CN111404360B

CN111404360B - A three-level inverter structure

Info

Publication number: CN111404360B
Application number: CN202010378879.9A
Authority: CN
Inventors: 王亮
Original assignee: Shenzhen Zhiding Driving Technology Co ltd
Current assignee: Shenzhen Zhiding Driving Technology Co ltd
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2025-01-03
Anticipated expiration: 2040-05-07
Also published as: CN111404360A

Abstract

The invention relates to the technical field of industrial automation, in particular to a three-level frequency converter structure which comprises a plurality of groups of module combinations and a direct current capacitor assembly, wherein the module combinations comprise three IGBT modules, the IGBT modules are provided with three wiring terminals, two IGBT modules are arranged side by side, the other IGBT module is vertically arranged on the other two IGBT modules, laminated copper bars are connected in parallel through the wiring terminals and connected with laminated busbar, the plurality of groups of module combinations are connected with an integrated laminated busbar through the laminated busbar, the integrated laminated busbar is connected with the direct current capacitor assembly, and the two IGBT modules arranged side by side are connected with an absorption capacitor assembly through the wiring terminals.

Description

Three-level frequency converter structure

Technical Field

The invention relates to the technical field of industrial automation, in particular to a three-level frequency converter structure.

Background

The three-level frequency converter is a special industrial product and is different from a common two-level product in the market. The loop structure has the characteristics of complex loop structure and multiple use modules. This causes a large amount of inductance to be parasitic in the electrical loop, and voltage spikes are generated on the module under the combined action due to the fact that the converter core device IGBT is operated in the state of a high frequency switch. If the influence of parasitic parameters is not considered in design, the product is difficult to stably operate.

The module layout structure adopted in the prior art has the characteristics of large current loop current and long module distance capacitance. Or other forms of single-phase grouping capacitor layout modes influence the capacitor capacity and the output of direct current energy, so that the bus voltage is lower, and the inter-group connection copper bars bear voltage heating.

While the usual approach to dealing with this problem is to use a stacked busbar or integral module to reduce parasitic parameters, this approach is of limited practical effectiveness and high cost.

Disclosure of Invention

The present invention is directed to a three-level frequency converter structure, so as to solve the problems set forth in the background art.

The three-level frequency converter structure comprises a plurality of groups of module combinations and a direct current capacitor assembly, wherein the module combinations comprise three IGBT modules, the IGBT modules are provided with three connecting terminals, two IGBT modules (1) are longitudinally arranged side by side, the other IGBT module (1) is transversely arranged above the other two IGBT modules (1), laminated copper bars are connected between the three IGBT modules in parallel through the connecting terminals, the laminated copper bars are connected with laminated busbar, the plurality of groups of module combinations are connected with an integrated laminated busbar through the laminated busbar, the integrated laminated busbar is connected with the direct current capacitor assembly, and the two IGBT modules arranged side by side are connected with an absorption capacitor assembly through the connecting terminals.

Preferably, the three connection terminals of the IGBT module are an OUT terminal, a negative terminal, and a positive terminal, respectively.

Preferably, the dc capacitor assembly includes a plurality of dc capacitors, and the plurality of dc capacitors are arranged side by side and connected in parallel with the integral laminated busbar.

Preferably, the snubber capacitor assembly includes a plurality of snubber capacitors, and the plurality of snubber capacitors are connected in parallel to the IGBT module through positive and negative terminals.

Preferably, the stacked copper bar comprises a positive copper bar and a negative copper bar, an insulating layer is arranged between the positive copper bar and the negative copper bar, the positive copper bar is connected with a positive terminal of one IGBT module and an OUT terminal of the other IGBT module, and the negative copper bar is connected with a negative terminal of the one IGBT module and an OUT terminal of the other IGBT module.

Preferably, an OUT terminal of one IGBT module arranged laterally above each group of module combination is connected with an output copper bar.

Compared with the prior art, the invention has the beneficial effects that:

The layout mode of the IGBT module, the stacking treatment of the IGBT module connection copper bars, the forward and reverse overlapping design of the copper bar current, and the nearby connection of the single-phase module combination unit with the direct-current support capacitor are different from the traditional circuit structure, so that the problems that the busbar voltage is low and the inter-group connection copper bars bear voltage to generate heat in the prior art are effectively avoided, the capacity utilization rate of the capacitor, the parasitic inductance of the circuit, the current loop reduction and other aspects are improved, the voltage stress of the module is effectively reduced, and the operation of the frequency converter is more stable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of a prior art structure;

FIG. 3 is a schematic diagram of a second prior art structure;

In the drawings, the list of components represented by the various numbers is as follows:

the IGBT module comprises a 1IGBT module body, a 2 wiring terminal, a 3-layer copper bar, a 4-layer bus, a 5-integrated-layer bus, a 6-direct-current capacitor, a 7-absorption capacitor, an 8-output copper bar and a 9-connection copper bar.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, the invention provides a three-level frequency converter structure, which comprises a plurality of groups of module combinations and a direct current capacitor assembly, wherein each module combination comprises three IGBT modules 1, each IGBT module 1 is provided with three connecting terminals 2, two IGBT modules (1) are longitudinally arranged side by side, the other IGBT module (1) is transversely arranged above the other two IGBT modules (1), laminated copper bars 3 are connected in parallel between the three IGBT modules 1 through the connecting terminals 2, the laminated copper bars 3 are connected with laminated busbar 4, the plurality of groups of module combinations are connected with an integrated laminated busbar 5 through the laminated busbar 4, the integrated laminated busbar 5 is connected with the direct current capacitor assembly, and the two IGBT modules 1 arranged side by side are connected with an absorption capacitor assembly through the connecting terminals 2.

The three connection terminals 2 of the IGBT module 1 are an OUT terminal, a negative terminal, and a positive terminal, respectively.

The dc capacitor assembly includes a plurality of dc capacitors 6, where the plurality of dc capacitors 6 are arranged side by side and connected in parallel with the integrated laminated busbar 5.

The absorption capacitor assembly comprises a plurality of absorption capacitors 7, and the absorption capacitors 7 are connected to the IGBT module 1 in parallel through positive and negative terminals.

The laminated copper bar 3 comprises a positive copper bar and a negative copper bar, an insulating layer is arranged between the positive copper bar and the negative copper bar, the positive copper bar is connected with a positive terminal of one IGBT module 1 and an OUT terminal of the other IGBT module 1, and the negative copper bar is connected with a negative terminal of the one IGBT module 1 and an OUT terminal of the other IGBT module 1.

The OUT terminal of one IGBT module 1 arranged horizontally above each group of module combination is connected with an output copper bar 8.

Referring to fig. 1 and 2 or fig. 1 and 3, the current paths of the modules and the layout schemes thereof adopted by other products are longer and have loops, and the current paths of the module layout mode of the invention are short and have no current loops.

The special lamination treatment of the copper bar is connected to the module, the copper bar 9 is not treated in the existing scheme, the lamination treatment is performed on a currentless loop of the copper bar, and the voltage spike is lower when the IGBT works at high frequency.

The invention installs a plurality of absorption capacitors 7 on the module, and the existing technical proposal installs one absorption capacitor 7 for each module, and more absorption capacitors 7 provide better peak absorption effect.

Each phase module combination of the invention is connected to an integrated laminated busbar 5. The direct distance between the IGBT module 1 and the direct current capacitor 6 is effectively improved by adopting the connection different from the existing mode, and the inductance value of the connection copper bar is reduced.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "configured," "connected," "secured," "screwed," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, or indirectly connected through an intermediate medium, and may be a communication between two elements or an interaction relationship between two elements, unless explicitly specified otherwise, and it will be understood by those of ordinary skill in the art that the above terms are in specific terms of the present invention as appropriate.

The preferred embodiments of the invention disclosed above are intended only to assist in the explanation of the invention. The preferred embodiments are not exhaustive or to limit the invention to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best understand and utilize the invention. The invention is limited only by the claims and the full scope and equivalents thereof.

Claims

1. The utility model provides a three-level frequency converter structure, includes multiunit module combination and direct current capacitance subassembly, the module combination includes three IGBT module (1), IGBT module (1) is equipped with three binding post (2), its characterized in that, two of them IGBT module (1) are vertically arranged side by side, and another IGBT module (1) transversely sets up in two other IGBT module (1) top, and three be connected with stromatolite copper bar (3) through binding post (2) in parallel between IGBT module (1), stromatolite copper bar (3) are connected with stromatolite busbar (4), multiunit module combination is connected with integrative stromatolite busbar (5) through stromatolite busbar (4), integrative stromatolite busbar (5) are connected with direct current capacitance subassembly, and two IGBT module (1) of arranging side by side are connected with the absorption capacitance subassembly through binding post (2), every group the top transversely sets up the OUT of IGBT module (1) is connected with output copper bar (8).

2. A three-level converter structure according to claim 1, characterized in that the three connection terminals (2) of the IGBT module (1) are OUT terminal, negative terminal and positive terminal, respectively.

3. A three-level frequency converter structure according to claim 2, characterized in that the dc capacitor assembly comprises a plurality of dc capacitors (6), a plurality of said dc capacitors (6) being arranged side by side and connected in parallel with the integral laminated busbar (5).

4. A three-level frequency converter structure according to claim 2, characterized in that the absorption capacitance assembly comprises a plurality of absorption capacitances (7), the plurality of absorption capacitances (7) being connected in parallel to the IGBT module (1) via positive and negative terminals.

5. The three-level frequency converter structure according to claim 2, wherein the laminated copper bar (3) comprises a positive copper bar and a negative copper bar, an insulating layer is arranged between the positive copper bar and the negative copper bar, the positive copper bar is connected with a positive terminal of one IGBT module (1) and an OUT terminal of the other IGBT module (1), and the negative copper bar is connected with a negative terminal of the one IGBT module (1) and an OUT terminal of the other IGBT module (1).