A three-phase combined overvoltage protector

Abstract

The application belongs to the field of overvoltage protector of power system, and discloses a three-phase combined overvoltage protector, which comprises a plurality of phase units and a plurality of ground units, and each phase unit and ground unit comprises a nonlinear resistor and a discharge gap in series, and the discharge gap is provided with a lead wire at one end away from the nonlinear resistor; the discharge gap comprises a second metal sheet connected with the nonlinear resistor, and the second metal sheet is sequentially provided with a second electrode, an electrode support body and a gasket at one end away from the nonlinear resistor; the inside of the electrode support body is provided with an insulating cylinder, and the insulating cylinder is provided with a first electrode at one end close to the gasket and located outside the electrode support body, and the first electrode is sequentially provided with a first metal sheet and a mesh metal sheet at one end away from the gasket, and the first metal sheet and the mesh metal sheet are provided with a spring therebetween. The application can prevent overvoltage protector from overheating and causing accidents due to continuous discharge temperature being too high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of overvoltage protector of power system, in particular to a three-phase combined overvoltage protector. BACKGROUND

[0002] The three-phase combined overvoltage protector (hereinafter referred to as overvoltage protector) is a new type of overvoltage protector, which is mainly used in power grid of power generation, power supply and power consumption enterprises, and is used for protecting electrical equipment such as transformer, switch, bus and motor, and can limit atmospheric overvoltage and operating overvoltage caused by various switches, and can reliably limit overvoltage between phases and between phase and ground.

[0003] The overvoltage protector adopts the structure of combination of zinc oxide nonlinear resistor and discharge gap, so that the two are protected each other. The discharge gap makes the charge rate of zinc oxide resistor zero, and the nonlinear characteristic of zinc oxide makes the discharge gap extinguish arc immediately after action, without current continuation and cut-off, so that the discharge gap no longer undertakes the task of arc extinguishing, and the service life of the product is improved. However, due to the influence of various factors such as damp, aging and pollution, defects may occur in the overvoltage protector during operation, which causes the discharge gap to frequently arc discharge, and causes the internal zinc oxide resistor to heat seriously, and the overvoltage protector to heat collapse and cause accidents, and further causes serious accidents such as short circuit of high-voltage bus. In order to avoid this problem, the main technical means currently adopted is to regularly check, test and replace the overvoltage protector, and there is also a scheme for online monitoring the working state of the overvoltage protector in the prior art. However, when the overvoltage protector heats seriously due to internal defects and is not timely found and treated, the prior art cannot solve the problem of accidental accidents caused by heat collapse.

[0004] Therefore, how to provide a three-phase combined overvoltage protector is a problem to be solved at present. SUMMARY

[0005] The embodiment of the present application provides a three-phase combined overvoltage protector to solve the problem that the overvoltage protector cannot solve the problem of accidental accidents caused by heat collapse in the prior art when the overvoltage protector heats seriously due to internal defects.

[0006] The following presents a simplified summary of some aspects of the disclosed embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of the application. It is not intended to identify key / critical elements of the embodiments or to delineate the scope of the embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0007] According to the embodiment of the present application, a three-phase combined overvoltage protector is provided.

[0008] In one embodiment, the three-phase combined overvoltage protector includes a plurality of phase units and a plurality of ground units, and each of the phase units and the ground units includes a nonlinear resistor and a discharge gap in series, and the discharge gap is provided with a lead wire away from one end of the nonlinear resistor; the discharge gap includes a second metal sheet connected with the nonlinear resistor, and the second metal sheet is provided with a second electrode, an electrode support body and a gasket in sequence away from one end of the nonlinear resistor; the electrode support body is provided with an insulating cylinder inside, and the insulating cylinder is provided with a first electrode at one end close to the gasket and outside the electrode support body, and the first electrode is provided with a first metal sheet and a mesh metal sheet in sequence away from the gasket, and the first metal sheet and the mesh metal sheet are provided with a spring therebetween.

[0009] In one embodiment, the first electrode, the first metal sheet and the mesh metal sheet jointly serve as an electrode for providing a discharge path when overvoltage occurs, and when the voltage exceeds a threshold value set by the three-phase combined overvoltage protector, the gap between the first electrode, the first metal sheet and the mesh metal sheet discharges to guide the overvoltage to the ground.

[0010] In one embodiment, the mesh metal sheet is connected with the lead wire, and the second metal sheet is connected with the nonlinear resistor in series.

[0011] In one embodiment, when the three-phase combined overvoltage protector is under a normal operating voltage, the discharge gap is not conductive and isolates the power frequency voltage.

[0012] When overvoltage occurs in the power system and the voltage value of the overvoltage reaches a gap breakdown value of the three-phase combined overvoltage protector, the discharge gap breaks down and discharges, and the nonlinear resistor is conductive and limits the voltage.

[0013] In one embodiment, when the three-phase combined overvoltage protector is under normal operation, the temperature is less than 70 degrees Celsius, and the first electrode and the gasket have magnetism and are in an attraction state.

[0014] When the inside of the three-phase combined overvoltage protector is in a defective discharge state, the temperature reaches a Curie temperature point of the material of the first electrode and the gasket; the first electrode and the gasket lose magnetism, the discharge gap becomes larger, and the electrode stops discharging.

[0015] In one embodiment, the first electrode and the gasket losing magnetism and the discharge gap becoming larger include:

[0016] When the first electrode and the gasket lose magnetism, the spring drives the first metal sheet and the first electrode to move away from the second electrode, so that the distance between the first electrode and the second electrode becomes larger.

[0017] In one embodiment, when the first metal sheet and the first electrode move away from the second electrode, the insulating cylinder connected with the first electrode and the electrode support body slide fit to ensure the sealing of the gap cavity.

[0018] In one embodiment, the portion of the first electrode in contact with the gasket is provided with a magnetic steel layer, and the magnetic steel layer is made of the same material as the gasket.

[0019] In one embodiment, the material composition of the magnetic steel layer and the gasket both include diiron trioxide, magnesium oxide and copper oxide, and the Curie temperature of the magnetic steel layer and the gasket is greater than or equal to 102 degrees Celsius.

[0020] In one embodiment, the insulating cylinder and the electrode support body are made of the same electric porcelain material, and the electrode support body is in a cylindrical structure.

[0021] The technical scheme provided by the embodiment of the present application can include the following beneficial effects:

[0022] The present application provides a three-phase combined overvoltage protector with temperature-controllable discharge gap. By improving the existing discharge gap electrode, when the internal defects of the overvoltage protector cause frequent discharge of the discharge gap and generate a large amount of heat, and the temperature reaches above the Curie temperature point of the electrode and the gasket, the gasket and the first electrode lose magnetism, the electromagnetic force between the gasket and the first electrode disappears, the spring returns to the normal state, the first metal sheet and the first electrode are driven to move upward together, the distance between the first electrode and the second electrode (i.e. the discharge gap) becomes larger, and the electrode stops discharging, preventing the continuous discharge temperature from being too high to cause the overvoltage protector to overheat and cause accidents.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application.

[0025] Figure 1 is a structure diagram of a phase unit / ground unit of an overvoltage protector according to an exemplary embodiment;

[0026] Figure 2 is an internal component diagram of a phase unit / ground unit according to an exemplary embodiment;

[0027] Figure 3 is a component position diagram when the electrode temperature is normal according to an exemplary embodiment;

[0028] Figure 4 is a component position diagram when the electrode temperature is abnormal according to an exemplary embodiment;

[0029] Figure 5 is one of the structure diagrams of a three-phase combined overvoltage protector according to an exemplary embodiment;

[0030] Figure 6 Fig. 2 is a structural view of a three-phase combined overvoltage protector according to an exemplary embodiment.

[0031] Reference Signs:

[0032] 1: Nonlinear resistor; 2: Discharge gap; 21: Second metal sheet; 22: Second electrode; 23: Electrode support; 24: Washer; 25: Insulating cylinder; 26: First electrode; 27: First metal sheet; 28: Spring; 29: Mesh metal sheet; 3: Lead wire. DETAILED DESCRIPTION

[0033] The following description and drawings are illustrative of the specific embodiments herein and are not intended to limit the scope of the embodiments. Various modifications of specific embodiments incorporating elements of the general nature stated herein can be made without departing from the spirit and scope of the disclosure. The scope of the embodiments encompasses the whole scope of the claims and all available equivalents of the claims. In this document, the terms "first", "second", and the like, are used merely to distinguish one element from another, and do not require or imply that these elements have to be in a certain order or relation. In fact, the first element can be referred to as the second element, and vice versa. Furthermore, the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusions, such that a structure, device, or apparatus that comprises a list of elements does not include only those elements in the list, but can also include other elements not expressly listed or inherent to such structure, device, or apparatus. Without more limitations, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the structure, device, or apparatus that includes the element. The various embodiments are described in a progressive manner, each focusing on the differences from other embodiments, and the same or similar parts between embodiments can be referred to each other.

[0034] The terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate the orientation or positional relationship shown in the drawings, and are used herein merely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure. In the description herein, unless otherwise specified and limited, the terms "mount", "connect", "connection" should be interpreted broadly, for example, it can be a mechanical connection or an electrical connection, it can be a communication between two elements inside, it can be a direct connection or an indirect connection through an intermediate medium, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0035] Herein, the term "plurality" means two or more, unless otherwise specified.

[0036] Herein, the character " / " means that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0037] Herein, the term "and / or" is a description of the relationship between the objects, which means that there can be three relationships. For example, A and / or B means: A or B, or, A and B, the three relationships.

[0038] It should be understood that although each step in the flowchart is shown in sequence according to the direction of the arrow, these steps are not necessarily executed in sequence according to the direction of the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the figure can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but can be alternately or alternately executed with at least part of other steps or sub-steps or stages of other steps.

[0039] Each module in the device or system of the present application can be realized by software, hardware and their combination in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or stored in the memory in the computer device in software form, so as to call and execute the operations corresponding to the above modules by the processor.

[0040] In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0041] Figures 1-6 An embodiment of a three-phase combined overvoltage protector of the present application is shown.

[0042] In the optional embodiment, the three-phase combined overvoltage protector comprises a plurality of phase units and a plurality of ground units, and each phase unit and ground unit comprises a nonlinear resistor 1 and a discharge gap 2 connected in series, and the discharge gap 2 is provided with a lead wire 3 away from one end of the nonlinear resistor 1; the discharge gap 2 comprises a second metal sheet 21 connected with the nonlinear resistor 1, and the second metal sheet 21 is sequentially provided with a second electrode 22, an electrode support 23 and a gasket 24 away from one end of the nonlinear resistor 1; the electrode support 23 is internally provided with an insulating cylinder 25, and the insulating cylinder 25 is provided with a first electrode 26 at one end close to the gasket 24 and outside the electrode support 23, and the first electrode 26 is sequentially provided with a first metal sheet 27 and a mesh metal sheet 29 away from the gasket 24, and the first metal sheet 27 and the mesh metal sheet 29 are provided with a spring 28 therebetween.

[0043] In the optional embodiment, the first electrode 26, the first metal sheet 27 and the mesh metal sheet 29 jointly serve as an electrode for providing a discharge path when overvoltage occurs, and when the voltage exceeds the threshold value set by the three-phase combined overvoltage protector, the gap between the first electrode 26, the first metal sheet 27 and the mesh metal sheet 29 discharges to guide the overvoltage to the ground.

[0044] In the optional embodiment, the mesh metal sheet 29 is connected with the lead wire 3, and the second metal sheet 21 is connected with the nonlinear resistor 1 in series.

[0045] In the optional embodiment, when the three-phase combined overvoltage protector is under normal operation at a working voltage, the discharge gap 2 is not conductive and isolates the power frequency voltage; when overvoltage occurs in the power system and the voltage value of the overvoltage reaches the gap breakdown value of the three-phase combined overvoltage protector, the discharge gap 2 breaks down and discharges, and the nonlinear resistor 1 is conductive and limits the voltage.

[0046] In the optional embodiment, when the three-phase combined overvoltage protector is under normal operation, the temperature is less than 70 degrees Celsius, and the first electrode 26 and the gasket 24 have magnetism and are in an attraction state; when the inside of the three-phase combined overvoltage protector is in a defect discharge state, the temperature reaches the Curie temperature point of the material of the first electrode 26 and the gasket 24; the first electrode 26 and the gasket 24 lose magnetism, the discharge gap becomes larger, and the electrode stops discharging.

[0047] In the optional embodiment, the first electrode 26 and the gasket 24 losing magnetism and the discharge gap becoming larger comprise:

[0048] When the first electrode 26 and the gasket 24 lose magnetism, the spring 28 drives the first metal sheet 27 and the first electrode 26 to move away from the second electrode 22, so that the distance between the first electrode 26 and the second electrode 22 becomes larger.

[0049] In the optional embodiment, when the first metal sheet 27 and the first electrode 26 move away from the second electrode 22, the insulating cylinder 25 connected with the first electrode 26 slides with the electrode support 23 to ensure the sealing of the gap cavity.

[0050] In the optional embodiment, the part of the first electrode 26 contacting the gasket 24 is provided with a magnetic steel layer, and the magnetic steel layer has the same material composition as the gasket 24.

[0051] In the optional embodiment, the material composition of the magnetic steel layer and the gasket 24 both includes ferric oxide, magnesium oxide and copper oxide, and the Curie temperature of the magnetic steel layer and the gasket 24 is greater than or equal to 102 degrees Celsius.

[0052] In the optional embodiment, the insulating cylinder 25 and the electrode support 23 are made of the same electric porcelain material, and the electrode support 23 has a cylindrical structure.

[0053] In order to facilitate the understanding of the above technical solutions of the present application, the above technical solutions of the present application are further described from the aspects of architecture and principle as follows:

[0054] The present application provides a three-phase combined overvoltage protector capable of adjusting the discharge gap under temperature control, which can avoid accidental accidents caused by internal defect faults of the overvoltage protector. The present application improves the discharge gap electrode of the existing overvoltage protector.

[0055] 1. A gasket is added between the first electrode and the electrode support, the gasket is fixed on the electrode support, the gasket is made of magnetic steel with main materials of ferric oxide (Fe2O3), magnesium oxide (MgO) and copper oxide (CuO), and the Curie temperature of the gasket is about 102 degrees Celsius.

[0056] 2. A layer of magnetic steel with main materials of ferric oxide (Fe2O3), magnesium oxide (MgO) and copper oxide (CuO) is added to the part of the first electrode contacting the gasket.

[0057] 3. An insulating cylinder is added, the insulating cylinder is fixedly connected with the first electrode, and the insulating cylinder and the electrode support are made of the same material, which is generally special electric porcelain material, and has good electrical insulation performance, dielectric strength, anti-electric corrosion, aging resistance and other characteristics.

[0058] 4. A pair of springs is added between the first metal sheet and the mesh metal sheet, one end of the spring is fixedly connected with the first metal sheet, and the other end of the spring is fixedly connected with the mesh metal sheet.

[0059] For example, Figure 2As shown, the present application provides a three-phase combined overvoltage protector which can control and adjust the discharge gap. The discharge electrode of the existing overvoltage protector is improved by adding a gasket 24, an insulating cylinder 25 and a spring 28. The first electrode is also improved by adding a layer of magnetic steel mainly made of Fe2O3, MgO and CuO on the part of the first electrode 26 in contact with the gasket 24. The insulating cylinder 25 is fixedly connected with the first electrode 26.

[0060] In order to reach the Curie temperature of 102 degrees Celsius, the magnetic steel mainly made of Fe2O3, MgO and CuO can be prepared by the following proportioning:

[0061] MgO: 5.5-7 mol%.

[0062] CuO: 6-9 mol%.

[0063] Fe2O3: 47-49.5 mol%.

[0064] The first electrode 26, the second electrode 22 and the electrode support 23 form the discharge gap of the overvoltage protector. The electrode is usually made of metal material with good electrical conductivity and adopts a spherical structure. The present application adds a layer of magnetic steel mainly made of Fe2O3, MgO and CuO on the part of the first electrode 26 in contact with the gasket 24. The electrode support 23 is made of special electric porcelain material and adopts a cylindrical structure. The spacing of the discharge gap is usually between several millimeters and several centimeters under normal circumstances. It can withstand a certain voltage and discharge under overvoltage conditions.

[0065] A gasket 24 is added between the first electrode 26 and the electrode support 23. The gasket 24 is fixed on the electrode support 23. The gasket 24 is made of the above-mentioned magnetic steel material. The gasket is mainly made of Fe2O3, MgO and CuO magnetic steel. The Curie temperature thereof is about 102 degrees Celsius.

[0066] The first metal sheet 27 is fixedly connected with the first electrode 26. The spring at the lower part of the mesh metal sheet 29 has a certain elasticity and can ensure that it is always in contact with the first metal sheet 27. The first electrode 26, the first metal sheet 27 and the mesh metal sheet 29 jointly play the role of the electrode and provide a discharge path when overvoltage occurs. When the voltage exceeds the threshold value set by the protector, the gap between the electrodes will discharge, thereby guiding the overvoltage to the ground and protecting the circuit from damage.

[0067] The design of the mesh structure of the mesh metal sheet 29 helps to uniformly distribute the electric field, reduce the local electric field intensity, avoid local discharge, thereby protecting the electrode from being electrically eroded, and ensuring the uniformity and stability of the discharge.

[0068] A pair of springs 28 is arranged between the first metal sheet 27 and the mesh metal sheet 29, one end of the spring 28 is fixedly connected with the first metal sheet 27, and the other end is fixedly connected with the mesh metal sheet 29.

[0069] The mesh metal sheet 29 is connected with the high-voltage lead and is cast together with the shell; the second metal sheet 21 is connected in series with a zinc oxide nonlinear resistor, and the zinc oxide nonlinear resistor is directly hot-pressed with the shell material, thereby forming a phase unit of the overvoltage protector. The overvoltage protector selects silicone rubber as the shell material, and four silicone rubber high-voltage cables and zinc oxide valve pieces are integrally vulcanized and molded once from the inside, which is mainly used to prevent moisture and explosion problems.

[0070] As shown in Figures 5-6 , the overvoltage protector is composed of three phase units and one ground unit to form a four-star structure, and each unit is composed of a discharge gap 2 and a zinc oxide nonlinear resistor in series. Figure 6 The FR is a zinc oxide nonlinear resistor, and the CG is a discharge gap. The three-phase high-voltage lead is led out by the three phase units, and since a symmetrical structure is adopted, any three of them can be connected to the A, B, and C three-phase respectively. The ground lead is led out by the ground unit. Under normal operating voltage, the gap is not conductive, isolates the power frequency voltage, and protects the zinc oxide nonlinear resistor, at which time there is no current flowing through the ground lead. When an overvoltage occurs in the power system and the voltage value reaches the gap breakdown value of the overvoltage protector, the gap breaks down and discharges, and the zinc oxide nonlinear resistor of the overvoltage protector conducts and limits the voltage. After the overvoltage disappears, the discharge gap component automatically recovers immediately, and the overvoltage generated by the general system is instantaneous. However, when a defect occurs in the overvoltage protector, the gap may also frequently break down and discharge under normal operating voltage, resulting in a sharp increase in temperature, and eventually causing an accident due to overheating of the overvoltage protector.

[0071] As shown in Figure 3 , when the overvoltage protector is working normally, the temperature is generally below 70 degrees Celsius, at which time the first electrode 26 and the gasket 24 have magnetism and will be attracted together, and the spring is stretched. As shown in Figure 4As shown, when the internal defects of the overvoltage protector frequently discharge to cause temperature rise, when the temperature rises to about 102 degrees Celsius, reaches the Curie temperature point of the material of the first electrode 26 and the gasket 24, the first electrode 26 and the gasket 24 lose magnetism, the electromagnetic force between the gasket 24 and the first electrode 26 disappears, the spring 28 returns to the normal state, drives the first metal sheet 27 and the first electrode 26 to move upward together, the distance between the first electrode 26 and the second electrode 22 (i.e. the discharge gap) becomes larger, and the electrode stops discharging, preventing the overvoltage protector from overheating due to continuous discharge at high temperature and causing accidents.

[0072] When the first electrode 26 and the gasket 24 lose magnetism, the insulating cylinder 25 fixedly connected with the first electrode 26 can slide freely between the electrode support body 23, but can ensure the sealing of the gap cavity during the process of the first metal sheet 27 and the first electrode 26 moving upward together.

[0073] The present application is not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is only limited by the appended claims.

Claims

1. A three-phase combined overvoltage protector, characterized in that, It includes several phase units and several ground units, and each phase unit and ground unit includes a nonlinear resistor (1) and a discharge gap (2) connected in series. The end of the discharge gap (2) away from the nonlinear resistor (1) is provided with a lead (3). The discharge gap (2) includes a second metal sheet (21) connected to the nonlinear resistor (1). A second electrode (22), an electrode support (23) and a washer (24) are sequentially arranged at the end of the second metal sheet (21) away from the nonlinear resistor (1). An insulating cylinder (25) is provided inside the electrode support (23). A first electrode (26) is provided at one end of the insulating cylinder (25) near the washer (24) and outside the electrode support (23). A first metal sheet (27) and a mesh metal sheet (29) are provided sequentially at one end of the first electrode (26) away from the washer (24). A spring (28) is provided between the first metal sheet (27) and the mesh metal sheet (29). When the three-phase combined overvoltage protector is operating at normal working voltage, the discharge gap (2) is not conducting and isolates the power frequency voltage; when an overvoltage occurs in the power system and the voltage value of the overvoltage reaches the gap breakdown value of the three-phase combined overvoltage protector, the discharge gap (2) breaks down and discharges, and the nonlinear resistor (1) conducts to limit the voltage. When the three-phase combined overvoltage protector is working normally, the temperature is less than 70 degrees Celsius, and the first electrode (26) and the gasket (24) are magnetic and in an attracted state; when the inside of the three-phase combined overvoltage protector is in a defect discharge state, the temperature reaches the Curie temperature point of the material of the first electrode (26) and the gasket (24); the first electrode (26) and the gasket (24) lose magnetism, the discharge gap becomes larger, and the electrode stops discharging; The first electrode (26) and the gasket (24) lose magnetism, and the discharge gap increases, including: When the first electrode (26) and the washer (24) lose magnetism, the spring (28) drives the first metal sheet (27) and the first electrode (26) to move away from the second electrode (22) so that the distance between the first electrode (26) and the second electrode (22) increases.

2. A three-phase combined overvoltage protector according to claim 1, characterized in that, The first electrode (26), the first metal sheet (27) and the mesh metal sheet (29) together act as electrodes to provide a discharge path when an overvoltage occurs. When the voltage exceeds the threshold set by the three-phase combined overvoltage protector, the gap between the first electrode (26), the first metal sheet (27) and the mesh metal sheet (29) discharges to guide the overvoltage to the ground.

3. A three-phase combined overvoltage protector according to claim 1, characterized in that, The mesh metal sheet (29) is connected to the lead wire (3), and the second metal sheet (21) is connected in series with the nonlinear resistor (1).

4. A three-phase combined overvoltage protector according to claim 1, characterized in that, When the first metal sheet (27) and the first electrode (26) move away from the second electrode (22), the insulating cylinder (25) connected to the first electrode (26) slides in conjunction with the electrode support (23) to ensure the sealing of the gap cavity.

5. A three-phase combined overvoltage protector according to claim 1, characterized in that, The portion of the first electrode (26) that contacts the gasket (24) is provided with a magnetic steel layer, and the magnetic steel layer has the same material composition as the gasket (24).

6. A three-phase combined overvoltage protector according to claim 5, characterized in that, The materials of the magnet layer and the gasket (24) both include ferric oxide, magnesium oxide and copper oxide, and the Curie temperature of the magnet layer and the gasket (24) is greater than or equal to 102 degrees Celsius.

7. A three-phase combined overvoltage protector according to claim 1, characterized in that, The insulating cylinder (25) and the electrode support (23) are made of the same ceramic material, and the electrode support (23) is a cylindrical structure.

Images