A multi-stage combined voltage transformer

Abstract

The application discloses a multi-stage combined voltage transformer and belongs to the technical field of transformer combination. The multi-stage combined voltage transformer comprises a box body, a sealed space is formed in the box body, and an oil nozzle is arranged on the vertical side wall of the box body; and a core is arranged in the sealed space and adopts a five-column shape. The first-stage winding, the second-stage voltage winding, the second-stage current winding and the wiring device are arranged on the core, so that the second-stage voltage induction coil and the second-stage current induction coil can be combined on the core, the structure is compact, and the number of turns of the second-stage voltage winding and the second-stage current winding can be changed through the voltage terminal relay group and the current terminal relay group, thereby adapting to different measuring instruments and different load power systems.

Description

Technical Field

[0001] This invention belongs to the field of combined transformer technology, specifically relating to a multi-stage combined voltage transformer. Background Technology

[0002] Combined voltage transformers integrate the functions of voltage and current transformers into one compact structure. They are typically fully enclosed cast iron type, offering strong protection and are suitable for indoor use. Based on the principle of electromagnetic induction, they proportionally convert high voltage and high current, achieving synchronous voltage and current measurement. This provides support for power system monitoring and protection, and they are easy to install with strong anti-interference capabilities.

[0003] A Chinese invention patent with publication number CN102832035A discloses a combined voltage transformer, which uses a combination of voltage transformer and current transformer. This invention is small in size, has a reasonable layout, is easy to install, and saves manufacturing and maintenance costs. However, in actual use, due to design deficiencies, its function is limited and its range is fixed, resulting in poor applicability of the transformer to power systems and measuring instruments with different ranges. In view of this, a multi-stage combined voltage transformer is provided. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a multi-stage combined voltage transformer.

[0005] The technical solution adopted to solve the above technical problems is:

[0006] A multi-stage combined voltage transformer includes:

[0007] The housing has a sealed interior and an oil inlet is provided on the vertical side wall of the housing.

[0008] The iron core has a five-column design and is placed in a sealed space.

[0009] The primary winding has three sections which are coiled around the outside of the three columns in the center of the iron core.

[0010] The secondary voltage winding has three columns sleeved on the outside of the primary winding, including voltage winding one, voltage winding two and voltage winding three. Voltage connection column one, voltage connection column two and voltage connection column three are respectively provided at both ends of voltage winding one, voltage winding two and voltage winding three.

[0011] The secondary current winding has three posts sleeved on the outside of the primary winding, including current winding one, current winding two and current winding three. Current winding one, current winding two and current winding three are respectively provided at both ends of current winding one, current winding two and current winding three.

[0012] A connector, comprising a voltage terminal one and a voltage terminal two, and a current terminal one and a current terminal two, wherein the voltage terminal one and the voltage terminal two are electrically connected to voltage winding one, voltage winding two and voltage winding three via a voltage terminal relay group, and the current terminal one and the current terminal two are electrically connected to current winding one, current winding two and current winding three via a current terminal relay group.

[0013] The primary winding is connected to the circuit. When high-voltage current is introduced into the primary winding, it is cooled by being immersed in the protective oil inside the enclosure. Based on electromagnetic induction, at the secondary voltage winding position, the number of turns in the primary winding is much greater than that in the secondary voltage winding. Through the high turns ratio, the high voltage is proportionally reduced to a low voltage. At the secondary current winding position, the number of turns in the primary winding is much less than that in the secondary current winding. Through electromagnetic induction, the large current is reduced to a small current. By connecting the measuring device between voltage terminal one and voltage terminal two, or between current terminal one and current terminal two, the proportionally reduced voltage and current can be measured, ensuring accurate voltage and current measurement and protecting the safe use of the equipment. At the connector position, the voltage terminal relay group can combine voltage winding one, voltage winding two, and voltage winding three with the measuring device. Similarly, the current terminal relay group can combine current winding one, current winding two, and current winding three with the measuring device. It can adapt to measuring devices with different ranges and circuit systems with different loads, making it highly practical.

[0014] Furthermore, the voltage terminal relay group includes voltage terminal relay one, voltage terminal relay two, voltage terminal relay three, voltage terminal relay four, and voltage terminal relay five. One voltage terminal of voltage winding one is electrically connected to voltage terminal one. Voltage terminal relay one and voltage terminal relay two are connected in parallel to voltage terminal relay one at the other end of voltage winding one. One voltage terminal of voltage winding two is electrically connected to voltage terminal relay one. Voltage terminal relay three and voltage terminal relay four are connected in parallel to voltage terminal relay two at the other end of voltage winding two. One voltage terminal of voltage winding three is electrically connected to voltage terminal relay three. Voltage terminal relay five is connected in series to voltage terminal relay three at the other end of voltage winding three. Voltage terminal relay two, voltage terminal relay four, and voltage terminal relay five are connected in parallel at the end of voltage terminal two.

[0015] The above technical solution discloses the specific configuration of the voltage-terminal relay group, which can form three combinations: voltage winding one, voltage winding one and voltage winding two, or voltage winding one, voltage winding two and voltage winding three. By changing the total number of turns of the secondary voltage winding, the magnitude of the generated induced voltage can be changed.

[0016] Furthermore, the current-end relay group includes current-end relay one, current-end relay two, current-end relay three, current-end relay four, and current-end relay five. The current terminal one at one end of current winding one is electrically connected to current terminal one. Current terminal relay one and current terminal relay two are connected in parallel to the current terminal one at the other end of current winding one. Current terminal relay two at one end of current winding two is electrically connected to current-end relay one. Current terminal relay three and current terminal relay four are connected in parallel to the current terminal two at the other end of current winding two. Current terminal relay three at one end of current winding three is electrically connected to current terminal relay three. Current terminal relay five is connected in series to the current terminal three at the other end of current winding three. Current terminal relay two, current terminal relay four, and current terminal relay five are connected in parallel at the end of current terminal two.

[0017] The above technical solution discloses the specific configuration of the current-terminal relay group, which can form three combinations: current winding one, current winding one and current winding two, or current winding one, current winding two and current winding three. By changing the total number of turns of the secondary current winding, the magnitude of the generated induced current can be changed.

[0018] Furthermore, voltage winding one, voltage winding two and voltage winding three are respectively provided with voltage sub-wires at both ends, and the three voltage sub-wires located on the same side are combined to form a voltage winding bundle. The secondary voltage winding is provided with a total of two voltage winding bundles.

[0019] Through the above technical solution, voltage sub-wires are led out from both ends of voltage winding one, voltage winding two and voltage winding three, and formed into voltage winding bundles by wrapping them with outer sheaths. After integration, they are not easy to break. When led out into the connector, they are connected again to voltage terminals one, voltage terminals two and voltage terminals three arranged at equal intervals, which facilitates wiring operations.

[0020] Furthermore, each of the three current windings (current winding one, current winding two, and current winding three) is provided with a current sub-wire at both ends. The three current sub-wires located on the same side are combined to form a current winding bundle. The secondary current winding is provided with a total of two current winding bundles.

[0021] With the above technical solution, current sub-wires are led out from both ends of current winding one, current winding two and current winding three, and formed into current winding bundles by wrapping them with an outer sheath. After integration, they are not easy to break. When led out into the connector, they are connected again to the equidistant current terminals one, current terminal two and current terminal three, which facilitates wiring operations.

[0022] Furthermore, the housing contains a zero-sequence winding, which is coiled around the outermost column of the iron core, and zero-sequence terminals are provided at both ends of the zero-sequence winding.

[0023] Through the above technical solution, the zero-sequence winding can be used in a three-phase circuit. Under normal circumstances, the vector sum of the three-phase currents is zero. However, when a single-phase ground fault occurs, the vector sum of the three-phase currents is no longer zero, and a zero-sequence current is generated at the position of the zero-sequence winding. By inducing the change in magnetic flux of the zero-sequence current, an induced electrical signal is generated in the zero-sequence winding to detect single-phase ground faults and improve the applicability of the equipment.

[0024] Furthermore, the connector also includes a housing, which is fixed to the outer wall of the top of the enclosure, and the zero-sequence terminal is located inside the housing.

[0025] With the above technical solution, the outer casing has a top cover that can be opened to reveal the internal zero-sequence terminals, voltage terminal one and voltage terminal two, as well as current terminal one and current terminal two, making it convenient for users to connect to measuring equipment via a data cable for circuit testing.

[0026] Furthermore, the connector also includes a communication controller, which is connected in series via a wiring harness between two zero-sequence terminals, between voltage terminal one and voltage terminal two, and between current terminal one and current terminal two.

[0027] Through the above technical solution, the communication controller has built-in measuring instruments, an execution circuit board, and a remote communication device. It can detect the detection voltage between two zero-sequence terminals and measure the induced voltage and induced current generated between voltage terminal one and voltage terminal two, and between current terminal one and current terminal two. The remote communication device can send control signals to the execution circuit board to control the on / off state of the voltage terminal relay group and the current terminal relay group, and remotely change the number of turns of the secondary voltage winding and the secondary current winding, thereby adapting more quickly to different measurement ranges and circuit systems.

[0028] Furthermore, the primary winding includes an insulating sleeve that completely encloses the coil of the primary winding; the secondary voltage winding includes a voltage blocking sleeve that completely encloses voltage winding one, voltage winding two, and voltage winding three; the secondary current winding includes a current blocking sleeve that completely encloses current winding one, current winding two, and current winding three; and a cover is fitted around the zero-sequence winding, the primary winding, the secondary voltage winding, and the secondary current winding.

[0029] Through the above technical solutions, the insulating sleeve has insulation capabilities, which can prevent excessive voltage in the primary winding from causing breakdown faults between the iron core and the primary winding. The voltage blocking sleeve and the current blocking sleeve can provide insulation protection between the primary winding and further improve the breakdown resistance. In addition, by increasing the contact area between the casing and the protective oil inside the box, the temperature is reduced, which helps to reduce abnormal breakdown and short circuits caused by high temperature in the insulating sleeve, voltage blocking sleeve and current blocking sleeve.

[0030] Furthermore, the iron core includes a stacked main body, the top and bottom ends of which are clamped and pressed by two pressure plates, and a clamping member is connected between the two pressure plates.

[0031] The above technical solution uses multiple metal sheets stacked together. The metal sheet core is made of thin and insulated silicon steel sheets stacked together. Each sheet is coated with an insulating layer to reduce eddy current heating. The structural design of the metal sheet core makes its heat dissipation area large, which can effectively reduce the operating temperature. The pressure plate presses the main body together with a detachable clamping component. The overall structure is stable. When the insulation layer is damaged due to heat, it can be quickly disassembled for replacement and maintenance, resulting in low maintenance costs in the later stage.

[0032] The beneficial effects of this invention are as follows:

[0033] (1) By setting up an iron core, a primary winding, a secondary voltage winding, a secondary current winding and a connector, the present invention can combine a secondary voltage induction coil and a secondary current induction coil on an iron core, resulting in a compact structure. At the same time, the number of turns of the secondary voltage winding and the secondary current winding can be changed by the voltage end relay group and the current end relay group to adapt to measuring instruments with different ranges and power systems with different loads.

[0034] (2) Through the design of the connector, the coaxially wound secondary voltage winding and secondary current winding can be quickly combined to change the on and off states of different relays. The combination method can be quickly changed to adapt to the load changes of the circuit system. When the circuit system is abnormal, the remote control will reduce the induced voltage and induced current to the minimum, and minimize the damage of abnormal fluctuations to the transformer. Attached Figure Description

[0035] Figure 1This is an overall structural diagram of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the present invention in the state of removing the box. Figure 1 ;

[0037] Figure 3 This is a schematic diagram of the structure of the present invention in the state of removing the box. Figure 2 ;

[0038] Figure 4 This is a schematic diagram of the structure between the iron core, primary winding, secondary voltage winding, secondary current winding and zero-sequence winding of the present invention;

[0039] Figure 5 This is a schematic diagram of the structure of the secondary voltage winding of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of the secondary current winding of the present invention;

[0041] Figure 7 This is a schematic diagram of the structure between the secondary voltage winding, the secondary current winding, the zero-sequence winding, and the connector of the present invention;

[0042] Figure 8 This is a schematic diagram of the structure between the voltage winding harness, voltage terminal one, and voltage terminal two of the present invention;

[0043] Figure 9 This is a schematic diagram of the structure between the current winding harness, current terminal one, and current terminal two of the present invention.

[0044] Figure 10 This is a schematic diagram of the structure between the housing and the communication controller of the present invention.

[0045] Figure reference numerals: 1. Housing; 11. Viewing window; 12. Oil nozzle; 13. Base; 2. Iron core; 21. Main body; 22. Pressure plate; 23. Clamping component; 3. Secondary voltage winding; 31. Voltage winding one; 32. Voltage winding two; 33. Voltage winding three; 34. Voltage sub-wire; 35. Voltage winding harness; 36. Voltage isolation sleeve; 37. Voltage connection post one; 38. Voltage connection post two; 39. Voltage connection post three; 4. Secondary current winding; 41. Current winding one; 42. Current winding two; 43. Current winding three; 44. Current sub-wire; 45. Current winding harness; 46. Current isolation sleeve; 47. Current connection post one; 48. Current connection post two; 4 9. Current terminal three; 5. Primary winding; 51. Insulating sleeve; 52. Primary winding harness; 6. Connector; 61. Housing; 62. Voltage terminal one; 63. Voltage terminal two; 631. Voltage terminal relay one; 632. Voltage terminal relay two; 633. Voltage terminal relay three; 634. Voltage terminal relay four; 635. Voltage terminal relay five; 64. Current terminal one; 65. Current terminal two; 651. Current terminal relay one; 652. Current terminal relay two; 653. Current terminal relay three; 654. Current terminal relay four; 655. Current terminal relay five; 66. Communication controller; 7. Zero-sequence winding; 71. Zero-sequence terminal; 8. Cover. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0047] like Figures 1-10 As shown, this embodiment provides a multi-stage combined voltage transformer. To address the practical problems of existing transformers having limited functionality and fixed range, a specific configuration is disclosed:

[0048] Regarding box 1, refer to... Figure 1 and Figure 2 The interior of the housing 1 forms a sealed space. The vertical side wall of the housing 1 is provided with two oil inlets 12, one high and one low, which can fill the housing 1 with protective oil. A viewing window 11 is designed to allow the level of the protective oil to be seen. A base 13 is installed at the bottom of the housing 1 to support the iron core 2 installed inside the housing 1.

[0049] Regarding core 2, refer to... Figure 2 The iron core 2 adopts a five-column design and is placed in a sealed space, that is, installed above the base 13. The base 13 is made of insulating material to prevent the box 1 from becoming electrified.

[0050] Regarding primary winding 5, refer to... Figure 3The primary winding 5 has three columns coiled around the outside of the three columns in the center of the iron core 2. The column ends are connected to the top through the primary winding harness 52 so that they can be connected to the circuit system through wires. The column ends have multiple layers of insulating strings to prevent the box 1 from becoming live. When used on the ground, it protects the safety of people passing by or accidentally touching the box 1.

[0051] Regarding the secondary voltage winding 3, refer to the figure. Figure 3 and Figure 5 The secondary voltage winding 3 has three posts on the outside of the primary winding 5, which can generate induced voltage. These include voltage winding 1 31, voltage winding 2 32, and voltage winding 33 with gradually increasing number of turns. For example, the number of turns of voltage winding 1 31 is equal to half that of voltage winding 2 32, and the number of turns of voltage winding 2 32 is equal to one-quarter that of voltage winding 33. This design can increase the range of detectable voltage values. Voltage terminals 1 37, 2 38, and 3 39 are respectively provided at both ends of voltage winding 1 31, voltage winding 2 32, and voltage winding 33 for connection to connector 6.

[0052] Regarding the secondary current winding 4, refer to... Figure 4 and Figure 6 The secondary current winding 4 has three columns that are sleeved on the outside of the column below the primary winding 5, which can generate induced current. These include current winding 1 41, current winding 2 42 and current winding 3 43 with gradually increasing number of turns. Current winding 1 41, current winding 2 42 and current winding 3 43 are respectively provided with current connection post 1 47, current connection post 2 48 and current connection post 3 49 at both ends for connection with connector 6.

[0053] Regarding connector 6, refer to... Figure 8 and Figure 9 The connector 6 includes a voltage terminal 62 and a voltage terminal 63 for connecting a voltage measuring instrument to output the induced voltage value, and a current terminal 64 and a current terminal 65 for connecting a current measuring instrument to output the induced current value. The voltage terminal 62 and the voltage terminal 63 are electrically connected to the voltage winding 31, the voltage winding 32 and the voltage winding 33 via a voltage terminal relay group. The voltage terminal relay group can change the series connection of the voltage winding 31, the voltage winding 32 and the voltage winding 33. The current terminal 64 and the current terminal 65 are electrically connected to the current winding 41, the current winding 42 and the current winding 43 via a current terminal relay group. The current terminal relay group can change the series connection of the current winding 41, the current winding 42 and the current winding 43.

[0054] The working principle of this embodiment is as follows:

[0055] When the primary winding 5 is connected to the circuit, the high voltage current is introduced into the primary winding 5 and is cooled by the protective oil inside the housing 1. Based on electromagnetic induction, at the secondary voltage winding 3 position, the number of turns of the primary winding 5 is much greater than the number of turns of the secondary voltage winding 3. The high voltage is reduced to a low voltage proportionally through the high turns ratio. At the secondary current winding 4 position, the number of turns of the primary winding 5 is much less than the number of turns of the secondary current winding 4. The large current is reduced to a small current through electromagnetic induction. By connecting the measuring device between voltage terminal 1 62 and voltage terminal 2 63, or between current terminal 1 64 and current terminal 2 65, the proportionally reduced voltage and current can be measured, ensuring the accurate measurement of voltage and current and protecting the safe use of the equipment.

[0056] The measuring instrument is connected between voltage terminals 62 and 63 at position 6 of the connector, and between current terminals 64 and 65. The voltage terminal relay group can connect voltage windings 31, 32, and 33 to the measuring equipment. Similarly, the current terminal relay group can connect current windings 41, 42, and 43 to the measuring equipment. When connecting to a small-range measuring device or when the power system load is large, the number of turns in the secondary voltage winding 3 can be reduced and the number of turns in the secondary current winding 4 can be increased to reduce the values ​​of induced voltage and induced current for accurate detection. When connecting to a large-range measuring device or when the circuit system load is small, the number of turns in the secondary voltage winding 3 can be increased and the number of turns in the secondary current winding 4 can be reduced to increase the values ​​of induced voltage and induced current and improve the measurement range. It can adapt to measuring devices with different ranges and circuit systems with different loads, making it highly practical.

[0057] In a further embodiment, the specific configuration of the disclosed voltage-terminal relay group is shown in reference to... Figure 8The voltage terminal relay group includes voltage terminal relay 631, voltage terminal relay 632, voltage terminal relay 633, voltage terminal relay 634, and voltage terminal relay 635. One end of voltage winding 31 has a voltage terminal 37 electrically connected to voltage terminal 62. The other end of voltage winding 31 has a voltage terminal 37 connected in parallel with voltage terminal relay 631 and voltage terminal relay 632. One end of voltage winding 32 has a voltage terminal 38 electrically connected to voltage terminal relay 631. The other end of voltage winding 32 has a voltage terminal 38 connected in parallel with voltage terminal relay 633 and voltage terminal relay 634. One end of voltage winding 33 has a voltage terminal 39 electrically connected to voltage terminal relay 633. The other end of voltage winding 33... Voltage terminal 39 is connected in series with voltage terminal relay 5 635, and voltage terminal relays 2 632, 4 634 and 5 635 are connected in parallel at the end of voltage terminal 2 63. Specifically, voltage winding 1 31 can be connected alone between voltage terminal 1 62 and voltage terminal 2 63. In this case, the number of turns of the secondary voltage winding 3 participating in the induced voltage generation is the minimum. When voltage winding 1 31 and voltage winding 2 32 are connected between voltage terminal 1 62 and voltage terminal 2 63, the number of turns of the secondary voltage winding 3 can be increased. Alternatively, voltage winding 1 31, voltage winding 2 32 and voltage winding 3 33 can be connected between voltage terminal 1 62 and voltage terminal 2 63 to maximize the number of turns of the secondary voltage winding 3. Thus, the magnitude of the induced voltage generated can be changed by changing the number of turns.

[0058] In a further embodiment, the specific configuration of the disclosed current-terminal relay group is shown in reference to... Figure 9The current-terminal relay group includes current-terminal relay 651, current-terminal relay 652, current-terminal relay 653, current-terminal relay 654, and current-terminal relay 655. One end of current winding 41 has a current terminal 47 electrically connected to current terminal 64. The other end of current winding 41 has current terminal 47 connected in parallel with current-terminal relay 651 and current-terminal relay 652. One end of current winding 42 has a current terminal 48 electrically connected to current-terminal relay 651. The other end of current winding 42 has current terminal 48 connected in parallel with current-terminal relay 653 and current-terminal relay 654. One end of current winding 43 has a current terminal 49 electrically connected to current-terminal relay 653. The other end of current winding 43... The current terminal 3 49 is connected in series with the current terminal relay 5 655, and the current terminal relays 2 652, 4 654 and 5 655 are connected in parallel at the end of the current terminal 2 65. Specifically, the current winding 1 41 can be connected alone between the current terminal 1 64 and the current terminal 2 65. At this time, the number of turns of the secondary current winding 4 participating in the induction current generation is the minimum. When the current winding 1 41 and the current winding 2 42 are connected between the current terminal 1 64 and the current terminal 2 65, the number of turns of the secondary current winding 4 can be increased. Alternatively, the current winding 1 41, the current winding 2 42 and the current winding 3 43 can be connected between the current terminal 1 64 and the current terminal 2 65 to maximize the number of turns of the secondary current winding 4. Thus, the magnitude of the generated induced current can be changed by changing the number of turns.

[0059] In a further embodiment, refer to Figure 5 Voltage winding 1 31, voltage winding 2 32 and voltage winding 33 are respectively provided with voltage sub-wires 34 at both ends. The three voltage sub-wires 34 located on the same side are combined to form a voltage winding bundle 35. Voltage sub-wires 34 are led out from both ends of voltage winding 1 31, voltage winding 2 32 and voltage winding 33 and wrapped with an outer sheath to form a voltage winding bundle 35. After integration, it is not easy to break. The secondary voltage winding 3 is provided with two voltage winding bundles 35. When led out into the connector 6, they are connected again to the voltage terminals 1 37, voltage terminal 2 38 and voltage terminal 3 39 arranged at equal intervals, which facilitates the wiring operation.

[0060] In a further embodiment, refer to Figure 6The current windings 41, 42, and 43 are each provided with a current sub-wire 44 at both ends. The three current sub-wires 44 located on the same side are combined to form a current winding bundle 45. The current sub-wires 44 are led out from both ends of the current windings 41, 42, and 43 and are wrapped with an outer sheath to form a current winding bundle 45. After integration, it is not easy to break. The secondary current winding 4 is provided with two current winding bundles 45. When they are led out into the connector 6, they are connected again to the equidistant current terminals 47, 48, and 49 for easy wiring.

[0061] In a further embodiment, refer to Figure 2 and Figure 4 The housing 1 contains a zero-sequence winding 7, which is coiled around the outermost column of the iron core 2. The zero-sequence winding 7 has zero-sequence terminals 71 at both ends. The zero-sequence winding 7 can be used in a three-phase circuit. Under normal conditions, the vector sum of the three-phase currents is zero. However, when a single-phase ground fault occurs, the vector sum of the three-phase currents is no longer zero, and a zero-sequence current is generated at the position of the zero-sequence winding 7. By inducing the change in magnetic flux of the zero-sequence current, an induced electrical signal is generated in the zero-sequence winding 7 to detect single-phase ground faults and improve the applicability of the inductive equipment to three-phase circuit systems.

[0062] In a further embodiment, refer to Figure 1 and Figure 7 The connector 6 also includes a housing 61 with a top cover that can be opened to reveal the internal zero-sequence terminal 71, voltage terminal 1 62 and voltage terminal 2 63, and current terminal 1 64 and current terminal 2 65. The housing 61 is fixed to the top outer wall of the enclosure 1. The zero-sequence terminal 71 is located inside the housing 61, which allows users to connect to measuring equipment via a data cable for circuit testing and single-phase short-circuit testing.

[0063] In a further embodiment, refer to Figure 10The connector 6 also includes a communication controller 66, which integrates measuring instruments, an execution circuit board, and a remote communication device. The measuring instruments are voltmeters and ammeters with different ranges. The execution circuit board can turn different relays on or off based on received control signals. The remote communication device is used to send and receive control signals and detection data. The communication controller 66 is connected in series via a wiring harness between two zero-sequence terminals 71, between voltage terminal 1 62 and voltage terminal 2 63, and between current terminal 1 64 and current terminal 2 65. It can detect the voltage between the two zero-sequence terminals 71 and measure the voltage. The induced voltage and induced current generated between terminal 62 and voltage terminal 63, and between current terminal 64 and current terminal 65, can be controlled by sending control signals to the execution circuit board via a remote communication device. This controls the on / off state of the voltage and current relay groups, remotely changing the number of turns in the secondary voltage winding 3 and the secondary current winding 4. This allows for faster adaptation to different measurement ranges and circuit systems. In case of circuit system abnormalities, such as abnormal increases in circuit voltage and current, the remote control minimizes the induced voltage and induced current, reducing the load on the secondary windings and minimizing damage to the transformer caused by abnormal fluctuations.

[0064] In a further embodiment, refer to Figure 4 The primary winding 5 includes an insulating sleeve 51, which completely encloses the coil of the primary winding 5. The insulating sleeve 51 has insulating capabilities, which can prevent excessive voltage in the primary winding 5 from causing a breakdown fault between the coil and the iron core 2. (Refer to...) Figure 5 and Figure 6 The secondary voltage winding 3 includes a voltage isolation sleeve 36, which completely encloses voltage winding 1 31, voltage winding 2 32, and voltage winding 33. The secondary current winding 4 includes a current isolation sleeve 46, which completely encloses current winding 1 41, current winding 2 42, and current winding 3 43. The voltage isolation sleeve 36 and current isolation sleeve 46 can further improve the insulation capability with the primary winding 5 and further improve the breakdown capability. The zero-sequence winding 7, primary winding 5, secondary voltage winding 3, and secondary current winding 4 are covered with a cover 8. The cover 8 increases the contact area with the protective oil inside the housing 1, which provides protection and cooling, and helps to reduce abnormal breakdown and short circuits caused by high temperature in the insulating sleeve 51, voltage isolation sleeve 36, and current isolation sleeve 46, ensuring that the inductor works stably in a high-voltage environment.

[0065] In a further embodiment, refer to Figure 4The iron core 2 includes a stacked main body 21, which is composed of multiple stacked metal sheets. The metal sheet iron core is made of thin and insulating silicon steel sheets, with an insulating layer between each sheet to reduce eddy current heating. The structural design of the metal sheet iron core gives it a large heat dissipation area, which can effectively reduce the operating temperature. The top and bottom ends of the main body 21 are clamped and squeezed by two pressure plates 22. A clamping member 23 is connected between the two pressure plates 22. The pressure plates 22 are pressed together by the detachable clamping member 23. The overall structure is stable. When the insulation layer is damaged due to heat, it can be quickly disassembled for replacement and maintenance, resulting in low maintenance costs.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A multi-stage combined voltage transformer, characterized in that, include: The box (1) has a sealed space inside and an oil inlet (12) is provided on the vertical side wall of the box (1). Iron core (2), the iron core (2) adopts a five-column shape, and the iron core (2) is placed in a sealed space; The primary winding (5) has three sections which are coiled around the three columns in the center of the iron core (2); The secondary voltage winding (3) has three columns on the outside of the primary winding (5), including voltage winding one (31), voltage winding two (32) and voltage winding three (33). The number of turns of voltage winding one (31) is equal to half of voltage winding two (32), and the number of turns of voltage winding two (32) is equal to one-quarter of voltage winding three (33). Voltage connection column one (37), voltage connection column two (38) and voltage connection column three (39) are respectively provided at both ends of voltage winding one (31), voltage winding two (32) and voltage winding three (33). The secondary current winding (4) has three columns that are sleeved on the outside of the primary winding (5), including current winding one (41), current winding two (42) and current winding three (43). The number of turns of current winding one (41), current winding two (42) and current winding three (43) gradually increases. Current connection column one (47), current connection column two (48) and current connection column three (49) are respectively provided at both ends of current winding one (41), current winding two (42) and current winding three (43). The connector (6) includes a voltage terminal 1 (62) and a voltage terminal 2 (63), as well as a current terminal 1 (64) and a current terminal 2 (65). The voltage terminal 1 (62) and the voltage terminal 2 (63) are electrically connected to the voltage winding 1 (31), the voltage winding 2 (32) and the voltage winding 3 (33) through a voltage terminal relay group. The current terminal 1 (64) and the current terminal 2 (65) are electrically connected to the current winding 1 (41), the current winding 2 (42) and the current winding 3 (43) through a current terminal relay group. The voltage terminal relay group includes voltage terminal relay one (631), voltage terminal relay two (632), voltage terminal relay three (633), voltage terminal relay four (634), and voltage terminal relay five (635). One voltage terminal post one (37) at one end of voltage winding one (31) is electrically connected to voltage terminal one (62). The voltage terminal post one (37) at the other end of voltage winding one (31) is connected in parallel with one end of voltage terminal relay one (631) and one end of voltage terminal relay two (632). The other end of voltage terminal relay one (631) is electrically connected to voltage terminal post two (38) at one end of voltage winding two (32). The voltage terminal of the second voltage winding (32) is connected in parallel with one end of the third voltage relay (633) and one end of the fourth voltage relay (634). The other end of the third voltage relay (633) is electrically connected to the voltage terminal of the third voltage winding (33) at one end (39). The voltage terminal of the third voltage winding (33) at the other end (39) is connected in series with one end of the fifth voltage relay (635). The other end of the second voltage relay (632), the other end of the fourth voltage relay (634), and the other end of the fifth voltage relay (635) are connected in parallel with the second voltage terminal (63). The current-end relay group includes current-end relay one (651), current-end relay two (652), current-end relay three (653), current-end relay four (654), and current-end relay five (655). One end of the current winding one (41) has a current terminal one (47) electrically connected to the current terminal one (64). The other end of the current winding one (41) has a current terminal one (47) connected in parallel with one end of current-end relay one (651) and one end of current-end relay two (652). The other end of the current-end relay one (651) is electrically connected to the current terminal two (48) at one end of current winding two (42). The current terminal of the second current winding (42) is connected in parallel with one end of the current terminal relay (653) and one end of the current terminal relay (654). The other end of the current terminal relay (653) is electrically connected to the current terminal of the third current winding (43) at one end (49). The current terminal of the third current winding (43) at the other end (49) is connected in series with one end of the current terminal relay (655). The other end of the second current terminal relay (652), the other end of the fourth current terminal relay (654), and the other end of the fifth current terminal relay (655) are connected in parallel with the second current terminal (65). The housing (1) contains a zero-sequence winding (7), which is coiled around the outermost column of the iron core (2). The zero-sequence winding (7) has zero-sequence terminals (71) at both ends.

2. The multi-stage combined voltage transformer according to claim 1, characterized in that, The voltage winding 1 (31), voltage winding 2 (32) and voltage winding 3 (33) are respectively provided with voltage sub-wires (34) at both ends. The three voltage sub-wires (34) located on the same side are combined to form a voltage winding bundle (35). The secondary voltage winding (3) is provided with two voltage winding bundles (35).

3. The multi-stage combined voltage transformer according to claim 1, characterized in that, The current winding 1 (41), current winding 2 (42) and current winding 3 (43) are respectively provided with current sub-wires (44) at both ends. The three current sub-wires (44) located on the same side are combined to form a current winding bundle (45). The secondary current winding (4) is provided with two current winding bundles (45).

4. The multi-stage combined voltage transformer according to claim 1, characterized in that, The connector (6) also includes a housing (61), which is fixed to the top outer wall of the box (1), and the zero-sequence terminal (71) is located inside the housing (61).

5. The multi-stage combined voltage transformer according to claim 1, characterized in that, The connector (6) also includes a communication controller (66), which is connected in series between two zero-sequence terminals (71), between voltage terminal one (62) and voltage terminal two (63), and between current terminal one (64) and current terminal two (65) via a wire harness.

6. The multi-stage combined voltage transformer according to claim 1, characterized in that, The primary winding (5) includes an insulating sleeve (51) that completely encloses the coil of the primary winding (5). The secondary voltage winding (3) includes a voltage blocking sleeve (36) that completely encloses voltage winding one (31), voltage winding two (32), and voltage winding three (33). The secondary current winding (4) includes a current blocking sleeve (46) that completely encloses current winding one (41), current winding two (42), and current winding three (43). The zero-sequence winding (7), primary winding (5), secondary voltage winding (3), and secondary current winding (4) are covered with a casing (8).

7. The multi-stage combined voltage transformer according to claim 1, characterized in that, The iron core (2) includes a stacked main body (21), the top and bottom ends of the main body (21) are clamped and squeezed by two pressure plates (22), and a clamping member (23) is connected between the two pressure plates (22).

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