阅读说明：本技术 一种应用于电力电子变压器的单相中频变压器 (Be applied to single-phase intermediate frequency transformer of power electronic transformer ) 是由 顾小虎 高�浩 潘明 张士岩 卢倩倩 胡海 于 2021-01-11 设计创作，主要内容包括：本发明公开了一种应用于电力电子变压器的单相中频变压器,包括一次绕组、二次绕组和铁芯,其中一次绕组、二次绕组和铁芯相互绝缘,铁芯材料为纳米晶,一次绕组和二次绕组在铁芯上对称绕制,一次绕组和二次绕组均采用利兹线绕制。使用环氧树脂将变压器整体灌封。本发明应用于电力电子变压器,解决现有技术中无法满足中频变压器标准漏感值的问题。(The invention discloses a single-phase intermediate frequency transformer applied to a power electronic transformer, which comprises a primary winding, a secondary winding and an iron core, wherein the primary winding, the secondary winding and the iron core are mutually insulated, the iron core is made of nanocrystalline, the primary winding and the secondary winding are symmetrically wound on the iron core, and the primary winding and the secondary winding are wound by litz wires. And (5) encapsulating the whole transformer by using epoxy resin. The invention is applied to the power electronic transformer and solves the problem that the standard leakage inductance value of the medium-frequency transformer cannot be met in the prior art.)

1. A single-phase intermediate frequency transformer applied to a power electronic transformer is characterized by comprising a primary winding, a secondary winding and an iron core, wherein the primary winding, the secondary winding and the iron core are mutually insulated, and the primary winding and the secondary winding are symmetrically wound on the iron core;

the iron core is made of nanocrystalline, and the primary winding and the secondary winding are wound by litz wires.

2. The single-phase intermediate frequency transformer applied to the power electronic transformer as claimed in claim 1, wherein the iron core is ring-shaped.

3. The single-phase intermediate frequency transformer applied to the power electronic transformer as claimed in claim 1, wherein the iron core is rectangular.

4. The single-phase intermediate frequency transformer for the power electronic transformer as recited in claim 1, wherein the transformer is integrally encapsulated by an insulating encapsulating material.

5. The single-phase intermediate frequency transformer applied to the power electronic transformer as claimed in claim 1, wherein the iron core is wrapped with a shell.

6. A single-phase intermediate frequency transformer applied to a power electronic transformer according to claim 1, wherein a gap is left between the primary winding, the secondary winding or between the windings inside the same winding.

Technical Field

The invention belongs to the technical field of power electronic transformers, and particularly relates to a single-phase intermediate-frequency transformer applied to a power electronic transformer.

Background

At present, the transformer for the iron core oil-immersed distribution system is adopted domestically, and has the main advantages that: the manufacturing process is simple, the operation is reliable, and the energy conversion efficiency is high; the disadvantages are as follows: the volume is large, the equipment is heavy, the mineral oil causes the problem of environmental pollution and is not easy to maintain, the voltage of the secondary side can not be maintained to be constant, the waveform distortion of voltage and current is caused when the iron core is saturated, harmonic waves are generated, the load fluctuation influences the network side, relay protection measures need to be equipped, and the like.

With the development of high-power electronic devices and control technologies thereof, power electronic conversion technologies play an active and important role in improving direct-current driving performance, improving various power supply performances and saving energy, and with the development of high-power electronic devices and control technologies thereof, power electronic conversion technologies play an active and important role in improving direct-current driving performance, improving various power supply performances and saving energy. In recent years, a novel Transformer has appeared, which realizes voltage conversion and energy transfer in an electric Power system through a Power Electronic conversion technology, the Transformer is a solid-state Transformer (also called an Electronic Power Transformer, EPT), and is a novel Transformer which realizes voltage conversion and energy transfer in an electric Power system through a Power Electronic conversion technology, and primary and secondary side voltages adopt intermediate frequency Transformer isolation protection. As a novel energy conversion device, compared with the traditional transformer, the power electronic transformer has the advantages of small volume, light weight, small no-load loss, no need of insulating oil and the like. Due to the rapid development of the technology of high-capacity high-frequency power, the novel transformer must be widely applied to power systems and actual life.

The intermediate frequency transformer is an important part of the power electronic transformer, the power electronic transformer realizes voltage conversion and energy transfer by means of the intermediate frequency transformer, the leakage inductance value of the intermediate frequency transformer is an important parameter of the energy transfer, the loss of the transformer is increased due to overlarge leakage inductance, and otherwise, the performance of the energy transfer is influenced.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, provides a single-phase intermediate-frequency transformer applied to a power electronic transformer, and solves the technical problem of large loss of the conventional transformer.

In order to solve the technical problem, the invention provides a single-phase intermediate frequency transformer applied to a power electronic transformer, which comprises a primary winding, a secondary winding and an iron core, wherein the primary winding, the secondary winding and the iron core are mutually insulated, and the primary winding and the secondary winding are symmetrically wound on the iron core;

the iron core is made of nanocrystalline, and the primary winding and the secondary winding are wound by litz wires.

Further, the iron core is annular.

Further, the iron core is rectangular.

Further, the transformer is integrally encapsulated by adopting an insulating encapsulating material.

Furthermore, the outer side of the iron core is wrapped with a shell.

Further, a gap is left between the primary and secondary windings or between the windings inside the same winding.

Compared with the prior art, the invention has the following beneficial effects: according to the invention, the nanocrystalline iron core and the litz wire winding are adopted, the magnetic conductivity of the iron core is high, the excitation power is reduced, and the copper loss and the iron loss are reduced, so that the no-load loss and the load loss of the medium-frequency transformer are reduced, and the integral working efficiency of equipment is improved.

Drawings

FIG. 1 is a schematic diagram of a single-phase IF transformer according to the present invention;

FIG. 2 is a schematic diagram of a toroidal core corresponding to a transformer;

fig. 3 is a schematic structural diagram of a square iron core corresponding to a transformer.

Reference numbers in the figures: 1. a primary winding; 2. a secondary winding; 3. a void; 4. and (3) an iron core.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The single-phase intermediate frequency transformer applied to the power electronic transformer has the input power frequency (intermediate frequency) range of 150Hz-5000Hz, and the circuit framework of the transformer is shown in figure 1 and comprises a primary winding 1, a secondary winding 2 and an iron core 4, wherein the primary winding 1, the secondary winding 2 and the iron core 4 are mutually insulated, and the primary winding 1 and the secondary winding 2 are symmetrically wound on the iron core 4.

The core 4 is a ring-shaped, rectangular, racetrack-shaped, or oval core, and is not limited to the shapes exemplified in the present invention. The iron core material is nanocrystalline or other high magnetic conductive materials, the static initial magnetic permeability of the nanocrystalline can be as high as 12-14 ten thousand, and the magnetostrictive coefficient is reduced by the nanocrystalline adopted by the invention, so that the noise of the transformer can be reduced, and the no-load loss of the transformer can be reduced.

The primary winding 1 and the secondary winding 2 are wound by litz wires and calculated according to a skin depth calculation formulaWhere f is frequency, μ is permeability, and ξ is conductivity. The litz wire adopted by the invention has small wire diameter which is far less than the skin depth, thereby greatly weakening the eddy current loss caused by the skin effect and reducing the winding loss caused by the skin effect. And performing basic insulation treatment on the primary winding and the secondary winding.

According to the invention, the nanocrystalline iron core and the litz wire winding are adopted, the magnetic conductivity of the iron core is high, the excitation power is reduced, and the copper loss and the iron loss are reduced, so that the no-load loss and the load loss of the medium-frequency transformer are reduced, and the integral working efficiency of equipment is improved.

Preferably, the outer side of the iron core 4 is wrapped with a shell for supporting the stress of the winding.

Preferably, the primary winding and the secondary winding are wound at symmetrical positions, and fig. 2 and fig. 3 are schematic structural diagrams of the annular iron core and the square iron core provided by the invention respectively. When the winding is wound, a certain gap 3 is reserved between the primary winding and the secondary winding or between the windings in the same winding according to different leakage inductance value requirements, so as to ensure that a certain leakage inductance value is achieved. The leakage inductance of the transformer is mainly concentrated between the secondary windings and is mainly related to the radial area of the windings and the distance of the secondary windings, so that the leakage inductance value can be controlled by controlling the distance of the secondary windings.

In order to insulate, prevent corrosion and protect an internal circuit, epoxy resin or other similar insulating potting materials are used for integral potting, and the windings and the iron cores are subjected to basic insulating treatment, so that the voltage-resistant grade is effectively improved. The voltage-resistant requirement of the primary side can be met, and the heat dissipation efficiency of the transformer can be improved.

The invention is applied to the power electronic transformer and solves the problem that the standard leakage inductance value of the medium-frequency transformer cannot be met in the prior art.

In the above embodiments, the transformer of the present invention is applied to an intermediate frequency transformer, and as another embodiment, it may be applied to a high frequency transformer and a low frequency transformer.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.