Addition transformer

Abstract

The embodiment of the invention provides an addition transformer, and relates to the technical field of electronic power. The addition transformer comprises a plurality of annular conductors; the multiple groups of input windings are in one-to-one correspondence with the annular conductors, and the annular conductors penetrate through the first axial cavities of the input windings; and the plurality of annular conductors all penetrate through the second axial cavity of the output winding, and the plurality of annular conductors are not intersected with one another. According to the adder provided by the embodiment of the invention, the performance of the adder transformer is improved from multiple dimensions such as capacity expansion, multi-stage voltage output providing, current / voltage ratio flexible adjustment, waveform optimization, voltage harmonic reduction and the like, the power supply requirements under multiple working conditions are met, and reliable electric energy conversion is provided for various high-power alternating-current transmission devices.

Description

Technical Field

[0001] The present application relates to the field of electronic power technology, and in particular, to an adding transformer. Background Art

[0002] With the continuous increase in energy and electricity, rail transit, large scientific facilities, agriculture and residential electricity consumption, the capacity of the power grid continues to rise, and the power supply capacity and voltage level of the transformer are also getting larger and larger. However, the capacity of traditional dry-type transformers commonly used on the power supply side cannot be further increased, and they do not have the function of increasing or decreasing voltage.

[0003] At present, the capacity of the largest dry-type transformer in China is about 20MVA, and its core and winding cannot be further improved. The traditional transformer has a fixed voltage level and cannot achieve voltage increase or decrease. Limited by the existing manufacturing process, the core winding cannot be infinitely increased, resulting in the transformer capacity being restricted. In some high-power electromagnetic propulsion fields, the capacity is in the tens of megawatts or even gigawatts, and the existing dry-type transformers cannot meet the needs of scientific and technological progress.

[0004] Therefore, there is an urgent need for a dry-type transformer with enlarged capacity and adjustable voltage. Summary of the invention

[0005] In order to solve the above technical problems, an adding transformer is provided in an embodiment of the present application to solve the above technical problems.

[0006] According to a first aspect of an embodiment of the present application, an adding transformer is provided, comprising:

[0007] A plurality of ring conductors;

[0008] A plurality of groups of input windings, corresponding one to one with the annular conductors, the annular conductors passing through the first axial cavity of the input windings;

[0009] The output winding, the plurality of annular conductors all penetrate the second axial cavity of the output winding, and the plurality of annular conductors do not intersect each other.

[0010] In an optional embodiment of the present application, the annular conductor is a symmetrical polygon.

[0011] In an optional embodiment of the present application, the output winding is a multi-tap winding.

[0012] In an optional embodiment of the present application, the plurality of annular conductors are evenly and symmetrically arranged along the axis of the output winding.

[0013] In an optional embodiment of the present application, the input winding and the output winding are both wound with copper foil.

[0014] In an optional embodiment of the present application, the annular conductor is a single-phase iron core.

[0015] In an optional embodiment of the present application, the annular conductor is made of silicon steel material.

[0016] In an optional embodiment of the present application, the silicon steel material is a polar-oriented silicon steel material.

[0017] In an optional embodiment of the present application, the above-mentioned adding transformer further includes:

[0018] The support frame includes a plurality of support sub-mechanisms, each of which is used to support the plurality of input windings and / or the plurality of annular conductors.

[0019] In an optional embodiment of the present application, the currents flowing through the input windings are not completely the same.

[0020] First, please continue to see Figure 2 and Figure 3 , when the voltage modulation waves of the three groups of input windings are different: the input modulation wave of the first input winding is 0.8V, the input modulation wave of the second input winding is 0.6V, and the input modulation wave of the third input winding is 1V, then the output voltage of the output winding is 0.8+0.6+1=2.4V; that is, the multi-phase superposition of the input is achieved to obtain the purpose of larger capacity output;

[0021] Please continue to see Figure 4 , Figure 4 This is a waveform diagram of carrier phase shift generation when the adding transformer has two inputs (i.e., there are two input windings) in the embodiment of the present application. Figure 4 (a) and Figure 4 (b) are the input voltage waveforms of the two input windings, Figure 4 (c) is the voltage waveform of the output winding, from which it can be clearly seen that its voltage u is superimposed to twice the input, thereby achieving the superposition and increase of capacity.

[0022] Secondly, for example, when two of the three input voltages are positive and the other is negative, a voltage effect of 2-1=1 is achieved. Thus, the adding transformer can meet various power demands under its flexible control mode, achieving the purpose of flexible adjustment of the voltage output by adjusting the input.

[0023] On the third aspect, since the adding transformer provided in the embodiment of the present application has multiple groups of input windings, a stepless voltage regulation effect can be achieved by using different modulation ratios of each input voltage in the multiple input windings; at the same time, the increase and decrease of the magnetic flux can be achieved by changing the direction of the input modulation waves of the multiple groups of input windings. Based on the multiple input single-phase output form, the transformer can output multiple voltage levels and expand its capacity, thereby achieving the purpose of diversifying the voltage output through input regulation.

[0024] Fourthly, carrier phase shifting can not only effectively improve the sinusoidality of the waveform, but also realize stepless voltage regulation. Assuming that the output of the output winding under a single input winding is a per-unit value of 1, the transformer can be steplessly regulated by controlling the size of the modulation wave, and the voltage can be adjusted from zero to rated voltage, thereby realizing the capacity expansion of the transformer.

[0025] Fifth, see Figure 4 When multiple groups of input windings are connected to the inverter, stacked carrier output is achieved through carrier phase shifting. For example, when the adding transformer provided in the embodiment of the present application has two inputs, the traditional method is to double the PWM waveform amplitude u. The present patent adopts a carrier phase shift control method when inputting PWM. A multi-level step wave is formed through carrier phase shifting, so that the output waveform is closer to a sine wave, reducing the system voltage harmonics and improving the system operation efficiency.

[0026] In summary, the adder provided in the embodiment of the present application improves the performance of the adding transformer in multiple dimensions, such as expanding capacity, providing multi-level voltage output, flexibly adjusting the current / voltage ratio, optimizing the waveform and reducing voltage harmonics, thereby meeting power supply requirements under multiple working conditions and providing reliable power conversion for various high-power AC transmission devices.

[0027] Especially considering the economic feasibility, traditional multiple output transformers are not suitable for configuring intelligent detection equipment due to their large number. The adding transformer provided in the embodiment of the present application can be equipped with intelligent health detection equipment due to its integration and flux addition characteristics. It has functions such as temperature detection, partial discharge detection, voltage and current imbalance detection, smoke detection, etc., to realize intelligent health detection of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 It is a schematic diagram of the topology of the traditional output transformer;

[0030] Figure 2 A schematic diagram of the structure of an adding transformer provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram comparing the winding structures of a conventional output transformer and an adding transformer provided in an embodiment of the present application;

[0032] Figure 4 The waveform diagram of carrier phase shift generation when the input winding of the adding transformer provided in the embodiment of the present application is two inputs (that is, the input winding is 2 groups); wherein, Figure 4(a) and Figure 4 (b) is the input waveform of the input winding. Figure 4 (c) is the output waveform after the output winding is superimposed on the input windings.

[0033] in:

[0034] 10. Adding transformer; 100. Input winding; 200. Output winding; 300. Ring conductor. DETAILED DESCRIPTION

[0035] At present, the capacity of the largest dry-type transformer in China is about 20MVA, and its core and winding cannot be further improved. Figure 1 , Figure 1 This is a common multi-split transformer topology diagram, which provides front-stage voltage conversion and isolation for high-voltage inverters. Through multiple split winding designs, the capacity reaches megawatt level. Multi-split transformers achieve phase shifting through extended triangles and multiple windings share one core to achieve multi-pulse rectification of the inverter. Traditional dry-type transformers have the following defects:

[0036] (1) Large core volume and complex winding: Although the multi-split transformer adopts the multi-split winding form to increase the capacity of the transformer, its core volume is huge as the capacity increases. In order to achieve multi-pulse rectification, the split winding of the multi-split transformer needs to be phase-shifted at different angles through the extended triangle, which makes the design and manufacturing process complicated.

[0037] (2) Fixed output voltage: Traditional transformers have fixed voltage levels and cannot adjust the voltage.

[0038] (3) Difficulty in increasing capacity: Due to the limitations of existing manufacturing processes, the core winding cannot be increased indefinitely, resulting in restrictions on the capacity of the transformer.

[0039] In some high-power electromagnetic propulsion fields, the capacity is in the tens of megawatts or even gigawatts, and the existing dry-type transformers cannot meet the needs of scientific and technological progress.

[0040] Therefore, there is an urgent need for a dry-type transformer with enlarged capacity and adjustable voltage.

[0041] In view of the above problems, an adding transformer is provided in the embodiment of the present application to provide one. In order to make the purpose, technical solution and advantages of the present application clearer, the following is a further detailed description of an adding transformer of the present application through embodiments and in combination with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of this application, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0043] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0044] With the continuous increase in energy and electricity, rail transit, large scientific facilities, agriculture and residential electricity consumption, the capacity of the power grid continues to rise, and the power supply capacity and voltage level of the transformer are also getting larger and larger. However, the capacity of traditional dry-type transformers commonly used on the power supply side cannot be further increased, and they do not have the function of increasing or decreasing voltage.

[0045] See also Figure 2 and Figure 3 The embodiment of the present application provides an adding transformer 10, comprising: a ring conductor 300, an input winding 100 and an output winding 200, wherein:

[0046] The number of the annular conductors 300 is multiple, and the annular conductors 300 are used as the iron core of the transformer and are made of conductive materials such as metal or graphite. The annular conductors 300 are closed loops, forming a complete loop. During operation, they can generate magnetic flux by moving.

[0047] The multiple groups of input windings 100 correspond to the annular conductors 300 one by one, and the annular conductors 300 penetrate the first axial cavity of the input windings 100; for example, there are three groups of annular conductors 300, corresponding to three groups of input windings 100, and the input windings 100 can be wound by any metal wire such as copper, iron, aluminum, and alloy. For example, the input winding 100 can be wound by copper foil to reduce the skin effect of the current, increase the current density, and improve the performance of the adding transformer 10. The input winding 100 has an axial cavity along the axial direction, and a group of input windings 100 is sleeved in the annular conductor 300, with partial area overlap, and does not completely cover all surfaces of the annular conductor 300. The input winding 100 is a primary winding, which is used as a current input during operation, and the multiple groups of input windings 100 correspond to multiple groups of current inputs. It should be explained that the number of turns of the input winding 100 can be fixed or adjustable, that is, the current and voltage passed into the transformer can be flexibly adjusted by the number of turns. The number of turns, capacity, etc. of the multiple groups of input windings 100 may be the same or different, and the embodiment of the present application does not specifically limit this, and it can be flexibly adjusted according to actual conditions.

[0048] The output winding 200, the plurality of annular conductors 300 all penetrate the second axial cavity of the output winding 200, and the plurality of annular conductors 300 do not intersect each other, for example, they can be parallel to each other, or evenly dispersed. The number of output windings 200 is less than the input winding 100, for example, there are three groups of annular conductors 300, for example, there are three groups of input windings 100, and the number of output windings 200 can be one group. The output winding 200 can be wound by any metal wire such as copper, iron, aluminum, alloy, etc., and has a second axial cavity in the axial direction. The output winding 200 is sleeved in the annular conductor 300, and the partial area overlaps, and does not completely cover all surfaces of the annular conductor 300, that is, at least one group of input windings 100 and output windings 200 is sleeved on a group of annular conductors 300, and the input windings 100 and output windings 200 do not intersect. For example, the input winding 100 and the output winding 200 sleeved on the same annular conductor 300 are parallel and axially symmetrical about the annular conductor 300. The input winding 100 is a secondary winding and serves as a current output terminal during operation. Multiple groups of input windings 100 correspond to multiple groups of current inputs, but the current output has only one terminal. It should be explained that the number of turns of the output winding 200 can be fixed or adjustable, that is, the current and voltage flowing out of the transformer can be flexibly adjusted by the number of turns.

[0049] The following briefly introduces the working principle of the adding transformer 10 provided in the embodiment of the present application, assuming that the input windings 100 are three groups and the output windings 200 are one group:

[0050] First, please continue to see Figure 2 and Figure 3, when the voltage modulation waves of the three input windings 100 are different: the input modulation wave of the first input winding 100 is 0.8V, the input modulation wave of the second input winding 100 is 0.6V, and the input modulation wave of the third input winding 100 is 1V, then the output voltage of the output winding 200 is 0.8+0.6+1=2.4V; that is, multi-phase superposition of the input is achieved to obtain the purpose of larger capacity output;

[0051] Please continue to see Figure 4 , Figure 4 This is a waveform diagram of carrier phase shift generation when the adding transformer 10 has two inputs (ie, the input winding 100 has two groups) according to the embodiment of the present application. Figure 4 (a) and Figure 4 (b) are input voltage waveforms of the two input windings 100, Figure 4 (c) is a voltage waveform diagram of the output winding 200, from which it can be clearly seen that its voltage is superimposed to twice the input, thereby achieving the superposition and increase of capacity.

[0052] Secondly, for example, when two of the three input voltages are positive and the other is negative, a voltage effect of 2-1=1 is achieved, whereby the adding transformer 10 can meet various power demands under its flexible control mode, thereby achieving the purpose of flexible adjustment of the voltage output by adjusting the input.

[0053] On the third aspect, since the adding transformer 10 provided in the embodiment of the present application has multiple groups of input windings 100, a stepless voltage regulation effect can be achieved by having different modulation ratios of the input voltages in the multiple input windings 100; at the same time, the increase and decrease of the magnetic flux can be achieved by changing the direction of the input modulation waves of the multiple groups of input windings 100. Based on the multiple input single-phase output form, the transformer can output multiple voltage levels and expand its capacity, thereby achieving the purpose of diversifying the voltage output through input regulation.

[0054] Fourthly, carrier phase shifting can not only effectively improve the sinusoidality of the waveform, but also realize stepless voltage regulation. Assuming that the output of the output winding 200 under a single input winding 100 is a per-unit value of 1, the transformer can be steplessly regulated by controlling the size of the modulation wave, and the voltage can be adjusted from zero to rated voltage, thereby realizing the capacity expansion of the transformer.

[0055] Fifth, see Figure 4 When multiple groups of input windings 100 are connected to the inverter, stacked carrier output is achieved through carrier phase shifting. For example, when the adding transformer 10 provided in the embodiment of the present application has two inputs, the traditional method is to double the amplitude of the PWM waveform. The present patent adopts a carrier phase shift control method when inputting PWM. A multi-level step wave is formed through carrier phase shifting, so that the output waveform is closer to a sine wave, which reduces the system voltage harmonics and improves the system operation efficiency.

[0056] In summary, the adder provided in the embodiment of the present application improves the performance of the adding transformer 10 in multiple dimensions, such as expanding capacity, providing multi-level voltage output, flexibly adjusting the current / voltage ratio, optimizing the waveform and reducing voltage harmonics, thereby meeting power supply requirements under multiple working conditions and providing reliable power conversion for various high-power AC transmission devices.

[0057] Especially considering the economic feasibility, traditional multiple output transformers are not suitable for configuring intelligent detection equipment due to their large number. The adding transformer 10 provided in the embodiment of the present application can be equipped with intelligent health detection equipment due to its integration and flux addition characteristics. It has functions such as temperature detection, partial discharge detection, voltage and current imbalance detection, smoke detection, etc., to realize intelligent health detection of the transformer.

[0058] In an optional embodiment of the present application, the annular conductor 300 is a symmetrical polygon, for example, can be set to a quadrilateral, and the stability of the structure installation and placement is high.

[0059] In an optional embodiment of the present application, the output winding 200 is a multi-tap winding. That is, the output winding 200 includes multiple taps, and the number of turns of the output winding 200 is adjusted by the taps, such as Figure 3 As shown, during multiple frequency conversion output, the variable flux adding transformer 10 windings are magnetically coupled with all secondary cores. Compared with the secondary winding series output of a traditional transformer, the adding transformer 10 provided in the embodiment of the present application has no electrical connection, thereby better realizing the electrical isolation of the device.

[0060] In an optional embodiment of the present application, the plurality of annular conductors 300 are evenly and symmetrically arranged along the axis of the output winding 200, so that the generated magnetic fields and the magnetic flux in the magnetic field are more uniform, and the magnetic flux overlap of adjacent annular conductors 300 is also more uniform, so that the adding transformer 10 provided in the embodiment of the present application works more stably.

[0061] In an optional embodiment of the present application, the input winding 100 and the output winding 200 are both wound with copper foil. The copper foil winding method can reduce the skin effect of the current, increase the current density, and improve the working efficiency and working performance of the adding transformer 10 in the embodiment of the present application.

[0062] In an optional embodiment of the present application, the annular conductor 300 is a single-phase iron core, that is, a combination of multiple single-phase iron cores in the embodiment of the present application realizes multi-phase superposition of input to obtain a larger capacity output.

[0063] In an optional embodiment of the present application, the annular conductor 300 is made of silicon steel material. The silicon steel material is polarity-oriented silicon steel material. The polarity-oriented silicon steel material has low hysteresis loss compared to iron material, which can further improve the working performance and working efficiency of the adding transformer 10 of the embodiment of the present application.

[0064] In an optional embodiment of the present application, the adding transformer 10 further includes a support frame, which includes a plurality of support sub-mechanisms, each of which is used to support the plurality of input windings 100 and / or the plurality of annular conductors 300 , so as to improve the structural stability of the adding transformer 10 .

[0065] In an optional embodiment of the present application, the currents of the input windings 100 are not completely the same. For example, the input windings 100 are single-phase AC inputs with the same phase, and single input, dual input, ... N inputs can be realized according to the power consumption capacity, which effectively increases the flexible configuration of the capacitance of the adding transformer and improves the scalability and flexibility of the input and output voltages or currents.

[0066] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0067] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An adding transformer, characterized in that: include: A plurality of ring conductors; A plurality of groups of input windings, corresponding one to one with the annular conductors, the annular conductors passing through the first axial cavity of the input windings; The output winding, the plurality of annular conductors all penetrate the second axial cavity of the output winding, and the plurality of annular conductors do not intersect each other.

2. The adding transformer according to claim 1, characterized in that: The annular conductor is a symmetrical polygon.

3. The adding transformer according to claim 1, characterized in that: The output winding is a multi-tap winding.

4. The adding transformer according to claim 1, characterized in that: The plurality of annular conductors are evenly and symmetrically arranged along the axis of the output winding.

5. The adding transformer according to claim 1, characterized in that: The input winding and the output winding are both wound with copper foil.

6. The adding transformer according to claim 1, characterized in that: The annular conductor is a single-phase iron core.

7. The adding transformer according to claim 6, characterized in that: The annular conductor is made of silicon steel material.

8. The adding transformer according to claim 7, characterized in that: The silicon steel material is a polarity-oriented silicon steel material.

9. The adding transformer according to claim 1, characterized in that: Also includes: The support frame includes a plurality of support sub-mechanisms, each of which is used to support the plurality of input windings and / or the plurality of annular conductors.

10. The adding transformer according to claim 1, characterized in that: The currents flowing through the input windings are not exactly the same.

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