A vacuum interrupter vacuum degree monitoring component and monitoring method thereof

Abstract

The present invention discloses a vacuum degree monitoring assembly for a vacuum interrupter and a monitoring method thereof, belonging to the technical field of vacuum circuit breakers. The monitoring assembly includes a measuring cavity disposed within a static conductive rod, the measuring cavity being connected to the internal cavity of an insulating ceramic housing via a connecting hole. An oxygen sensor and a heating device are installed within the measuring cavity. A ceramic insulating plate is mounted on the static end cover plate, the ceramic insulating plate being provided with an exposure opening for exposing the static conductive rod and the static end conductive block. Wiring for the oxygen sensor and the heating device extends into the ceramic insulating plate and out through the side wall. The monitoring method comprises: S1, disposing the monitoring assembly on the vacuum interrupter; S2, turning on the heating device and adjusting the temperature to the operating temperature of the oxygen sensor; S3, starting the measuring device and receiving monitoring data from the oxygen sensor. This method enables online monitoring of the vacuum degree of the vacuum interrupter, achieving not only high detection accuracy and a wide vacuum degree detection range, but also avoiding disturbances and losses caused by equipment withdrawal and connection during offline detection.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum circuit breakers, and in particular to a vacuum degree monitoring component for a vacuum interrupter and a monitoring method thereof. Background Art

[0002] The vacuum interrupter is the core component of medium and high voltage power switches. Its main function is to quickly extinguish the arc when the vacuum circuit breaker is disconnected through the excellent insulation of the high vacuum inside the tube, thus avoiding accidents and unexpected events. The Ministry of Industry and Information Technology (JB) stipulates that the maximum allowable pressure inside the vacuum interrupter is 1.33×10 -2 When the pressure inside the vacuum interrupter exceeds this value, it indicates that the vacuum level inside the vacuum interrupter has seriously deteriorated, affecting the interrupter's breaking capacity. In severe cases, breakdown may even occur, preventing normal circuit operation. In practical applications, there is an urgent need to measure the vacuum level of the vacuum interrupter. Existing circuit breaker vacuum level detection technologies are divided into two categories: offline detection and online detection.

[0003] The more mature detection methods in offline detection are the power frequency withstand voltage method and the pulse magnetron discharge method. However, the power frequency withstand voltage method requires the vacuum circuit breaker to be in the shutdown state, and can only detect the vacuum degree qualitatively. The arc extinguishing chamber with a vacuum degree lower than the operating standard can still pass the withstand voltage test. Although the pulse magnetron discharge method can quantitatively detect the vacuum degree, the arc extinguishing chamber needs to be removed from the circuit breaker and placed in the electromagnetic coil during detection. That is, both methods will affect the normal use of the vacuum circuit breaker. The more mature detection methods in online detection are the coupling capacitance method. The coupling capacitance method is based on the principles of dynamic charge distribution and capacitance voltage division. When the vacuum degree changes, the distributed capacitance between the contact and the shielding cover and the distributed capacitance between the shielding cover and the sensing electrode will change. Since the coupling capacitance is connected in series with the distributed capacitance, the coupling capacitance voltage will change. By measuring the coupling capacitance voltage, the vacuum degree can be detected online. Although this method will not affect the normal use of the vacuum circuit breaker, its detection accuracy is low and can only reach 10 -1 ~10 -2 Pa. Summary of the Invention

[0004] The purpose of the present invention is to solve the above technical problems and provide a vacuum degree monitoring component and a monitoring method for a vacuum interrupter. By setting a measuring cavity connected to the interior of the interrupter in a static conductive rod and detecting the oxygen content in the vacuum interrupter by an oxygen sensitive sensor in the measuring cavity, online monitoring of the vacuum degree of the vacuum interrupter can be achieved. This not only has high detection accuracy and a wide detection range, but also avoids the problem of offline detection methods causing the vacuum circuit breaker to be taken out of operation and affecting normal use.

[0005] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention discloses a vacuum degree monitoring assembly for a vacuum interrupter, comprising a measuring cavity arranged in a static conductive rod of the vacuum interrupter, the measuring cavity being connected to the internal cavity of the insulating ceramic shell of the vacuum interrupter through a connecting hole, an oxygen sensor and a heating device being installed in the measuring cavity, a ceramic insulating plate being installed on the static end cover of the vacuum interrupter, the ceramic insulating plate and the static conductive rod extending out of one end of the static end cover being joined, an exposure opening being provided on the ceramic insulating plate for exposing the static conductive rod and the static end conductive block, the wiring of the oxygen sensor and the heating device extending into the ceramic insulating plate from the joining point between the static conductive rod and the ceramic insulating plate, and extending out from the side wall of the ceramic insulating plate.

[0006] Preferably, the oxygen sensor is a strontium titanate oxygen sensor.

[0007] Preferably, the static conductive rod and the ceramic insulating plate are provided with corresponding extension holes and wiring holes at the joint, the extension holes are connected to the measuring cavity, the number of the extension holes is consistent with the number of wiring connections between the oxygen sensor and the heating device, and the wiring holes extend from the joint of the ceramic insulating plate to the side wall of the ceramic insulating plate.

[0008] Preferably, an insulating collar is provided between the wiring hole and the extension hole, and the insulating collar is sleeved outside the wiring between the oxygen sensor and the heating device.

[0009] Preferably, the diameter of the wire portion of the wiring located within the insulating ring is larger than the wiring hole and the extension hole.

[0010] Preferably, the length of the insulating ring is greater than 5 mm.

[0011] Preferably, the ceramic insulating plate includes a mounting ring, a cross buckle plate is fixedly connected inside the mounting ring, an embedding groove is provided on the cross buckle plate, the static conductive rod and the static end conductive block are embedded in the embedding groove, the wiring hole extends from the center of the cross buckle plate to the side wall of the mounting ring, and a cover plate extension ring is coaxially fixedly connected to the outer wall of the static end cover plate, and the cover plate extension ring is fixedly connected to the mounting ring.

[0012] Preferably, the cover plate extension ring and the mounting ring are connected by screws.

[0013] Also disclosed is a method for monitoring the vacuum degree of a vacuum interrupter, comprising the following steps:

[0014] S1. Install the vacuum interrupter vacuum monitoring assembly on the vacuum interrupter, connect the wiring of the oxygen sensor to the measuring device, and connect the wiring of the heating device to the power supply device;

[0015] S2. Turn on the heating device to adjust the temperature in the measurement cavity to the operating temperature of the oxygen sensor;

[0016] S3. Start the measuring device to receive monitoring data from the oxygen sensor.

[0017] Preferably, in step S3, when the oxygen concentration exceeds a set value, the measuring device issues an alarm.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] The present invention adopts an online monitoring method of the vacuum degree of the vacuum interrupter using an oxygen sensor. Compared with the existing offline detection scheme, there is no need to disconnect the vacuum interrupter before detection, that is, the vacuum circuit breaker can be tested under power, avoiding the disturbance and loss caused by the equipment exiting and connecting to the system during offline detection. Compared with the existing online detection scheme, the oxygen sensor is extremely sensitive to oxygen. In an environment with extremely high vacuum degree, its resistance changes linearly when the vacuum degree changes. Therefore, its resistance change can reflect the vacuum degree change inside the vacuum interrupter at high vacuum degree, thereby improving the vacuum degree detection range of the online vacuum degree detection. At the same time, the oxygen sensor has high stability and a high operating temperature, so it can withstand the high temperature process in the current vacuum interrupter manufacturing process, and will not encounter the problem of other types of sensors failing after being subjected to high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a rear perspective structural diagram of the vacuum interrupter and monitoring components;

[0022] Figure 2 It is a front perspective structural diagram of the vacuum interrupter and monitoring components;

[0023] Figure 3 Schematic diagram of the three-dimensional structure of the vacuum interrupter and monitoring component (without insulating ceramic housing);

[0024] Figure 4 A perspective diagram of a monitoring assembly installed in a vacuum interrupter;

[0025] Figure 5 is a cross-sectional view of the vacuum interrupter and monitoring components;

[0026] Figure 6 for Figure 5 A partial enlarged view of

[0027] Figure 7 Schematic diagram of the connection relationship between wiring and insulating collar.

[0028] Description of reference numerals:

[0029] 1. Measurement cavity; 2. Connecting hole; 3. Oxygen sensor; 4. Heating device; 5. Mounting ring; 6. Cross plate; 7. Exposure opening; 8. Cover extension ring; 9. Screw hole; 10. Measurement connection; 11. Power connection; 12. Insulation collar;

[0030] 100, static conductive rod; 200, dynamic conductive rod; 300, static end cover; 400, dynamic end cover; 500, insulating ceramic shell; 600, static contact; 700, dynamic contact; 800, static end conductive block; 900, dynamic end conductive block; 1000, main shielding cover. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a vacuum degree monitoring assembly for a vacuum interrupter, which is used to be installed on a vacuum interrupter to achieve online monitoring of the vacuum degree of the vacuum interrupter, especially for medium and high voltage vacuum interrupters.

[0034] Vacuum interrupter, such as Figures 1 to 7As shown, it includes a static conductive rod 100, a dynamic conductive rod 200, a static end cover plate 300, a dynamic end cover plate 400, an insulating ceramic housing 500, a static contact 600, a dynamic contact 700, a static end conductive block 800, a dynamic end conductive block 900, a main shield 1000, a voltage-equalizing shield, and a bellows. The static conductive rod 100 and the dynamic conductive rod 200 are located within the insulating ceramic housing 500. The static end cover plate 300 is fixedly sealed to one end of the insulating ceramic housing 500, and the dynamic end cover plate 400 is fixedly sealed to the other end of the insulating ceramic housing 500. One end of the static conductive rod 100 is embedded in the embedding hole of the static end cover plate 300. The static end conductive block 800 is fixedly connected to the static end cover plate 300 and is sleeved on the static conductive rod 100. The other end of the static conductive rod 100 is fixedly connected to the static contact 600. One end of the movable end cover plate 400 slides into the mounting hole of the movable end cover plate 400. The movable end conductive block 900 is fixedly connected to the movable end cover plate 400 and sleeved onto the movable end cover plate 400. The end of the movable end cover plate 400 located within the insulating ceramic housing 500 is fixedly connected to the movable contact 700. The main shield 1000 is located within the insulating ceramic housing 500, and the static contact 600 and the movable contact 700 are located within the main shield 1000. When the vacuum load switch and vacuum contactor are closed, the operating mechanism moves the movable conductive rod 200, closing the static contact 600 and the movable contact 700, completing the circuit.

[0035] Vacuum interrupter vacuum degree monitoring components, such as Figures 1 to 7As shown, the device includes a measurement cavity 1 disposed within a static conductive rod 100. This cavity 1 communicates with the interior of an insulating ceramic housing 500 via a connecting hole 2, ensuring that the air environment within the measurement cavity 1 and the interior of the insulating ceramic housing 500 is the same. Monitoring the vacuum level of the measurement cavity 1 is equivalent to monitoring the vacuum level of the vacuum interrupter. The number of connecting holes 2 can be adjusted as needed, for example, five connecting holes 2 are provided. An oxygen sensor 3 and a heating device 4 are installed within the measurement cavity 1. The oxygen sensor 3 monitors the oxygen content of the air within the measurement cavity 1, while the heating device 4 maintains a suitable operating temperature for the oxygen sensor 3. A ceramic insulating plate is mounted on the static end cover 300. The ceramic insulating plate is fitted to the end of the static conductive rod 100 extending beyond the static end cover 300. An exposure opening 7 is provided on the ceramic insulating plate to expose the static conductive rod 100 and the static end conductive block 800 to the external air environment, facilitating electrical connection and proper operation of the vacuum interrupter. Two measuring wires 10 are led out from the two poles of the oxygen sensor 3, and two power supply wires 11 are led out from the heating device 4. The measuring wires 10 and the power supply wires 11 extend from the static conductive rod 100 into the ceramic insulating plate and extend from the side wall of the ceramic insulating plate. The measuring wires 10 and the power supply wires 11 are routed inside the static conductive rod 100 and are protected by the insulating ceramic housing 500. The portion extending from the static conductive rod 100 is routed inside the ceramic insulating plate and is protected by the ceramic insulating plate, thereby avoiding measurement errors.

[0036] The oxygen sensor 3 transmits the monitoring results to the measuring device in real time through the measuring connection 10, thereby obtaining the vacuum degree in the vacuum interrupter. The higher the oxygen content, the lower the vacuum degree, and vice versa, the lower the oxygen content, the higher the vacuum degree. The vacuum degree value is obtained according to the oxygen content value. The oxygen sensor 3 is extremely sensitive to oxygen. In an environment with extremely high vacuum, when the vacuum degree changes, that is, when the oxygen content changes, the resistance of the oxygen sensor 3 changes linearly, and then the change in resistance can reflect the change in oxygen content, and then reflect the change in vacuum degree. Usually the oxygen partial pressure is 10 -15 Pa to 10 -1 When Pa decreases monotonically, the resistivity of the oxygen sensor 3 increases monotonically and the conductivity decreases monotonically.

[0037] In this embodiment, Figures 1 to 7 As shown, the oxygen sensor 3 is a strontium titanate (SrTiO3) oxygen sensor. The operating temperature of the strontium titanate oxygen sensor is generally 700°C to 1000°C.

[0038] In this embodiment, Figures 1 to 7As shown, one end of the static conductive rod 100 extends out of the static end cover plate 300, and the joint with the ceramic insulating plate is provided with a plurality of extension holes, which are connected to the measurement cavity 1. The number of the extension holes matches the number of connections for the oxygen sensor 3 and the heating device 4, that is, there are four extension holes in total, two for the two measurement wires 10 to extend, and the other two for the two power wires 11 to extend. The joint between the ceramic insulating plate and the static conductive rod 100 is provided with a plurality of wiring holes, each corresponding to the plurality of extension holes. The wiring holes extend from the joint of the ceramic insulating plate to the side wall of the ceramic insulating plate, so that the two measurement wires 10 and the two power wires 11 extending out of the extension holes respectively extend into the four wiring holes and extend out of the side wall of the ceramic insulating plate.

[0039] In this embodiment, Figures 1 to 7 As shown, an insulating collar 12 is provided between each wiring hole and the corresponding extension hole, and the insulating collar 12 is sleeved on the measurement wiring 10 and the power wiring 11 .

[0040] Furthermore, in this embodiment, if Figures 1 to 7 As shown, the wire diameter of the portion of the wiring located within the insulating collar 12 is larger than the wiring hole and extension hole. The remaining wire diameter is the same as the wire barrel of the wiring hole and extension hole. In other words, the wire diameters of both the measurement wire 10 and the power wire 11 located within the insulating collar 12 are larger than the wiring hole and extension hole. This reduces the impact of sealing issues caused by manufacturing tolerances that prevent the wire diameter from perfectly matching the wiring hole diameter.

[0041] Furthermore, in this embodiment, if Figures 1 to 7 As shown, the length of the insulating collar 12 is at least 5 mm. This means that the wire diameters of the measurement wire 10 and the power wire 11 inside the extension hole match those of the extension hole, while the wire diameter inside the insulating collar 12 is larger than the extension hole. After extending 5 mm, the wire diameter decreases back to its original diameter, and the four wires now enter the four routing holes.

[0042] In this embodiment, Figures 1 to 7 As shown, the ceramic insulating plate includes a mounting ring 5, in which a cross buckle plate 6 is fixedly connected. The cross buckle plate 6 is provided with an embedding groove 13 for the static conductive rod 100 and the static end conductive block 800 to be embedded, so as to achieve the fit between the cross buckle plate 6 and the static conductive rod 100. Four exposure openings 7 are formed between the cross buckle plate 6 and the mounting ring 5 to expose the static conductive rod 100 and the static end conductive block 800 so that the vacuum arc chamber can be electrically connected and work normally. The wiring hole extends from the center of the cross buckle plate 6 to the side wall of the mounting ring 5. A cover extension ring 8 is coaxially fixedly connected to the outer wall of the static end cover plate 300, and the cover extension ring 8 is fixedly connected to the mounting ring 5.

[0043] Furthermore, in this embodiment, if Figures 1 to 7As shown, the cover plate extension ring 8 and the mounting ring 5 are connected by screws. Specifically, the mounting ring 5 and the cover plate extension ring 8 are respectively provided with screw holes 9 for screwing in. As an example, the screw holes 9 on the mounting ring 5 and the cover plate extension ring 8 are arranged circumferentially, as shown in FIG. Figure 1 As shown, each of the mounting ring 5 and the cover plate extension ring 8 is provided with a screw hole 9. Of course, the above is only a specific number of settings, which does not mean that there must be eleven screw holes 9. Other numbers are also possible.

[0044] Example 2

[0045] This embodiment provides a method for monitoring the vacuum degree of a vacuum interrupter. Figures 1 to 7 As shown, the following steps are included:

[0046] S1. Install the vacuum interrupter vacuum monitoring assembly in Example 1 on the vacuum interrupter, connect the measurement connection 10 of the oxygen sensor 3 to the measurement device, and connect the power connection 11 of the heating device 4 to the power supply device;

[0047] S2, turn on the heating device 4 to adjust the temperature in the measurement cavity 1 to the operating temperature of the oxygen sensor 3;

[0048] S3. Start the measuring device, receive the monitoring data from the oxygen sensor 3, obtain the oxygen content in the vacuum interrupter, and then obtain the vacuum degree value, and then take timely action.

[0049] In this embodiment, Figures 1 to 7 As shown, in step S3, when the oxygen concentration exceeds the set value, that is, the vacuum degree is lower than the operating standard of the vacuum interrupter, the measuring device will alarm and remind people to take action.

[0050] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A vacuum degree monitoring component for a vacuum interrupter, characterized in that: The vacuum interrupter comprises a measuring cavity disposed within a static conductive rod of the vacuum interrupter, the measuring cavity being in communication with an internal cavity of an insulating ceramic shell of the vacuum interrupter via a communicating hole, an oxygen sensor and a heating device being mounted within the measuring cavity, a ceramic insulating plate being mounted on a static end cover of the vacuum interrupter, the ceramic insulating plate being in contact with an end of the static conductive rod extending out of the static end cover, the ceramic insulating plate being provided with an exposure opening for exposing the static conductive rod and a static end conductive block sleeved on the static conductive rod, the wiring for the oxygen sensor and the heating device extending from the contact point between the static conductive rod and the ceramic insulating plate into the ceramic insulating plate and extending out from a side wall of the ceramic insulating plate; The joint between the static conductive rod and the ceramic insulating plate is provided with corresponding extension holes and wiring holes, the extension holes are connected to the measurement cavity, the number of the extension holes is consistent with the number of wiring between the oxygen sensor and the heating device, and the wiring holes extend from the joint between the ceramic insulating plates to the side wall of the ceramic insulating plates; The ceramic insulating plate includes a mounting ring, a cross buckle plate is fixedly connected inside the mounting ring, an embedding groove is provided on the cross buckle plate, the static conductive rod and the static end conductive block are embedded in the embedding groove, the wiring hole extends from the center of the cross buckle plate to the side wall of the mounting ring, and a cover plate extension ring is coaxially fixedly connected to the outer wall of the static end cover plate, and the cover plate extension ring is fixedly connected to the mounting ring.

2. A vacuum interrupter vacuum degree monitoring assembly according to claim 1, characterized in that: The oxygen sensitive sensor adopts a strontium titanate oxygen sensitive sensor.

3. A vacuum interrupter vacuum degree monitoring assembly according to claim 1, characterized in that: An insulating collar is provided between the wiring hole and the extension hole, and the insulating collar is sleeved outside the wiring of the oxygen sensor and the heating device.

4. A vacuum interrupter vacuum degree monitoring assembly according to claim 3, characterized in that: The diameter of the wire portion of the wiring located within the insulating collar is larger than the wiring hole and the extension hole.

5. A vacuum interrupter vacuum degree monitoring assembly according to claim 4, characterized in that: The length of the insulating ring is more than 5 mm.

6. A vacuum interrupter vacuum degree monitoring assembly according to claim 1, characterized in that: The cover plate extension ring and the mounting ring are connected by screws.

7. A method for monitoring the vacuum degree of a vacuum interrupter, characterized in that: The following steps are involved: S1. Install the vacuum interrupter vacuum monitoring assembly according to any one of claims 1 to 6 on the vacuum interrupter, connect the wiring of the oxygen sensor to the measuring device, and connect the wiring of the heating device to the power supply device; S2. Turn on the heating device to adjust the temperature in the measurement cavity to the operating temperature of the oxygen sensor; S3. Start the measuring device to receive monitoring data from the oxygen sensor.

8. A vacuum interrupter vacuum degree monitoring method according to claim 7, characterized in that: In step S3, when the oxygen concentration exceeds a set value, the measuring device issues an alarm.

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