A test device for measuring the temperature rise of transformer shielded tube leads

Abstract

The present invention belongs to the field of shielded tube lead testing, specifically a test device for measuring the temperature rise of transformer shielded tube leads, including an oil tank, a coil, a coil bracket, an aluminum plate, a thermal resistor connector, a temperature digital display, an input end bushing, an output end bushing and a plurality of thermal resistors. The present invention, through the coordinated arrangement of multiple groups of output end bushings, thermal resistor connectors and thermal resistors, allows one or more shielded tube leads of different shapes to be tested to be placed inside the oil tank at the same time for testing, and can measure the temperature rise of various shielded tube leads to be tested separately. The present invention can conveniently measure the influence of different path shapes on the temperature rise of shielded tube leads and the temperature rise of shielded tube leads under different current loads, providing reliable test data for the simulation model and calculation of the temperature rise of the commutation transformer, meeting the application of product structure design engineering, thereby avoiding local overheating in the lead shielding tube and ensuring the safe and reliable operation of the transformer.

Description

Technical Field

[0001] The invention belongs to the field of shielded tube lead testing, in particular to a testing device for measuring the temperature rise of transformer shielded tube lead. Background Art

[0002] With the rapid development of ultra-high voltage (UHV) power grid technology, the capacity and voltage levels of AC / DC transformers used in power grids are continuously increasing, placing increasingly stringent demands on the temperature rise performance of transformer shielded tube leads. Currently, transformer-assisted calculation software does not yet have a dedicated calculation method for the temperature rise of shielded tube leads. Under low capacity and current conditions, the temperature rise of the shielded tube and internal leads can meet the requirements. However, as the capacity, current, or harmonics of the converter transformer increase, the lead losses in the shielded tube and the eddy current losses caused by the leakage magnetic field at the transformer winding ends increase dramatically. If the shielded tube and lead specifications are not properly selected, the shielded tube and internal leads are prone to a sharp increase in temperature, even burning and carbonization. Summary of the Invention

[0003] In view of the problem that there is currently no test device specifically used to measure the temperature rise of the lead wire of a transformer with a shielded tube, the purpose of the present invention is to provide a test device for measuring the temperature rise of the lead wire of a transformer with a shielded tube.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] A test device for measuring the temperature rise of a transformer shielded tube lead, comprising an oil tank, a coil, a coil support, an aluminum plate, a thermal resistor connector, a temperature digital display, an input end bushing, an output end bushing and several thermal resistors;

[0006] The input end sleeve and the output end sleeve are respectively installed on the oil tank, and the input end sleeve and the output end sleeve are respectively provided with a terminal. The bottom end of the coil bracket is installed in the inner cavity of the oil tank, and the top end is fixed to the aluminum plate. The coil is fixed to the aluminum plate. The input end lead of the coil is connected to the terminal on the input end sleeve, the output end lead of the coil is connected to the input end of the shielded tube lead to be tested, and the output end of the shielded tube lead to be tested is connected to the terminal on the output end sleeve.

[0007] The thermal resistor connector is installed on the oil tank, and the thermal resistor connector is respectively connected to the temperature digital display for displaying the measured temperature and each thermal resistor for measuring the temperature rise of the shielded tube lead; the temperature measuring probe end of each thermal resistor is respectively buried in the outer insulation layer of the shielded tube lead to be measured and the lead cable inside the shielded tube.

[0008] The temperature digital display is fixedly installed on the outer surface of the oil tank.

[0009] A shielded tube lead wire mounting bracket for fixing the shielded tube lead wire to be tested is fixedly installed in the oil tank.

[0010] The shielded tube lead mounting frame includes an oil tank connection seat and a plurality of shielded tube clamps connected together. The oil tank connection seat is installed on the inner wall of the oil tank, and the shielded tube clamps respectively clamp the shielded tube parts of the shielded tube lead to be tested.

[0011] The coil is a hollow coil with a multi-layer cylindrical structure.

[0012] It comprises at least two groups of the output end sleeves, the thermal resistor connectors and several thermal resistors which are arranged in cooperation for testing the shielded tube lead to be tested. Each group of the output end sleeves, the thermal resistor connectors and each thermal resistor is used to measure a corresponding shielded tube lead to be tested. The coil has at least two output end leads. The output end of each coil is respectively connected to the input end of a corresponding shielded tube lead to be tested, and the output end of the shielded tube lead to be tested is connected to the wiring terminal on the output end sleeve of the corresponding group; the temperature measuring probe end of each thermal resistor of the corresponding group is respectively buried in the outer insulation layer of the shielded tube of the corresponding shielded tube lead to be tested and the lead inside the shielded tube, and each thermal resistor is respectively connected to the thermal resistor connector of the corresponding group.

[0013] Each of the thermal resistance connectors is connected to the same temperature digital display via a communication cable.

[0014] The advantages and positive effects of the present invention are:

[0015] The present invention utilizes multiple sets of output-end bushings, thermal resistor connectors, and thermal resistors to simultaneously place one or more shielded tube leads of different shapes within the oil tank for testing, allowing for separate temperature measurements of the various shielded tube leads. Furthermore, the provision of a shielded tube lead mounting bracket facilitates the installation of shielded tube leads of varying shapes and sizes. The present invention can conveniently measure the effects of different path shapes on the temperature rise of shielded tube leads, as well as the temperature rise of shielded tube leads under different current loads. This provides reliable test data for simulation models and calculations of commutation transformer temperature rise, meeting product structural design engineering requirements. This prevents local overheating within the lead shielding tube, ensuring safe and reliable transformer operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the internal structure of the present invention;

[0017] Figure 2 It is a top view schematic diagram of the internal structure of the present invention;

[0018] Figure 3It is a schematic side view of the internal structure of the present invention;

[0019] Figure 4 Schematic diagram of the external structure of the present invention;

[0020] Figure 5 This is a schematic diagram of the thermal resistor buried point setting structure of the present invention;

[0021] Figure 6 It is a schematic diagram of the cross-sectional structure of the buried point of the thermal resistor of the present invention.

[0022] In the figure: 1 is the oil tank, 2 is the coil, 3 is the coil bracket, 4 is the aluminum plate, 5 is the thermal resistor, 6 is the thermal resistor connector, 7 is the temperature digital display, 8 is the input end sleeve, 9 is the output end sleeve, 10 is the shielded tube lead mounting bracket, 1001 is the oil tank connecting seat, 1002 is the shielded tube clamp, 11 is the communication cable, 001 is the shielded tube lead to be tested, 0011 is the shielded tube, 0012 is the lead cable inside the shielded tube, and 0013 is the outer insulation layer of the shielded tube. DETAILED DESCRIPTION

[0023] The following is combined with Figure 1-6 The present invention is described in further detail.

[0024] A test device for measuring the temperature rise of transformer shielded tube leads, such as Figure 1-4 As shown, this embodiment includes an oil tank 1, a coil 2, a coil holder 3, an aluminum plate 4, a thermal resistor connector 6, a temperature digital display 7, an input sleeve 8, an output sleeve 9, and several thermal resistors 5. During operation, the interior of the oil tank 1 is filled with transformer oil. The input sleeve 8 and the output sleeve 9 are mounted on the oil tank 1 and each has a terminal block. The bottom end of the coil holder 3 is mounted on the inner bottom surface of the oil tank 1, and the top end is fixedly connected to the aluminum plate 4. The coil 2 is fixedly attached to the aluminum plate 4, and the input lead of the coil 2 is connected to the terminal block on the input sleeve 8. The coil holder 3 supports the coil 2 and, through the aluminum plate 4, shields the coil 2.

[0025] This embodiment includes two groups of output end sleeves 9, thermal resistor connectors 6 and a plurality of thermal resistors 5 for testing the shielded tube lead to be tested. Each group of output end sleeves 9, thermal resistor connectors 6 and thermal resistors 5 are used to measure a corresponding shielded tube lead 001 to be tested. The coil 2 has two output end leads. The output end of each coil 2 is connected to the input end of a corresponding shielded tube lead 001 to be tested. The output end of the shielded tube lead 001 to be tested is connected to the terminal on the output end sleeve 9 of the corresponding group. Figure 5 and Figure 6As shown, the temperature probe ends of each thermal resistor 5 of the corresponding group are respectively buried in the outer insulation layer 0013 of the shielded tube with shielded tube lead 001 to be measured and the shielded tube internal lead cable 0012 inside the shielded tube 0011. The number of buried points is evenly arranged according to the length of the shielded tube internal lead cable 0012. Each thermal resistor 5 is connected to the thermal resistor connector 6 of the corresponding group. Each thermal resistor connector 6 is respectively installed on the oil tank 1. Each thermal resistor connector 6 is connected to the same temperature digital display 7 via a communication cable 11. The temperature digital display 7 is fixedly installed on the outer surface of the oil tank 1 to facilitate unified temperature viewing. In this embodiment, the thermal resistor connector 6, temperature digital display 7, communication cable 11 and thermal resistor 5 are all commercially available products.

[0026] Specifically, in this embodiment, the coil 2 is a hollow coil with a multi-layer cylindrical structure.

[0027] Specifically, if Figure 1-3 As shown, a shielded-tube lead-wire mounting bracket 10 for securing shielded-tube leads to be tested is fixedly mounted in fuel tank 1. This bracket 10 comprises a tank connector 1001 and several shielded-tube clamps 1002, which are connected together. Tank connector 1001 is mounted on the inner wall of fuel tank 1, and shielded-tube clamps 1002 respectively clamp the shielded tube portions of shielded-tube leads 001 to be tested. The provision of this bracket 10 facilitates the installation of shielded-tube leads 001 of various shapes and sizes.

[0028] Working principle:

[0029] Before the test, the shielded tube lead wire 001 to be tested is installed in the oil tank 1 through the shielded tube lead wire mounting bracket 10, and is respectively connected to the coil 2 and the corresponding output end bushing 9. Then, the temperature probe end of each thermal resistor 5 is buried in the corresponding shielded tube outer insulation layer 0013 of the shielded tube lead wire 001 to be tested and the shielded tube internal lead cable 0012 inside the shielded tube 0011. After the oil tank 1 is filled with transformer oil, the test can be carried out. During the test, voltage is applied from the top of the input end bushing 8. The output end bushing 9 is grounded, and the applied voltage is equivalent to the rated operation or overload operation of the transformer. The temperature data measured by the thermal resistor 5 is transmitted to the temperature digital display 7 through the thermal resistor connector 6 and the communication cable 11 for real-time display; through the coordinated arrangement of multiple groups of output end bushings 9, thermal resistor connectors 6 and thermal resistors 5, one or more shielded tube leads 001 of different shapes to be tested can be placed inside the oil tank 1 at the same time for testing, and the temperature rise of various shielded tube leads 001 to be tested can be measured separately.

Claims

1. A test device for measuring the temperature rise of transformer shielded tube leads, characterized by: It comprises an oil tank (1), a coil (2), a coil support (3), an aluminum plate (4), a thermal resistor connector (6), a temperature digital display (7), an input end sleeve (8), an output end sleeve (9) and a plurality of thermal resistors (5); The input end sleeve (8) and the output end sleeve (9) are respectively installed on the oil tank (1), and the input end sleeve (8) and the output end sleeve (9) are respectively provided with connection terminals. The bottom end of the coil support (3) is installed in the inner cavity of the oil tank (1), and the top end is fixed to the aluminum plate (4). The coil (2) is fixed to the aluminum plate (4). The input end lead of the coil (2) is connected to the connection terminal on the input end sleeve (8), the output end lead of the coil (2) is connected to the input end of the shielded tube lead to be tested, and the output end of the shielded tube lead to be tested is connected to the connection terminal on the output end sleeve (9); The thermal resistor connector (6) is mounted on the oil tank (1), and the thermal resistor connector (6) is respectively connected to the temperature digital display (7) for displaying the measured temperature and each thermal resistor (5) for measuring the temperature rise of the shielded tube lead wire; the temperature measuring probe end of each thermal resistor (5) is respectively buried in the outer insulation layer of the shielded tube lead wire to be measured and the lead cable inside the shielded tube; A shielded tube lead mounting frame (10) for fixing a shielded tube lead to be tested is fixedly installed in the oil tank (1), and the shielded tube lead mounting frame (10) comprises an oil tank connection seat (1001) and a plurality of shielded tube clamps (1002) connected together. The oil tank connection seat (1001) is installed on the inner wall of the oil tank (1), and the shielded tube clamps (1002) respectively clamp the shielded tube parts of the shielded tube lead to be tested.

2. The test device for measuring the temperature rise of transformer shielded tube leads according to claim 1, characterized in that: The temperature digital display (7) is fixedly mounted on the outer surface of the oil tank (1).

3. The test device for measuring the temperature rise of transformer shielded tube leads according to claim 1, characterized in that: The coil (2) is a hollow coil with a multi-layer cylindrical structure.

4. The test device for measuring the temperature rise of transformer shielded tube leads according to claim 1, characterized in that: The invention comprises at least two groups of matched output end sleeves (9), thermal resistor connectors (6) and a plurality of thermal resistors (5) for testing the shielded tube lead to be tested. Each group of matched output end sleeves (9), thermal resistor connectors (6) and thermal resistors (5) is used to measure a corresponding shielded tube lead to be tested. The coil (2) has at least two output end leads. The output end of each coil (2) is respectively connected to the input end of a corresponding shielded tube lead to be tested. The output end of the shielded tube lead to be tested is connected to the wiring terminal on the output end sleeve (9) of the corresponding group. The temperature measuring probe end of each thermal resistor (5) of the corresponding group is respectively buried in the outer insulation layer of the shielded tube of the corresponding shielded tube lead to be tested and the lead inside the shielded tube. Each thermal resistor (5) is respectively connected to the thermal resistor connector (6) of the corresponding group.

5. The test device for measuring the temperature rise of transformer shielded tube leads according to claim 4, characterized in that: Each of the thermal resistor connectors (6) is connected to the same temperature digital display (7) via a communication cable (11).

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