阅读说明：本技术 一种紧凑式储能变流器系统 (Compact energy storage converter system ) 是由 梁崇淦 易斌 罗敏 盛超 曾杰 于 2019-09-29 设计创作，主要内容包括：本申请实施例公开了一种紧凑式储能变流器系统,包括：AC/DC功率变换器、四绕组隔离变压器和滤波电容器；AC/DC功率变换器的直流侧通过直流侧电容连接储能装置；四绕组隔离变压器包括变压器铁芯和绕制在变压器铁芯上的原边绕组、副边绕组和滤波电抗器绕组；AC/DC功率变换器的交流输出端连接原边绕组；滤波电抗器绕组与滤波电容器联接组成交流侧的滤波装置；副边绕组通过滤波装置连接低压配电线路。本发明使得储能变流器系统的集成度更高、结构更加紧凑,可以应用于更小型的设备,是一种优质的紧凑式储能变流器系统。(The embodiment of the application discloses compact energy storage converter system includes: an AC/DC power converter, a four-winding isolation transformer and a filter capacitor; the direct current side of the AC/DC power converter is connected with an energy storage device through a direct current side capacitor; the four-winding isolation transformer comprises a transformer iron core, a primary winding, a secondary winding and a filter reactor winding, wherein the primary winding, the secondary winding and the filter reactor winding are wound on the transformer iron core; the alternating current output end of the AC/DC power converter is connected with the primary winding; the filter reactor winding is connected with the filter capacitor to form a filter device on the alternating current side; the secondary winding is connected with a low-voltage distribution line through a filter device. The invention ensures that the energy storage converter system has higher integration level and more compact structure, can be applied to smaller equipment and is a high-quality compact energy storage converter system.)

1. A compact energy storage converter system, comprising: an AC/DC power converter, a four-winding isolation transformer and a filter capacitor;

the direct current side of the AC/DC power converter is connected with an energy storage device through a direct current side capacitor;

the four-winding isolation transformer comprises a transformer iron core, and a primary winding, a secondary winding and a filter reactor winding which are wound on the transformer iron core;

the alternating current output end of the AC/DC power converter is connected with the primary winding;

the filter reactor winding is connected with the filter capacitor to form a filter device on an alternating current side;

and the secondary winding is connected with a low-voltage distribution line through the filter device.

2. The compact energy storage converter system of claim 1, wherein said filter reactor winding comprises a first reactor winding and a second reactor winding;

the first reactor winding and the second reactor winding are connected in series in an opposite direction.

3. The compact energy storage converter system of claim 2, wherein said first reactor winding and said second reactor winding are wound in an up-down interleaved manner.

4. The compact energy storage converter system of claim 3, wherein said first reactor winding and said second reactor winding have the same number of turns, height and inner and outer diameters.

5. The compact energy storage converter system of claim 1, wherein said primary winding and said secondary winding are wound concentrically.

6. The compact energy storage converter system of claim 1, wherein said energy storage device is an energy storage battery pack.

7. The compact energy storage converter system of claim 1, wherein said AC/DC power converter is a three-phase full-bridge converter circuit.

8. The compact energy storage converter system of claim 1, wherein said AC/DC power converter, said four-winding isolation transformer and said filter capacitor are integrated within an appliance cabinet.

9. The compact energy storage converter system of claim 8, wherein said electrical cabinet is a vertical electrical cabinet.

Technical Field

The application relates to the technical field of converters, in particular to a compact energy storage converter system.

Background

The low-voltage distribution system is directly connected with various loads of power consumers, and the power supply reliability and the power quality of the low-voltage distribution system directly influence the normal power consumption of the power consumers, so that the upgrading and the transformation of a power distribution network with complex and huge network networks are also one of key work concerned by power companies.

The electrochemical energy storage system is applied to a low-voltage distribution network, and can effectively delay or reduce the expansion and construction of distribution equipment, provide active and reactive power support, improve the power supply reliability and the electric energy quality, realize the load of a power grid, such as peak clipping and valley filling. The electrochemical energy storage system applied to the low-voltage distribution network generally adopts a modularized and miniaturized distributed installation mode. In practical application, for such a distributed energy storage system, because the size of the equipment is strictly limited, the energy storage converter system is usually integrated in an electrical cabinet, and includes key components such as a variable current power unit, a control unit, an isolation transformer, and a filter, where the filter is usually composed of an iron core reactor and a filter capacitor with relatively small sizes. However, the existing energy storage converter system is not high in integration level and not compact enough in structure, and therefore the invention provides a compact energy storage converter system.

Disclosure of Invention

The embodiment of the application provides a compact energy storage converter system for the integration level of energy storage converter system is higher, the structure is compacter, can be applied to more miniature equipment.

In view of this, the present application provides a compact energy storage converter system comprising: an AC/DC power converter, a four-winding isolation transformer and a filter capacitor;

the direct current side of the AC/DC power converter is connected with an energy storage device through a direct current side capacitor;

the four-winding isolation transformer comprises a transformer iron core, and a primary winding, a secondary winding and a filter reactor winding which are wound on the transformer iron core;

the alternating current output end of the AC/DC power converter is connected with the primary winding;

the filter reactor winding is connected with the filter capacitor to form a filter device on an alternating current side;

and the secondary winding is connected with a low-voltage distribution line through the filter device.

Optionally, the filter reactor winding comprises a first reactor winding and a second reactor winding;

the first reactor winding and the second reactor winding are connected in series in an opposite direction.

Optionally, the first reactor winding and the second reactor winding are wound in an up-and-down staggered manner.

Optionally, the first reactor winding and the second reactor winding have the same number of turns, height, and inner and outer diameters.

Optionally, the primary winding and the secondary winding are wound concentrically.

Optionally, the energy storage device is an energy storage battery pack.

Optionally, the AC/DC power converter is a three-phase full-bridge inverter circuit.

Optionally, the AC/DC power converter, the four-winding isolation transformer, and the filter capacitor are all integrated within an electrical cabinet.

Optionally, the electrical cabinet is a vertical electrical cabinet.

According to the technical scheme, the embodiment of the application has the following advantages: the four-winding isolation transformer comprises a transformer core, a primary winding, a secondary winding and a filter reactor winding which are wound on the transformer core, the filter reactor winding is connected with the filter capacitor to form a filter device on an alternating current side, and the primary winding, the secondary winding and the filter reactor winding of the isolation transformer are wound on the same magnetic core together by adopting the four-winding isolation transformer, so that the filter reactor and the isolation transformer are integrated into a whole, and the energy storage converter system is more compact in overall structure and high in integration level.

Drawings

Fig. 1 is a topology structure diagram of a compact energy storage converter system in an embodiment of the present application;

FIG. 2 is a winding layout of a four-winding isolation transformer in an embodiment of the present application;

wherein the reference numerals are:

1-primary winding, 2-secondary winding, 3-first reactor winding, 4-second reactor winding and 5-transformer iron core.

Detailed Description

In order to make the technical solutions of the present application better understood, 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 only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The present application provides one embodiment of a compact energy storage converter system, and particularly refers to fig. 1.

The compact energy storage converter system in this embodiment includes: an AC/DC power converter, a four-winding isolation transformer and a filter capacitor; the direct current side of the AC/DC power converter is connected with an energy storage device through a direct current side capacitor; the four-winding isolation transformer comprises a transformer iron core 5, and a primary winding 1, a secondary winding 2 and a filter reactor winding which are wound on the transformer iron core 5; the alternating current output end of the AC/DC power converter is connected with the primary winding 1; the filter reactor winding is connected with the filter capacitor to form a filter device on the alternating current side; the secondary winding 2 is connected with a low-voltage distribution line through a filter device.

It should be noted that: the four-winding isolation transformer comprises a transformer core 5, a primary winding 1, a secondary winding 2 and a filter reactor winding which are wound on the transformer core 5, the filter reactor winding is connected with the filter capacitor to form a filter device on an alternating current side, and the primary winding 1, the secondary winding 2 and the filter reactor winding of the isolation transformer are wound on the same magnetic core together by adopting the four-winding isolation transformer, so that the filter reactor and the isolation transformer are integrated into a whole, the integral structure of the energy storage converter system is more compact, and the integration level is high.

The above is a first embodiment of a compact energy storage converter system provided in the embodiments of the present application, and the following is a second embodiment of a compact energy storage converter system provided in the embodiments of the present application, please refer to fig. 1 to fig. 2 specifically.

The compact energy storage converter system in this embodiment includes: an AC/DC power converter, a four-winding isolation transformer and a filter capacitor; the direct current side of the AC/DC power converter is connected with the energy storage device after being filtered by a direct current side capacitor; the four-winding isolation transformer comprises a transformer iron core 5, and a primary winding 1, a secondary winding 2 and a filter reactor winding which are wound on the transformer iron core 5, wherein the filter reactor winding is wound on the transformer iron core 5 and is used as a filter reactor of the filter device; the alternating current output end of the AC/DC power converter is connected with the primary winding 1; the filter reactor winding is connected with the filter capacitor to form a filter device on the alternating current side; the secondary winding 2 is connected with a low-voltage distribution line through a filter device, and the secondary winding 2 of the isolation transformer is connected with the low-voltage distribution line after being filtered by the filter device.

Specifically, as shown in fig. 2, a secondary winding 2, a primary winding 1 and a filter reactor winding are sequentially wound on a transformer core 5 from inside to outside, that is, the secondary winding 2 is wound on the transformer core 5, the primary winding 1 is wound outside the secondary winding 2, and the filter reactor winding is wound outside the primary winding 1, it can be understood that the position relationship between the primary winding 1 and the secondary winding 2 can be determined according to specific conditions, that is, the primary winding 1 can be inside and the secondary winding 2 can be outside.

The filter reactor winding comprises a first reactor winding 3 and a second reactor winding 4, the first reactor winding 3 and the second reactor winding 4 are connected in series in a reverse direction, and the filter reactor is formed by the first reactor winding 3 and the second reactor winding 4 which are connected in series in the reverse direction.

The first reactor winding 3 and the second reactor winding 4 are wound in an up-and-down staggered manner.

It should be noted that: the first reactor winding 3 and the second reactor winding 4 which are connected in series in an opposite direction are arranged up and down, if the reactor winding is arranged left and right, because the magnetic field of the sub-winding close to the inner is larger than that of the sub-winding close to the outer (the air gap of the sub-winding close to the outer is large, the magnetic resistance is large, and therefore the magnetic field is weak), the decoupling performance of the filter reactor winding formed by the two sub-windings arranged left and right, and the primary winding 1 and the secondary winding 2 of the isolation transformer can be poor, therefore, the isolation transformer winding and the filter reactor winding can interfere with each other due to electromagnetic induction, and the independence between the isolation transformer and the filter reactor which are integrated into a whole can not be kept.

After the first reactor winding 3 and the second reactor winding 4 wound in an up-and-down staggered manner are reversely connected in series, the number of turns, the height and the inner and outer diameters of the first reactor winding 3 and the second reactor winding 4 are the same, and the main magnetic fluxes generated in the transformer core 5 respectively are mutually offset due to the same magnitude and opposite polarities, so that the whole filter reactor winding consisting of the first reactor winding 3 and the second reactor winding 4 only has magnetic flux leakage. Because the filter reactor winding does not generate main magnetic flux in the transformer core 5, the filter reactor winding does not form magnetic flux linkage with the primary winding 1 and the secondary winding 2 of the isolation transformer, and does not have magnetic chain coupling with the primary winding 1 and the secondary winding 2 of the isolation transformer, so that the filter reactor winding is independent of each other and does not influence each other even if the filter reactor winding and the primary winding 1 and the secondary winding 2 of the isolation transformer are wound on the same transformer core 5 (magnetic core) together.

The correlation principle analysis is as follows:

the filter reactor winding is formed by reversely connecting a first reactor winding 3 and a second reactor winding 4 which are wound in an up-and-down staggered manner in series, so that the main magnetic flux and the leakage magnetic flux of the filter reactor winding are respectively

Wherein the magnetic path expression of the main flux circulating in the transformer core 5 is:

in the formula (I), the compound is shown in the specification,is magnetomotive force; n is the number of winding turns;is the current in the winding;is the reluctance of the core. Due to the first reactor winding 3 and the second reactor windingThe two reactor windings 4 have equal turns and opposite winding directions, so N₃＝N₄，Whereby formula (2) can be converted into

Since the main magnetic fields of the first reactor winding 3 and the second reactor winding 4 are both built into the transformer core 5, i.e.Andall circulate in the same magnetic circuit, so they cancel each other out because of equal amplitude and opposite direction. Since the leakage fields of the first reactor winding 3 and the second reactor winding 4 are established in different spatial regions, the leakage fields are independent of each other.

By substituting formula (3) for formula (1)

Because the first reactor winding 3 and the second reactor winding 4 do not generate main magnetic flux in the transformer iron core 5, the main magnetic flux generated in the transformer iron core 5 by the primary winding 1 and the secondary winding 2 of the isolation transformer can not form a cross link, and therefore, the filter reactor winding can not form a magnetic coupling relation with the primary winding 1 and the secondary winding 2 of the isolation transformer due to the electromagnetic induction principle, and can be kept independent, namely, the filter reactor winding can not influence each other during working.

The primary winding 1 and the secondary winding 2 are wound concentrically.

It should be noted that: the main magnetic fluxes generated by the first reactor winding 3 and the second reactor winding 4 in the transformer core 5 are mutually offset, so that the main magnetic flux of the filter reactor winding formed by the first reactor winding 3 and the second reactor winding 4 in the transformer core 5 is zero, and the filter reactor winding only has leakage magnetic flux, and the inductance value of the filter reactor winding is completely determined by the leakage magnetic flux, so that the filter reactor winding has good inductance linearity, is very suitable to be used as a filter reactor, and has small working noise and is environment-friendly; the heating is low, so that the heat dissipation of the energy storage converter cabinet with narrow space is facilitated; the heating loss is low, so that the overall electric energy loss of the system is reduced, and the overall electric energy efficiency of the energy storage system is improved.

The energy storage device may be an energy storage battery pack, or may be other devices having an energy storage function, and is not limited herein.

The AC/DC power converter is a three-phase full-bridge converter circuit. The AC/DC power converter, the four-winding isolation transformer and the filter capacitor are all integrated in an electric appliance cabinet, and the electric appliance cabinet is a vertical electric appliance cabinet.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.