Triboelectricity speed and displacement sensor for switch contact detection

Abstract

The invention provides a triboelectric speed and displacement sensor for switch contact detection, and the sensor comprises a vibrator slidably disposed on a power shaft, a displacement pad disposed at the rear end of the power shaft, a first buffer assembly connected between a moving contact and the vibrator, a second buffer assembly connected between the vibrator and the displacement pad, and a friction layer tube. The power shaft is slidably sleeved with the friction layer pipe, and the outer surfaces of the vibrator and the displacement pad make contact with the inner surface of the friction layer pipe. A friction layer of a cross structure is arranged on the inner surface of the friction layer pipe, and cross electrodes are arranged on the outer surface of the vibrator and the outer surface of the displacement pad. According to the invention, the structure of the switch contact is optimized, the spring is added for damping, signal frequency loss of the switch contact caused by high acceleration and millimeter-level amplitude vibration is avoided, and the displacement measurement precision is remarkably improved; meanwhile, accurate measurement of the instantaneous rate is realized by combining the vibration frequency change of the spring, and real-time and accurate detection of the motion state of the vacuum circuit breaker contact is realized.

Description

Technical Field

[0001] This application belongs to the field of switchgear technology, and specifically relates to a triboelectric velocity and displacement sensor for detecting switch contacts. Background Technology

[0002] As vacuum circuit breakers continue to evolve towards smaller sizes and higher voltage levels, their applications in the power sector are becoming increasingly widespread. Vacuum circuit breakers, when performing opening and closing operations, are characterized by high contact speed, high acceleration, large vibration amplitude, frequent operation, and strong electromagnetic interference. Monitoring the displacement and velocity of the vacuum circuit breaker contacts to determine whether the circuit breaker is in normal operating condition has always been a common method in the power industry. Conventional monitoring sensors, however, require additional power supply equipment and face strong interference in strong electromagnetic fields, thus affecting the accuracy of the displacement sensors. Summary of the Invention

[0003] The purpose of this application is to provide a triboelectric velocity and displacement sensor for detecting switch contacts, aiming to solve the problem of low measurement accuracy of conventional sensors for monitoring the displacement and velocity of vacuum circuit breaker contacts.

[0004] This application provides a triboelectric velocity and displacement sensor for detecting switch contacts. The switch contact includes a fixed contact and a drive shaft. A movable contact is fixed at the front end of the drive shaft. The sensor includes an oscillator slidably disposed on the drive shaft, a displacement pad disposed at the rear end of the drive shaft, a first buffer assembly connecting the movable contact and the oscillator, a second buffer assembly connecting the oscillator and the displacement pad, and a friction layer tube. The drive shaft is slidably sleeved inside the friction layer tube. The outer surfaces of the oscillator and the displacement pad are in contact with the inner surface of the friction layer tube. The inner surface of the friction layer tube is provided with a cross-structured friction layer, and the outer surfaces of the oscillator and the displacement pad are both provided with cross electrodes.

[0005] Preferably, the power shaft is cylindrical.

[0006] Preferably, the oscillator is a hollow cylinder.

[0007] Preferably, the displacement pad is cylindrical.

[0008] Preferably, the first buffer component is a first spring.

[0009] Preferably, the second buffer component is a second spring.

[0010] Preferably, the radius of the first spring is smaller than the inner diameter of the friction layer tube.

[0011] Preferably, the radius of the second spring is smaller than the inner diameter of the friction layer tube.

[0012] Preferably, the material of the friction layer is an organic thin film.

[0013] The beneficial effects of the triboelectric velocity and displacement sensor for switch contact detection provided in this application include at least the following: The spring structure design in this application reduces mechanical vibration caused by switch closure and solves the problem of frequency loss in triboelectric signal measurement due to mechanical vibration. Furthermore, the spring allows the oscillator to return to its original position after the switch is closed or opened, facilitating the next speed and displacement detection of the switch contacts. Additionally, by analyzing the triboelectric signal frequency during speed detection, this application accurately identifies the instantaneous speed, time point, and displacement of the switch closure, solving the problems of frequency loss and poor displacement accuracy under high acceleration conditions. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the triboelectric velocity and displacement sensor for switch contact detection provided in this application.

[0016] Figure 2 This is an exploded view of the triboelectric velocity and displacement sensor for switch contact detection provided in this application.

[0017] Figure 3(a) is a schematic diagram of the cross electrode structure on the surface of the oscillator; Figure 3(b) is a schematic diagram of the friction layer structure on the inner surface of the friction layer tube.

[0018] Figure 4 This is a waveform diagram of the triboelectric signal when the displacement sensor detects the speed for switch contact detection, as provided in this application.

[0019] Among them, 1. fixed contact; 2. power shaft; 3. moving contact; 4. displacement pad; 5. first spring; 6. oscillator; 7. second spring; 8. friction layer tube. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] like Figure 1 , Figure 2 As shown, this application embodiment provides a triboelectric velocity and displacement sensor for detecting switch contacts. The switch contact includes a fixed contact 1 and a cylindrical power shaft 2. A movable contact 3 is fixed at the front end of the power shaft 2. The contact or separation of the fixed contact 1 and the movable contact 3 can realize the closing or opening of the switch. The sensor includes a hollow cylindrical vibrator 6 slidably disposed on the power shaft 2, a cylindrical displacement pad 4 disposed at the rear end of the power shaft 2, a first buffer assembly connecting the movable contact 3 and the vibrator 6, a first buffer assembly connecting the vibrator 6 and the displacement pad 4, and a friction layer tube 8. The power shaft 2 is slidably sleeved inside the friction layer tube 8, and the outer surfaces of the vibrator 6 and the displacement pad 4 are in contact with the inner surface of the friction layer tube 8. The inner surface of the friction layer tube 8 is provided with a cross-structured friction layer, and the outer surfaces of the vibrator 6 and the displacement pad 4 are both provided with cross electrodes.

[0022] Preferably, the first buffer component is a first spring 5, with its front end connected to the rear end of the moving contact 3 and its rear end connected to the front end of the oscillator 6; the second buffer component is a second spring 7, with its front end connected to the rear end of the oscillator 6 and its rear end connected to the front end of the displacement pad 4; the radii of the first spring 5 and the second spring 7 are smaller than the inner diameter of the friction layer tube 8. In a preferred embodiment, the elastic coefficients of the two springs are optimized so that when the moving contact 3 and the fixed contact 1 are closed, the tensile and compressive values ​​of the first spring 5 and the second spring 7 have reached their maximum. At this time, the speed of the oscillator is consistent with the speed of the moving contact 3, which is used to detect the movement speed of the moving contact 3. The spring coefficients and lengths of the first spring 5 and the second spring 7 can be determined based on the movement distance of the moving contact 3.

[0023] Preferably, the inner surface of the friction layer tube 8 is provided with a cross-structured friction layer. The friction layer material includes, but is not limited to, organic films, such as polytetrafluoroethylene (PTFE) and vinylidene fluoroethylene (DOM). Cross electrodes are provided on the surface of the oscillator 6 to measure the electrical signal when relative displacement occurs between the oscillator 6 and the friction layer tube 8. By calculating the frequency, the velocity at the instant the switch contacts close can be accurately measured. The structure of the cross electrodes is shown in Figure 3(a), wherein the width of each cross electrode is... The spacing between the two electrodes Much smaller than the width of the electrode The cross structure on the inner surface of the friction layer tube 8 is shown in Figure 3(b), wherein the width of each friction strip in the cross structure is... The interval between the two friction strips is .

[0024] The working principle of the sensor for detecting speed provided in this application is as follows: When the relay switch is open, the fixed contact 1 and the moving contact 3 at the front end of the power shaft 2 are disconnected; when the relay switch is closed, the moving contact 3, the first spring 5, the oscillator 6, the second spring 7, and the displacement pad 4 move as a whole toward the fixed contact 1. During this process, the first spring 5 and the second spring 7 are in a stretched state and a compressed state, respectively. It should be noted that when the moving contact 3 is closed with the fixed contact 1, the stretched value of the first spring 5 and the compressed value of the second spring 7 reach their maximum. At this time, the speed of the oscillator 6 is consistent with the speed of the moving contact 3, which is used to detect the movement speed of the moving contact 3. When the moving contact 3 is closed with the fixed contact 1, the oscillator 6 compresses the first spring 5 and stretches the second spring 7 due to inertia, and stores the kinetic energy of the collision between the moving contact 3 and the fixed contact 1 in the first spring 5 and the second spring 7 and releases it later. This reduces the vibration of the power shaft 2 when closed, thereby reducing its impact on the accuracy of the displacement sensor. The speed detection mechanism of the sensor is as follows: Before the moving contact 3 closes with the fixed contact 1, the first spring 5 and the second spring 7 are in a stretched state and a compressed state, respectively. At this time, the frequency of the triboelectric signal generated by the relative displacement between the oscillator 6 and the friction layer tube 8 increases. When the stretching value of the first spring 5 and the compression value of the second spring 7 reach their maximum, the frequency of the triboelectric signal stabilizes. After the collision, the oscillator 6 decelerates, and the frequency of the triboelectric signal gradually decreases. The output waveform of the triboelectric signal is as follows: Figure 4 As shown, the triboelectric signal gradually increases to its maximum in the early stage. At this time, the speed of the oscillator 6 is the same as the speed of the fixed contact 1, which also means that the fixed contact 1 and the moving contact 3 are in contact. The frequency decreases (that is, the maximum frequency) and is the instantaneous velocity when the tube is closed. The frequency at this time is measured. In general, the principle of the sensor for detecting speed provided in this application is to calculate the instantaneous speed of the switch contacts at the moment of collision based on the frequency change (maximum frequency) of the triboelectric signal. Instantaneous speed =Maximum frequency * Electrode width of cross electrodes .

[0025] The working principle of the sensor for displacement detection provided in this application is as follows: The cross electrodes set on the surface of the displacement pad have the same structure as the cross electrodes set on the surface of the oscillator 6, and the displacement of the moving contact 3... =The total number of electrical pulses measured on the displacement pad Spacing with cross electrodes The product of.

[0026] In summary, the sensor provided in this application solves the problem of low accuracy in detecting the speed and displacement of vacuum circuit breaker contacts. Specifically, by optimizing the switch contact structure and adding spring damping, this application avoids the signal frequency loss caused by high acceleration and millimeter-level amplitude vibration of the switch contacts, significantly improving measurement accuracy and realizing real-time and accurate detection of the motion state of vacuum circuit breaker contacts, providing a new technical means for the condition monitoring of smart grid equipment.

[0027] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A triboelectric velocity and displacement sensor for detecting switch contacts, the switch contact comprising a fixed contact (1) and a drive shaft (2), wherein a movable contact (3) is fixed to the front end of the drive shaft (2), characterized in that, The sensor includes an oscillator (6) slidably mounted on the power shaft (2), a displacement pad (4) disposed at the rear end of the power shaft (2), a first buffer assembly connected between the moving contact (3) and the oscillator (6), a second buffer assembly connected between the oscillator (6) and the displacement pad (4), and a friction layer tube (8). The power shaft (2) is slidably mounted inside the friction layer tube (8). The outer surfaces of the oscillator (6) and the displacement pad (4) are in contact with the inner surface of the friction layer tube (8). The inner surface of the friction layer tube (8) is provided with a friction layer of a cross structure, and the outer surfaces of the oscillator (6) and the displacement pad (4) are both provided with cross electrodes.

2. The triboelectric velocity and displacement sensor for switch contact detection according to claim 1, characterized in that, The power shaft (2) is cylindrical.

3. The triboelectric velocity and displacement sensor for switch contact detection according to claim 2, characterized in that, The oscillator (6) is a hollow cylinder.

4. The triboelectric velocity and displacement sensor for switch contact detection according to claim 3, characterized in that, The displacement pad (4) is cylindrical.

5. The triboelectric velocity and displacement sensor for switch contact detection according to claim 4, characterized in that, The first buffer component is the first spring (5).

6. The triboelectric velocity and displacement sensor for switch contact detection according to claim 5, characterized in that, The second buffer component is the second spring (7).

7. The triboelectric velocity and displacement sensor for switch contact detection according to claim 6, characterized in that, The radius of the first spring (5) is smaller than the inner diameter of the friction layer tube (8).

8. The triboelectric velocity and displacement sensor for switch contact detection according to claim 7, characterized in that, The radius of the second spring (7) is smaller than the inner diameter of the friction layer tube (8).

9. The triboelectric velocity and displacement sensor for switch contact detection according to claim 1, characterized in that, The friction layer is made of an organic thin film.

Images