Transformer on-load tap-changer contact structure and control system

Abstract

The invention relates to the technical field of transformers, and discloses a transformer on-load tap-changer contact structure and a control system, the transformer on-load tap-changer contact structure comprises a static contact and a rotating moving contact, and the moving contact is provided with an embedding cavity for embedding the static contact; the moving contact is provided with a contact clamping piece which is elastically and movably arranged, and the contact clamping piece is arranged on the periphery of the embedding cavity; the periphery of the static contact is provided with a static peripheral surface, the contact clamping piece is provided with a movable contact surface facing the embedding cavity, and the static peripheral surface and the movable contact surface are in cambered surface-shaped surface fitting and abutting connection. The static peripheral surface of the static contact and the moving contact surface of the moving contact are in cambered surface-shaped surface fitting and abutting connection, so that the contact area between the static contact and the moving contact can be greatly increased, the power transmission efficiency is improved, the contact resistance is further reduced, the stability and durability of the contact structure are improved, and the phenomenon of poor contact of the contact structure is avoided.

Description

Technical Field

[0001] The invention patent relates to the technical field of transformers, and specifically, to the contact structure of transformer on-load tap changers. Background Art

[0002] In the electric power field, the on-load tap changer is an important component of the transformer. The on-load tap changer is suitable for operation under transformer excitation or load. It is used to change the connection position of the transformer winding tapping and realize the switching between the taps in the transformer winding, thereby changing the number of turns of the winding, that is, the voltage ratio of the transformer, and ultimately achieving the purpose of voltage regulation.

[0003] The on-load tap changer has a contact structure. As the service time increases, the contact structure of the on-load tap changer often faces problems such as increased contact resistance, poor contact, overheating, oxidation, etc., which leads to decreased efficiency and frequent maintenance of the transformer. In severe cases, it may even cause power system failure and shutdown, thereby affecting the stability of the power system and the reliability of power supply. Summary of the invention

[0004] The object of the present invention is to provide a transformer on-load tap changer contact structure, aiming to solve the problem of poor contact in the transformer on-load tap changer contact structure in the prior art.

[0005] The present invention is implemented as follows: a transformer on-load tap changer contact structure comprises a stationary contact and a rotatably arranged moving contact, wherein the moving contact has an embedding cavity for the stationary contact to be embedded in; the moving contact has a contact clip elastically arranged, and the contact clip is arranged on the periphery of the embedding cavity;

[0006] The outer periphery of the stationary contact has a stationary outer peripheral surface, and the contact clip has a dynamic contact surface facing the embedding cavity, and the stationary outer peripheral surface and the dynamic contact surface are in arc-shaped surface contacting contact.

[0007] Furthermore, the static outer peripheral surface is convex outwardly in the shape of a convex arc surface, and the dynamic contact surface is concave inwardly in the shape of a concave arc surface.

[0008] Furthermore, metal coatings are formed on the static outer peripheral surface and the dynamic contact surface respectively.

[0009] Furthermore, the metal coating is made of silver-copper material; the thickness of the metal coating is between 5 microns and 15 microns.

[0010] Furthermore, the moving contact and the stationary contact are made of a copper-aluminum composite material, and the aluminum content is between 10% and 30%.

[0011] Furthermore, the movable contact comprises a contact frame, the contact clip is arranged in the contact frame, and a spring is connected between the contact clip and the inner side wall of the contact frame; the diameter of the embedded cavity changes through the expansion and contraction deformation of the spring.

[0012] Furthermore, the stationary contact has a connection portion extending outwardly and connected to a connection terminal of a lead wire, the connection portion is arranged away from the moving contact, and is arranged in a bent shape with respect to the stationary contact;

[0013] The wiring part and the wiring terminal are respectively flat, the wiring part includes two clamping walls that are butted against each other, the two clamping walls enclose a fixing cavity, the wiring terminal is inserted into the fixing cavity, the wiring part is penetrated by a bolt, the bolt passes through the wiring terminal, and the wiring terminal is relatively fixed to the wiring part;

[0014] The clamping wall has a facing side wall facing the fixed cavity, a clamping gap is provided between the facing side wall and the connecting terminal, the clamping gap is provided with an elastic structure, the elastic structure is fixedly connected to the facing side wall, the elastic structure presses against the connecting terminal and is in an elastic compression deformation state.

[0015] Further, the elastic structure includes a plurality of curved sheet-shaped elastic arms, one end of the elastic arm is fixedly connected to the side wall, along the direction in which the wiring terminal is inserted into the fixed cavity, the other end of the elastic arm is bent inwardly to form a pressing end, the pressing end is pressed against the wiring terminal, and the elastic arm is in an elastically compressed deformation state;

[0016] A hollow area is provided in the middle of the elastic arm, and the hollow area passes through the elastic arm and extends along the bending direction of the elastic arm; the wiring terminal has a middle hole for the bolt to pass through, and the inner side wall of the middle hole is raised to form a plurality of raised positions, and the plurality of raised positions are spaced around the circumference of the middle hole, and recessed positions are formed between adjacent raised positions, and the plurality of raised positions are respectively abutted against the outer periphery of the bolt.

[0017] Furthermore, the end of the terminal block has an end wall, the fixed cavity has a bottom wall facing the end wall, the bottom wall is concave in a concave arc surface, the end wall is convex in a convex arc surface, the convex arc surface abuts against the concave arc surface, and the diameter of the concave arc surface is greater than the diameter of the convex arc surface.

[0018] Compared with the prior art, the transformer on-load tap changer contact structure provided by the present invention has an arc-shaped surface between the static outer peripheral surface of the static contact and the dynamic contact surface of the dynamic contact, which can greatly increase the contact area between the static contact and the dynamic contact, improve the power transmission efficiency, further reduce the contact resistance, improve the stability and durability of the contact structure, and avoid the phenomenon of poor contact of the contact structure.

[0019] The present invention also provides a control system, including the above-mentioned transformer on-load tap changer contact structure, a controller and a sensor for monitoring the contact resistance between the moving contact and the static contact. When the contact resistance exceeds a set threshold, the controller issues an alarm.

[0020] Compared with the prior art, the control system provided by the present invention has a better stability of the contact structure and will not have poor contact, thereby ensuring the stability of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional schematic diagram of the contact structure of the transformer on-load tap changer provided by the present invention;

[0022] Figure 2 is a schematic cross-sectional view of a contact clip provided by the present invention;

[0023] Figure 3 It is an internal schematic diagram of the wiring terminal provided by the present invention being inserted into the wiring portion;

[0024] Figure 4 is a cross-sectional schematic diagram of a bolt provided by the present invention being inserted into a wiring terminal;

[0025] Figure 5 It is a partial schematic diagram of the wiring terminal provided by the present invention being inserted into the wiring portion;

[0026] Figure 6 It is a flow chart of the control system provided by the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0029] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] Reference Figure 1-6 The figure shows a preferred embodiment of the present invention.

[0031] The transformer on-load tap changer contact structure comprises a stationary contact 200 and a rotatably arranged moving contact 100, wherein the moving contact 100 has an embedding cavity for embedding the stationary contact 200; the moving contact 100 has an elastically movable contact clip 103, and the contact clip 103 is arranged on the periphery of the embedding cavity.

[0032] The outer periphery of the stationary contact 200 has a stationary outer peripheral surface 202 , and the contact clip 103 has a dynamic contact surface 104 facing the embedding cavity. The stationary outer peripheral surface 202 and the dynamic contact surface 104 are in arc-shaped contact with each other.

[0033] In the transformer on-load tap changer contact structure provided above, the static outer peripheral surface 202 of the static contact 200 and the dynamic contact surface 104 of the dynamic contact 100 are in arc-shaped contact and abutment with each other, which can greatly increase the contact area between the static contact 200 and the dynamic contact 100, improve the power transmission efficiency, further reduce the contact resistance, improve the stability and durability of the contact structure, and avoid the phenomenon of poor contact of the contact structure.

[0034] In addition, the contact clips 103 of the stationary contact 200 and the moving contact 100 can be arranged in different shapes, as long as they can fit and abut against the curved surfaces.

[0035] In this embodiment, the static outer peripheral surface 202 protrudes outward in the shape of a convex arc surface, and the dynamic contact surface 104 is recessed inward in the shape of a recessed arc surface. In this way, the static outer peripheral surface 202 can protrude and be embedded in the area surrounded by the dynamic contact surface 104, and make surface-to-surface contact with the dynamic contact surface 104, so that the contact area between the static contact 200 and the dynamic contact 100 is increased, the contact is better and more stable, and poor contact is avoided.

[0036] In this embodiment, metal coatings are formed on the static outer surface 202 and the dynamic contact surface 104, respectively, which can greatly enhance the oxidation resistance and wear resistance of the static outer surface 202 and the dynamic contact surface 104. In addition, the static outer surface 202 and the dynamic contact surface 104 can be subjected to micro-arc oxidation or other high-efficiency coating treatments.

[0037] In this embodiment, the metal plating layer is made of silver-copper material; the thickness of the metal plating layer is between 5 microns and 15 microns, and the metal plating layer is made by chemical plating or electroplating process. The good conductivity of silver can effectively reduce the contact resistance and improve the conduction efficiency. At the same time, the silver layer can also effectively resist oxidation and corrosion, and enhance the stability of the contact structure under high-frequency operation and high-load conditions.

[0038] In this embodiment, the moving contact 100 and the stationary contact 200 are made of copper-aluminum composite material, and the aluminum content is between 10% and 30% to improve conductivity and corrosion resistance. The high strength and good electrical conductivity of aluminum alloy enable the contact structure to carry a larger current and still work stably in harsh environments such as high temperature and humidity.

[0039] In addition, the silver-copper material is formed by hot pressing or cold extrusion process, which ensures the uniformity and stability of the contact structure and avoids the influence of material defects on the contact structure performance.

[0040] In this embodiment, the moving contact 100 includes a contact frame 101, and a contact clip 103 is arranged in the contact frame 101. A spring 102 is connected between the contact clip 103 and the inner wall of the contact frame 101; the spring 102 is stretched and deformed to change the diameter of the embedding cavity, so that the static contact 200 is easily embedded in the embedding cavity, and when the static contact 200 is embedded in the embedding cavity, the abutment between the static contact 200 and the contact clip 103 of the moving contact 100 can be made more stable.

[0041] In this embodiment, the stationary contact 200 extends outward to have a connection portion 201 connected to the connection terminal 400 of the lead wire. The connection portion 201 is arranged away from the moving contact 100 and is arranged in a bent shape with respect to the stationary contact 200, so as to facilitate the connection between the connection terminal 400 and the connection portion 201.

[0042] The wiring portion 201 and the wiring terminal 400 are respectively flat, and the wiring portion 201 includes two clamping walls 203 that are connected to each other, and the two clamping walls 203 enclose a fixing cavity 204. The wiring terminal 400 is inserted into the fixing cavity 204. The wiring portion 201 is penetrated by a bolt 300, and the bolt 300 passes through the wiring terminal 400 to fix the wiring terminal 400 and the wiring portion 201 relatively.

[0043] The clamping wall 203 has a side wall 206 facing the fixing cavity 204, and a clamping gap is provided between the side wall 206 and the connecting terminal 400. The clamping gap is provided with an elastic structure, and the elastic structure is fixedly connected to the side wall 206. The elastic structure presses against the connecting terminal 400 and is in an elastic compression deformation state.

[0044] The connecting terminal 400 can be directly inserted into the fixed cavity 204, and the connecting terminal 400 presses against the elastic structure in the fixed cavity 204, so that the elastic structure is elastically compressed and deformed, and there is a clamping gap between the side wall 206 and the connecting terminal 400, so that the elastic structure can elastically clamp the connecting terminal 400 in the reverse direction, and elastically fix the connecting terminal 400 in the fixed cavity 204, and then use the bolt 300 to pass through the wiring part 201 and the connecting terminal 400, so that the connecting terminal 400 is fixed in the fixed cavity 204.

[0045] By arranging the elastic structure, the elastic fixing effect between the connecting terminal 400 and the connecting part 201 can be increased. The elastic structure can play a role in vibration buffering for the connecting terminal 400, thereby preventing the static contact 200 from being pulled when the connecting terminal 400 shakes.

[0046] In this embodiment, the elastic structure includes a plurality of curved sheet-shaped elastic arms 205, one end of the elastic arm 205 is fixedly connected to the side wall 206, and the other end of the elastic arm 205 is bent inwardly along the direction in which the terminal block 400 is inserted into the fixed cavity 204 to form a pressing end, which presses against the terminal block 400, and the elastic arm 205 is in an elastically compressed deformation state.

[0047] A hollow area is provided in the middle of the elastic arm 205, which passes through the elastic arm 205 and extends along the bending direction of the elastic arm 205; the terminal block 400 has a middle hole for the bolt 300 to pass through, and the inner wall of the middle hole is raised to form a plurality of raised positions 402, and the plurality of raised positions 402 are spaced around the circumference of the middle hole, and recessed positions 401 are formed between adjacent raised positions 402, and the plurality of raised positions 402 are respectively abutted against the outer periphery of the bolt 300.

[0048] One end of the elastic arm 205 is fixed on the side wall 206, and the pressing section extends outward, so that the other end of the elastic arm 205 is suspended, and after being pressed by the connection terminal 400, it can be elastically compressed and deformed, so as to achieve elastic clamping of the connection terminal 400. Secondly, the multiple elastic arms 205 are bent inward to form a barb shape, which facilitates the insertion of the connection terminal 400 into the fixed cavity 204 and can limit the connection terminal 400 from being separated from the fixed cavity 204.

[0049] By arranging the hollow area, the bending deformation of the elastic arm 205 can be enhanced. The multiple protrusions 402 of the middle hole form multiple abutments on the bolt 300, which can achieve multiple circumferential restrictions on the bolt 300, and can better adjust the swing of the bolt 300 in the middle hole, thereby further reducing the shock between the terminal 400 and the wiring portion 201.

[0050] In this embodiment, the end of the terminal block 400 has an end wall 403, and the fixed cavity 204 has a bottom wall 207 facing the end wall 403. The bottom wall 207 is concave and arranged in a concave arc surface, and the end wall 403 is convex and arranged in a convex arc surface. The convex arc surface abuts against the concave arc surface, and the diameter of the concave arc surface is greater than the diameter of the convex arc surface.

[0051] In this way, a line contact is formed between the end wall 403 and the bottom wall 207 . When the connecting terminal 400 is inserted into the fixing cavity 204 , the position of the connecting terminal 400 can be swung and adjusted, and the shock absorption between the connecting terminal 400 and the connecting portion 201 can be further enhanced.

[0052] This embodiment also provides a control system, including the above-mentioned transformer on-load tap changer contact structure, a controller, and a sensor for monitoring the contact resistance between the moving contact 100 and the stationary contact 200. When the contact resistance exceeds a set threshold, the controller issues an alarm.

[0053] The control system provided above has a better stability of the contact structure and will not have poor contact, thereby ensuring the stability of the control system.

[0054] The controller can adopt a programmable logic controller (PLC), which is combined with a variety of sensors to achieve real-time monitoring of the contact resistance and temperature of the contact structure through a closed-loop feedback mechanism. When the contact resistance or temperature exceeds the set threshold, the control system automatically switches the operation mode, issues an alarm and takes protective measures to prevent failures caused by poor contact or excessive temperature.

[0055] In addition, the control system also has data recording and remote monitoring functions, which can grasp the operating status of the equipment in real time and optimize maintenance management.

[0056] The controller of the control system has good real-time processing capabilities and high-precision control output. Through the digital communication interface between the controller and the sensor, it can quickly collect and process working data to determine whether the equipment is in normal working condition.

[0057] The sensors include temperature sensors and contact resistance sensors. The temperature sensors are used to monitor the temperature of the contact structure surface and the surrounding environment in real time. The resistance temperature sensor can provide high-precision temperature data. The measurement range of the temperature sensor is "-40℃ to 150℃", with high temperature resistance, suitable for high temperature environments such as transformers.

[0058] The contact resistance sensor is installed near the contact surface of the contact structure. It uses a Hall effect sensor or resistance change measurement method to monitor changes in contact resistance in real time. When the contact resistance exceeds 100 milliohms, the control system will automatically trigger an alarm and execute preset protection measures, such as reducing the load or cutting off the power supply.

[0059] The control system uses a closed-loop feedback mechanism to adjust the system operating status based on real-time monitoring data. When the contact resistance or temperature exceeds the safe range, the controller will automatically adjust the load, switch the operating mode or start the cooling system to ensure that the equipment is always in the best working condition.

[0060] The control system not only supports local alarm and protection, but also has data storage and remote monitoring functions. Through wireless communication modules (such as Wi-Fi or LoRa), it can transmit real-time data to a remote server. Users can view the equipment operating status, historical data and maintenance recommendations in real time through dedicated applications or web pages.

[0061] The control system fully considers the application requirements in different industrial environments. The device casing adopts IP65 protection grade design, which is waterproof, dustproof and corrosion-resistant, and can operate stably in harsh environments (such as high humidity, high temperature, and dusty environments).

[0062] The control system has an operating temperature range of -40°C to +85°C, and can adapt to various environmental conditions commonly found in power systems. Environmental adaptability tests conducted in extreme environments such as high temperature, high humidity, and high vibration have shown that the control system can operate normally in an operating temperature range of -40°C to 150°C without any failures. The control system successfully identified situations where the contact resistance exceeded the preset threshold and automatically executed protective measures, successfully avoiding equipment damage.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The transformer on-load tap changer contact structure is characterized by: It comprises a stationary contact and a rotatably arranged moving contact, wherein the moving contact has an embedding cavity for the stationary contact to be embedded in; the moving contact has a contact clip elastically arranged, and the contact clip is arranged on the periphery of the embedding cavity; The outer periphery of the stationary contact has a stationary outer peripheral surface, and the contact clip has a dynamic contact surface facing the embedding cavity, and the stationary outer peripheral surface and the dynamic contact surface are in arc-shaped surface contacting contact.

2. The transformer on-load tap changer contact structure according to claim 1, characterized in that: The static outer peripheral surface is convex outwardly in the shape of a convex arc surface, and the dynamic contact surface is concave inwardly in the shape of a concave arc surface.

3. The transformer on-load tap changer contact structure according to claim 1, characterized in that: The static outer peripheral surface and the dynamic contact surface are respectively formed with metal plating layers.

4. The transformer on-load tap changer contact structure according to claim 3, characterized in that: The metal plating layer is made of silver-copper material; the thickness of the metal plating layer is between 5 microns and 15 microns.

5. The transformer on-load tap changer contact structure according to claim 1, characterized in that: The moving contact and the stationary contact are made of copper-aluminum composite material, and the aluminum content is between 10% and 30%.

6. The transformer on-load tap changer contact structure according to any one of claims 1 to 5, characterized in that: The movable contact comprises a contact frame, the contact clip is arranged in the contact frame, and a spring is connected between the contact clip and the inner side wall of the contact frame; the diameter of the embedded cavity changes through the expansion and contraction deformation of the spring.

7. The transformer on-load tap changer contact structure according to claim 7, characterized in that: The stationary contact has a connection portion extending outwardly and connected to a connection terminal of a lead wire, the connection portion is arranged away from the moving contact and is arranged in a bent shape with respect to the stationary contact; The wiring part and the wiring terminal are respectively flat, the wiring part includes two clamping walls that are butted against each other, the two clamping walls enclose a fixing cavity, the wiring terminal is inserted into the fixing cavity, the wiring part is penetrated by a bolt, the bolt passes through the wiring terminal, and the wiring terminal is relatively fixed to the wiring part; The clamping wall has a facing side wall facing the fixed cavity, a clamping gap is provided between the facing side wall and the connecting terminal, the clamping gap is provided with an elastic structure, the elastic structure is fixedly connected to the facing side wall, the elastic structure presses against the connecting terminal and is in an elastic compression deformation state.

8. The transformer on-load tap changer contact structure according to claim 7, characterized in that: The elastic structure comprises a plurality of curved sheet-shaped elastic arms, one end of the elastic arm is fixedly connected to the side wall, and the other end of the elastic arm is bent inwardly along the direction in which the wiring terminal is inserted into the fixed cavity to form a pressing end, the pressing end is pressed against the wiring terminal, and the elastic arm is in an elastically compressed deformation state; A hollow area is provided in the middle of the elastic arm, and the hollow area passes through the elastic arm and extends along the bending direction of the elastic arm; the wiring terminal has a middle hole for the bolt to pass through, and the inner side wall of the middle hole is raised to form a plurality of raised positions, and the plurality of raised positions are spaced around the circumference of the middle hole, and recessed positions are formed between adjacent raised positions, and the plurality of raised positions are respectively abutted against the outer periphery of the bolt.

9. The transformer on-load tap changer contact structure according to claim 7, characterized in that: The end of the connecting terminal has an end wall, and the fixing cavity has a bottom wall facing the end wall. The bottom wall is concave and arranged in a concave arc surface, and the end wall is convex and arranged in a convex arc surface. The convex arc surface abuts against the concave arc surface, and the diameter of the concave arc surface is greater than the diameter of the convex arc surface.

10. A control system, characterized in that It comprises the transformer on-load tap changer contact structure as claimed in any one of claims 1 to 9, a controller and a sensor for monitoring the contact resistance between a moving contact and a stationary contact, wherein when the contact resistance exceeds a set threshold, the controller issues an alarm.

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