A transformer integrated full-automatic comprehensive test system

Abstract

The application provides a transformer integrated full-automatic comprehensive test system and relates to the technical field of high-voltage electrical test equipment, which comprises a test equipment box and a low-voltage test rack, the low-voltage test rack is installed on one side of the test equipment box, and a high-voltage wire hanging plate for hanging high-voltage wires is installed on the low-voltage test rack; the high-voltage wire hanging plate comprises a high-voltage fixed hanging plate, a high-voltage buffer hanging plate, a buffer protection mechanism and an adaptive adjustment mechanism; and the high-voltage fixed hanging plate is fixedly installed on the low-voltage test rack. The application provides a transformer integrated full-automatic comprehensive test system, the high-voltage wire hanging plate is set as a split structure composed of the high-voltage fixed hanging plate and the high-voltage buffer hanging plate, and the buffer protection mechanism is configured, so that the gravity load and impact force during the hanging of the high-voltage wires are effectively absorbed and attenuated, direct rigid impact on high-voltage terminals and cabinet contacts is avoided, and the stability of electrical connection and the service life of the equipment are protected.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical testing equipment technology, and in particular to an integrated fully automatic comprehensive testing system for transformers. Background Technology

[0002] During the factory testing and maintenance of power transformers, 10kV, 35kV, and 110kV transformers need to undergo multiple high-voltage tests, including power frequency withstand voltage, induced withstand voltage, DC resistance, turns ratio, and partial discharge. During the tests, the high-voltage test line needs to be connected, supported, and positioned to the high-voltage winding terminals of the transformer using a high-voltage hanging plate to ensure reliable electrical connection of the test circuit, stable posture of the high-voltage lead, and to meet the safety clearance requirements to ground and low-voltage components.

[0003] Currently, most high-voltage wiring devices used in test sites are rigid insulated plate structures. In practical use, these present the following problems: the high-voltage lines themselves are heavy and relatively rigid, causing direct mechanical impact on the high-voltage terminals and internal cabinet connections during connection. Long-term use can easily lead to loosening of high-voltage connections, poor contact, and even damage to the terminal insulation structure, affecting the stability of test data and the lifespan of the equipment; 10kV, 35kV, 110kV The test high-voltage lines exhibited significant differences in wire diameter and weight. Existing cable hanger buffers mostly have fixed spring force specifications, which cannot adapt to different cable loads: buffers adapted for light-load cables are easily compressed and lose their buffering effect when used with heavy-load cables; buffers adapted for heavy-load cables have excessive rebound when used with light-load cables, easily causing cable bounce, unstable hanging, and difficulty in maintaining a stable safe clearance; a few adjustable buffer hanging structures use manual mechanical pre-tightening, requiring manual disassembly and adjustment when switching voltage levels, which is cumbersome, time-consuming, and difficult to achieve precise quantitative adjustment; at the same time, some structures do not provide proper electrical isolation between high and low voltage, and high-voltage lines are prone to approach grounded metal components such as low-voltage tooling fixing frames due to displacement deviation, posing safety hazards such as high-voltage flashover and arc discharge. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes an integrated fully automatic comprehensive testing system for transformers.

[0005] The present invention proposes an integrated fully automatic comprehensive testing system for transformers, comprising a test equipment enclosure and a low-voltage test rack. The low-voltage test rack is installed on one side of the test equipment enclosure, and a high-voltage hanging plate for hanging high-voltage lines is installed on the low-voltage test rack. The high-voltage mounting plate includes a high-voltage fixed mounting plate, a high-voltage buffer mounting plate, a buffer protection mechanism, and an adaptive adjustment mechanism; the high-voltage fixed mounting plate is fixedly installed on the low-voltage test frame, and the high-voltage fixed mounting plate and the high-voltage buffer mounting plate are connected by the buffer protection mechanism, with the high-voltage buffer mounting plate located below the high-voltage fixed mounting plate; The adaptive adjustment mechanism is used to adjust the buffer spring force of the high-voltage hanging plate.

[0006] Preferably, the buffer protection mechanism includes an insulating cylinder, a piston block, and an elastic element; the insulating cylinder is fixedly connected to the bottom end of the high-voltage fixed mounting plate, the top end of the high-voltage buffer mounting plate slides through the bottom end of the insulating cylinder and extends into the insulating cylinder to connect with the piston block, the piston block is slidably installed inside the insulating cylinder, and the diameter of the piston block is the same as the inner diameter of the insulating cylinder; The elastic element can cause the piston block to have a downward tendency.

[0007] Preferably, the elastic element includes a partial discharge-free insulating elastomer; the partial discharge-free insulating elastomer is located inside the insulating cylinder and is located on top of the piston block.

[0008] Preferably, the adaptation adjustment mechanism includes an external rigid tube and a cylinder; the cylinder is mounted on the low-pressure test frame, the external rigid tube is mounted on the side of the high-pressure fixed mounting plate, the two ends of the external rigid tube are respectively connected to the cylinder and the insulating cylinder, and the connection port between the external rigid tube and the insulating cylinder is located at the bottom of the insulating cylinder.

[0009] Preferably, the insulating cylinder has a connecting channel inside, which is used to connect the insulating cylinder with an external rigid tube.

[0010] Preferably, it also includes a high-voltage switching execution component; the high-voltage switching execution component is used to realize the automatic switching and connection of different test circuits on the high-voltage side of the transformer, and to complete the switching and conduction of high-voltage test items.

[0011] Preferably, the high-voltage switching execution component includes a high-voltage switching fixture, a high-voltage side power frequency cylinder, a high-voltage side direct resistance ratio cylinder, and a connection point inside the high-voltage side terminal cabinet; the high-voltage switching fixture, the high-voltage side power frequency cylinder, the high-voltage side direct resistance ratio cylinder, and the connection point inside the high-voltage side terminal cabinet are all installed inside the test equipment housing, and the high-voltage side power frequency cylinder, the high-voltage side direct resistance ratio cylinder, and the connection point inside the high-voltage side terminal cabinet are all installed on the high-voltage switching fixture; The internal connection point of the high-voltage side terminal cabinet is the high-voltage common connection terminal; The high-voltage side power frequency cylinder and the high-voltage side direct resistance ratio cylinder operate independently, selectively connecting and energizing the contacts inside the high-voltage side terminal cabinet to achieve switching between different high-voltage test circuits.

[0012] Preferably, it also includes a low-voltage test fixture assembly; the low-voltage test fixture assembly is used to realize the low-voltage terminal wiring connection of the transformer, circuit switching and high-current connection, and integrates low-voltage pneumatic actuation and power distribution protection functions.

[0013] Preferably, the low-voltage test fixture assembly includes a low-voltage fixture fixing frame, a low-voltage switching fixture, a low-voltage direct resistance ratio cylinder, a low-voltage no-load sensing cylinder, a low-voltage power frequency fixture cylinder, a low-voltage short-circuit fixture electrical box, and a low-voltage load adaptive pressure connector; the low-voltage fixture fixing frame is mounted on the low-voltage short-circuit fixture electrical box, the low-voltage switching fixture is mounted on the low-voltage fixture fixing frame, the low-voltage direct resistance ratio cylinder, the low-voltage no-load sensing cylinder, and the low-voltage power frequency fixture cylinder are all mounted on the low-voltage switching fixture, and the low-voltage load adaptive pressure connector is mounted on the low-voltage fixture fixing frame.

[0014] Preferably, it also includes a partial discharge-free frequency converter and a compensation capacitor bank; the partial discharge-free frequency converter and the compensation capacitor bank are both installed in the test equipment enclosure, the partial discharge-free frequency converter is used to output low partial discharge, adjustable voltage and frequency test excitation power, and meet the power supply requirements of transformer withstand voltage and partial discharge tests; The compensation capacitor bank is used to compensate for reactive power loss in the test circuit and stabilize the test output voltage.

[0015] The integrated fully automatic comprehensive testing system for transformers proposed in this invention has the following beneficial effects: By setting the high-voltage hanging plate as a split structure consisting of a high-voltage fixed hanging plate and a high-voltage buffer hanging plate, and configuring a buffer protection mechanism, the gravity load and impact force during high-voltage line connection are effectively absorbed and attenuated, avoiding direct rigid impact on high-voltage terminals and cabinet contacts, thus protecting the stability of electrical connections and the service life of equipment; by setting an adaptive adjustment mechanism to adjust the size of the buffer spring force, the same set of hanging plates can be adapted to high-voltage test lines of different voltage levels and wire diameters, solving the problem of poor versatility of fixed spring buffer structures, ensuring stable high-voltage line suspension posture under various working conditions, maintaining a stable safe insulation clearance, and reducing the risk of flashover and arc discharge. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a fully automated integrated transformer testing system proposed in this invention. Figure 2 This is a schematic diagram of the high-voltage hanging plate in an integrated fully automatic comprehensive testing system for transformers proposed in this invention. Figure 3 This is a cross-sectional view of the insulating cylinder in an integrated fully automated comprehensive testing system for transformers proposed in this invention. Figure 4 This is a schematic diagram of the internal structure of the test equipment housing in the fully automated integrated transformer testing system proposed in this invention; Figure 5 This invention relates to a high-voltage switching execution component in a fully automated integrated transformer testing system. Figure 6 This is a schematic diagram of the low-voltage test fixture assembly in a fully automated integrated transformer testing system proposed in this invention. Figure 7 This is a side view of the test equipment enclosure in an integrated fully automatic comprehensive testing system for transformers proposed in this invention.

[0017] In the diagram: 1. Test equipment enclosure; 2. Low-voltage test frame; 3. High-voltage fixed mounting plate; 4. High-voltage buffer mounting plate; 5. Insulating cylinder; 6. Piston block; 7. Partial discharge-free insulating elastomer; 8. External rigid pipe; 9. Connecting channel; 10. High-voltage switching fixture; 11. High-voltage side power frequency cylinder; 12. High-voltage side direct resistance ratio cylinder; 13. High-voltage side terminal cabinet internal contact; 14. Low-voltage fixture fixing frame; 15. Low-voltage switching fixture; 16. Low-voltage direct resistance ratio cylinder; 17. Low-voltage no-load induction cylinder; 18. Low-voltage power frequency fixture cylinder; 19. Low-voltage short-circuit fixture electrical box; 20. Low-voltage load adaptive pressure connector; 21. Partial discharge-free frequency converter; 22. Compensating capacitor bank; 23. Power frequency test transformer. Detailed Implementation

[0018] Reference Figures 1-7 This invention proposes an integrated fully automatic comprehensive testing system for transformers, comprising a test equipment enclosure 1 and a low-voltage test frame 2. The low-voltage test frame 2 is installed on one side of the test equipment enclosure 1, and a high-voltage hanging plate for hanging high-voltage lines is installed on the low-voltage test frame 2. The high-voltage hanging plate includes a high-voltage fixed hanging plate 3, a high-voltage buffer hanging plate 4, a buffer protection mechanism, and an adaptation adjustment mechanism. The high-voltage fixed hanging plate 3 is fixedly installed on the low-voltage test frame 2, and the high-voltage fixed hanging plate 3 and the high-voltage buffer hanging plate 4 are connected by the buffer protection mechanism, with the high-voltage buffer hanging plate 4 located below the high-voltage fixed hanging plate 3. The adaptation adjustment mechanism is used to adjust the buffer spring force of the high-voltage hanging plate to adapt to the load of high-voltage test lines of different voltage levels and wire diameters. In actual use, when the high-voltage line is hung on the high-voltage buffer hanging plate 4, the gravity load of the high-voltage line is transferred to the buffer protection mechanism through the high-voltage buffer hanging plate 4. The buffer protection mechanism absorbs and attenuates the load, avoiding direct rigid impact on the high-voltage fixed hanging plate 3 and the low-voltage test frame 2, and protecting the fitting accuracy and insulation reliability of the high-voltage terminals and internal contacts.

[0019] like Figure 2 and Figure 3As shown, the buffer protection mechanism includes an insulating cylinder 5, a piston block 6, and an elastic element. The insulating cylinder 5 is fixedly connected to the bottom end of the high-voltage fixed mounting plate 3. The top end of the high-voltage buffer mounting plate 4 slides through the bottom end of the insulating cylinder 5 and extends into the insulating cylinder 5 to connect with the piston block 6. The piston block 6 is slidably installed inside the insulating cylinder 5, and the diameter of the piston block 6 is the same as the inner diameter of the insulating cylinder 5, forming a slidingly fitted sealed chamber. The elastic element allows the piston block 6 to have a downward tendency. In actual use, when the high-voltage line is hung on the high-voltage buffer mounting plate 4, the gravity load of the high-voltage line is transmitted to the buffer protection mechanism through the high-voltage buffer mounting plate 4. After the high-voltage buffer mounting plate 4 bears the downward pulling force, it drives the piston block 6, which is fixedly connected to its top end, to have a downward tendency within the insulating cylinder 5. At this time, the elastic element located above the piston block 6 is stretched by the piston block 6 and begins to produce elastic deformation, converting the impact kinetic energy and gravitational potential energy applied by the high-voltage line into elastic potential energy, which is gradually stored and slowly released. During this process, the sliding between the piston block 6 and the inner wall of the insulating cylinder 5... The mechanism acts as a guide and limiter, ensuring that the high-voltage buffer plate 4 moves smoothly in the vertical direction without lateral swaying. Furthermore, since the diameter of the piston block 6 is the same as the inner diameter of the insulating cylinder 5, a piston-cylinder-like damping structure is formed between them. During the deformation and recovery of the elastic element, the internal friction of the gas in the chamber or the elastic element itself generates a certain damping effect, further consuming vibration energy and making the reset action of the high-voltage buffer plate 4 smoother. This avoids secondary disturbance to the high-voltage line caused by rapid rebound. The buffer protection mechanism absorbs and attenuates this load, preventing direct rigid impact on the high-voltage fixed plate 3 and the low-voltage test frame 2, protecting the fitting accuracy and insulation reliability of the high-voltage terminals and cabinet contacts, and extending the service life of the connectors. Simultaneously, since the insulating cylinder 5 itself is made of insulating material, it is located between the high-voltage fixed plate 3 and the high-voltage buffer plate 4, forming a reliable electrical isolation section, increasing the creepage distance from the high-voltage live conductor to the grounding component, and reducing the risk of surface flashover.

[0020] like Figure 3As shown, the elastic element includes a partial discharge-free insulating elastomer 7. The partial discharge-free insulating elastomer 7 is made of dense, high-resilience insulating polyurethane elastomer material. It is located inside the insulating cylinder 5 and on top of the piston block 6. During high-voltage tests, especially partial discharge tests, partial discharge signals at any point in the test circuit can be captured by the detection system, thus interfering with the accurate judgment of the transformer's insulation status. Ordinary metal springs or elastomers containing metal fillers are prone to corona discharge or internal air gap discharge under high electric field conditions, becoming sources of interference. Therefore, selecting the partial discharge-free insulating elastomer 7 as the elastic element and placing it on top of the piston block 6 ensures buffering. When the entire protective mechanism is in operation, the piston block 6 compresses the partial discharge-free insulating elastomer 7, and no additional partial discharge power source is introduced into the area. When the partial discharge-free insulating elastomer 7 is subjected to alternating compressive stress, the electric field distribution inside and on the surface of the elastomer 7 is uniform, and there will be no continuous discharge phenomenon due to internal material defects or the interface with metal parts. This ensures that the partial discharge level of the entire high-voltage hanging plate area meets the test standard requirements under the rated test voltage, and ensures the authenticity and accuracy of the partial discharge test data. At the same time, the partial discharge-free insulating elastomer 7 has the dual functions of elastic energy storage and electrical insulation, simplifying the structural complexity.

[0021] like Figure 2 and Figure 3As shown, the adaptive adjustment mechanism includes an external rigid tube 8 and a cylinder. The cylinder is mounted on the low-voltage test frame 2, and the external rigid tube 8 is mounted on the side of the high-voltage fixed mounting plate 3. Both ends of the external rigid tube 8 are connected to the cylinder and the insulating cylinder 5, respectively. The connection port between the external rigid tube 8 and the insulating cylinder 5 is located at the bottom of the insulating cylinder 5. A connecting channel 9 is provided inside the insulating cylinder 5 to connect the insulating cylinder 5 and the external rigid tube 8. The connecting channel 9 is located inside the insulating cylinder 5, making the overall structure compact and avoiding the reduction of the high-voltage to ground insulation distance caused by the external redundant pipeline. The structure of the external rigid tube 8 ensures the rigidity of the gas transmission channel and will not affect the response speed and accuracy of pressure adjustment due to pipeline bending or expansion. In actual use, the connecting channel 9 is provided inside the insulating cylinder 5 to connect the insulating cylinder 5 and the external rigid tube 8. When it is necessary to adjust the buffer spring force according to the weight of the high-voltage line, the operator sends a command to the cylinder through the control system. The piston rod of the cylinder moves, changing the volume of its internal chamber, and then through the external rigid tube 8 and the connecting channel... 9. Gas medium is injected or extracted into the sealed chamber below the piston block 6 inside the insulating cylinder 5. Since the diameter of the piston block 6 is the same as the inner diameter of the insulating cylinder 5, the two form a good gas seal. The pressure change in the chamber below the piston block 6 will directly change the resistance that the piston block 6 needs to overcome when moving upward, which is equivalent to adjusting the pre-compression force or auxiliary support force of the partial discharge-free insulating elastomer 7. When a heavier high-voltage line is attached, the cylinder pressurizes the bottom chamber of the insulating cylinder 5 to provide an upward auxiliary support force, share part of the gravity load, and prevent the partial discharge-free insulating elastomer 7 from being completely compressed to the bottom and losing its buffer stroke. When a lighter high-voltage line is attached, the cylinder appropriately depressurizes to reduce the upward support force, so that the partial discharge-free insulating elastomer 7 can generate sufficient elastic deformation within a suitable range to absorb the impact. Through the pneumatic-assisted adjustment method, the stepless, quantitative, and remote automatic adjustment of the buffer force is realized. No manual disassembly or assembly of any parts is required. The adaptation to high-voltage lines of different voltage levels can be completed within seconds, which greatly improves the automation level and operating efficiency of the test system.

[0022] like Figure 4 and Figure 5The diagram also includes a high-voltage switching execution component. This component is used to automatically switch and connect different test circuits on the high-voltage side of the transformer, completing the switching and conduction of high-voltage test items. In the integrated fully automatic comprehensive testing of the transformer, multiple items such as DC resistance testing, turns ratio testing, power frequency withstand voltage testing, induced withstand voltage testing, and partial discharge testing need to be performed on the transformer in sequence. The test wiring method, the winding terminals to be connected, and the type of power supply applied for each test item are different. In the traditional way, when changing test items, test personnel need to enter the test area and manually disconnect and connect the high-voltage test lines. This is not only labor-intensive and time-consuming, but also poses safety risks such as incorrect wiring and electric shock. The high-voltage switching execution component enables the system to automatically complete the switching of different test circuits on the high-voltage side through program control without manual intervention, automatically connecting the power supply or measuring cables of each test item to the corresponding terminals of the transformer's high-voltage terminals, realizing one-click sequential automatic execution of multiple test items.

[0023] like Figure 4 and Figure 5 As shown, the high-voltage switching actuator includes a high-voltage switching fixture 10, a high-voltage side power frequency cylinder 11, a high-voltage side DC resistance ratio cylinder 12, and a high-voltage side terminal cabinet internal contact 13. The high-voltage switching fixture 10 provides a rigid mounting base and a precise positioning reference. The high-voltage switching fixture 10, the high-voltage side power frequency cylinder 11, the high-voltage side DC resistance ratio cylinder 12, and the high-voltage side terminal cabinet internal contact 13 are all installed inside the test equipment housing 1. The high-voltage side power frequency cylinder 11, the high-voltage side DC resistance ratio cylinder 12, and the high-voltage side terminal cabinet internal contact 13 are all mounted on the high-voltage switching fixture 10. The high-voltage side terminal cabinet internal contact 13 is the high-voltage common connection terminal. The high-voltage side power frequency cylinder 11 and the high-voltage side DC resistance ratio cylinder 12 operate independently, selectively connecting and conducting the high-voltage side terminal cabinet internal contact 13 to achieve switching between different high-voltage test circuits. In actual use, when the system performs power frequency withstand voltage, induced withstand voltage, or partial discharge tests, etc., requiring a switch... During the high-voltage power supply test, the control system drives the high-voltage side power frequency cylinder 11 to extend its piston rod, connecting the power frequency test circuit to the terminal 13 in the high-voltage side terminal cabinet, thereby connecting the high-voltage winding of the transformer. At this time, the high-voltage side DC resistance ratio cylinder 12 is in the retracted and disconnected state. When the system performs DC resistance test or ratio test, the high-voltage side power frequency cylinder 11 retracts and disconnects, and the high-voltage side DC resistance ratio cylinder 12 extends, connecting the measurement circuit of the DC resistance tester or ratio tester. The independent interlocking action of the two sets of cylinders avoids the possibility of the power frequency high-voltage test circuit and the DC resistance ratio measurement low-voltage circuit being connected at the same time, reducing the major hidden dangers of high voltage entering the measuring instrument, burning out precision instruments, or even endangering personal safety due to misoperation. The action position of each cylinder is detected and fed back by the position sensor to ensure that the subsequent test program can only be started after switching to the correct position, forming a reliable electrical and mechanical dual interlock protection.

[0024] like Figure 4 and Figure 6 The diagram also includes a low-voltage test fixture assembly. This assembly is used to realize the low-voltage terminal wiring connection, circuit switching, and high-current connection of the transformer. It integrates low-voltage pneumatic actuation and power distribution protection functions. In various transformer tests, the low-voltage side is not always in an unused state. For example, during the induced withstand voltage test, a frequency multiplier power supply needs to be applied to the low-voltage side; during the load test or temperature rise test, the low-voltage side needs to be short-circuited and able to carry a large current; during the DC resistance test, the low-voltage side needs to be connected to the measuring line. The low-voltage test fixture assembly integrates these functional requirements and, through automatic docking with the low-voltage terminals of the transformer, coordinates with the high-voltage switching actuation assembly to complete the fully automatic construction and switching of the entire transformer test circuit.

[0025] like Figure 4 and Figure 6 As shown, the low-voltage test fixture assembly includes a low-voltage fixture fixing frame 14, a low-voltage switching fixture 15, a low-voltage DC resistance ratio cylinder 16, a low-voltage no-load induction cylinder 17, a low-voltage power frequency fixture cylinder 18, a low-voltage short-circuit fixture distribution box 19, and a low-voltage load adaptive pressure connector 20. The low-voltage short-circuit fixture distribution box 19 integrates the low-voltage side power distribution protection components and short-circuit busbar, providing overcurrent and short-circuit protection for the low-voltage circuit and ensuring electrical safety under low-voltage high-current conditions. The low-voltage fixture fixing frame 14 is mounted on the low-voltage short-circuit fixture electrical box 19. The low-voltage switching fixture 15 is mounted on the low-voltage fixture fixing frame 14. The low-voltage switching fixture 15 serves as the mounting and positioning base for the various functional cylinders on the low-voltage side. The low-voltage DC resistance ratio cylinder 16, the low-voltage no-load sensing cylinder 17, and the low-voltage power frequency fixture cylinder 18 are all mounted on the low-voltage switching fixture 15. The low-voltage load adaptive pressure connector 20 is mounted on the low-voltage fixture fixing frame. On frame 14, in actual use, when performing DC resistance or turns ratio tests, the low-voltage DC resistance turns ratio cylinder 16 operates, connecting the corresponding measuring line to the low-voltage terminal of the transformer; when performing no-load tests or induced withstand voltage tests, the low-voltage no-load induction cylinder 17 operates, connecting the frequency multiplier power supply or measuring circuit; when power frequency related tests or specific short circuits are required, the low-voltage power frequency tooling cylinder 18 performs the docking. These cylinders are driven independently and operate in a time-sharing manner according to the instructions of the test program, avoiding conflicts between different test circuits. The low-voltage load adaptive pressure connector 20 is set to provide sufficient and uniform contact pressure during high-current tests. If the contact pressure is insufficient during high-current connections, the contact resistance will increase sharply, causing the connector to overheat or even burn out. The low-voltage load adaptive pressure connector 20 can automatically compensate and maintain stable contact pressure according to the connection situation, ensuring the high-current carrying capacity, reducing contact resistance loss, and ensuring the safe and stable conduct of high-current tests.

[0026] like Figure 7 As shown, the system also includes a partial discharge-free frequency converter 21 and a compensation capacitor bank 22. Both the partial discharge-free frequency converter 21 and the compensation capacitor bank 22 are installed inside the test equipment enclosure 1. The partial discharge-free frequency converter 21 is used to output low partial discharge, adjustable voltage and frequency regulated test excitation energy, and to meet the power supply requirements for transformer withstand voltage and partial discharge tests. When conducting transformer induced withstand voltage tests and partial discharge tests, the quality of the test power supply directly determines the accuracy and validity of the test results. The voltage waveform output by ordinary frequency converters may contain high harmonic components, or the partial discharge level generated internally may be high, which will be superimposed on the partial discharge signal of the transformer under test, resulting in excessive background noise, seriously interfering with or even drowning out the real partial discharge signal of the transformer itself, leading to misjudgment or missed judgment. The partial discharge-free frequency converter 21, through special circuit topology design, filtering measures, and shielding insulation structure, suppresses its partial discharge at rated output voltage to an extremely low level, typically measured in picocoulombs. Simultaneously, the output voltage waveform closely approximates an ideal sine wave with extremely low harmonic distortion. This clean power supply provides a clean test electric field environment for the transformer, ensuring that the detected partial discharge signal originates from internal insulation defects in the transformer under test rather than from the test power supply. This significantly improves the signal-to-noise ratio and detection sensitivity of the partial discharge test. When conducting transformer tests with long-distance cable connections or large-capacity transformer tests, the test circuit exhibits significant capacitive or inductive reactive power, causing the power supply to output a large amount of reactive current, occupying power supply capacity and causing output voltage drops or instability. The compensation capacitor bank 22, by switching capacitors of appropriate capacity and connecting them in parallel in the test circuit, generates a capacitive reactive current that leads the voltage, offsetting the lagging reactive current in the inductive test circuit. This improves the power factor of the test circuit and reduces the apparent power required by the power supply, thus alleviating the burden on the partial discharge-free frequency converter 21. It also automatically or manually adjusts to stabilize the test voltage when the test voltage rises, ensuring the stability and accuracy of the output voltage across the entire test voltage range. The compensation capacitor bank 22 is used to compensate for reactive power losses in the test circuit and stabilize the test output voltage. In actual use, the power frequency test... The test transformer 23 is used to provide high-voltage test voltage for the power frequency withstand voltage test. It works in conjunction with the partial discharge-free frequency converter 21 to cover all high-voltage test requirements from power frequency withstand voltage to induced withstand voltage and partial discharge. When performing the power frequency withstand voltage test, the power frequency test transformer 23 directly draws power from the grid to provide the power frequency high voltage that meets the standard requirements. When performing the induced withstand voltage test, it is driven by the partial discharge-free frequency converter 21, and the power frequency test transformer 23 acts as a step-up unit to increase the voltage output by the frequency converter to the voltage required for the test. The switching and coordination of the two high-voltage sources are automatically completed through the system control logic without the need for manual wiring changes.

[0027] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A fully automated integrated testing system for transformers, characterized in that, The test equipment includes a test equipment housing (1) and a low-voltage test rack (2). The low-voltage test rack (2) is installed on one side of the test equipment housing (1), and a high-voltage hanging plate for hanging high-voltage lines is installed on the low-voltage test rack (2). The high voltage mounting plate includes a high voltage fixed mounting plate (3), a high voltage buffer mounting plate (4), a buffer protection mechanism, and an adaptation adjustment mechanism; the high voltage fixed mounting plate (3) is fixedly installed on the low voltage test frame (2), the high voltage fixed mounting plate (3) and the high voltage buffer mounting plate (4) are connected by the buffer protection mechanism, and the high voltage buffer mounting plate (4) is located below the high voltage fixed mounting plate (3); The adaptive adjustment mechanism is used to adjust the buffer spring force of the high-voltage hanging plate.

2. The fully automated integrated transformer testing system according to claim 1, characterized in that, The buffer protection mechanism includes an insulating cylinder (5), a piston block (6), and an elastic element; the insulating cylinder (5) is fixedly connected to the bottom end of the high-voltage fixed mounting plate (3), and the top end of the high-voltage buffer mounting plate (4) slides through the bottom end of the insulating cylinder (5) and extends into the insulating cylinder (5) to connect with the piston block (6). The piston block (6) is slidably installed inside the insulating cylinder (5), and the diameter of the piston block (6) is the same as the inner diameter of the insulating cylinder (5). The elastic element can cause the piston block (6) to have a downward tendency.

3. The fully automated integrated transformer testing system according to claim 2, characterized in that, The elastic element includes a partial discharge-free insulating elastomer (7); the partial discharge-free insulating elastomer (7) is located inside the insulating cylinder (5) and is located on top of the piston block (6).

4. The fully automated integrated transformer testing system according to claim 3, characterized in that, The adaptive adjustment mechanism includes an external rigid tube (8) and a cylinder; the cylinder is installed on the low-pressure test frame (2), the external rigid tube (8) is installed on the side of the high-pressure fixed mounting plate (3), the two ends of the external rigid tube (8) are respectively connected to the cylinder and the insulating cylinder (5), and the connection port between the external rigid tube (8) and the insulating cylinder (5) is located at the bottom of the insulating cylinder (5).

5. The fully automated integrated transformer testing system according to claim 4, characterized in that, The insulating cylinder (5) has a connecting channel (9) inside, which is used to connect the insulating cylinder (5) with the external rigid pipe (8).

6. The fully automated integrated transformer testing system according to claim 5, characterized in that, It also includes a high-voltage switching execution component; the high-voltage switching execution component is used to realize the automatic switching and connection of different test circuits on the high-voltage side of the transformer, and to complete the switching and conduction of high-voltage test items.

7. The fully automated integrated transformer testing system according to claim 6, characterized in that, The high-voltage switching execution component includes a high-voltage switching fixture (10), a high-voltage side power frequency cylinder (11), a high-voltage side direct resistance ratio cylinder (12), and a high-voltage side terminal cabinet internal contact (13); the high-voltage switching fixture (10), the high-voltage side power frequency cylinder (11), the high-voltage side direct resistance ratio cylinder (12), and the high-voltage side terminal cabinet internal contact (13) are all installed inside the test equipment housing (1), and the high-voltage side power frequency cylinder (11), the high-voltage side direct resistance ratio cylinder (12), and the high-voltage side terminal cabinet internal contact (13) are all installed on the high-voltage switching fixture (10); The high-voltage side terminal cabinet internal contact (13) is the high-voltage common connection terminal; The high-voltage side power frequency cylinder (11) and the high-voltage side direct resistance ratio cylinder (12) operate independently, selectively connecting and conducting the contacts (13) in the high-voltage side terminal cabinet to achieve switching of different high-voltage test circuits.

8. The fully automated integrated transformer testing system according to claim 7, characterized in that, It also includes a low-voltage test fixture assembly; the low-voltage test fixture assembly is used to realize the low-voltage terminal wiring connection, circuit switching and high-current connection of the transformer, and integrates low-voltage pneumatic actuation and power distribution protection functions.

9. The fully automated integrated transformer testing system according to claim 8, characterized in that, The low-voltage test fixture assembly includes a low-voltage fixture fixing frame (14), a low-voltage switching fixture (15), a low-voltage direct resistance ratio cylinder (16), a low-voltage no-load sensing cylinder (17), a low-voltage power frequency fixture cylinder (18), a low-voltage short-circuit fixture electrical box (19), and a low-voltage load adaptive pressure connector (20). The low-voltage fixture fixing frame (14) is installed on the low-voltage short-circuit fixture electrical box (19), the low-voltage switching fixture (15) is installed on the low-voltage fixture fixing frame (14), the low-voltage direct resistance ratio cylinder (16), the low-voltage no-load sensing cylinder (17), and the low-voltage power frequency fixture cylinder (18) are all installed on the low-voltage switching fixture (15), and the low-voltage load adaptive pressure connector (20) is installed on the low-voltage fixture fixing frame (14).

10. The fully automated integrated transformer testing system according to claim 1, characterized in that, It also includes a partial discharge-free frequency converter (21) and a compensation capacitor bank (22); the partial discharge-free frequency converter (21) and the compensation capacitor bank (22) are both installed in the test equipment box (1). The partial discharge-free frequency converter (21) is used to output low partial discharge, adjustable voltage and frequency modulation test excitation power, and meet the power supply requirements of transformer withstand voltage and partial discharge test. The compensation capacitor bank (22) is used to compensate for the reactive power loss of the test circuit and stabilize the test output voltage.

Images