Anti-interference stable partial discharge sensor
By setting multiple shielding layers and filling the partial discharge sensor housing with specific particulate materials, the problem of anti-interference of the sensor in strong electromagnetic fields and mechanical vibration environments is solved, and the stability of signal output and positioning accuracy are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-03-31
AI Technical Summary
Existing partial discharge sensors have insufficient anti-interference performance in strong electromagnetic fields and mechanical vibration environments, resulting in unstable signal output and decreased positioning accuracy and long-term monitoring reliability.
Three shielding layers are set inside the sensor housing, including a conductive layer, a permalloy intermediate layer, and a copper inner lining layer, and filled with soft magnetic particles and heavy metal particles to build a collaborative anti-interference system. Electromagnetic and mechanical interference energy is consumed through eddy current loss and inertial friction.
It improves the stability of sensor signal output in strong interference environments, reduces false alarm rate, and enhances positioning accuracy and long-term monitoring reliability.
Smart Images
Figure CN121763018A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of partial discharge sensor technology, specifically relating to an anti-interference stable partial discharge sensor. Background Technology
[0002] Partial discharge (PD) sensors are specialized sensors used to detect partial discharge phenomena in electrical equipment. Their core function is to monitor the insulation status of equipment in real time by capturing weak discharge signals caused by concentrated electric fields, insulation aging, or defects within the insulating material. When partial discharge exists inside electrical equipment, it generates characteristic signals such as electromagnetic waves, ultrasonic waves, optical signals, or chemical gases. PD sensors receive these signals with high sensitivity and convert them into quantifiable electrical signals, thereby analyzing key parameters such as discharge intensity, frequency, and location.
[0003] Due to the complex operating environment of electrical equipment, the strong electromagnetic field generated by high-voltage equipment in the substation may introduce induced noise into the sensor circuit through electromagnetic coupling. In addition, the vibration of nearby mechanical equipment may interfere with the weak signal acquisition module of the sensor through structural conduction. These interference signals overlap with the frequency band of the characteristic signal generated by partial discharge, causing the sensor output data to drift or false alarm, directly reducing the discharge positioning accuracy and the reliability of quantitative analysis, and weakening its long-term monitoring stability requirements. Summary of the Invention
[0004] The purpose of this invention is to provide an anti-interference stable partial discharge sensor to solve the problem of insufficient anti-interference performance of existing partial discharge sensors mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: an anti-interference stable partial discharge sensor, comprising... Back cover; The front cover is mounted on the front surface of the rear shell; The front cover is equipped with a shielding assembly, which includes a conductive layer, a permalloy intermediate layer, and a copper inner liner layer arranged sequentially from the outside to the inside. In use, the conductive layer shields high-frequency electromagnetic fields, while the permalloy intermediate layer is a high-permeability magnetic material that can shield low-frequency magnetic fields. The copper inner liner layer further absorbs residual electromagnetic waves. Since the three are separated by a first particle mixing layer, direct contact is avoided to prevent the formation of an electrical continuum that could cause eddy current interference, while vibration attenuation is achieved. A first cavity is formed between the conductive layer and the permalloy intermediate layer, and a second cavity is formed between the permalloy intermediate layer and the copper inner liner layer. The first cavity is filled with a first particle mixture layer, while the second cavity is filled with a second particle mixture layer.
[0006] In a preferred embodiment of this invention, the first particle mixing layer comprises soft magnetic particles. These soft magnetic particles are formed by mixing micron-sized carbonyl iron powder as the main absorber with insulating silicon nitride ceramic microspheres in a volume ratio. The dry, loose powder state of the first particle mixing layer is sealed within a first cavity. When an external time-varying electromagnetic field penetrates the conductive layer and acts on this particle layer, the individual carbonyl iron powder particles, due to their size being much smaller than the wavelength of the electromagnetic wave, generate strong eddy currents and hysteresis losses, converting electromagnetic energy into heat energy. The weak displacement and friction between particles further consume energy. The greater the interference field strength, the more intense the microscopic eddy currents and magnetization effects of the particles, exhibiting nonlinearly enhanced attenuation characteristics, thus achieving adaptive dynamic suppression.
[0007] As a preferred technical solution of the present invention, the volume ratio of the micron-sized carbonyl iron powder to the silicon nitride ceramic microspheres is 7:3. The carbonyl iron powder particles are passivated with phosphate to form an insulating layer to prevent conductive agglomeration between particles. The ceramic microspheres serve as a dispersion medium to ensure that the particles are in a loose and slightly movable physical state.
[0008] In a preferred embodiment of this invention, the second particle mixing layer comprises tungsten alloy microspheres and a mixture formed in dimethyl silicone oil. The tungsten alloy microspheres have a diameter of 0.5–2 mm, providing high quality and inertia. The silicone oil, as a viscous medium, has a carefully selected viscosity and a flat viscosity-temperature curve. Inside the sensor, this mixture exists as a non-flowing, paste-like semi-solid. The tungsten microspheres are approximately suspended in the silicone oil, with tiny gaps between them. When external vibrations are transmitted to this layer through the structure, the tungsten microspheres undergo slight relative motion due to inertia. This motion is constrained by the strong viscous resistance of the silicone oil, and the vibrational kinetic energy is rapidly converted into heat energy dissipation through the internal friction of the silicone oil. Vibrations of different frequencies will excite the dominant motion of tungsten microspheres of different sizes, thereby broadening the effective vibration suppression frequency band. The entire system remains stable over a long period without sedimentation or separation.
[0009] As a preferred technical solution of the present invention, the end faces of the conductive layer, the permalloy intermediate layer, and the copper inner lining layer are flush with each other and are all in contact with the inner end face of the rear shell.
[0010] As a preferred technical solution of the present invention, at least two silicone damping rings are provided between the conductive layer and the permalloy intermediate layer, and between the permalloy intermediate layer and the copper inner liner layer, and the first cavity and the second cavity are both sealed chambers formed by the silicone damping rings.
[0011] As a preferred technical solution of the present invention, the top of the rear shell is connected to a connector, and the top of the conductive layer, the permalloy intermediate layer and the copper inner lining layer are all provided with slots for the connector to be inserted, and a sealing ring is provided at the connection between the connector and the three, so as to achieve sealing.
[0012] As a preferred technical solution of the present invention, the cross-sections of the rear shell and the front cover are equal, and the two are fixed together by bolts or adhesive.
[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention constructs a synergistic anti-interference system by setting three shielding layers inside the sensor housing, forming two independent cavities, and filling them with heavy metal damping particles and soft magnetic absorbing particles respectively. The heavy metal particles in the inner cavity, mixed with a viscous medium, efficiently absorb mechanical vibration energy through inertial friction, especially suppressing low- and mid-frequency vibration interference. Meanwhile, the soft magnetic particles in the outer cavity generate nonlinear eddy current losses in response to external time-varying electromagnetic fields; the stronger the interference, the more pronounced the absorption, thus adaptively suppressing high-frequency electromagnetic noise. This all-mechanical structure significantly improves the signal output stability of the sensor under strong interference environments, reduces the false alarm rate, and simultaneously enhances positioning accuracy and long-term monitoring reliability. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is a schematic diagram showing the distribution of the first particle mixing layer and the second particle mixing layer within the front cover of the present invention; Figure 4 This is a schematic diagram of the silicone damping ring of the present invention.
[0015] In the picture: 100. Rear shell; 101. Front cover; 102. Connector; 200. Conductive layer; 201. Permalloy intermediate layer; 202. Copper inner liner; 203. Silicone damping ring; 204. First particle mixing layer; 205. Second particle mixing layer. Detailed Implementation
[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0017] Please see Figures 1 to 4 This invention provides a technical solution: an anti-interference stable partial discharge sensor, comprising... Back cover 100; The front cover 101 is mounted on the front surface of the rear cover 100; The front cover 101 is equipped with a shielding assembly, which includes a conductive layer 200, a permalloy intermediate layer 201, and a copper inner liner layer 202, which are sequentially arranged from the outside to the inside. In use, the conductive layer 200 shields high-frequency electromagnetic fields, while the permalloy intermediate layer 201 is a high-permeability magnetic material that can shield low-frequency magnetic fields. The copper inner liner layer 202 further absorbs residual electromagnetic waves. Since the three are separated by a first particle mixing layer 204, direct contact is avoided to form an electric continuum that would cause eddy current interference, while vibration attenuation is achieved. A first cavity is formed between the conductive layer 200 and the permalloy intermediate layer 201, and a second cavity is formed between the permalloy intermediate layer 201 and the copper inner liner layer 202. The first cavity is filled with a first particle mixing layer 204, while the second cavity is filled with a second particle mixing layer 205.
[0018] In this embodiment, the first particle mixing layer 204 is composed of soft magnetic particles. These soft magnetic particles are formed by mixing micron-sized carbonyl iron powder as the main absorber with insulating silicon nitride ceramic microspheres in a volume ratio. The dry, loose powder state of the first particle mixing layer 204 is sealed within the first cavity. When an external time-varying electromagnetic field penetrates the conductive layer 200 and acts on this particle layer, the individual carbonyl iron powder particles, due to their size being much smaller than the wavelength of the electromagnetic wave, will generate strong eddy currents and hysteresis losses, converting electromagnetic energy into heat energy. The weak displacement and friction between particles further consume energy. The greater the interference field strength, the more intense the microscopic eddy currents and magnetization effects of the particles, exhibiting nonlinearly enhanced attenuation characteristics, thus achieving adaptive dynamic suppression.
[0019] In this embodiment, the volume ratio of micron-sized carbonyl iron powder to silicon nitride ceramic microspheres is 7:3. The carbonyl iron powder particles are passivated with phosphate to form an insulating layer to prevent conductive agglomeration between particles. The ceramic microspheres serve as a dispersion medium to ensure that the particles are in a loose and slightly movable physical state.
[0020] In this embodiment, the second particle mixing layer 205 is a mixture of tungsten alloy microspheres and dimethyl silicone oil. The tungsten alloy microspheres have a diameter of 0.5–2 mm, providing high quality and inertia. The silicone oil, as a viscous medium, has a carefully selected viscosity and a flat viscosity-temperature curve. Inside the sensor, this mixture is a non-flowing, paste-like semi-solid. The tungsten microspheres are approximately suspended in the silicone oil, with tiny gaps between them. When external vibrations are transmitted to this layer through the structure, the tungsten microspheres undergo slight relative motion due to inertia. This motion is constrained by the strong viscous resistance of the silicone oil, and the vibrational kinetic energy is rapidly converted into heat energy and dissipated through the internal friction of the silicone oil. Vibrations of different frequencies will excite the dominant motion of tungsten microspheres of different sizes, thereby broadening the effective vibration suppression frequency band. The entire system remains stable over a long period without sedimentation or separation.
[0021] In this embodiment, the end faces of the conductive layer 200, the permalloy intermediate layer 201, and the copper inner lining layer 202 are flush with each other and are all in contact with the inner end face of the rear shell 100.
[0022] In this embodiment, at least two silicone damping rings 203 are provided between the conductive layer 200 and the permalloy intermediate layer 201, and between the permalloy intermediate layer 201 and the copper inner liner layer 202. The first cavity and the second cavity are both sealed chambers formed by the silicone damping rings 203.
[0023] In this embodiment, the top of the rear shell 100 is connected to a connector 102. The tops of the conductive layer 200, the permalloy intermediate layer 201, and the copper inner lining layer 202 are all provided with slots for the connector 102 to be inserted into, and a sealing ring is provided at the connection between the connector 102 and the three components to achieve sealing.
[0024] In this embodiment, the rear shell 100 and the front cover 101 have the same cross-section, and the two are fixed together by bolts or adhesive.
[0025] Although embodiments of the invention have been shown and described (see the detailed description above), it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An anti-interference stable partial discharge sensor, comprising a rear shell (100); a front cover (101) mounted at the front surface of the rear shell (100); characterized in that: an inner part of the front cover (101) is provided with a shielding assembly, which comprises, from outside to inside, a conductive layer (200), a permalloy intermediate layer (201), and a copper inner lining layer (202); a first clamping cavity is formed between the conductive layer (200) and the permalloy intermediate layer (201), and a second clamping cavity is formed between the permalloy intermediate layer (201) and the copper inner lining layer (202); the first clamping cavity is filled with a first particle mixture layer (204), and the second clamping cavity is filled with a second particle mixture layer (205).
2. The anti-interference stable partial discharge sensor according to claim 1, characterized in that: The first particle mixture layer (204) is a soft magnetic particle, which is mixed with insulating silicon nitride ceramic microbeads in a volume ratio with micron-sized carbonyl iron powder as the main absorber.
3. The anti-interference stable partial discharge sensor according to claim 2, characterized in that: The volume ratio of micron-sized carbonyl iron powder to silicon nitride ceramic microbeads is 7:3, wherein the surface of the carbonyl iron powder particles is subjected to phosphate passivation treatment.
4. The anti-interference stable partial discharge sensor according to claim 1, characterized in that: The second particle mixture layer (205) is a mixture of tungsten alloy pellets and dimethyl silicone oil, wherein the tungsten alloy pellets have a diameter of 0.5-2 mm.
5. The anti-interference stable partial discharge sensor according to claim 1, characterized in that: The end faces of the conductive layer (200), the permalloy intermediate layer (201), and the copper inner lining layer (202) are flush and are all attached to the inner end face of the rear shell (100).
6. The anti-interference stable partial discharge sensor according to claim 1, characterized in that: At least two silica gel damping rings (203) are arranged between the conductive layer (200) and the permalloy intermediate layer (201), and between the permalloy intermediate layer (201) and the copper inner lining layer (202), and the first clamping cavity and the second clamping cavity are both formed into sealed chambers by the silica gel damping rings (203).
7. The anti-interference stable partial discharge sensor according to claim 6, characterized in that: A connecting head (102) is connected to the top of the rear shell (100), and the top of each of the conductive layer (200), the permalloy intermediate layer (201), and the copper inner lining layer (202) is provided with a notch for the connecting head (102) to be inserted into, and a sealing ring is arranged at the connection between the connecting head (102) and the three layers.
8. The anti-interference stable partial discharge sensor according to claim 6, characterized in that: The cross sections of the rear shell (100) and the front cover (101) are equal, and the two are fixed by bolts or adhesion.