CN218333400U - Transformer applicable to flexible traction substation and utilizing leakage inductance - Google Patents

Abstract

The application discloses a transformer applicable to a flexible traction substation by utilizing leakage inductance, which comprises a box body and an iron core assembly arranged in the box body; the iron core assembly comprises three double-frame iron cores arranged in an equilateral triangle, vertical frames of every two double-frame iron cores are spliced with each other to form an iron core column, and a winding is arranged on the vertical periphery of the iron core column; the winding comprises a high-voltage side winding and a low-voltage side winding, the high-voltage side winding adopts a star connection mode, the low-voltage side winding adopts a triangular connection mode, and multiple paths of low-voltage side windings respectively output voltages with equal amplitude; the high-voltage side winding is connected with the low-voltage side winding through main magnetic flux generated by the high-voltage side winding; and the output end of each low-voltage side winding is respectively connected to the converter module, and the leakage inductance of the low-voltage side is used as the input filter inductance of the rear-end converter. This application adopts many winding structures, can realize secondary limit multiplexed output, and every way output mutual independence, converter module in the flexible traction substation of adaptation well.

Description

Transformer applicable to flexible traction substation and utilizing leakage inductance

Technical Field

The utility model relates to a flexible power supply system traction transformer technical field that pulls, specificly relate to an utilize transformer that is applicable to flexible traction substation who leaks inductance.

Background

At present, electrified railways in China mainly adopt a power frequency single-phase alternating current traction system, and a substation takes electricity from a three-phase power grid, reduces the voltage of the electricity through a traction transformer, and outputs the electricity through two power supply arms to supply power for the traction grid. However, because the voltage phase, amplitude and frequency between the two power supply arms and between the power substations are difficult to be consistent, the electric phase splitting must be arranged between the two power supply arms and between the power substations, and the speed increase and the load capacity increase of the new generation of trains are seriously influenced by the existence of the electric phase splitting. On one hand, when the train passes through the electric phase separation, the speed needs to be reduced; on the other hand, some existing traction power supply systems are provided with automatic passing neutral sections at electric neutral sections, are relatively complex in structure and low in reliability, and are weak links and accident multiple points of the traction power supply systems.

The traction load of the electrified railway is a single-phase alternating current load, and negative sequence current can be injected into a three-phase power grid through a traction substation, so that three phases of a traction power supply system are seriously unbalanced, and meanwhile, the problems of idle work, harmonic waves and the like exist. How to solve the problem of electric energy quality of a traction power supply system and cancel an electric phase splitting device is a research hotspot in the field of the current traction system. With the gradual maturity of power electronic devices, power electronic equipment taking a current transformer as a core is gradually put into a traction power supply system, so that the problem of inconsistent voltage amplitude, frequency and phase is solved. The three-phase-single-phase converter is used in a traction power supply system, so that an electric phase splitting device is reduced, and the problem of electric energy quality of the traction power supply system is solved. Patent CN110931222A provides a four-winding traction transformer device of a flexible traction power supply system, which includes four windings T1, T2, T3 and T4; the T1 winding is used as a high-voltage side of a transformer TM4 and connected to a 35kV side bus of a traction substation in a three-phase delta-shaped connection mode; the T2 winding is used as one of the low-voltage sides of the transformer TM4, adopts three-phase Y-shaped connection and is connected to the primary side of an RN (relay node) of a rectifier device of a traction substation; the T3 winding is used as one of the low-voltage sides of the transformer TM4, connected to the primary side of a rectifier device RN of the traction substation by adopting three-phase delta connection; the T4 winding is used as one of the low-voltage sides of the transformer TM4, is connected in a three-phase Y-shaped mode, is connected to the primary side of the PCS of the bidirectional converter device of the traction substation, and is used for supplying power to a traction network or feeding regenerative braking energy back to a medium-voltage network by matching with a rectifier unit, so that the equipment investment of the transformer is saved. And patent CN113077979A provides an amplitude and phase angle adjustable electrified railway traction transformer for a flexible through bilateral traction power supply system, the voltage amplitude and the voltage phase of the electrified railway traction transformer are adjustable, the difference between the no-load voltage amplitude and the phase difference of the no-load bus open loop point of two adjacent traction stations tend to zero, and important guarantee zero is provided for the reliable and continuous operation of the flexible through bilateral power supply system. However, the existing three-phase to single-phase converters cannot solve the problems that the power supply capacity of a traction substation is large, the output voltage is high, and the power supply is limited by the development level of power electronic devices, the existing three-phase to single-phase converters cannot be directly connected to a three-phase power grid, and cannot directly output 27.5kV traction grid voltage, so that a plurality of converter modules need to be connected in parallel and cascaded to improve the voltage and current withstand capability of the converters, the parallel converter modules need a plurality of alternating current power supplies with equal amplitude and independent of each other to supply power, and the power supply voltage grade needs to be adapted to the converter modules. Because the capacity of the traction substation is large, the input current of each converter module is large, and therefore the floor area and the volume of the input filter inductor at the front end of the converter are large; if a plurality of transformers are used to supply power to the converter modules, the floor space of the traction substation is further increased and the efficiency of the traction substation is reduced.

Therefore, how to design a transformer which utilizes leakage inductance and is suitable for a flexible traction substation, reduces the floor area and the cost of the flexible traction substation, and meets the requirement of a flexible traction power supply system is a matter which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

In order to achieve the above purpose, the present application provides the following technical solutions:

a transformer suitable for a flexible traction substation utilizing leakage inductance is characterized by comprising a box body and an iron core assembly arranged in the box body.

Preferably, the iron core assembly comprises three double-frame iron cores arranged in an equilateral triangle, vertical frames of every two double-frame iron cores are mutually spliced to form an iron core column, and a winding is arranged on the vertical periphery of the iron core column;

preferably, the windings comprise a high-voltage side winding and a low-voltage side winding, the high-voltage side winding adopts a star connection mode, the low-voltage side winding adopts a triangular connection mode, and multiple paths of low-voltage side windings respectively output voltages with equal amplitude;

preferably, the high-voltage side winding is connected with the low-voltage side winding through the main magnetic flux generated by the high-voltage side winding.

Preferably, the iron core column comprises an A-phase iron core column, a B-phase iron core column and a C-phase iron core column.

Preferably, the low-voltage side winding comprises a plurality of sets of secondary low-voltage coils, and the high-voltage side winding comprises a set of primary high-voltage coils; the secondary low-voltage coil is not less than 10 groups and is wound on the iron core column from top to bottom in sequence, and the high-voltage coil is wound on the outer side of the secondary low-voltage coil.

Preferably, the low-voltage side windings are low-coupled and electrically isolated.

Preferably, the input voltage of the primary side high-voltage winding is 27.5kV, and the output voltage of each low-voltage side winding is thousands of volts.

Preferably, an insulation assembly is arranged between each group of secondary low-voltage coils, and an insulation assembly is arranged between the high-voltage coil and the secondary low-voltage coil.

Preferably, the top of the transformer box is provided with 1 group of high-voltage sleeve assemblies, and the front of the transformer box is provided with a plurality of groups of low-voltage sleeve assemblies with the same number as the low-voltage side windings.

Preferably, the high-voltage bushing assembly comprises a phase A high-voltage bushing, a phase B high-voltage bushing, a phase C high-voltage bushing and a high-voltage common bushing; the head end of high tension coil links to each other with A looks high tension bushing on the A looks core limb, the head end of high tension coil links to each other with B looks high tension bushing on the B looks core limb, the head end of high tension coil links to each other with C looks high tension bushing on the C looks core limb.

Preferably, the tail end of the high-voltage coil on the phase A iron core column, the tail end of the high-voltage coil on the phase B iron core column and the tail end of the high-voltage coil on the phase C iron core column are connected with a high-voltage common sleeve.

Preferably, the low-pressure sleeve assembly comprises a phase-a low-pressure sleeve, a phase-b low-pressure sleeve and a phase-c low-pressure sleeve; the head end of each group of low-voltage coils on the A-phase core limb is respectively connected with each corresponding group of a-phase low-voltage sleeves; the head end of each group of low-voltage coils on the B-phase iron core column is respectively connected with each corresponding group of B-phase low-voltage sleeves; the head end of each group of low-voltage coils on the C-phase core limb is respectively connected with each corresponding group of C-phase low-voltage sleeves.

Preferably, the tail end of each group of secondary low-voltage coils on the phase a core limb, the tail end of each group of secondary low-voltage coils on the phase B core limb and the tail end of each group of secondary low-voltage coils on the phase C core limb are correspondingly connected according to the marks of the low-voltage connecting groups.

Preferably, the output ends of the low-voltage side windings are respectively connected to the converter modules, and the leakage inductance of the low-voltage side is used as the input filter inductance of the rear-end converter.

The application has the advantages and effects that:

1. the utility model discloses an utilize transformer that is applicable to flexible traction substation of leakage inductance, the secondary limit of transformer adopts the multiple winding structure, can realize secondary limit multiplexed output, and every way output mutual independence, converter module in the flexible traction substation of adaptation well.

2. The leakage inductance of the low-voltage side winding is used as the input filter inductance of the rear-end converter, so that the size, the occupied area, the power consumption and the cost of the flexible traction substation can be effectively reduced.

3. The transformer adopts a three-dimensional wound core, and has low no-load loss, low no-load current, low noise and strong short-circuit resistance; the no-load energy loss is expected to be reduced by 30%, the load energy loss is expected to be reduced by 15%, and the noise is expected to be reduced to 60dB.

The foregoing description is only an overview of the technical solutions of the present application, so that the technical means of the present application can be more clearly understood and the present application can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present application more clearly understood, the following detailed description is made with reference to the preferred embodiments of the present application and the accompanying drawings.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, as illustrated in the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic diagram of a transformer in the present application;

FIG. 2 is a schematic view of a core assembly of the present application;

FIG. 3 is another perspective view of the transformer of the present application;

FIG. 4 is a schematic diagram of a prior art transformer;

FIG. 5 is a schematic diagram of a prior art transformer to converter connection;

FIG. 6 is a schematic diagram of a transformer suitable for use in the present application;

FIG. 7 is a schematic diagram of the transformer to converter connection of the present application;

wherein, 1, a box body; 2. an iron core assembly; 201. a double-frame iron core; 3. a high pressure bushing assembly; 4. a low pressure bushing assembly.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. In the following description, specific details such as specific configurations and components are provided only to help the embodiments of the present application be fully understood. Accordingly, it will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, descriptions of well-known functions and constructions are omitted in the embodiments for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrase "one embodiment" or "the present embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Further, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: the three cases of A alone, B alone and A and B together exist, and the term "/and" in this document describes another associated object relationship, which means that two relationships may exist, for example, A/and B, which may mean: the presence of a alone, and both cases a and B alone, and further, the character "/" herein generally means that the former and latter associated objects are in an "or" relationship.

The term "at least one" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, at least one of a and B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion.

Example 1

This embodiment describes a transformer suitable for a flexible traction substation using leakage inductance.

Referring to fig. 1 and 2, fig. 1 is a schematic diagram of a transformer in the present application, and fig. 2 is a schematic diagram of a core assembly in the present application.

A transformer suitable for a flexible traction substation utilizing leakage inductance comprises a box body 1 and a core assembly 2 arranged in the box body 1.

The iron core assembly 2 includes three double-frame iron cores 201 arranged in an equilateral triangle, and an included angle between the two iron cores 201 is 60 °.

The double-frame iron core 201 adopts a winding manufacturing process: the three double-frame iron cores 201 are respectively wound, high-temperature annealing treatment is carried out on the wound double-frame iron cores 201, the double-frame iron cores 201 after the high-temperature annealing treatment are spliced, vertical frames of every two double-frame iron cores 201 are spliced into an iron core column, and a winding is arranged on the vertical periphery of the iron core column.

The winding comprises a high-voltage side winding and a low-voltage side winding, the high-voltage side winding is in a star connection mode, the low-voltage side winding is in a triangular connection mode, and multiple paths of low-voltage side windings respectively output voltages with equal amplitude.

Further, the high-voltage side winding is connected with the low-voltage side winding through the main magnetic flux generated by the high-voltage side winding. And the output end of each low-voltage side winding is respectively connected to the converter module, and the leakage inductance of the low-voltage side is used as the input filter inductance of the rear-end converter.

Further, the core limb comprises an A-phase core limb, a B-phase core limb and a C-phase core limb.

The low-voltage side winding comprises a plurality of groups of secondary low-voltage coils, and the high-voltage side winding comprises a group of primary high-voltage coils; the secondary low-voltage coil is not less than 10 groups and is wound on the iron core column 1 from top to bottom in sequence, and the high-voltage coil is wound on the outer side of the secondary low-voltage coil.

Further, the low-voltage side windings are low in coupling and electrically isolated.

Further, the input voltage of the primary side high-voltage winding is 27.5kV, and the output voltage of each low-voltage side winding is thousands of volts.

Furthermore, an insulation assembly is arranged between each group of secondary low-voltage coils, and an insulation assembly is arranged between the high-voltage coil and the secondary low-voltage coil.

The transformer in the embodiment adopts the three-dimensional wound core, so that the no-load loss is low, the no-load current is low, the noise is low, the short-circuit resistance is high, the predicted no-load loss can be reduced by 30%, the load loss energy consumption can be reduced by 15%, and the noise can be reduced to 60dB. The secondary side adopts a multi-winding structure, so that multi-path output can be realized, and the output paths are mutually independent.

Example 2

This embodiment explains the structure of the case of the transformer.

Referring to fig. 3, fig. 3 is a schematic view of another angle of the transformer in the present application.

A group of high-voltage sleeve pipe assemblies 3 are arranged at the top of a box body 1 of the transformer, and a plurality of groups of low-voltage sleeve pipe assemblies 4 equal to the number of low-voltage side windings are arranged on the front surface of the box body 1.

Further, high-voltage bushing subassembly 3 includes A looks high-voltage bushing, B looks high-voltage bushing, C looks high-voltage bushing and high-pressure public sleeve pipe, the head end of high-voltage coil links to each other with A looks high-voltage bushing on the A looks stem iron, the head end of high-voltage coil links to each other with B looks high-voltage bushing on the B looks stem iron, the head end of high-voltage coil links to each other with C looks high-voltage bushing on the C looks stem iron, high-voltage coil's tail end on A looks stem iron, B looks stem iron and C looks stem iron go up high-voltage coil's tail end and C looks stem iron and all link to each other with high-pressure public sleeve pipe.

Further, the low-voltage bushing assembly 4 includes an a-phase low-voltage bushing, a B-phase low-voltage bushing, and a C-phase low-voltage bushing, the head end of each group of secondary low-voltage coils on the a-phase core limb is respectively connected to each corresponding group of a-phase low-voltage bushings, the head end of each group of secondary low-voltage coils on the B-phase core limb is respectively connected to each corresponding group of B-phase low-voltage bushings, the head end of each group of secondary low-voltage coils on the C-phase core limb is respectively connected to each corresponding group of C-phase low-voltage bushings, and the tail end of each group of secondary low-voltage coils on the a-phase core limb, the tail end of each group of secondary low-voltage coils on the B-phase core limb, and the tail end of each group of secondary low-voltage coils on the C-phase core limb are correspondingly connected according to each group of low-voltage connection group number.

The box body 1 is also provided with a plurality of radiators.

And the multi-path output is connected according to a specific connection group number, so that the applicability is stronger and the voltage resistance of the converter is improved compared with the existing three-winding transformer in power frequency.

Example 3

Based on embodiments 1 and 2, this embodiment briefly explains the technical effects of the transformer.

Referring to fig. 4 and 5, fig. 4 is a schematic diagram of a transformer in the prior art, and fig. 5 is a schematic diagram of a transformer and a converter in the prior art. And fig. 6 and 7, fig. 6 is a schematic diagram of a converter suitable for the transformer in the present application, and fig. 7 is a schematic diagram of the connection between the transformer and the converter in the present application.

The leakage inductance of the low-voltage side winding is used as the input filter inductance of the rear-end converter, so that the size, the occupied area, the power consumption and the cost of the flexible traction substation are effectively reduced. Compared with the prior art, the utility model provides a transformer secondary adopts the many windings structure, can realize secondary multiple output, and every way output is mutually independent, satisfies parallelly connected converter module and needs a plurality of amplitude equal and mutually independent alternating current power supply for its power supply, and the mains voltage grade should adapt to the requirement that the converter module used, can adapt to the flexible converter module that pulls in the transformer station well, has improved the withstand voltage resistant current ability of converter.

The current transformer structures in fig. 5 and 6 belong to the prior art, and those that can be understood and used by those skilled in the art will not be described in detail herein.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. A transformer suitable for a flexible traction substation utilizing leakage inductance is characterized by comprising a box body (1) and an iron core assembly (2) arranged in the box body (1);

the iron core assembly (2) comprises three double-frame iron cores (201) which are arranged in an equilateral triangle, vertical frames of every two double-frame iron cores (201) are spliced into an iron core column, and a winding is arranged on the vertical periphery of the iron core column;

the windings comprise a high-voltage side winding and a low-voltage side winding, the high-voltage side winding adopts a star connection mode, the low-voltage side winding adopts a triangular connection mode, and multiple paths of low-voltage side windings respectively output voltages with equal amplitude;

the high-voltage side winding is connected with the low-voltage side winding through main magnetic flux generated by the high-voltage side winding;

and the output end of each low-voltage side winding is respectively connected to the converter module, and the leakage inductance of the low-voltage side is used as the input filter inductance of the rear-end converter.

2. The transformer applicable to the flexible traction substation utilizing the leakage inductance as claimed in claim 1, wherein the core limb comprises an a-phase core limb, a B-phase core limb and a C-phase core limb.

3. The transformer for the flexible traction substation using the leakage inductance according to claim 2, wherein the low-voltage side winding comprises a plurality of sets of secondary low-voltage coils, and the high-voltage side winding comprises a set of primary high-voltage coils;

the secondary low-voltage coil is not less than 10 groups and is wound on the iron core column from top to bottom in sequence, and the high-voltage coil is wound on the outer side of the secondary low-voltage coil.

4. The transformer for a flexible traction substation using leakage inductance as claimed in claim 2, wherein the low-voltage side windings are low-coupled and electrically isolated.

5. The transformer for a flexible traction substation using leakage inductance as claimed in claim 3, wherein the input voltage of the high side winding is 27.5kV and the output voltage of each low side winding is several kilovolts.

6. The transformer for a flexible traction substation using leakage inductance as claimed in claim 3, wherein an insulating member is disposed between each set of the secondary low voltage coils, and an insulating member is disposed between the high voltage coil and the secondary low voltage coil.

7. The transformer for the flexible traction substation using the leakage inductance is characterized in that a set of high voltage bushing assemblies (3) is arranged on the top of a box body (1) of the transformer, and a plurality of sets of low voltage bushing assemblies (4) with the same number as that of low voltage side windings are arranged on the front surface of the box body (1).

8. The transformer for a flexible traction substation using leakage inductance according to claim 7, wherein the high voltage bushing assembly (3) comprises an A-phase high voltage bushing, a B-phase high voltage bushing, a C-phase high voltage bushing and a high voltage common bushing; the head end of the high-voltage coil on the A-phase iron core column is connected with the A-phase high-voltage sleeve; the head end of the high-voltage coil on the B-phase iron core column is connected with the B-phase high-voltage sleeve; the head end of the high-voltage coil on the C-phase iron core column is connected with the C-phase high-voltage sleeve;

and the tail end of the high-voltage coil on the phase A iron core column, the tail end of the high-voltage coil on the phase B iron core column and the tail end of the high-voltage coil on the phase C iron core column are connected with a high-voltage common sleeve.

9. The transformer applicable to the flexible traction substation utilizing the leakage inductance is characterized in that the low-voltage sleeve assembly (4) comprises an a-phase low-voltage sleeve, a b-phase low-voltage sleeve and a c-phase low-voltage sleeve, and the head ends of each group of secondary low-voltage coils on the A-phase core limb are respectively connected with the corresponding groups of the a-phase low-voltage sleeves; the head end of each group of secondary low-voltage coils on the B-phase core limb is respectively connected with each corresponding group of B-phase low-voltage sleeves; the head end of each group of secondary low-voltage coils on the C-phase core limb is respectively connected with each corresponding group of C-phase low-voltage sleeves;

and the tail end of each group of secondary low-voltage coils on the A-phase core limb, the tail end of each group of secondary low-voltage coils on the B-phase core limb and the tail end of each group of secondary low-voltage coils on the C-phase core limb are correspondingly connected according to the low-voltage connecting group labels of each group.

Images