Laminated busbar with heat dissipation structure and use method thereof

Abstract

The invention relates to the field of laminated busbars, and provides a laminated busbar with a heat dissipation structure in order to solve the problems that an existing laminated busbar is low in heat dissipation efficiency, the temperature of the busbar is likely to be too high, the current-carrying capacity and the insulation performance of the busbar can be reduced, and the stability and the service life of a whole power electronic system can be possibly affected. Comprising a lamination main body, an insulation packaging layer and a heat dissipation pipeline. The laminated main body is formed by alternately overlapping a plurality of conducting layers and insulating medium layers, and the insulating medium layers are arranged between the adjacent conducting layers; the insulating packaging layer coats the outer surface of the laminated main body; the heat dissipation pipeline is embedded in the insulation packaging layer; the two ends of the heat dissipation pipeline extend out of the insulation packaging layer. According to the invention, the water cooling channel formed by the heat dissipation pipeline is directly contacted with the laminated main body, and the cooling medium can quickly take away heat, so that the heat dissipation bottleneck caused by traditional insulation film packaging is solved; the heat dissipation pipeline is embedded in the insulation packaging layer, does not occupy too much space additionally, and meets the installation requirements of high-power-density equipment.

Description

Technical Field

[0001] This invention relates to the field of laminated busbars, and more specifically, to a laminated busbar with a heat dissipation structure and its usage method. Background Technology

[0002] Laminated busbars, as key components in power electronic devices for achieving high-current, low-impedance connections, are widely used in new energy vehicles, photovoltaic inverters, energy storage systems, and other fields. Traditional laminated busbars are typically composed of multiple layers of conductive sheets (copper or aluminum) encapsulated by an insulating film. While the insulating film ensures insulation performance, it also hinders heat dissipation from the busbar to the outside. Under high-power conditions, the busbar generates a large amount of heat when carrying high currents. Traditional laminated busbars rely solely on natural heat dissipation from the insulating film surface or air cooling, resulting in low heat dissipation efficiency and a tendency for the busbar temperature to become excessively high. This not only reduces the busbar's current-carrying capacity and insulation performance but may also affect the stability and lifespan of the entire power electronic system. Summary of the Invention

[0003] The purpose of this invention is to provide a laminated busbar with a heat dissipation structure, which solves the problem that the existing laminated busbars have low heat dissipation efficiency, which easily leads to excessively high busbar temperature. This not only reduces the current carrying capacity and insulation performance of the busbar, but may also affect the stability and service life of the entire power electronic system.

[0004] Another objective of this invention is to provide a method for using stacked busbars to reduce energy loss during the cooling process and lower equipment operating costs.

[0005] The embodiments of the present invention are achieved through the following technical solutions:

[0006] A stacked busbar with a heat dissipation structure includes: a stacked body, an insulating encapsulation layer, and heat dissipation pipes; the stacked body is composed of several conductive layers and insulating dielectric layers that are alternately overlapped, and the insulating dielectric layer is provided between adjacent guiding layers; the insulating encapsulation layer covers the outer surface of the stacked body; the heat dissipation pipes are embedded in the insulating encapsulation layer; and both ends of the heat dissipation pipes extend from the insulating encapsulation layer.

[0007] Preferably, the heat dissipation pipe includes: a plurality of first pipes and second pipes, wherein the plurality of first pipes are arranged along the length or width direction of the stacked body, and the extension direction of the first pipes is consistent with the width or length direction of the stacked body; the ends of adjacent first pipes are connected through the second pipes.

[0008] Preferably, the heat dissipation pipe has at least one planar wall, which abuts against the outer surface of the stacked body.

[0009] Preferably, the distance between the adjacent first pipe bodies is 30-200 mm, the inner diameter of the heat dissipation pipe is 8-15 mm, and the wall thickness of the heat dissipation pipe is 1-2 mm.

[0010] A method for using the laminated busbar, comprising:

[0011] S100, obtaining a first relationship curve of a heat generation parameter of the laminated busbar and a cooling medium parameter through historical data; the heat generation parameter comprises busbar power and activation time; the cooling medium parameter comprises a conveying speed of the cooling medium;

[0012] S200, adjusting the cooling medium parameter according to the heat generation parameter of the laminated busbar in actual data and the first relationship curve.

[0013] Preferably, the S200 comprises:

[0014] obtaining a second relationship curve among the power, the activation time and the temperature of the laminated busbar;

[0015] obtaining a conveying time point and an initial speed of the cooling medium according to the power of the laminated busbar.

[0016] Preferably, when the power of the laminated busbar is constant, the activation time of the laminated busbar is obtained according to the second relationship curve when the temperature of the laminated busbar is equal to a temperature threshold value.

[0017] obtaining a conveying time point of the cooling medium according to the activation time of the laminated busbar.

[0018] obtaining a conveying speed of the cooling medium according to the first relationship curve and the heat generation parameter of the laminated busbar.

[0019] Preferably, the conveying speed of the cooling medium comprises an initial speed and an adaptive speed.

[0020] obtaining the initial speed of the cooling medium according to the first relationship curve and the heat generation parameter of the laminated busbar.

[0021] monitoring a heat generation parameter change rate of the laminated busbar in real time, and adjusting the speed of the cooling medium to the adaptive speed when the heat generation parameter change rate is greater than a change threshold value.

[0022] Preferably, the heat generation parameter change rate comprises a change amplitude and a change frequency.

[0023] When at least one of the change amplitude and the change frequency exceeds a preset threshold value, the speed of the cooling medium is adjusted to the adaptive speed.

[0024] Preferably, when the change frequency exceeds the preset threshold value, an effective power P of the laminated busbar is obtained according to the change frequency f and the change amplitude D, and the cooling medium parameter is adjusted according to the effective power of the laminated busbar and the first relationship curve.

[0025] D=I(T); T is the change period of the power of the laminated busbar, f is the change frequency, I is the input current, R is the DC resistance of the busbar, and k is a correction coefficient.

[0026] The present application has at least the following beneficial effects:

[0027] The water cooling channel formed by the heat dissipation pipeline directly contacts the laminated main body, and the cooling medium can quickly take away heat, solving the heat dissipation bottleneck caused by traditional insulation film packaging; the heat dissipation pipeline is embedded in the insulation packaging layer, without occupying too much space, and meets the installation requirements of high-power-density equipment; welding fixation and sealing glue are used for sealing, ensuring good heat conduction between the water cooling channel and the busbar and no leakage of the cooling medium, while the insulation performance is also considered. Through the first relationship curve between the heating parameters of the laminated busbar in historical data and the cooling medium parameters, the cooling medium parameters can be adjusted according to the heating parameters in actual use, so as to reduce the cooling surplus and reduce the equipment operation cost while ensuring the cooling effect. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0029] Figure 1 It is a structure schematic view of the laminated busbar with heat dissipation structure.

[0030] Figure 2 It is a side view of the laminated busbar.

[0031] Figure legend: 1-laminated main body, 11-conductive layer, 12-insulating medium layer, 2-insulating packaging layer, 3-heat dissipation pipeline, 31-first pipe body, 32-second pipe body. DETAILED DESCRIPTION

[0032] In order to make the purpose, method scheme and advantages of the embodiments of the present application more clear, the method scheme in the embodiments of the present application is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments.

[0033] Embodiment 1: as Figures 1-2As shown in the drawings, a laminated busbar with a heat dissipation structure comprises a laminated body 1, an insulating packaging layer 2 and a heat dissipation pipe 3. The laminated body 1 is composed of a plurality of conductive layers 11 and insulating medium layers 12 which are alternately overlapped, and the insulating medium layer 12 is arranged between adjacent conductive layers. The insulating packaging layer 2 is wrapped on the outer surface of the laminated body 1. The heat dissipation pipe 3 is embedded in the insulating packaging layer 2, and the two ends of the heat dissipation pipe 3 extend out of the insulating packaging layer 2.

[0034] In the implementation process, as shown in the drawings, the insulating packaging layer 2 and the laminated body form a through hole for the heat dissipation pipe. Figures 1-2 As shown in the drawings, the insulating packaging layer 2 and the laminated body form a through hole for the heat dissipation pipe. The heat dissipation pipe 3 can be made of red copper material, and the heat dissipation pipe 3 and the laminated body 1 can be connected by welding. The welding method can be laser welding or high-frequency welding. The heat-affected zone diameter of the welding point is not more than 5mm, which avoids damaging the conductive performance of the busbar body due to high temperature welding. The insulating packaging layer 2 or the insulating medium layer 12 can be made of insulating materials with good high-temperature resistance, such as polyimide or PET polyester with excellent insulating performance. The contact area between the heat dissipation pipe 3 and the insulating packaging layer 2 can be sealed by hot pressing to prevent leakage of the cooling medium and ensure the insulating performance. The two ends of the heat dissipation pipe 3 can be provided with connectors. If the heat dissipation pipe 3 is provided with multiple groups, such as heat dissipation pipes 3 arranged on the upper and lower sides of the laminated body 1, a shunt connector can be arranged at the inlet of each heat dissipation pipe 3, and a bus connector can be arranged at the outlet. After the cooling medium is distributed through the shunt connector, it enters different heat dissipation pipes 3, and then is collected and recycled through the bus connector after absorbing heat, forming a circulating water circuit. The shunt connector and the bus connector can be wrapped with insulating materials such as nylon or polytetrafluoroethylene. The two connectors and the insulating packaging layer 2 can be connected by buckles or bolts, which can be easily installed and maintained. The conductive layer 11 of the laminated body can be made of copper or aluminum, and the total thickness can be 2-20mm. The number of layers and the thickness of each layer can be designed according to the current carrying requirement. The cooling medium can be deionized cooling water. The thickness of the insulating medium layer 12 can be 5mm.

[0035] In order to improve the heat dissipation efficiency, the embodiment 2 is improved on the basis of the embodiment 1, as shown in the drawings. Figure 1 In this embodiment, the heat dissipation pipe 3 comprises a plurality of first pipe bodies 31 and second pipe bodies 32. The first pipe bodies 31 are arranged along the length direction or the width direction of the laminated body 1, and the extension direction of the first pipe bodies 31 is consistent with the width direction or the length direction of the laminated body 1. The first pipe bodies 31 are connected by the second pipe bodies 32 at the head and tail of adjacent first pipe bodies 31.

[0036] In the implementation process, as shown in the drawings, the insulating packaging layer 2 and the laminated body form a through hole for the heat dissipation pipe. Figure 1As shown, to increase the contact area between the heat dissipation pipe 3 and the laminated body 1, the heat dissipation pipe 3 can be arranged in an S-shape. When the washing pipe extends along the length direction of the laminated body 1, the second pipe 32 extends along the width direction of the laminated body 1. To reduce the resistance of the cooling medium passing through the first pipe 31, the second pipe 32 can be arranged as follows: Figure 1 As shown, it is set in an arc shape. The specifications and material of the second tube 32 can be the same as those of the first tube 31. The beginning and end of the first tube 31 can refer to the liquid inlet and liquid outlet of the first tube 31, respectively.

[0037] Example 3: To further increase heat dissipation efficiency, improvements were made based on Example 2, such as... Figure 1 As shown, in this embodiment, the heat dissipation pipe 3 has at least one planar wall, which abuts against the outer surface of the stacked body 1.

[0038] In the specific implementation process, if the cross-section of the heat dissipation pipe 3 is a conventional circle, the contact between it and the stacked body 1 is mainly line contact, resulting in low heat exchange efficiency. Therefore, this implementation limits the bottom surface of the heat dissipation pipe 3 to a plane, so that the contact between the heat dissipation pipe 3 and the stacked body 1 is surface contact.

[0039] Exemplary, such as Figure 1 As shown, the cross-section of the heat dissipation pipe 3 is a rectangular ring. The outer ring is 10mm long and 6mm wide. With a wall thickness of 1mm, the inner ring is 8mm long and 4mm wide.

[0040] Example 4: In this example, the distance between adjacent first tubes 31 is 30-200mm, the inner diameter of the heat dissipation pipe 3 is 8-15mm, and the wall thickness of the heat dissipation pipe 3 is 1-2mm.

[0041] In practice, by reasonably setting the inner diameter of the heat dissipation pipe 3 and the spacing between the first pipe bodies 31, the heat dissipation pipe 3 can be kept from occupying too much space while ensuring flow rate. The wall thickness setting takes into account both structural strength and heat conduction efficiency.

[0042] Example 5: This example provides a method for using the aforementioned stacked busbar, including:

[0043] S100. Obtain the first relationship curve between the heating parameters and cooling medium parameters of the laminated busbar through historical data; the heating parameters include: busbar power and start-up time; the cooling medium parameters include: the delivery speed of the cooling medium;

[0044] S200. Adjust the cooling medium parameters based on the actual data, the heating parameters of the stacked busbar, and the first relationship curve.

[0045] In practice, the heating of the laminated busbar is usually related to its power; for example, the higher the input current, the more severe the heating. Similarly, the higher the resistance of the conductive layer, the more severe the heating. Although the heating will change when the shape of the laminated busbar changes, this embodiment mainly focuses on adjusting the heat dissipation medium parameters when the structure of the laminated busbar is fixed. Therefore, this embodiment does not introduce the shape parameters of the laminated busbar when obtaining the first relationship curve.

[0046] Historical data can be obtained through experiments. For example, with the busbar power confirmed, the surface temperature of the busbar increases with the increase of the activation time until it reaches its maximum value. The cooling medium is usually input before the surface temperature of the stacked busbar reaches its maximum value. Therefore, the temperature of the stacked busbar when the cooling medium is input can be set to X, based on the busbar's operating environment or material. Once the temperature of the stacked busbar reaches X, the cooling medium is input. The cooling medium parameters can be determined by setting the maximum time for the stacked busbar temperature to drop from X to Y. The value of Y can be determined according to the actual situation, such as Y equaling the ambient temperature. By adjusting the cooling medium rate, the temperature of the stacked busbar is reduced to Y at the set maximum time. The aforementioned power of the stacked busbar, activation time, and cooling medium rate are used as data sets. After continuously changing the power of the stacked busbar, a large number of data sets are obtained. These data sets can then be used to construct a three-dimensional curve, i.e., the first relationship curve. The activation time corresponds to the time it takes for the temperature of the stacked busbar to rise to X after activation.

[0047] In this embodiment, the reason for choosing to regulate the speed of the cooling medium rather than its temperature is that the response speed of flow rate change is faster than that of temperature regulation. When regulating the speed of the cooling medium by adjusting the pump speed, the response time can reach the second to millisecond level. For the use of laminated busbars, speed regulation is more effective. For example, when the environment in which laminated busbars are used experiences high-frequency power changes, the regulation of the cooling medium temperature may not be able to keep up with the speed of the aforementioned power changes, resulting in cooling lag, or a certain cooling margin may be needed to cope with sudden changes, leading to increased energy loss.

[0048] Example 6: In this example, S200 includes:

[0049] Obtain the second relationship curve between the power, start-up time and temperature of the laminated busbar;

[0050] The delivery time and initial velocity of the cooling medium are obtained based on the power of the stacked busbar.

[0051] When the power of the stacked busbar is constant, the start-up time of the stacked busbar is obtained from the second relationship curve when the temperature of the stacked busbar is equal to the temperature threshold.

[0052] The delivery time of the cooling medium is obtained based on the activation time of the stacked busbar;

[0053] The delivery speed of the cooling medium is obtained based on the first relationship curve and the heating parameters of the laminated busbar.

[0054] In practical implementation, if cooling water is supplied simultaneously when the stacked busbar is activated, it usually results in excess cooling, meaning the cooling efficiency of the cooling water is much higher than the current cooling efficiency required by the stacked busbar. Therefore, this embodiment needs to determine the timing of cooling medium supply, specifically when the stacked busbar is activated and reaches the temperature threshold, to improve energy efficiency. At a certain power, as the busbar's activation time increases, its temperature gradually increases. After a certain time, the busbar's temperature stabilizes. The temperature at which the busbar stabilizes is taken as the maximum temperature corresponding to the power. The temperature threshold can be selected as 60%-80% of the maximum temperature. The activation time of the busbar can be obtained through the second relationship curve, the power of the stacked busbar, and the temperature threshold. For example, if the activation time is 45 minutes, the cooling medium supply is started at 45 minutes.

[0055] Since the power of the laminated busbar may change during use, this embodiment only obtains the initial velocity of the cooling medium. Given a fixed busbar power and activation time, the delivery velocity of the cooling medium, i.e., the initial velocity, can be obtained based on the first relationship curve.

[0056] Example 7: In this example, the delivery speed of the cooling medium includes: initial speed and adaptation speed;

[0057] The initial velocity of the cooling medium is obtained based on the first relationship curve and the heating parameters of the stacked busbar.

[0058] The rate of change of the heating parameters of the stacked busbar is monitored in real time. When the rate of change of the heating parameters exceeds the change threshold, the speed of the cooling medium is adjusted to the appropriate speed.

[0059] In practice, since the power of the laminated busbar may change during use, this embodiment acquires the heating parameters in real time and determines whether the cooling medium parameters need to be changed based on the rate of change of the heating parameters. The change threshold can be determined according to the actual situation. For example, when the power change rate exceeds 20%, the speed of the cooling medium is adjusted to adapt to the new power.

[0060] Since the cooling medium delivery speed in the first relationship curve of this embodiment is mainly determined by the cooling speed, and the initial temperature of the stacked busbar is greater than the temperature when the stacked busbar is put into use when obtaining the adaptation speed in this embodiment, the degree of cooling required is lower. Therefore, the adaptation speed obtained by using the first relationship curve can still meet the cooling requirements.

[0061] Example 8: In this example, the rate of change of the heating parameter includes: the magnitude of change and the frequency of change;

[0062] When at least one of the change amplitude and change frequency exceeds the preset threshold, the speed of the cooling medium is adjusted to the appropriate speed.

[0063] In practical implementation, the power of the laminated busbar may be subject to high-frequency changes. For example, when used in an electric vehicle drive system, the power switches frequently during motor speed regulation; when used in a high-frequency switching power supply, the operating frequency can reach hundreds of kHz; and when used in a multi-level current converter, the capacitor voltage fluctuates frequently in the hybrid clamping circuit. Therefore, this embodiment divides the rate of change of the heating parameter into the amplitude and the frequency. The amplitude can be characterized by the rate of change of the input current, and the frequency is equal to the reciprocal of the time taken for one cycle of current change. When the amplitude is too large, the heating efficiency of the laminated busbar will change significantly, thus requiring adjustment of the cooling medium. When the frequency is too high, even if the maximum current value remains unchanged, the degree of heating will increase due to eddy current losses and narrow channels with high current density. Therefore, in this embodiment, the adjustment factor for the cooling medium includes the frequency.

[0064] Example 9: In this example, when the frequency of change exceeds a preset threshold, the effective power P of the stacked busbar is obtained according to the frequency of change f and the amplitude of change D, and the cooling medium parameters are adjusted according to the effective power of the stacked busbar and the first relationship curve.

[0065] D = I(T); T is the power variation period of the stacked busbar, f is the variation frequency, I is the input current, R is the DC resistance of the busbar, and k is the correction coefficient.

[0066] In the specific implementation process, to better integrate the influence of the amplitude and frequency of change on the degree of heating, this embodiment uses the effective power of the laminated busbar as the variable of the first and second curves. The average value of the current undergoing one cycle of change is included in the effective current in the effective power calculation. Generally, the higher the frequency of change, the greater the impact on the heating of the laminated busbar. Therefore, this embodiment adds kf as a factor in the effective power calculation, making the effective power proportional to f, and the value of k can be determined experimentally. For example, during the experiment, after changing f, the maximum temperature that the laminated busbar can reach is detected. Then, in the first relationship curve, the power corresponding to the maximum temperature is found as the effective power of the laminated busbar. Then, by substituting it into the effective power calculation formula, and given the current change and a fixed R, the value of k can be derived.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laminated busbar with a heat dissipation structure, characterized in that, include: The stacked body (1) is composed of several conductive layers (11) and insulating dielectric layers (12) that are alternately overlapped, and the insulating dielectric layers (12) are provided between adjacent guiding layers; An insulating encapsulation layer (2) is provided, which covers the outer surface of the stacked body (1). Heat dissipation pipe (3) is embedded in the insulating encapsulation layer (2); both ends of the heat dissipation pipe (3) extend out from the insulating encapsulation layer (2).

2. The stacked busbar according to claim 1, characterized in that, The heat dissipation pipe (3) includes: A plurality of first tubes (31) are arranged along the length or width direction of the stacked body (1), and the extension direction of the first tubes (31) is consistent with the width or length direction of the stacked body (1). The second tube (32) connects the beginning and end of the adjacent first tube (31).

3. The stacked busbar according to claim 2, characterized in that, The heat dissipation pipe (3) has at least one planar wall, which abuts against the outer surface of the stacked body (1).

4. The laminated busbar according to any one of claims 1-3, characterized in that, The spacing between adjacent first tubes (31) is 30-200mm, the inner diameter of the heat dissipation pipe (3) is 8-15mm, and the wall thickness of the heat dissipation pipe (3) is 1-2mm.

5. A method of using the laminated busbar according to any one of claims 1-4, characterized in that, include: S100. Obtain the first relationship curve between the heating parameters and cooling medium parameters of the laminated busbar through historical data; The heating parameters include: busbar power and start-up time; the cooling medium parameters include: cooling medium delivery speed; S200. Adjust the cooling medium parameters based on the actual data, the heating parameters of the stacked busbar, and the first relationship curve.

6. The method of use according to claim 5, characterized in that, S200 includes: Obtain the second relationship curve between the power, start-up time and temperature of the laminated busbar; The delivery time and initial velocity of the cooling medium are obtained based on the power of the stacked busbar.

7. The method of use according to claim 6, characterized in that, When the power of the stacked busbar is constant, the start-up time of the stacked busbar is obtained from the second relationship curve when the temperature of the stacked busbar is equal to the temperature threshold. The delivery time of the cooling medium is obtained based on the activation time of the stacked busbar; The delivery speed of the cooling medium is obtained based on the first relationship curve and the heating parameters of the laminated busbar.

8. The method of use according to any one of claims 5-7, characterized in that, The delivery speed of the cooling medium includes: initial speed and adaptation speed; The initial velocity of the cooling medium is obtained based on the first relationship curve and the heating parameters of the stacked busbar. The rate of change of the heating parameters of the stacked busbar is monitored in real time. When the rate of change of the heating parameters exceeds the change threshold, the speed of the cooling medium is adjusted to the appropriate speed.

9. The method of use according to claim 8, characterized in that, The rate of change of the heating parameters includes: the magnitude of change and the frequency of change; When at least one of the change amplitude and change frequency exceeds the preset threshold, the speed of the cooling medium is adjusted to the appropriate speed.

10. The method of use according to claim 9, characterized in that, When the frequency of change exceeds the preset threshold, the effective power P of the stacked busbar is obtained according to the frequency of change f and the amplitude of change D, and the cooling medium parameters are adjusted according to the effective power of the stacked busbar and the first relationship curve. D = I(T); T is the power variation period of the stacked busbar, f is the variation frequency, I is the input current, R is the DC resistance of the busbar, and k is the correction coefficient.

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