A multi-output transformer body and transformer for in-phase power supply

Abstract

This application discloses a multi-output transformer body and transformer for in-phase power supply, belonging to the field of transformer technology. The multi-output transformer body for in-phase power supply includes an iron core, a primary winding, and a secondary winding. The iron core has two core columns, and at least two primary windings are wound on each core column. The secondary windings are nested with the primary windings. All primary windings on the transformer body are connected in parallel to the same input terminal. Each secondary winding has a separate output terminal. This device can realize the output function of the secondary multi-winding required for in-phase power supply. It is suitable for high-capacity power conversion of single-phase AC-DC-AC in parallel multiplexing and cascaded H-bridge topologies. The rectifier side obtains excellent current harmonic characteristics through the multi-winding output transformer, and the inverter side obtains a near-sine wave multi-level SPWM waveform, achieving excellent voltage harmonic characteristics and voltage transient regulation characteristics.

Description

Technical Field

[0001] This application belongs to the field of transformer technology, and specifically relates to a multi-output transformer body and transformer for in-phase power supply. Background Technology

[0002] The traction power supply systems of my country's high-speed, heavy-haul railways, and intercity rapid rail transit all adopt a "single-phase AC + single-sided power supply" system. Due to the inconsistency in phase and voltage between power sources, a "phase-separated" de-energized zone is required during phase conversion to prevent short circuits and explosions. The length of this de-energized zone is stipulated to be no less than 18 meters. To ensure smooth passage for locomotives, the de-energized zone typically features a complex mechanical structure and requires relatively complex operations from the driver, leading to increased probability of train malfunctions and reduced efficiency in heavy-haul transportation.

[0003] Transformers are key components of traction power supply systems, hindering the safe, reliable, and efficient operation of my country's electrified railways. Furthermore, this power supply system and traction load operation mode are prone to causing numerous serious power quality problems and affecting the external power grid. It also results in insufficient utilization of regenerative energy from traction locomotives, low traction capacity utilization, and limited system reliability.

[0004] Therefore, there is an urgent need for a new type of traction power supply system that can completely solve the drawbacks of the "single-phase AC + single-sided power supply" power supply system. At present, the through-type traction power supply system based on power electronics technology is the best solution. Among them, the successful realization of the power input transformer, which is the key equipment of the through-type in-phase traction power supply system, solves the problem that has been troubling those skilled in the art in the existing technology. Summary of the Invention

[0005] To address the shortcomings of the prior art, this application provides a transformer body and transformer for in-phase power supply with multiple independent transformer bodies and multiple windings, solving the problem of inconsistent output electrical parameters of split units in single-phase power supplies in the prior art. This multi-output transformer for in-phase power supply exhibits good consistency of electrical parameters among its output units, high decoupling rate, meets the input power requirements of through-type in-phase power supply systems for rail transit, and has strong scalability and high versatility.

[0006] The technical effect to be achieved in this application is accomplished through the following solution:

[0007] According to a first aspect of the present invention, a multi-output transformer body for in-phase power supply is provided, comprising an iron core, a primary winding and a secondary winding, wherein the iron core is provided with two core posts, and at least two of the primary windings are wound on each core post, and the secondary windings are nested and cooperated with the primary windings.

[0008] All primary windings on the transformer are connected in parallel to the same input terminal; each secondary winding has a separate output terminal.

[0009] Preferably, the core post has two primary windings wound around it, and the two primary windings are arranged vertically along the axial direction of the core post.

[0010] Preferably, the secondary winding is sleeved outside the primary winding; or the primary winding is sleeved outside the secondary winding.

[0011] According to a second aspect of the present invention, a transformer employing a multi-output transformer body for in-phase power supply as described in any of the preceding claims is provided, comprising a housing, wherein a plurality of the transformer bodies are installed in the housing, and the primary windings of all the transformer bodies are connected in parallel to the primary side terminals on the housing; the secondary windings are respectively connected to the secondary side terminals on the housing.

[0012] Preferably, the housing is provided with several independent oil chambers, and the transformer body is arranged in each of the oil chambers in a corresponding manner. The primary windings in adjacent oil chambers are connected by through-wall bushings.

[0013] Preferably, the transformer bodies are arranged in a single line within the housing; or the transformer bodies are arranged symmetrically in two rows within the housing.

[0014] Preferably, each of the oil chambers is provided with a circulation system, the circulation system including a circulation pipe and a cooling device, the circulation pipe being located in the oil chamber and communicating with the oil chamber, and the cooling device being connected to the circulation pipe.

[0015] Preferably, the circulation pipe includes a retainer and several pipe sections, which are arranged in a straight line to form a tubular structure. The pipe sections are fixed together by the retainer, and several through holes are provided on the side of each pipe section.

[0016] Preferably, the fixture includes a support frame, clamping screws, and clamping plates. The support frame is fixed to the iron core, and both ends of the support frame are bent toward the side away from the iron core to form mounting parts. The clamping screws are rotatably connected to the mounting parts, and each clamping screw is threadedly connected to a clamping plate. The clamping plates are used to press and fix several pipe sections.

[0017] Preferably, the fixing device includes a fixing ring, and the pipe section is provided with a fixing groove. After the pipe sections are assembled, the fixing grooves are connected to form a ring that matches the fixing ring. The fixing ring is inserted into the fixing groove to fix the pipe section.

[0018] According to an embodiment of the present invention, the multi-output transformer body and the transformer for in-phase power supply in this application have the following technical effects: This device can realize the output function of the secondary side multi-winding required for in-phase power supply. The rectifier device can effectively eliminate high-order harmonics through carrier phase shift. When there are many transformer bodies connected in parallel through multi-winding transformers, most high-frequency harmonics can be canceled by the carrier phase difference π / n method, so that they cannot propagate to the primary side of the transformer, reducing the filtering branch, reducing the resonance risk, improving the reliability of the device operation, and reducing the magnitude of high-frequency harmonics through the H-bridge. It is suitable for high-capacity power conversion of single-phase AC-DC-AC in parallel multiplexing and cascaded H-bridge topologies. The rectifier side obtains excellent current harmonic characteristics through the multi-winding output transformer, and the inverter side obtains a near-sine wave multi-level SPWM waveform, obtaining excellent voltage harmonic characteristics and voltage transient regulation characteristics.

[0019] The transformer adopts an oil-immersed design, using transformer oil as the insulation and cooling medium. Each oil chamber is equipped with an independent oil circulation system, which has good insulation and heat dissipation performance. It can effectively protect the iron core and windings from the influence of moisture in the air, while ensuring the safe operation of multiple transformers and avoiding the impact of long-term heavy load operation on voltage output, thus greatly improving the safety of multi-output transformers. Attached Figure Description

[0020] To more clearly illustrate the embodiments of this application or the existing technical solutions, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a multi-output transformer body for in-phase power supply in one embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the transformer structure in one embodiment of this application;

[0023] Figure 3 for Figure 2 A schematic diagram of the circuit structure of the transformer body;

[0024] Figure 4 This is a schematic diagram of the arrangement structure of the transformer body in a transformer according to one embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the arrangement structure of the transformer body in another embodiment of this application;

[0026] Figure 6This is a schematic diagram of the circulation tube in one embodiment of this application;

[0027] Figure 7 for Figure 6 A top view of the circulation pipe in the middle;

[0028] Figure 8 This is a schematic diagram of the circulation tube in another embodiment of this application;

[0029] Figure 9 for Figure 8 Schematic diagram of the installation position of the middle fixing ring;

[0030] Figure 10 for Figure 9 A schematic diagram of the middle pipe section.

[0031] Reference numerals: 1. Housing; 11. Primary side terminal; 12. Secondary side terminal; 13. Oil chamber; 131. Through-wall bushing; 2. Transformer body; 21. Iron core; 211. Core column; 22. Primary side winding; 23. Secondary side winding; 31. Circulation pipe; 32. Cooling device; 312. Pipe section; 313. Through hole; 314. Fixing groove; 315. Boss; 316. Groove; 3111. Support frame; 3112. Mounting part; 3113. Clamping screw; 3114. Clamping plate; 3115. Connecting part; 3116. Limiting rod; 3117. Fixing ring. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] like Figure 1 As shown, in one embodiment of this application, the body 2 of the multi-output transformer for in-phase power supply includes an iron core 21, a primary winding 22 and a secondary winding 23. The iron core 21 is provided with two core posts 211, and at least two primary windings 22 are wound on each core post 211 to reserve redundancy for the system. The secondary windings 23 are nested with the primary windings 22.

[0034] All primary windings 22 on the transformer body 2 are connected in parallel to the same input terminal; the secondary windings 23 are each provided with a separate output terminal.

[0035] In this embodiment, two primary windings 22 are wound on the core post 211, and the two primary windings 22 are arranged vertically along the axial direction of the core post 211. The secondary winding 23 is sleeved outside the primary windings 22;

[0036] In other embodiments, the primary winding 22 is sleeved outside the secondary winding 23.

[0037] In this embodiment, the primary windings 22 of the transformer body are all connected in parallel, which can ensure that the input terminals of the primary windings 22 have the same current characteristics, thereby ensuring that the secondary windings 23 can output currents of the same phase and improve power quality. The transformer body 2 adopts a single-column and two-column splitting method to realize the output of multiple secondary windings and reserve redundancy for the system.

[0038] One embodiment of this application also provides a transformer employing the above-described transformer body, such as... Figure 1 and Figure 2 As shown, the transformer includes a housing 1 and a transformer body 2. The transformer body 2 is disposed in the housing 1. Several transformer bodies 2 are installed in the housing 1. The transformer body 2 includes an iron core 21. The iron core 21 is provided with two core columns 211. Each core column 211 is wound with two primary windings 22. The two primary windings 22 are arranged vertically along the axial direction of the core column 211. A secondary winding 23 is nested and cooperated with the primary windings 22. The winding arrangement of the two core columns 211 is completely consistent. Each secondary winding 23 is symmetrical in structure with respect to the parallel primary windings 22.

[0039] All primary windings 22 on the transformer body 2 are connected in parallel to the primary terminal 11 on the enclosure 1; the secondary windings 23 are respectively connected to the secondary terminal 12 on the enclosure. Each primary terminal 11 and secondary terminal 12 adopts a pluggable terminal bushing. The enclosure 1 adopts pluggable terminal bushings, which have no live distance requirements, no open connection, and can be densely arranged to meet the on-site wiring requirements of the transformer.

[0040] like Figure 3 As shown, this transformer includes four transformer bodies 2. The four primary windings 22 of one transformer body 2 have their first and last output terminals A1, X1, A2, X2, A3, X3, A4, X4 in sequence. The four secondary windings 23 have their first and last output terminals a1, x1, a2, x2, a3, x3, a4, x4 in sequence. All output terminals marked A of the four primary windings 22 are connected in parallel, and all output terminals marked X are connected in parallel, ultimately leading to the primary side terminals A and X of the housing 1. All terminals of the four secondary windings 23 are individually led to the secondary side terminals a1, x1, a2, x2…a16, x16 of the housing 1.

[0041] In this embodiment or other embodiments, the housing 1 is provided with several independent oil chambers 13, and the transformer body 2 is arranged in the oil chambers 13 in a corresponding manner. The primary windings 22 in adjacent oil chambers 13 are connected by through bushings 131 to ensure the relative sealing between the oil chambers 13 and avoid mutual interference.

[0042] like Figure 4 and Figure 5 As shown, the transformer bodies 2 are arranged symmetrically in two rows in the enclosure 1; several transformer bodies 2 can also be arranged in a line in the enclosure 1, and multiple single-phase transformer bodies 2 can be arranged in various combinations in the enclosure 1, thereby changing the overall external dimensions and adapting to the installation requirements of various foundation sizes.

[0043] In one embodiment of this application, since a plurality of transformer bodies 2 are provided, and each transformer body 2 is provided with a plurality of primary windings 22 and secondary windings 23, the heat generation is relatively large. Therefore, in order to improve the heat dissipation effect and the reliability of this device, a circulation system is provided in each oil chamber 13. The circulation system includes a circulation pipe 31 and a cooling device 32. The circulation pipe 31 is located in the oil chamber 13 and communicates with the oil chamber 13, and the cooling device 32 is connected to the circulation pipe 31.

[0044] like Figure 7 and Figure 8 As shown, in this embodiment, the circulation tube 31 includes a retainer and several tube sections 312. The tube sections 312 are arranged in a line and assembled to form a tubular structure. The tube sections 312 are fixed together by the retainer. Different lengths can be formed by splicing the tube sections 312 to adapt to different sizes of iron cores 21 and to be suitable for the use of transformer bodies of different specifications.

[0045] The side of the pipe section 312 is provided with several through holes 313, which serve as channels for oil to enter the circulation pipe. Alternatively, an oil pipe can be connected to the through holes 313, and the opening of the oil pipe can be located in a position with a relatively high temperature inside the oil chamber 13, so that the high-temperature oil can enter the circulation first and improve the cooling effect.

[0046] In this embodiment, circulation pipes 31 are installed at both the upper and lower ends of the iron core 21. The oil inlet and oil outlet of the cooling device 32 are connected to the circulation pipe 31 above the iron core 21 and the circulation pipe 31 below the iron core 21, respectively. The oil in the oil chamber 13 is circulated and cooled through the circulation pipes 31 and the cooling device 32, resulting in better cooling effect. Moreover, the mounting bracket supporting the iron core 21 is integrated with the oil circulation pipe, eliminating the need for additional oil pipes and simplifying the overall structure.

[0047] The cooling device 32 extends out of the housing 1 and includes a circulating pump and several heat sinks. The heat sinks can increase the heat dissipation area, thereby improving the cooling effect of the oil.

[0048] In one embodiment of this application, the fixture includes a support frame 3111, clamping screws 3113, and clamping plates 3114. The support frame 3111 is fixed to the iron core 21. Both ends of the support frame 3111 are bent toward the side away from the iron core 21 to form mounting portions 3112. Clamping screws 3113 are rotatably connected to the mounting portions 3112 respectively. Each clamping screw 3113 is threadedly connected to a clamping plate 3114. The clamping plates 3114 are used to press and fix several pipe sections 313.

[0049] In this embodiment, a connecting part 3115 protrudes from the middle of the support frame 3111, and the end of the clamping screw 3113 is rotatably connected to the connecting part 3115, so that the clamping screw 3113 can rotate on the support frame 3111. The rotation of the two clamping screws 3113 can drive the clamping plates 3114 to move closer to each other. After the pipe section 312 is assembled, it can be clamped by the clamping plates 3114 to ensure the sealing effect between the pipe sections 312. The sliding of the two clamping plates 3114 can adjust the distance between them to accommodate different numbers of pipe sections 312, which can adapt to more scenarios.

[0050] To improve the stability of the clamping plate 3114 during the clamping process, a limiting rod 3116 is fixed between the mounting part 3112 and the connecting part 3115. The limiting rod 3116 is arranged in parallel with the clamping screw 3113, and the clamping plate 3114 is slidably connected to the limiting rod 3116 to stabilize the clamping plate 3114.

[0051] In another embodiment of this application, such as Figure 9 and Figure 10 As shown, the fixture includes a fixing ring 3117 and a fixing groove 314 on the pipe section 312. After the pipe sections 312 are assembled, the fixing grooves 314 are connected to form a ring that matches the fixing ring 3117. The fixing ring 3117 is inserted into the fixing groove 314 to fix the pipe section 312.

[0052] Among them, the fixing ring 3117 is made of metal. According to the splicing length of different numbers of pipe sections 312, several fixing rings 3117 of different specifications are set. After the fixing ring 3117 is inserted into the fixing groove 314, it can be fixed by adhesive bonding to prevent it from falling out due to vibration or other reasons.

[0053] The fixing grooves 314 on the two outermost pipe sections 312 are semi-circular rings, while the fixing grooves 314 on the remaining pipe sections 312 are arranged parallel to each other on the upper and lower sides of the through hole 313, and can form a ring after splicing.

[0054] To ensure the firmness of the joint between pipe sections 312, a boss 315 is provided at one end of the pipe section 312, and a groove 316 matching the boss is provided at the other end of the pipe section 312. The boss 315 can be inserted into the groove 316 to realize the joint between the pipe sections 312, thereby improving the accuracy of the joint position and avoiding the impact of the height difference between the fixing grooves 314 on the snap-fit ​​of the fixing ring 3117. Moreover, placing a sealing ring in the groove 316 can also improve the sealing between the pipe sections 312.

[0055] The tube section 312 is a square tube, which facilitates the installation of the iron core 21 and provides more stable support. The square shape of the tube section 312 can also increase the contact area between it and the iron core 21, directly absorbing the heat from the iron core 21 to further improve the heat dissipation effect. Moreover, after the boss 315 is inserted into the groove 316, it can also play a role in preventing the tube section 312 from rotating. The tube section 312 located at both ends is closed at one end and is equipped with a connector for connecting to the oil pipe.

[0056] According to an embodiment of the present invention, the multi-output transformer for in-phase power supply in this application has the following technical effects: This device can realize the output function of the secondary side multi-winding required for in-phase power supply. The rectifier device can effectively eliminate high-order harmonics through carrier phase shift. When there are many transformer bodies connected in parallel through the multi-winding transformer, most of the high-frequency harmonics can be canceled by the carrier phase difference π / n method, so that they cannot propagate to the primary side of the transformer, reducing the filtering branch, reducing the resonance risk, improving the reliability of the device operation, and reducing the magnitude of high-frequency harmonics through the H-bridge. It is suitable for high-capacity power conversion of single-phase AC-DC-AC in parallel multiplexing and cascaded H-bridge topologies. The rectifier side obtains excellent current harmonic characteristics through the multi-winding output transformer, and the inverter side obtains a multi-level SPWM waveform close to a sine wave, obtaining excellent voltage harmonic characteristics and voltage transient regulation characteristics.

[0057] The transformer adopts an oil-immersed design, using transformer oil as the insulation and cooling medium. Each oil chamber is equipped with an independent oil circulation system, which has good insulation and heat dissipation performance. It can effectively protect the iron core and windings from the influence of moisture in the air, while ensuring the safe operation of multiple transformers and avoiding the impact of long-term heavy load operation on voltage output, thus greatly improving the safety of multi-output transformers.

[0058] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0059] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0060] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0061] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0062] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, such as rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0063] In the detailed description above, reference has been made to the accompanying drawings, which form part of this document. In the drawings, similar symbols typically identify similar parts unless the context otherwise indicates otherwise. The illustrated embodiments described in the detailed specification, drawings, and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A transformer, characterized by The box is provided with a plurality of transformer bodies, and all primary side windings of the transformer bodies are connected in parallel to a primary side terminal of the box; The transformer body comprises a core, a primary side winding and a secondary side winding, the secondary side winding is connected to a secondary side terminal of the box respectively, the core is provided with two core columns, at least two primary side windings are wound on each core column, the secondary side winding is nested with the primary side winding, two primary side windings are wound on the core column, the two primary side windings are arranged up and down along the axial direction of the core column, the secondary side winding is sleeved outside the primary side winding, or the primary side winding is sleeved outside the secondary side winding; All primary side windings of the transformer body are connected in parallel to the same input end, and the secondary side winding is provided with a separate output end; The box is provided with a plurality of independent oil rooms, the transformer body is arranged in the oil room one by one, the primary side windings in adjacent oil rooms are connected through a wall bushing, a plurality of transformer bodies are arranged in the box in a line, or a plurality of transformer bodies are arranged in the box in two rows in a symmetrical manner, the oil room is provided with a circulating system, the circulating system comprises a circulating pipe and a cooling device, the circulating pipe is located in the oil room and communicates with the oil room, the cooling device is connected to the circulating pipe, the circulating pipe comprises a fixing device and a plurality of pipe joints, the pipe joints are arranged in a line to form a tubular structure, the pipe joints are fixed by the fixing device, and a plurality of through holes are arranged on the side surface of the pipe joint; The fixing device comprises a supporting frame, a clamping screw and a clamping plate, the supporting frame is fixed to the core, the two ends of the supporting frame are bent to form mounting portions away from the core, the clamping screw is rotatably connected to the mounting portion respectively, the clamping screw is threadedly connected to the clamping plate, and the clamping plate is used for extruding and fixing the pipe joints; The fixing device comprises a fixing ring, the pipe joint is provided with a fixing groove, the fixing grooves are connected to form a ring matched with the fixing ring after the pipe joints are assembled, and the fixing ring is clamped into the fixing groove to fix the pipe joints.

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