WO2020191960A1

WO2020191960A1 - Composite busbar and power module

Info

Publication number: WO2020191960A1
Application number: PCT/CN2019/096529
Authority: WO
Inventors: 李庆洋; 王智鹏; 孔东晓; 王雪菲
Original assignee: 中车大连电力牵引研发中心有限公司
Priority date: 2019-03-22
Filing date: 2019-07-18
Publication date: 2020-10-01
Also published as: CN111724928A

Abstract

The present invention provides a composite busbar and a power module. The composite busbar comprises a capacitor structure layer and an alternating-current conductor layer; one side of the alternating current conductor layer is connected to the capacitor structure layer, and the other side of the alternating-current conductor layer is connected to a bridge arm of a power element; the alternating-current conductor layer is configured to input a current into the power element; and the capacitor structure layer is configured to absorb a peak current generated when the power element is turned on or turned off. The composite busbar provided in the present invention can absorb a peak current generated when the power element is turned on or turned off, so it is not necessary to provide a capacitor device in the power module, thereby reducing the volume of the power module.

Description

Composite busbar and power module

Technical field

The invention relates to the field of electrical control, in particular to a composite busbar and a power module.

Background technique

With the development of economy and science, various high-power power electronic converter devices are playing an increasingly important role in various fields. Especially in the field of rail transit, as demand continues to increase, rail vehicles are developing rapidly in the direction of high power, high speed, and high reliability, and the performance of converters has gradually become a bottleneck restricting the development of vehicles. The power module of the converter is the core of the converter, and its performance directly affects the performance of the converter and the entire vehicle. In the high-power converter power module, the composite busbar plays an important role. The composite busbar must not only serve as a conductive path for electric energy input, but also have the ability to block the interference of the magnetic field generated by the input current to the control element.

At present, the existing composite busbars only have the functions of conducting electricity and suppressing electromagnetic interference, and their structure is usually composed of polyethylene terephthalate (PET) insulation layer, conductor layer and insulation board. These parts are superimposed.

The existing composite busbar needs to be equipped with a capacitor device to absorb the peak voltage generated when the power element is turned on or off in actual use, which leads to an increase in the volume of the power module, thereby increasing the complexity and cost of the power module , Which reduces the reliability of the power module.

Summary of the invention

The invention provides a composite busbar and a power module to reduce the volume of the power module.

The first aspect of the present invention provides a composite busbar, the composite busbar includes: a capacitor structure layer and an AC conductor layer;

One side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element;

The AC conductor layer is used to input current into the power element;

The capacitor structure layer is used to absorb the peak current generated when the power element is turned on or off.

Optionally, it also includes: an insulating layer;

The insulating layer is arranged between the AC conductor layer and the capacitor structure layer;

The insulating layer is used to isolate the capacitor structure layer and the AC conductor layer.

Optionally, the capacitor structure layer includes: a direct current positive conductor sublayer, a direct current negative conductor sublayer and a dielectric layer;

The dielectric layer is disposed between the direct current positive conductor sublayer and the direct current negative conductor sublayer; the direct current positive conductor sublayer or the direct current negative conductor sublayer is connected to the insulating layer;

The dielectric layer is used to shield the magnetic field generated by the direct current positive conductor sublayer and the direct current negative conductor sublayer, and to prevent direct voltage between the direct current positive conductor sublayer and the direct current negative conductor sublayer breakdown.

Optionally, between the AC conductor layer and the insulating layer, and between the capacitor structure and the insulating layer, all are connected by a hot pressing process.

Optionally, between the direct current positive electrode conductor sublayer and the dielectric layer, and between the direct current negative electrode conductor sublayer and the dielectric layer are connected by a hot pressing process.

Optionally, the dielectric layer is made of mica and polytetrafluoroethylene PTFE.

Optionally, the thickness of the dielectric layer is less than 1 mm.

Optionally, the thickness of the insulating layer is greater than the thickness of the dielectric layer.

Optionally, the insulating layer is made of high-resistance polyethylene terephthalate PET material.

A second aspect of the present invention provides a power module, which includes: a power element and the composite busbar described in the first aspect.

In the composite bus bar and the power module provided by the present invention, the composite bus bar includes a capacitor structure layer and an AC conductor layer. Wherein, one side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element; the AC conductor layer is used to input current into the power element; the capacitor structure layer is used to absorb The peak current generated when the power element is turned on or off. The above composite busbar has the function of absorbing peak current, so that the power module does not need to add additional capacitor devices, thereby reducing the volume of the power module, reducing the complexity and cost of the power module, and improving the power module Reliability.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings used in the description of the embodiments or the prior art. Obviously, the drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

Figure 1 is a schematic structural diagram of a composite busbar provided by an embodiment of the present invention;

Figure 2 is a schematic structural diagram of another composite busbar provided by an embodiment of the present invention;

Fig. 3 is an electrical schematic diagram of a composite busbar provided by an embodiment of the present invention.

Reference signs:

1- Composite busbar;

2-IGBT;

11-Capacitance structure layer;

12-AC conductor layer;

13-Insulation layer;

111-DC negative conductor sublayer;

112-dielectric layer;

113-DC positive conductor sublayer.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention. , Not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Through the above-mentioned drawings, the specific embodiments of the present invention have been shown, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the inventive concept in any way, but to explain the concept of the invention to those skilled in the art by referring to specific embodiments.

The composite bus bar can be a copper bar or aluminum bar connecting the main circuit and the sub-circuit, which is a key component for large current transmission.

The spike current can be a transient high-amplitude current appearing in an electronic circuit, which can be generated by the closing or opening of a switch.

The hot pressing process may be a manufacturing process of an electrical component, and specifically may be a process of pressing multiple materials under preset hot pressing pressure, hot pressing temperature, and hot pressing time.

Mica can be a rock-forming mineral and can be used as a dielectric material. The mica has a layered structure inside, which has the characteristics of insulation and high temperature resistance.

Polytetrafluoroethylene (PTEF), generally called "non-stick coating" or "easy-to-clean material", can be a dielectric material, which usually has resistance to acids, alkalis, and various organic solvents , High temperature resistance, low friction coefficient, etc.

In the high-power converter power module, the composite busbar must not only serve as a conductive path for electrical energy input, but also have the ability to block the interference of the magnetic field generated by the input current to the control element. At the same time, due to the frequent switching on and off of semiconductor power components in the rail transit industry, the peak current generated by them is also closely related to the composite busbar.

In the prior art, a composite busbar usually includes an insulating layer, a conductor layer, and an insulating plate in sequence. The conductor layer includes an AC output plate conductor layer, a positive plate conductor layer and a negative plate conductor layer, and an AC output plate conductor layer A long slot is provided on the current output end side of the conductor layer of the negative plate. The conductor layer includes a copper plate and a copper pad arranged on the copper plate by welding. The composite busbar is provided with test holes penetrating the conductor layer, the insulating layer and the insulating plate.

The manufacturing process can be specifically as follows: first, according to the first insulating layer, the AC output electrode plate conductor layer, the second insulating layer, the first insulating plate, the third insulating layer, the positive plate conductor layer, the fourth insulating layer, and the second insulating plate. , The fifth insulating layer, the negative plate conductor layer and the sixth insulating layer are stacked one by one on the mold in sequence; then, the composite busbar after stacking is hot-pressed; finally, the hot-pressing is completed After that, the edge of the composite busbar is pressed and sealed and insulated.

The composite busbar in the prior art only has two functions of conduction and suppression of electromagnetic interference. Therefore, a capacitor device needs to be added in the power module to absorb the peak voltage generated when the power element is turned on or off. This increases the volume of the power module, thereby increasing the complexity and cost of the power module, and reducing the reliability of the power module.

In consideration of the above-mentioned problems, the present invention provides a composite busbar that has the functions of conducting electricity, suppressing electromagnetic interference and absorbing peak current at the same time. The composite bus bar includes a capacitor structure layer and an AC conductor layer. Among them, one side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element; the AC conductor layer is used to input current into the power element; the capacitor structure layer is used to absorb the power element The spike current generated during turn-on or turn-off. The above composite busbar has the function of absorbing peak current, so that the power module does not need to add additional capacitor devices, thereby reducing the volume of the power module, and correspondingly, reducing the complexity and cost of the power module, and improving Improve the reliability of the power module.

The technical solution of the present invention will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

FIG. 1 is a schematic structural diagram of a composite busbar provided by an embodiment of the present invention.

Please refer to FIG. 1. The composite busbar 1 provided in this embodiment includes: a capacitor structure layer 11 and an AC conductor layer 12;

Wherein, one side of the AC conductor layer 12 is connected to the capacitor structure layer 11, and the other side of the AC conductor layer 12 is connected to the bridge arm of the power element;

The AC conductor layer 12 is used to input current into the power element;

The capacitor structure layer 11 is used to absorb the peak current generated when the power element is turned on or off.

In practical applications, the AC conductor layer 12 may be made of a conductive material, so that the AC material layer has conductivity. Specifically, the conductive material may be copper or aluminum.

One side of the AC conductor layer 12 is connected to the AC input end of the bridge arm of the power module. The AC output ends of the bridge arms are all arranged on the same side of the AC conductor layer 12, and the AC input ends of each bridge arm are different from each other. Connected. In addition, a copper pad may be provided on the AC conductor layer 12, and the copper pad is used as a connection point with the AC input end of the bridge arm.

The first surface and the second surface of the capacitor structure layer 11 are made of conductive materials, and a capacitor structure is formed between the first surface and the second surface of the capacitor structure layer 11, so that the power element is switched on and off The generated peak current can be absorbed by the capacitor structure to prevent the peak capacitor from damaging other components in the power module and causing damage to the power module.

Optionally, the composite busbar 1 further includes: an insulating layer 13;

The insulating layer 13 is arranged between the AC conductor layer 12 and the capacitor structure layer 11;

The insulating layer 13 is used to isolate the capacitor structure layer 11 and the AC conductor layer 12.

In practical applications, an insulating layer 13 is provided between the capacitor structure layer 11 and the AC conductor layer 12 to avoid direct contact between the capacitor structure layer 11 and the AC conductor layer 12. At the same time, the thickness of the insulating layer 13 is relatively high. The effect of isolating the energy exchange between the capacitor structure layer 11 and the AC conductor layer 12 is achieved.

Optionally, the insulating layer 13 may be made of a high-resistance polyethylene terephthalate PET material to ensure that the insulating layer 13 has a higher insulating ability.

Specifically, polyethylene terephthalate (PET) is a kind of plastic material. The PET material has excellent physical and mechanical properties in a wide temperature range, and the long-term use temperature can reach 120°C. Excellent electrical insulation. Even at high temperature and high frequency, PET material still has good electrical properties, creep resistance, fatigue resistance, friction resistance, and dimensional stability. Therefore, the insulating layer made of PET material has higher stability.

In another possible embodiment, the insulating layer 13 may also be made of unsaturated polyester agglomerated molding compound.

The composite busbar provided in this embodiment includes a capacitor structure layer and an AC conductor layer. Among them, one side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element; the AC conductor layer is used to input current into the power element; the capacitor structure layer is used to absorb the power element The spike current generated during turn-on or turn-off. The above composite busbar has the function of absorbing peak current through the capacitor structure layer, so that the power module does not need to add additional capacitor devices, thereby reducing the volume of the power module, and also reducing the complexity and cost of the power module , Improve the reliability of the power module.

Figure 2 is a schematic structural diagram of another composite busbar provided by an embodiment of the present invention.

As shown in FIG. 2, on the basis of the block diagram shown in FIG. 1, the capacitor structure layer 11 may specifically include:

DC negative conductor sublayer 113, DC negative conductor sublayer 111 and dielectric layer 112;

The dielectric layer 112 is arranged between the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111; the direct current negative conductor sublayer 113 or the direct current negative conductor sublayer 111 is connected to the insulating layer 13;

The dielectric layer 112 is used to shield the magnetic field generated by the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111, and to prevent the direct current voltage breakdown between the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111.

In practical applications, the capacitor structure in the capacitor structure layer 11 may be superimposed from top to bottom in the order of the DC negative conductor sublayer 113, the dielectric layer 112, and the tributary negative conductor sublayer.

In actual situations, the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 can be respectively used as the first surface and the second surface of the capacitor structure layer 11, and the positions of the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 Can be exchanged with each other.

One of the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 may be connected to the insulating layer 13; correspondingly, the other sublayer of the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 may be It is connected with the power element in the power module, so that the sublayer connected with the power element in the power module can play a role of conduction. Therefore, both the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 need to be made of a conductive material. Specifically, the conductive material may be copper or aluminum.

It should be noted that the sublayer connected to the power element in the power module can be any one of the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111. Similarly, the sublayer connected to the insulating layer 12 is also It may be any one of the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111, which is not limited here.

In actual use, the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111 will generate a magnetic field when energized, thereby affecting the normal operation of the power module. At the same time, the direct current negative conductor sublayer 113 and the direct current negative conductor sublayer 111 also need to avoid conduction to form a capacitor structure. Therefore, a dielectric layer 112 is also provided between the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 to absorb the peak current generated when the power element of the power module is turned on or off, and at the same time shield the magnetic field.

Optionally, the dielectric layer 112 is made of mica and polytetrafluoroethylene PTFE.

Optionally, the thickness of the dielectric layer 112 is less than 1 mm.

In actual use, based on the material and thickness requirements of the dielectric layer 112, mica and PTFE can be selected as the material of the dielectric layer 112, and the dielectric layer 112 is made into a thin plate or film with a thickness of less than 1 mm. The dielectric layer 112 can shield the magnetic field formed by the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111, so as to avoid the influence of the magnetic field on the components in the power module during use. At the same time, the dielectric layer 112 can also prevent the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111 from being broken down by a DC voltage, and at the same time, ensure the contact between the DC negative conductor sublayer 113 and the DC negative conductor sublayer 111. Normal high-frequency signals can pass normally.

In addition, optionally, the thickness of the insulating layer 13 is greater than the thickness of the dielectric layer 112, so as to prevent the insulating layer 13 from breaking down before the dielectric layer 112, so as to ensure the safety of the power device.

In the process of manufacturing the above-mentioned composite busbar 1, usually the stacking sequence of the layers can be determined first, and then the layers can be combined into a whole. Taking the actual situation as an example, when fabricating the above-mentioned re-cored busbar, the DC negative conductor sublayer 111, the dielectric layer 112, the DC positive conductor sublayer 113, the insulating layer 13 and the AC conductor layer 12 can be first arranged from top to bottom. Then, the stacked layers are combined into a complete composite busbar 1 through a hot pressing process.

In another possible embodiment, the DC negative conductor sublayer 111, the dielectric layer 112, and the DC negative conductor sublayer 113 can be pressed into the capacitor structure layer 11 through a hot pressing process, and then the capacitor structure layer 11 , The insulating layer 13 and the AC conductor layer 12 are pressed into the composite busbar 1 through a hot pressing process, where the insulating layer 13 can be connected to the DC negative conductor sublayer 113 in the capacitor structure layer 11, or can be connected to the capacitor structure layer 11 The DC negative conductor sublayer 111 is connected.

Based on the simulation of actual use, it can be seen that the above composite busbar 1 with a size of 400mm×600mm can have a parasitic capacitance greater than or equal to 1μF, which can save the corresponding power module special electrical components that absorb peak voltages, and increase Improve the system integration and reliability of the power module.

In the composite busbar provided in this embodiment, the capacitor structure layer of the composite busbar includes a DC negative conductor sublayer, a dielectric electron layer, and a DC positive conductor sublayer. The dielectric layer is arranged on the DC negative conductor sublayer and the DC negative conductor sublayer. Between; DC negative conductor sublayer or DC negative conductor sublayer, connected with the insulating layer; dielectric layer, used to shield the magnetic field generated by the DC negative conductor sublayer and DC negative conductor sublayer, and prevent the DC negative conductor sublayer and DC voltage breakdown between the DC negative conductor sublayers. While the above composite busbar realizes the two functions of conduction and suppression of electromagnetic interference, it also realizes the function of absorbing the peak voltage caused by the closing and turning off of power components, so that the power module installed with the composite busbar has high integration and volume. Small and highly reliable.

The present invention also provides a power module, including: a power element and the composite busbar 1 described above.

Among them, the power element may specifically be an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT for short).

Illustratively, FIG. 3 is an electrical schematic diagram of a composite busbar 1 provided by an embodiment of the present invention. As shown in Figure 3, based on the structure of the composite busbar 1 shown in Figure 2, a capacitor structure is formed between the DC negative conductor sublayer DC+ and the DC negative conductor sublayer DC- to absorb peak current; power element IGBT2 One end of the IGBT is connected to the DC negative conductor sublayer DC+ or the DC negative conductor sublayer DC-, and the other end of the power element IGBT2 is connected to the AC conductor layer AC. The IGBT2 receives the direct current output from the direct current negative conductor sublayer DC+ or the direct current negative conductor sublayer DC- while receiving the alternating current input from the alternating current conductor layer AC.

The composite busbar provided in this embodiment includes a capacitor structure layer and an AC conductor layer. Among them, one side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element; the AC conductor layer is used to input current into the power element; the capacitor structure layer is used to absorb the power element The spike current generated during turn-on or turn-off. The above composite busbar has the function of absorbing peak current, so that the power module does not need to add additional capacitor devices, thereby reducing the volume of the power module, reducing the complexity and cost of the power module, and improving the power module Reliability.

In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "top", "bottom", "upper", "lower" and " "Left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "axial", "circumferential" and other indications or positional relationships are based on the drawings The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the position or the original must have a specific orientation, with a specific structure and operation, and therefore cannot be understood as an impact on the present invention. limit.

In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be interpreted broadly, for example, it may be a fixed connection or a detachable connection, or Become a whole; it can be mechanically connected, or electrically connected, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, which can make the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise clearly defined and defined, the "above" or "below" of the first feature of the second feature may include the first and second features in direct contact, or may include the first and second features Not in direct contact but through other features between them. Moreover, the "above", "above" and "above" of the first feature on the second feature include the first feature directly above and obliquely above the second feature, or it simply means that the level of the first feature is higher than the second feature. The "below", "below" and "below" the first feature of the second feature include the first feature directly below and obliquely below the second feature, or it simply means that the level of the first feature is smaller than the second feature.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention range.

Claims

A composite busbar, characterized by comprising: a capacitor structure layer and an AC conductor layer;

One side of the AC conductor layer is connected to the capacitor structure layer, and the other side of the AC conductor layer is connected to the bridge arm of the power element;

The AC conductor layer is used to input current into the power element;

The capacitor structure layer is used to absorb the peak current generated when the power element is turned on or off.
The composite busbar according to claim 1, further comprising: an insulating layer;

The insulating layer is arranged between the AC conductor layer and the capacitor structure layer;

The insulating layer is used to isolate the capacitor structure layer and the AC conductor layer.
The composite busbar according to claim 2, wherein the capacitor structure layer comprises: a direct current positive conductor sublayer, a direct current negative conductor sublayer and a dielectric layer;

The dielectric layer is disposed between the direct current positive conductor sublayer and the direct current negative conductor sublayer; the direct current positive conductor sublayer or the direct current negative conductor sublayer is connected to the insulating layer;

The dielectric layer is used to shield the magnetic field generated by the direct current positive conductor sublayer and the direct current negative conductor sublayer, and to prevent direct voltage between the direct current positive conductor sublayer and the direct current negative conductor sublayer breakdown.
3. The composite busbar according to claim 3, wherein the AC conductor layer and the insulating layer, and the capacitor structure and the insulating layer are connected by a hot pressing process.
The composite busbar according to claim 3, characterized in that, between the DC positive conductor sublayer and the dielectric layer, and between the DC negative conductor sublayer and the dielectric layer, both pass Hot pressing process connection.
The composite busbar of claim 3, wherein the dielectric layer is made of mica and polytetrafluoroethylene (PTEF).
The composite busbar according to claim 3, wherein the thickness of the dielectric layer is less than 1 mm.
4. The composite busbar of claim 3, wherein the thickness of the insulating layer is greater than the thickness of the dielectric layer.
The composite busbar according to claim 3, wherein the insulating layer is made of high-resistance polyethylene terephthalate PET material.
A power module, characterized by comprising: a power element and the composite busbar according to any one of claims 1-9.