Oil-immersed transformer winding temperature monitoring system and construction method thereof

Abstract

The application provides an oil-immersed transformer winding temperature monitoring system and a construction method thereof. The oil-immersed transformer winding temperature monitoring system replaces the whole-section optical fiber temperature sensor in the transformer with a segmented pre-assembled structure connected by the optical fiber temperature sensor and a first adapter optical cable, reduces the risk of damage of the temperature sensor during the installation of the transformer, realizes risk isolation, node measurement and segmented maintenance, greatly reduces the construction difficulty and protection and maintenance cost, and only the first adapter optical cable needs to be replaced when being replaced, and the efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of transformer winding temperature measurement technology, specifically relating to an oil-immersed transformer winding temperature monitoring system and a method for constructing such a system. Background Technology

[0002] Currently, transformer winding temperature measurement adopts a continuous wiring scheme, which means that a continuous optical cable is used inside the oil tank to connect the measuring point to the transfer plate on the oil tank wall. During installation, the sensor end is buried in the winding pad, and the remaining several meters of optical cable are moved synchronously with the winding processing, insulation assembly, and transformer body assembly processes, and finally led out of the oil tank through the through plate.

[0003] During system installation, there is one technical aspect of the "integral" sensor that can be improved, but two risk points exist:

[0004] "Risk of Inadequate Protection" during Assembly: Due to the long distance between the windings and the tank cover, and the sensor having an optical cable lead-out, it is currently typically coiled, placed in a storage bag, and then suspended from the transformer body. The transformer manufacturing process involves complex procedures such as winding rotation, transformer body assembly, and lead wire arrangement. The optical cable is at risk of damage if subjected to abnormal pulling or scraping during these dynamic processes.

[0005] "Disassembly and rework risk" during the final assembly stage: If the optical cable is damaged before the device body is installed in the housing, the assembled windings need to be disassembled and the sensors replaced, resulting in a lot of wasted time and economic losses.

[0006] Overall, the current installation method has two main problems: high protection difficulty (the entire optical cable needs to be protected during transformer assembly) and high maintenance cost (the cost of rework is high if abnormalities are found before oil filling). Summary of the Invention

[0007] The primary objective of this invention is to provide an oil-immersed transformer winding temperature monitoring system that addresses the shortcomings of existing oil-immersed transformer winding temperature monitoring systems, which are prone to damaging optical cables during installation, leading to high rework and maintenance costs.

[0008] The second objective of this invention is to provide a method for constructing an oil-immersed transformer winding temperature monitoring system.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A temperature monitoring system for the windings of an oil-immersed transformer includes a transformer, which comprises a housing, a core, and winding coils, the winding coils being fixed to the core. The system further comprises an optical fiber temperature sensor, a first adapter optical cable, and a second adapter optical cable. The optical fiber temperature sensor is disposed between the winding coils. The first adapter optical cable is disposed inside the transformer housing, and the second adapter optical cable is disposed outside the transformer housing. One end of the first adapter optical cable is connected to the optical fiber temperature sensor, and the other end of the first adapter optical cable is connected to the second adapter optical cable.

[0011] In this invention, the fiber optic temperature sensor includes a temperature sensing probe, a temperature measuring optical cable, and a fiber optic connector; one end of the temperature measuring optical cable is connected to the temperature sensing probe, and the other end is connected to the fiber optic connector.

[0012] In some embodiments of the present invention, the first adapter optical cable and the optical fiber temperature sensor are detachably connected via a docking adapter.

[0013] Furthermore, the first adapter cable is equipped with an optical fiber connector, which is connected to one end of the docking adapter, and the optical fiber connector of the optical fiber temperature sensor is connected to the other end of the docking adapter.

[0014] In this invention, the fiber optic connector includes a connector, a fixing member, a limiting member, and an optical connector; the connector is connected to the optical cable at one end and to the optical connector at the other end, so that the optical fiber inside the optical cable contacts and connects with the optical connector; the fixing member is sleeved outside the connector; the limiting member is sleeved outside the connector and is fixedly connected to the optical connector, so that the limiting member limits and fixes the fixing member.

[0015] Furthermore, the connector includes a first fixing part and a second fixing part. The first fixing part has a through hole for accommodating the optical cable, and the second fixing part has a through hole for accommodating the optical fiber. The limiting member is sleeved on the second fixing part and is located between the first fixing part and the limiting member. The optical connector is in contact with the second fixing part.

[0016] In this invention, the docking adapter includes two third fixing parts and two fourth fixing parts, which are symmetrically arranged, and the two fourth fixing parts are located between the two third fixing parts; the third fixing parts are connected to the fixing parts of the fiber optic connector, and the fourth fixing parts are provided with receiving grooves, so that the optical connector of the fiber optic connector is placed in the receiving grooves.

[0017] In some embodiments of the present invention, the fixing part of the optical fiber connector is provided with an external thread, the third fixing part of the docking adapter is provided with an internal thread, and the optical fiber connector is threadedly connected to the third fixing part of the docking adapter through the fixing part, so that the two optical connectors of the optical fiber temperature sensor and the optical fiber connector of the second adapter cable abut against each other at the connection of the two receiving slots.

[0018] The invention also includes an adapter plate, which is fixed to the outside of the transformer housing. The first adapter optical cable is connected to the adapter plate, and the second adapter optical cable is connected to the adapter plate.

[0019] Furthermore, the adapter plate is equipped with a protective cover.

[0020] The invention also includes a demodulator, which is connected to a second adapter optical cable.

[0021] Furthermore, the demodulator is equipped with a protection box, which is fixed to the outside of the transformer housing.

[0022] A method for constructing a winding temperature monitoring system for an oil-immersed transformer includes the following steps:

[0023] S1. During the winding process, install the fiber optic temperature sensor on the winding coil and fix the end of the fiber optic temperature sensor cable to the winding coil or bracket.

[0024] S2. Before final assembly, fix one end of the first adapter optical cable to the fiber optic temperature sensor and the other end to the adapter plate on the transformer housing to complete the output of the sensor optical signal.

[0025] S3. After final assembly, connect the second adapter optical cable to the adapter plate to complete the construction of the temperature monitoring system.

[0026] The present invention has the following beneficial effects:

[0027] (1) The oil-immersed transformer winding temperature monitoring system of the present invention replaces the whole-section fiber optic temperature sensor inside the transformer with a segmented pre-assembled structure connected by the fiber optic temperature sensor and the first adapter cable, which reduces the risk of the temperature sensor being damaged during the transformer installation process, realizes risk isolation, node measurability and segmented maintenance, greatly reduces the construction difficulty and protection and maintenance cost, and only the first adapter cable needs to be replaced when replacing, which is highly efficient.

[0028] (2) The oil-immersed transformer winding temperature monitoring system of the present invention uses fiber optic connectors and docking adapters to detachably connect the fiber optic temperature sensor and the first adapter cable, which is convenient for installation and replacement and has high efficiency. At the same time, the connection structure has stable connection and no risk of falling off, ensuring that the connection point will not fall off or loosen when the transformer operating components are vibrated by electromagnetic force or flushed by transformer oil.

[0029] (3) The method for constructing the oil-immersed transformer winding temperature monitoring system of the present invention integrates the fiber optic temperature sensor structure with the transformer installation process. The fiber optic temperature sensor is fixed during the winding processing period and dried together with the winding coil. Before final assembly, the fiber optic temperature sensor is connected to the first adapter cable to complete the extraction of the sensor's optical signal. This reduces the risk of damage to the fiber optic temperature sensor during transformer assembly. Even if it is damaged, only the first adapter cable needs to be replaced, which greatly reduces the rework and maintenance costs after damage and improves assembly efficiency.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an existing oil-immersed transformer winding temperature monitoring system;

[0032] Figure 2 This is a schematic diagram of the structure of the oil-immersed transformer winding temperature monitoring system of the present invention;

[0033] Figure 3 This is a schematic diagram of the connection structure between the fiber optic temperature sensor and the first adapter cable of the present invention.

[0034] Figure 4 This is a diagram showing the connection structure between the fiber optic connector and the mating adapter.

[0035] Figure 5 for Figure 4 A sectional view;

[0036] The following are the markings in the attached diagram: 1. Housing; 2. Iron core; 3. Winding coil; 4. Fiber optic temperature sensor; 5. First adapter fiber optic cable; 6. Second adapter fiber optic cable; 7. Fiber optic connector; 8. Connecting adapter; 9. Adapter plate; 10. Protective cover; 11. Demodulator; 12. Protective box; 701. Connector; 702. Fixing part; 703. Limiting part; 704. Optical connector; 7011. First fixing part; 7012. Second fixing part; 801. Third fixing part; 802. Fourth fixing part; 803. Receiving groove. Detailed Implementation

[0037] This invention provides a temperature monitoring system for oil-immersed transformer windings and its construction method. The system adopts a "two-segment link, node-based installation" concept, physically disconnecting the integral fiber optic temperature sensor installed on the winding coil at the transformer lead bracket or a selected fixed position, dividing it into two parts: a "winding pre-installation segment" and an "oil tank transition segment." This segmented connection structure enables segmented installation of the fiber optic temperature sensor during transformer installation, achieving risk isolation, node measurability, and segmented maintenance. This significantly reduces the risk of temperature sensor damage, improves the efficiency of replacing damaged temperature sensors, and lowers protection and maintenance costs.

[0038] Example 1

[0039] like Figure 2-5 The oil-immersed transformer winding temperature monitoring system shown includes a transformer, an optical fiber temperature sensor 4, a first adapter optical cable 5, and a second adapter optical cable 6.

[0040] The transformer includes a housing 1, an iron core 2, and winding coils 3, with the winding coils 3 fixed to the iron core 2. A fiber optic temperature sensor 4 is located between the winding coils 3. A first adapter fiber optic cable 5 is located inside the transformer housing 1, and a second adapter fiber optic cable 6 is located outside the transformer housing 1. One end of the first adapter fiber optic cable 5 is connected to the fiber optic temperature sensor 4, and the other end is connected to the second adapter fiber optic cable 6. In this configuration, the fiber optic temperature sensor 4 is connected to the second adapter fiber optic cable 6 via the first adapter fiber optic cable 5.

[0041] In this embodiment, the fiber optic temperature sensor 4 includes a temperature sensing probe, a temperature measuring optical cable, and a fiber optic connector 7. One end of the temperature measuring optical cable is connected to the temperature sensing probe, and the other end is connected to the fiber optic connector 7. The first adapter optical cable 5 is detachably connected to the fiber optic temperature sensor 4 via a docking adapter 8. Specifically, the first adapter optical cable 5 is provided with a fiber optic connector 7, which is connected to one end of the docking adapter 8, and the fiber optic connector 7 of the fiber optic temperature sensor 4 is connected to the other end of the docking adapter 8.

[0042] The fiber optic connector 7 includes a connector 701, a fixing member 702, a limiting member 703, and an optical connector 704. The connector 701 connects to the optical cable at one end and to the optical connector 704 at the other, allowing the optical fiber inside the cable to contact and connect with the optical connector 704. The fixing member 702 is sleeved outside the connector 701. The limiting member 703 is sleeved outside the connector 701 and fixedly connected to the optical connector 704, thus limiting and fixing the fixing member 702. Specifically, the connector 701 includes a first fixing part 7011 and a second fixing part 7012. The first fixing part 7011 and the second fixing part 7012 are connected, arranged in a stepped shape, and integrally formed. The first fixing part 7011 has a through hole for accommodating the optical cable, through which it connects to the cable. The second fixing part 7012 has a through hole for accommodating optical fibers; the limiting member 703 is sleeved on the second fixing part 7012, and the fixing member 702 is sleeved on the second fixing part 7012 and located between the first fixing part 7011 and the limiting member 703; the optical connector 704 is fixedly connected to the limiting member 703 and is in contact with the second fixing part 7012.

[0043] The docking adapter 8 includes two third fixing parts 801 and two fourth fixing parts 802, symmetrically arranged, with the two fourth fixing parts 802 located between the two third fixing parts 801. The third fixing parts 801 are connected to the fixing members 702 of the fiber optic connector 7, and the fourth fixing parts 802 are provided with receiving grooves 803, so that the optical connectors 704 of the fiber optic connector 7 are placed in the receiving grooves 803. In this embodiment, the fixing members 702 of the fiber optic connector 7 are provided with external threads, and the third fixing parts 801 of the docking adapter 8 are provided with internal threads. The fiber optic connector 7 is threadedly connected to the third fixing parts 801 of the docking adapter 8 through the fixing members 702. With this arrangement, the fiber optic connector 7 of the fiber optic temperature sensor 4 is detachably connected to one end of the docking adapter 8, and the fiber optic connector 7 of the second adapter cable 6 is detachably connected to the other end of the docking adapter 8. The two optical connectors 704 of the fiber optic connector 7 of the fiber optic temperature sensor 4 and the fiber optic connector 7 of the second adapter cable 6 abut against each other at the connection of the two receiving grooves 803, thereby achieving stable transmission of optical signals and improving reliability.

[0044] An adapter plate 9 and a demodulator 11 are fixed to the outside of the transformer housing 1. The adapter plate 9 is equipped with a protective cover 10, and the first adapter optical cable 5 is connected to the adapter plate 9. One end of the second adapter optical cable 6 is connected to the adapter plate 9, and the other end is connected to the demodulator 11. The demodulator 11 is also equipped with a protective box 12 to protect the demodulator 11.

[0045] Example 2

[0046] A method for constructing an oil-immersed transformer winding temperature monitoring system, using the oil-immersed transformer winding temperature monitoring system of Example 1, includes the following steps:

[0047] S1. During the winding process, install the fiber optic temperature sensor 4 on the winding coil 3 and fix the end of the fiber optic cable of the fiber optic temperature sensor 4 to the winding coil 3 or the bracket.

[0048] Specifically, in this embodiment, the fiber optic temperature sensor 4 includes a temperature sensing probe, a temperature measuring optical cable, and a fiber optic connector 7. One end of the temperature measuring optical cable is connected to the temperature sensing probe, and the other end is connected to the fiber optic connector 7. The sensor's temperature sensing probe is encapsulated and structurally designed with gallium arsenide crystals. The inner and outer sheaths of the optical fiber adopt an oil-immersible perforated and rotary-cut tube structure. The length of the temperature measuring optical cable is 1-2 meters (the length is specified according to the winding size and construction process). The end integrates a precision ceramic ferrule and a fiber optic connector 7 made of insulating material compatible with transformer oil. This component undergoes a transformer body drying process (kerosene vapor phase drying or vacuum drying). All materials used for the sensor and connector are selected as temperature- and oil-resistant all-dielectric materials to ensure that no performance degradation occurs in a high-temperature vacuum environment above 200°C. The short-sized pigtail reduces the difficulty of cable coiling and can even be completely hidden in the lead groove or gap.

[0049] The fiber optic temperature sensor 4 is installed between the winding coils 3, and the end of the fiber optic cable of the fiber optic temperature sensor 4 is fixed to the winding coil 3 or the bracket. Then, the drying process and hoisting process are carried out.

[0050] S2. Before final assembly, one end of the first adapter optical cable 5 is fixedly connected to the fiber optic temperature sensor 4, and the other end is connected to the adapter plate 9 on the transformer housing 1 to complete the output of the sensor optical signal.

[0051] The specific process is as follows: In this embodiment, the first adapter optical cable 5 and the fiber optic temperature sensor 4 are connected via a docking adapter 8. Specifically, the first adapter optical cable 5 is connected to one end of the docking adapter 8 via a fiber optic connector 7, and the fiber optic connector 7 of the fiber optic temperature sensor 4 is connected to the other end of the docking adapter 8. The other end of the first adapter optical cable 5 is connected to the adapter plate 9 on the oil tank of the transformer housing 1, thereby completing the extraction of the sensor's optical signal.

[0052] Considering insulation and oil immersion requirements, the first adapter optical cable 5 adopts the same structure as the sensor, with an open inner sleeve and a rotary-cut outer sheath. The connection interface between the first adapter optical cable 5 and the docking adapter 8 uses the same temperature-resistant insulating material as the fiber optic connector 7 of the fiber optic temperature sensor 4. The housing 1 of the fiber optic connector 7 is provided with venting holes to ensure that there is no residual air inside during oil immersion, avoiding electric field distortion caused by air gaps, achieving 100% full insulation and qualified electrical performance. The connection between the fiber optic connector 7 and the docking adapter 8 adopts a threaded docking mechanism with a central binding and fixing position. After docking, the three ends (the optical cable at the sensor end, the optical cable at the docking adapter 8, and the optical cable at the first adapter optical cable 5 end) are bound and fixed to prevent detachment, ensuring that the connection point will not fall off or loosen during transformer operation due to electromagnetic vibration or transformer oil flushing.

[0053] S3. After final assembly, connect the second adapter optical cable 6 to the adapter plate 9 to complete the construction of the temperature monitoring system.

[0054] The specific process is as follows: After the transformer is assembled, one end of the second adapter optical cable 6 is connected to the adapter plate 9, and the other end is connected to the demodulator 11 to complete the construction of the temperature monitoring system.

[0055] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention. The implementation of the present invention is not limited thereto. All other modifications, substitutions or alterations made to the above structure of the present invention based on the above content of the present invention, in accordance with ordinary technical knowledge and common practice in the field, without departing from the basic technical idea of ​​the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for constructing a winding temperature monitoring system for an oil-immersed transformer, characterized in that, Includes the following steps: S1. During the winding process, install the fiber optic temperature sensor on the winding coil and fix the end of the fiber optic temperature sensor cable to the winding coil or bracket. S2. Before final assembly, fix one end of the first adapter optical cable to the fiber optic temperature sensor and the other end to the adapter plate on the transformer housing to complete the output of the sensor optical signal. S3. After final assembly, connect the second adapter optical cable to the adapter plate to complete the construction of the temperature monitoring system.

2. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 1, characterized in that, The oil-immersed transformer winding temperature monitoring system includes a transformer, which includes a shell, an iron core, and winding coils. The winding coils are fixed on the iron core. The system also includes an optical fiber temperature sensor, a first adapter optical cable, and a second adapter optical cable. The optical fiber temperature sensor is located between the winding coils. The first adapter optical cable is located inside the transformer housing, and the second adapter optical cable is located outside the transformer housing. One end of the first adapter optical cable is connected to the fiber optic temperature sensor, and the other end of the first adapter optical cable is connected to the second adapter optical cable.

3. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 2, characterized in that, The fiber optic temperature sensor includes a temperature sensing probe, a temperature measuring optical cable, and a fiber optic connector; one end of the temperature measuring optical cable is connected to the temperature sensing probe, and the other end is connected to the fiber optic connector.

4. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 3, characterized in that, The first adapter optical cable and the fiber optic temperature sensor are detachably connected via a docking adapter; the first adapter optical cable is equipped with a fiber optic connector, which is connected to one end of the docking adapter, and the fiber optic connector of the fiber optic temperature sensor is connected to the other end of the docking adapter.

5. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 3 or 4, characterized in that, The fiber optic connector includes a connector, a fixing component, a limiting component, and an optical connector; the connector is connected to the optical cable at one end and to the optical connector at the other end, so that the optical fiber inside the optical cable contacts and connects with the optical connector; the fixing component is sleeved outside the connector; the limiting component is sleeved outside the connector and is fixedly connected to the optical connector, so that the limiting component limits and fixes the fixing component.

6. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 5, characterized in that, The connector includes a first fixing part and a second fixing part. The first fixing part has a through hole for accommodating the optical cable, and the second fixing part has a through hole for accommodating the optical fiber. The limiting member is sleeved on the second fixing part and is located between the first fixing part and the limiting member. The optical connector is in contact with the second fixing part.

7. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 6, characterized in that, The docking adapter includes two third fixing parts and two fourth fixing parts, which are symmetrically arranged, and the two fourth fixing parts are located between the two third fixing parts; the third fixing parts are connected to the fixing parts of the fiber optic connector, and the fourth fixing parts are provided with receiving grooves so that the optical connector of the fiber optic connector is placed in the receiving grooves.

8. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 7, characterized in that, The fixing part of the fiber optic connector has an external thread, and the third fixing part of the docking adapter has an internal thread. The fiber optic connector is threadedly connected to the third fixing part of the docking adapter through the fixing part, so that the two optical connectors of the fiber optic temperature sensor and the fiber optic connector of the second adapter cable abut against each other at the connection of the two receiving slots.

9. The method for constructing an oil-immersed transformer winding temperature monitoring system according to any one of claims 6-8, characterized in that, The adapter plate is fixed to the outside of the transformer housing, and the first adapter optical cable is connected to the adapter plate; The second adapter optical cable is connected to the adapter plate.

10. The method for constructing an oil-immersed transformer winding temperature monitoring system according to claim 9, characterized in that, It also includes a demodulator, which is connected to the second adapter optical cable.

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