Sensor protection device

Abstract

The utility model discloses a sensor protection device, which belongs to the technical field of power transmission and transformation equipment, is mounted on an equipment shell, and comprises an insulating base and a dredging piece, one end of the insulating base is connected with the equipment shell, and the other end of the insulating base is connected with the sensor; the dredging piece is arranged on the insulating base in a sleeving manner and located between the equipment shell and the sensor at intervals, the dredging piece is connected with the grounding wire, and a protrusion extending towards the equipment shell is arranged on the dredging piece and used for releasing overvoltage generated by the equipment shell; and a gap is formed between the tip of the bulge and the equipment shell. According to the invention, a high-pressure dredging mode is adopted to protect the sensor. When an equipment shell generates overvoltage, the main overvoltage is released to the dredging piece in a point discharge mode and is led into a ground screen through a ground wire, and residual voltage is isolated by the insulating base; when the equipment operates normally, the protection device is insulated from the equipment shell, so that an equipment grounding system is prevented from being influenced, and the problem that the sensor is broken down due to overvoltage is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power transmission and transformation equipment, and relates to a sensor protection device, in particular to an overvoltage isolation protection device for protecting a sensor. Background Art

[0002] Overvoltage exists in many places, such as power systems or electrical equipment. In the power plant equipment operation monitoring device, the sensor is installed on the equipment casing. At the moment of closing the reverse power transformer in the power plant, the transformer generates an instantaneous overvoltage, and the equipment casing simultaneously senses the overvoltage. In addition, outdoor equipment is accidentally struck by lightning on rainy days, and accidents in the generator circuit lead to single-phase short circuits and three-phase imbalances, which may cause overvoltage problems on the equipment casing. Once the above problems occur, the potential difference between the sensor and the equipment casing will increase instantly, and the sensor connection cable will become an overvoltage discharge path, breaking down the sensor circuit.

[0003] The traditional solution is to add an insulating base to the bottom of the sensor. However, due to different causes, the overvoltage peak itself has a certain degree of randomness. As the unit gradually increases, the impact of very fast transient overvoltage (VFTO: Very Fast Transient Overvoltage) becomes greater and greater, and the overvoltage induced by the equipment shell also becomes greater and greater. Even after the insulating base is installed, the sensor still continues to have breakdown failures.

[0004] In view of the above problems, a sensor protection device for overvoltage isolation protection is urgently needed. Utility Model Content

[0005] In order to at least solve the problem of breakdown of the sensor due to overvoltage generated on the device housing in the above-mentioned prior art, the utility model provides the following technical solution: a sensor protection device is installed on the device housing, and the sensor protection device includes: an insulating base and a drainage member;

[0006] One end of the insulating base is connected to the device housing, and the other end of the insulating base is connected to the sensor;

[0007] The drainage piece is sleeved on the insulating base and is spaced between the device housing and the sensor. The drainage piece is connected to a grounding wire and is provided with a protrusion extending toward the device housing for releasing overvoltage generated in the device housing.

[0008] There is a gap between the tip of the protrusion and the device housing.

[0009] Optionally, in the above-mentioned sensor protection device, the guide member and the protrusion are both made of conductive material.

[0010] Optionally, in the above-mentioned sensor protection device, at least one protrusion is provided on the guide member, and the tip of the protrusion is 2 to 3 mm away from the device housing.

[0011] Optionally, in the above-mentioned sensor protection device, the drainage member includes: a positioning portion and a grounding portion;

[0012] The positioning portion is annular and sleeved on the insulating base, and the positioning portion is provided with the protrusion extending toward the device housing;

[0013] The grounding portion is located on the circumferential outer edge of the positioning portion, and the grounding portion is detachably connected to the grounding wire.

[0014] Optionally, in the above-mentioned sensor protection device, the circumferential outer wall of the positioning portion radially extends and bends toward the device housing to form the triangular protrusion.

[0015] Optionally, in the above-mentioned sensor protection device, the inner wall of the insulating base is provided with a thread structure along the length direction; and / or

[0016] The insulating base is located between the guide piece and the sensor, and an outer wall is provided with an umbrella skirt structure along the length direction.

[0017] Optionally, in the above-mentioned sensor protection device, the sensor protection device further comprises: an insulating pad and a sealing pad;

[0018] The insulating pad is sleeved on the insulating base to insulate the drainage member from the device housing; and / or

[0019] The sealing gasket is arranged between the insulating base and the sensor, and is used for sealing between the insulating base and the sensor.

[0020] Optionally, in the above-mentioned sensor protection device, the insulating base is a tubular structure, and the insulating base is arranged perpendicular to the device housing; and / or

[0021] The equipment housing is a busbar housing.

[0022] Optionally, in the above-mentioned sensor protection device, a mounting base is provided on the device housing, the mounting base has a threaded hole, and one end of the mounting base is welded to the surface of the device housing;

[0023] One end of the insulating base is fixed in the threaded hole at the other end of the mounting base.

[0024] Optionally, in the above-mentioned sensor protection device, the collection end of the sensor is threadedly connected to the other end of the insulating base, and the output end of the sensor is connected to a cable.

[0025] The beneficial effects brought by the technical solution provided by the embodiment of the utility model are:

[0026] This application adopts high-voltage drainage to protect the sensor. By setting drainage pieces and insulating bases, when overvoltage is generated in the device casing, the main overvoltage is released to the drainage pieces by tip discharge, and introduced into the ground grid through the grounding wire connected to the drainage pieces, and the residual pressure is isolated by the insulating base; when the device is operating normally, the protection device is insulated from the device casing to avoid affecting the device grounding system, thereby solving the problem of sensor breakdown caused by overvoltage generated on the device casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a partial cross-section of the structure of a sensor protection device provided by an embodiment of the utility model;

[0028] In the figure: 1. sensor; 2. insulating pad; 3. insulating base; 4. guide piece; 401. positioning part; 402. grounding part; 403. protrusion; 5. mounting base; 6. sealing pad; 7. equipment housing. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through an intermediate component. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] See also Figure 1The utility model provides a sensor protection device, which is installed on the device housing 7. The device here refers to a device that generates overvoltage. Any device can use this protection device to protect the sensor. For example, the device can be a closed busbar, and accordingly, the device housing is a busbar housing. The sensor protection device of the present application includes: an insulating base 3 and a drainage member 4.

[0032] The mounting base 5 has a threaded hole arranged along the length direction, and one end of the mounting base 5 is welded and fixed to the surface of the device housing 7, so that the inner cavity of the mounting base 5 is connected with the inner cavity of the device housing 7. The specific structure of the mounting base 5 is not limited in this embodiment. The insulating base 3 is a tubular structure and is made of insulating material. The insulating base 3 is arranged perpendicular to the device housing 7, and / or the device housing 7 is a busbar housing. One end of the insulating base 3 is fixed to the threaded hole of the mounting base 5 from the other end of the mounting base 5 (referring to the end away from the device housing 7) by threads, so that the inner cavity of the insulating base 3 is connected with the inner cavity of the device housing 7. The acquisition end of the sensor 1 is fixedly installed in the inner cavity of the other end of the insulating base 3 by threads. Since the inner cavity of the insulating base 3 is connected with the inner cavity of the device housing 7, it is convenient for the sensor 1 to collect data. The output end of the sensor 1 is connected to the cable. The drainage member 4 is made of conductive material, preferably aluminum alloy. The drainage member 4 is sleeved on the insulating base 4, and the drainage member 4 is located between the device housing 7 and the sensor 1 at intervals, and there is an interval between the drainage member 4 and the device housing 7, and there is an interval between the drainage member 4 and the sensor 1, and the drainage member 4 is connected to the grounding wire (not shown in the figure). The drainage member 4 is provided with a protrusion 403 extending toward the device housing 7, and there is a gap between the tip of the protrusion 403 and the device housing 7. When an overvoltage is generated on the device housing 7, the protrusion 403 plays a role of tip discharge. It should be noted that the protrusion 403 is also made of conductive material like the drainage member 4, preferably aluminum alloy. When an overvoltage is generated on the device housing 7, the device uses the drainage member 4 to guide the direction of the overvoltage, realizes the release of most of the overvoltage, and isolates the impact of the residual pressure on the sensor 1 through the insulating base 3, improves the withstand voltage level of the sensor 1, and when the device returns to normal operation, the insulation between the drainage member 4 and the device housing 7 is restored, and the entire protection device and the device housing 7 are still in an insulated state to avoid affecting the device grounding system.

[0033] Working principle of this device:

[0034] When the device is affected by the overvoltage generated by the closing of the main transformer external line, after the overvoltage induced on the device casing 7 reaches a certain value, the overvoltage breaks through the air gap between the device casing 7 and the tip of the protrusion 403 on the guide piece 4, and the main overvoltage is released to the guide piece 4, and is introduced into the ground grid through the grounding wire connected to the guide piece 4 for guide (release), effectively blocking most of the high voltage impact on the sensor 1, and using the insulating base 3 to isolate the residual pressure.

[0035] In order to make the drainage member 4 be located between the device housing 7 and the sensor 1, the sensor protection device further includes: an insulating pad 2 and a sealing pad 6. The insulating pad 2 is sleeved on the insulating base 3 and is made of insulating material, and is used to insulate and isolate the drainage member 4 from the device housing 7. And / or the sealing pad 6 is arranged between the insulating base 3 and the sensor 1, and the sealing pad 6 is preferably made of insulating material, and is used to seal between the insulating base 3 and the sensor 1, and at the same time plays the role of insulation isolation, preventing the external humid air and water from entering and reducing the insulation level.

[0036] In order to guide the overvoltage on the device housing 7 to the ground, at least one protrusion 403 is provided on the guide member 4. When the number of protrusions 403 is multiple, multiple protrusions 403 are arranged at intervals on the circumferential outer edge of the guide member 4. During installation, the guide member 4 and the insulating pad 2 are sequentially sleeved on the insulating base 3, and the guide member 4 is rotated so that (any) protrusion 403 is located (positively) above the insulating base 3, that is, the projection of the protrusion 403 falls on the axis of the insulating base 3, and one end of the insulating base 3 is fixed in the threaded hole of the mounting base 5 by thread. At this time, the tip of the protrusion 403 is 2 to 3 mm away from the device housing 7, that is, there is an air gap of 2 to 3 mm between the two. When an overvoltage is generated on the device housing 7, the overvoltage breaks through the air gap, and the main overvoltage is released to the guide member 4, and is released through the grounding wire connected to the guide member 4, effectively blocking most of the high voltage from impacting the sensor 1, thereby improving the withstand voltage level of the sensor 1. It should be noted that if the gap between the tip of the protrusion 403 and the device casing 7 is too small, local deformation or dimensional deviation may cause direct conduction between the guide piece 4 and the device casing 7, thereby introducing a new unreliable grounding point; if the gap between the tip of the protrusion 403 and the device casing 7 is too large, the overvoltage induced on the device casing 7 needs to reach a very high value before it can break through the air gap, thereby increasing the difficulty of grounding the overvoltage.

[0037] As an embodiment of the specific structure of the above-mentioned drainage member 4, in this embodiment, the drainage member 4 includes: a positioning portion 401 and a grounding portion 402. The positioning portion 401 is annular and is sleeved on the insulating base 3. At the same time, the positioning portion 401 is provided with a protrusion 403 extending toward the device housing 7. Preferably, the circumferential outer wall of the positioning portion 401 radially extends and bends toward the device housing 7 to form a triangular protrusion 403. This shape of the protrusion 403 has a certain strength. At the same time, when an overvoltage is generated on the device housing 7, it can play a role of tip discharge. The grounding portion 402 is located on the circumferential outer edge of the positioning portion 401. The grounding portion 402 is detachably connected to the grounding wire. Specifically, a through hole is opened on the grounding portion 402 for installing the grounding wire. In order to avoid direct conduction between the drainage member 4 and the mounting base 5, the above-mentioned insulating pad 2 is located between the positioning portion 401 and the mounting base 5, so that the drainage member 4 and the mounting base 5 can be insulated and isolated.

[0038] Although the guide piece 4 blocks most of the overvoltage, there may still be some residual pressure, so the inner wall of the insulating base 3 is provided with a threaded structure along the length direction, or the outer wall of the insulating base 3 located between the guide piece 4 and the sensor 1 is provided with an umbrella skirt structure along the length direction. The threaded structure and the umbrella skirt structure can also be provided on the insulating base 3 at the same time. The threaded structure and / or the umbrella skirt structure can extend the path of the inner surface and / or outer surface of the insulating base 3 and increase the creepage distance, thereby effectively isolating the residual pressure and reducing the influence of the residual pressure on the sensor 1.

[0039] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the embodiments disclosed above are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A sensor protection device, mounted on a device housing, characterized in that: The sensor protection device comprises: an insulating base and a guide piece; One end of the insulating base is connected to the device housing, and the other end of the insulating base is connected to the sensor; The drainage piece is sleeved on the insulating base and is spaced between the device housing and the sensor. The drainage piece is connected to a grounding wire and is provided with a protrusion extending toward the device housing for releasing overvoltage generated in the device housing. There is a gap between the tip of the protrusion and the device housing.

2. The sensor protection device according to claim 1, characterized in that: The guide piece and the protrusion are both made of conductive material.

3. The sensor protection device according to claim 1, characterized in that: At least one protrusion is arranged on the guide member, and the tip of the protrusion is 2 to 3 mm away from the device housing.

4. The sensor protection device according to claim 1, characterized in that: The drainage member comprises: a positioning portion and a grounding portion; The positioning portion is annular and sleeved on the insulating base, and the positioning portion is provided with the protrusion extending toward the device housing; The grounding portion is located on the circumferential outer edge of the positioning portion, and the grounding portion is detachably connected to the grounding wire.

5. The sensor protection device according to claim 4, characterized in that: The circumferential outer wall of the positioning portion radially extends and bends toward the device housing to form the triangular protrusion.

6. The sensor protection device according to claim 1, characterized in that: The inner wall of the insulating base is provided with a thread structure along the length direction; and / or The insulating base is located between the guide piece and the sensor, and an outer wall is provided with an umbrella skirt structure along the length direction.

7. The sensor protection device according to claim 1, characterized in that: The sensor protection device further comprises: an insulating pad and a sealing pad; The insulating pad is sleeved on the insulating base to insulate the drainage member from the device housing; and / or The sealing gasket is arranged between the insulating base and the sensor, and is used for sealing between the insulating base and the sensor.

8. The sensor protection device according to claim 1, characterized in that: The insulating base is a tubular structure, and the insulating base is arranged perpendicular to the device housing; and / or The equipment housing is a busbar housing.

9. The sensor protection device according to claim 1, characterized in that: The device housing is provided with a mounting base, the mounting base has a threaded hole, and one end of the mounting base is welded to the surface of the device housing; One end of the insulating base is fixed in the threaded hole at the other end of the mounting base.

10. The sensor protection device according to claim 1, characterized in that: The collecting end of the sensor is threadedly connected to the other end of the insulating base, and the output end of the sensor is connected to the cable.

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