Online monitoring device and method for wear of circuit breaker contact

Abstract

The invention discloses a breaker contact wear online monitoring device and method, the breaker contact wear online monitoring device is mounted on a moving end outlet seat of a breaker, a moving end fixing plate is fixed at one end, far away from a static contact, of a moving contact of the breaker, the moving end fixing plate is slidably connected in the moving end outlet seat, and the moving end fixing plate comprises a support rod; one end of the support rod is vertically fixed on one side plate surface of the moving end fixing plate away from the moving contact; the wear indication assembly comprises a mounting plate, a scale plate and a pointer; the mounting plate is fixed at the top end of the moving-end wire outlet seat; the scale plate is fixed on one side plate surface of the mounting plate; the upper end of the pointer can swing relative to the scale plate; the axis of the movable end pull rod is parallel to the axis of the supporting rod and located below the supporting rod. And one end of the moving end pull rod is vertically fixed on the moving end fixing plate, and the other end is in transmission connection with the lower end of the pointer to drive the pointer to swing after the moving contact is worn and closed. The problem that normal operation of the circuit breaker cannot be guaranteed in the existing monitoring technology is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit breakers, in particular to a circuit breaker contact wear online monitoring device and method. BACKGROUND

[0002] As an important source of clean energy, the safe and stable operation of hydropower stations is of great importance. As a key device in the power system of hydropower stations, the state of the circuit breaker contact directly affects the reliability and stability of the entire system. During long-term use, the circuit breaker contact will inevitably wear to varying degrees, which not only reduces the performance of the circuit breaker, but also may cause serious safety accidents.

[0003] Circuit breaker contact wear refers to the loss of contact material due to contact between contacts, friction, and arc erosion during circuit breaking (with or without load circuit). Due to contact wear, parameters such as contact overtravel reduction, contact pressure reduction, and contact resistance increase, which can seriously affect the reliability of the circuit breaker and the safety of the power system. Existing online monitoring of contact wear mainly includes cumulative breaking current integration method, which collects current through a current transformer, then installs an intelligent monitoring unit and a sensor, and draws an electrical life curve. The accuracy of this method is highly dependent on the "electrical life curve" (relationship curve between wear and breaking current) obtained through a large number of experiments in advance. If the model is not accurate, the estimation error will be large. Arc monitoring method is another method for online monitoring of contact wear, which evaluates contact wear by directly monitoring the characteristics of the arc. Contact wear can change arc pressure, arc intensity, and arc root movement. The rough surface and material deterioration of the worn contact can cause the arc voltage to rise. By measuring the arc voltage during breaking, the contact state can be indirectly inferred. However, this monitoring method requires the installation of sensors near the vacuum arc chamber, which faces engineering challenges such as high voltage, strong electromagnetic interference, and limited installation space. Moreover, the arc signal is very complex and easily disturbed by external factors, making it difficult to accurately establish the relationship between the signal and the degree of wear. Mechanical characteristics inference method is another method for online monitoring of contact wear. Contact wear can slightly change the movement quality and stroke of the moving contact, thereby affecting the mechanical characteristics parameters of the breaking and closing, such as stroke curve, speed, time, and bounce. Displacement sensors or rotary encoders are used to record the displacement-time curve of the breaking and closing coil current and the moving contact. The main difficulty of this method is that it is difficult to monitor the breaking point of the circuit breaker, and even it is difficult to achieve. Moreover, the changes in mechanical characteristics are affected by many factors (such as lubrication of the operating mechanism and spring fatigue), making it difficult to attribute the changes to contact wear. Therefore, this method can only be used as an auxiliary judgment.

[0004] Therefore, how to provide a circuit breaker contact wear monitoring device that can improve the efficiency of power station operation, prolong the service life of equipment, and ensure the safety of the power system is a problem that needs to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the application provides a circuit breaker contact wear online monitoring device and method, which solves the problem that the normal operation of the circuit breaker cannot be ensured in the prior art.

[0006] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme: A circuit breaker contact wear online monitoring device is installed on a moving end outgoing terminal of a circuit breaker, and a moving contact of the circuit breaker is fixed with a moving end fixed plate at an end far away from a static contact, and the moving end fixed plate is slidingly connected in the moving end outgoing terminal, and the device comprises: A support rod is vertically fixed at one end of the moving end fixed plate on a side plate surface far away from the moving contact; A wear indication assembly comprises a mounting plate, a scale plate and a pointer, the mounting plate is fixed at a top end of the moving end outgoing terminal, the scale plate is fixed on a side plate surface of the mounting plate, and the lower part of the pointer is hinged with the support rod through a pin shaft, and the upper end can swing relative to the scale plate; A moving end pull rod is arranged in parallel with the axis of the support rod and below the support rod, one end of the moving end pull rod is vertically fixed on the moving end fixed plate, and the other end is transmissionally connected with the lower end of the pointer to drive the pointer to swing when the moving contact is worn and the circuit breaker is closed.

[0007] The application has the beneficial effect that when the circuit breaker is closed, the moving contact contacts the static contact, and when the contact is worn, the relative distance between the moving contact and the static contact is reduced, so that when the moving contact contacts the static contact, the moving end pull rod pulls the pointer to swing, and the wear of the contact is determined according to the swing amplitude of the pointer.

[0008] Preferably, a long slot is formed along the axis of the moving end pull rod and on the rod wall, the lower end of the pointer is located in the long slot, and the lower end of the pointer abuts against a side slot wall of the long slot far away from the moving end fixed plate in the closed state. By providing the long slot, the moving end pull rod can be prevented from pulling the pointer to swing in the open state (i.e., the moving contact is far away from the static contact).

[0009] Preferably, an adjusting bolt is further included, the adjusting bolt is threadedly connected at an end of the moving end pull rod far away from the moving end fixed plate, the threaded end of the adjusting bolt extends into the long slot and abuts against the lower end of the pointer to adjust the initial position of the pointer.

[0010] Preferably, a reset spring is further included, the reset spring is located above the support rod, and the two ends of the reset spring are respectively fixed with two opposite surfaces of the pointer and the moving end fixed plate. By providing the reset spring, the pointer can be driven to reset in the case that the pointer is rotated due to the closing of the circuit breaker.

[0011] Preferably, a spring pull rod is fixed on the side panel of the moving end fixed plate away from the moving contact, one end of the reset spring is fixed with the pointer, and the other end is fixed with the spring pull rod. The connection between the reset spring and the moving end fixed plate is facilitated through the spring pull rod.

[0012] Preferably, a limit plate is detachably connected to the side panel of the mounting plate, and the limit plate has a swing gap with the mounting plate; and the upper end of the pointer is located in the swing gap.

[0013] Preferably, an observation window is arranged on the side wall of the circuit breaker corresponding to the scale plate. The swing amplitude of the pointer is observed through the observation window to determine the wear condition of the contact.

[0014] Preferably, a visual sensor for detecting the relative position of the pointer and the scale plate is fixed on the mounting plate, and the visual sensor is communicatively connected to a controller. In the case where the observation window cannot be arranged, the swing amplitude of the pointer can be detected through the visual sensor, and the wear condition of the contact can be determined through the controller.

[0015] The application also discloses a circuit breaker contact wear online monitoring device, which comprises: after a certain number of opening and closing actions of the circuit breaker, the moving contact has a certain wear; when the circuit breaker is closed, the moving contact is in contact with the static contact, the distance between the moving contact and the static contact decreases after the wear of the moving contact, the moving end pull rod drives the pointer, the upper end of the pointer swings, and when the pointer points to a limit threshold of the contact, the arc-extinguishing chamber is replaced.

[0016] Compared with the prior art, the circuit breaker contact wear online monitoring device and method provided by the application can indicate the position of the moving contact of the circuit breaker when the vacuum circuit breaker is in the closed position, the position indicated by the pointer in the closed position changes after a certain number of actions of the vacuum circuit breaker, and thus the wear amount and health state of the vacuum arc-extinguishing chamber contact can be monitored; the initial indication position of the pointer is adjusted by adjusting the bolt to ensure that the initial indication positions are the same, the impact of the opening and closing of the circuit breaker on the contact wear monitoring device is solved, that is, the circuit breaker is opened, and the pointer does not move; the circuit breaker is closed, and the contact is not worn, and the pointer does not move; the circuit breaker is closed, and the contact is worn, and the pointer swings, the health state of the arc-extinguishing chamber can be directly monitored, the normal operation of the circuit breaker is ensured, the structure is simple, the cost is reduced, and the application has important significance for improving the operation efficiency of the power station, prolonging the service life of the equipment, and ensuring the safety of the power system. BRIEF DESCRIPTION OF DRAWINGS

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the online monitoring device provided by the present invention; Figure 2 This is a schematic diagram of the moving end tie rod structure provided by the present invention; Figure 3 A schematic diagram of the installation structure of the online monitoring device provided by the present invention on a circuit breaker.

[0019] Among them, 1-stationary contact; 2-moving contact; 3-moving end fixing plate; 4-moving end pull rod; 41-adjusting bolt; 5-support rod; 51-pin; 6-reset spring; 61-spring pull rod; 7-wear indicator assembly; 71-scale plate; 72-pointer; 73-limit plate; 74-mounting plate; 8-moving end outlet. Detailed Implementation

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

[0021] like Figure 1 As shown in Figure 3, according to an embodiment of the present invention, an online monitoring device for contact wear of a circuit breaker is installed on the moving end outlet seat 8 of the circuit breaker. A moving end fixing plate 3 is fixed to the end of the moving contact 2 away from the stationary contact 1. The moving end fixing plate 3 is slidably connected within the moving end outlet seat 8 and includes a support rod 5, a wear indicator assembly 7, and a moving end pull rod 4. One end of the support rod 5 is vertically fixed to the side surface of the moving end fixing plate 3 away from the moving contact 2. The wear indicator assembly 7 includes a mounting plate 74, a scale plate 71, and a pointer 72. The mounting plate 74 is fixed to the top of the moving end outlet seat 8. The scale plate 71 is fixed to one side surface of the mounting plate 74. The lower part of the pointer 72 is hinged to the support rod 5 via a pin 51, and the upper end can swing relative to the scale plate 71. Figure 3As shown, the moving end mounting plate 3 is located in the moving end outgoing terminal seat 8 and can move in the moving end outgoing terminal seat 8 with the opening and closing of the circuit breaker (the moving contact 2 is away from or close to the static contact 1), the mounting plate 74 is embedded in the top end of the moving end outgoing terminal seat 8, the lower end of the pointer 72 is located in the moving end outgoing terminal seat 8, the upper end penetrates the top wall of the moving end outgoing terminal seat 8 and can swing relative to the scale plate 71, and the scale plate 71 is provided with scale marks of the moving contact wear amount 0mm, 3mm and 5mm. The axis of the moving end pull rod 4 is parallel to the axis of the support rod 5 and is located below the support rod 5; one end of the moving end pull rod 4 is fixed vertically on the moving end mounting plate 3, and the other end is transmissionally connected to the lower end of the pointer 72 to drive the pointer 72 to swing when the moving contact 2 is worn and closed.

[0022] In the embodiment, in order to prevent the pointer from swinging when the circuit breaker is opened, a long slot 42 is formed along the axis of the moving end pull rod 4 and on the rod wall thereof, the lower end of the pointer 72 is located in the long slot 42, and the lower end of the pointer 72 abuts against the slot wall away from the moving end mounting plate 3 in the closed state. As shown in the direction, Figure 1 When closed, that is, the moving contact 2 contacts the static contact 1, the pointer 72 abuts against the left end slot wall of the long slot 42; when opened, that is, the moving contact 2 is away from the static contact 1, the moving end pull rod 4 moves away from the static contact 1, at this time, the long slot 42 moves to the left, and the pointer 72 does not swing; when the moving contact 2 is worn and in the closed state, the distance between the moving contact 1 and the static contact 1 is reduced, in the state that the moving contact is worn and closed, the moving end pull rod 4 pulls the pointer 72 to swing along the support rod 5, at this time, the upper end of the pointer 72 swings to the left, and the wear amount of the moving contact 2 is determined according to the swing amplitude, for example, when the pointer 72 points to the contact wear 3mm, the state of the arc extinguishing chamber of the circuit breaker needs to be observed at any time, and when the pointer 72 points to the contact wear 5mm, the arc extinguishing chamber needs to be replaced.

[0023] In order to further optimize the above technical scheme, for the circuit breaker produced in large quantities, the initial pointing position of the pointer is different due to the different closed positions, in order to adjust the initial pointing position of the pointer to point to the contact wear 0mm position, the technical scheme further comprises an adjusting bolt 41, the adjusting bolt 41 is threadedly connected to the end of the moving end pull rod 4 away from the moving end mounting plate 3, the threaded end of the adjusting bolt 41 extends into the long slot 42 and abuts against the lower end of the pointer 72 to adjust the initial position of the pointer 72.

[0024] In some other specific embodiments, the pointer can be automatically reset after deflection, and the technical scheme further comprises a reset spring 6, the reset spring 6 is located above the support rod 5, and the two ends thereof are fixed to the two opposite surfaces of the pointer 72 and the moving end mounting plate 3 respectively.

[0025] In order to further optimize the above technical scheme, facilitate the connection between the reset spring and the moving end fixed plate, the spring pull rod 61 is fixed on the side panel of the moving end fixed plate 3 away from the moving contact 2, one end of the reset spring 6 is fixed with the pointer 72, and the other end is fixed with the spring pull rod 61.

[0026] In the embodiment, in order to ensure the effective swing of the pointer, the side panel of the mounting plate 74 is detachably connected with the limiting plate 73, and the limiting plate 73 and the mounting plate 74 have a swing gap therebetween; and the upper end of the pointer 72 is located in the swing gap.

[0027] In order to further optimize the above technical scheme, facilitate the observation of the swing of the pointer, the side wall of the circuit breaker corresponding to the scale plate 71 is provided with an observation window.

[0028] In other specific embodiments, for the case that the circuit breaker cannot or is inconvenient to open the observation window, the visual sensor for detecting the relative position of the pointer 72 and the scale plate 71 is fixed on the mounting plate 74, and the visual sensor is in communication connection with the controller. The controller is provided with an alarm device, when the pointer 72 is at the position where the straight contact is worn by 5mm, the controller controls the alarm device to generate sound and light alarm, reminding the operator to replace the arc extinguishing chamber.

[0029] The embodiment also discloses a circuit breaker contact wear online monitoring method, which utilizes the circuit breaker contact wear online monitoring device to monitor the wear of the moving contact, and the method comprises the following steps: when the circuit breaker is opened, the pointer 72 does not swing under the action of the long slot 42 on the moving end pull rod 4, after a certain number of opening and closing actions of the circuit breaker, the moving contact 2 is worn to a certain extent; when the circuit breaker is closed, the pointer does not swing under the action of the long slot 42; when the circuit breaker is closed, the moving contact 2 contacts the static contact 1, and since the distance between the moving contact 2 and the static contact 1 is reduced after the wear of the moving contact 2, the moving end pull rod 4 drives the pointer 72 to rotate around the hinge joint between the pointer 72 and the support rod 5, and the upper end of the pointer 72 swings, and when the pointer 72 points to the contact wear limit threshold, the arc extinguishing chamber is replaced.

[0030] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between the embodiments can be referred to each other. For the device disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0031] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An online monitoring device for contact wear of a circuit breaker, installed on the moving end outlet seat (8) of the circuit breaker, wherein a moving end fixing plate (3) is fixed at the end of the moving contact (2) away from the stationary contact (1), and the moving end fixing plate (3) is slidably connected inside the moving end outlet seat (8), characterized in that, include: Support rod (5), one end of which is vertically fixed to the side of the moving end fixing plate (3) away from the moving contact (2); Wear indicator assembly (7), the wear indicator assembly (7) includes a mounting plate (74), a scale plate (71) and a pointer (72); the mounting plate (74) is fixed to the top of the moving end outlet seat (8); the scale plate (71) is fixed to one side of the mounting plate (74); the lower part of the pointer (72) is hinged to the support rod (5) through a pin (51), and the upper end can swing relative to the scale plate (71); The moving end pull rod (4) is arranged with its axis parallel to the axis of the support rod (5) and located below the support rod (5); one end of the moving end pull rod (4) is vertically fixed on the moving end fixing plate (3), and the other end is connected to the lower end of the pointer (72) to drive the pointer (72) to swing after the moving contact (2) is worn and when the circuit is closed.

2. The circuit breaker contact wear online monitoring device according to claim 1, characterized in that, A long groove (42) is provided along the axis of the moving end pull rod (4) and on its rod wall. The lower end of the pointer (72) is located in the long groove (42), and in the closed state, the lower end of the pointer (72) abuts against the side wall of the long groove (42) away from the moving end fixing plate (3).

3. The circuit breaker contact wear online monitoring device according to claim 2, characterized in that, It also includes an adjusting bolt (41), which is threadedly connected to one end of the moving end pull rod (4) away from the moving end fixing plate (3). The threaded end of the adjusting bolt (41) extends into the elongated groove (42) and abuts against the lower end of the pointer (72) to adjust the initial position of the pointer (72).

4. The circuit breaker contact wear online monitoring device according to claim 1, characterized in that, It also includes a return spring (6), which is located above the support rod (5) and its two ends are fixed to the two surfaces opposite to the pointer (72) and the moving end fixing plate (3), respectively.

5. The circuit breaker contact wear online monitoring device according to claim 4, characterized in that, A spring rod (61) is fixed on the side panel of the moving end fixing plate (3) away from the moving contact (2). One end of the reset spring (6) is fixed to the pointer (72), and the other end is fixed to the spring rod (61).

6. The circuit breaker contact wear online monitoring device according to claim 1, characterized in that, A limiting plate (73) is detachably connected to one side of the mounting plate (74), and there is a swing gap between the limiting plate (73) and the mounting plate (74); the upper end of the pointer (72) is located within the swing gap.

7. The circuit breaker contact wear online monitoring device according to claim 1, characterized in that, The circuit breaker has an observation window on the side wall corresponding to the scale plate (71).

8. The online monitoring device for circuit breaker contact wear according to claim 1, characterized in that, A vision sensor is fixed on the mounting plate (74) to detect the relative position of the pointer (72) and the scale plate (71), and the vision sensor is communicatively connected to the controller.

9. A method for online monitoring of circuit breaker contact wear, characterized in that, The circuit breaker contact wear online monitoring device according to any one of claims 1 to 8 includes: after the circuit breaker has undergone a certain number of opening and closing operations, the moving contact (2) has a certain amount of wear; when the circuit breaker is closed, the moving contact (2) contacts the stationary contact (1), and the distance between the moving contact (2) and the stationary contact (1) decreases after the moving contact (2) is worn; the moving end pull rod (4) drives the pointer (72), and the upper end of the pointer (72) swings; when the pointer (72) points to the contact limit threshold, the arc-extinguishing chamber is replaced.

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