency sensor; The ultra-high frequency sensor is installed on the side of the transformer tank to detect ultra-high frequency signals of partial discharge.
10. The system according to claim 9, characterized in that, The system also includes: an oscilloscope; The oscilloscope is connected to the ultra-high frequency sensor, and the partial discharge ultra-high frequency signal is transmitted to the oscilloscope through a signal connection line.