Dc-dc device of vehicle-mounted power supply and vehicle

Abstract

The application relates to a DCDC device of a vehicle-mounted power supply and a vehicle, and aims to solve the problems of uneven current, uneven heating of switching devices and influence on product reliability caused by different current path impedances in parallel application of the switching devices. The device comprises a shell, an aluminum substrate fixed on the shell, at least one column of switching devices fixed on the aluminum substrate, each column of switching devices containing one switching device or multiple parallel switching devices, at least one input copper bar and one output copper bar fixed on the aluminum substrate, one input copper bar being electrically connected with one column of switching devices, all columns of switching devices being electrically connected with one output copper bar, in a first direction, one output copper bar being arranged in the middle of all columns of switching devices, one input copper bar being arranged on the side, away from the output copper bar, of each column of switching devices, and in a second direction, all input copper bars being arranged on one side of all columns of switching devices, and the output copper bar being arranged on the other side of all columns of switching devices.

Description

Technical Field

[0001] This application relates to the field of vehicle power supply, specifically to a DC-DC device and vehicle for vehicle power supply. Background Technology

[0002] Electric new energy vehicles are the current development trend of the automotive industry, and on-board power supplies (OBC+DCDC) are an important component of electric vehicles. Small size and lightweight have become design requirements for on-board power supplies; to meet these requirements, the combined application of aluminum substrates and switching devices has become the mainstream in the industry.

[0003] In DC-DC power supplies that convert high-voltage DC to low-voltage DC, the output traces of DC-DC power supplies are characterized by low voltage and high current (specifically 200A-300A). Whether the trace path of the DC-DC power supply is shortest or optimal will directly affect the working efficiency of the entire product and the current sharing effect of the parallel switching devices at low voltage output, that is, cause the heating difference of these devices, and further cause product reliability problems due to thermal imbalance.

[0004] Currently, in the combined application of aluminum substrates and switching devices, on the low-voltage output side of the DC-DC power supply, the large current path flows in and out from the same side of the aluminum substrate, causing inconsistent current paths for the parallel switching devices (current paths such as...). Figure 2 (As shown by the middle arrow), and the circuit impedance R is positively correlated with the current path length L, satisfying: R=ρ*L / A (1) Where ρ is resistivity, L is line length, and A is conductor cross-sectional area.

[0005] In this design, ρ and A can be considered to be the same for different switching devices.

[0006] by Figure 2 Analysis of left-side switching devices 1, 2, and 3: The current path length of switching device 1 is: L1 = a1 + b1 + c1 The current path length of switching device 2 is: L2 = a2 + b2 + c2 The current path length of switching device 3 is: L3 = a3 + b3 + c3 Depend on Figure 1 and Figure 2 We can conclude that: L1 < L2 < L3 From the above formula (1), we can conclude that: R1 < R2 < R3 According to Ohm's law, I = U / R (2) Since all different switching devices draw current from the same input copper busbar and have current flow out of the same output copper busbar, their voltages U can be considered to be the same. Therefore, according to formula (2), I3 < I2 < I1. Similarly, the switching devices on the right side can be concluded to be the same. It can be seen that due to the different current path impedances, the switching devices 1-3 have uneven current distribution, which in turn causes uneven heating of the switching devices, thus affecting the reliability of the product. Utility Model Content

[0007] This application provides a DC-DC device and vehicle for vehicle power supply, which solves the problem of uneven current caused by different current path impedances of parallel switching devices, resulting in uneven heating of the switching devices and thus affecting product reliability.

[0008] The technical solution of this application is as follows: This application provides a DC-DC device for vehicle power supply, comprising: case; An aluminum substrate fixed to the housing; At least one column of switching devices fixed on the aluminum substrate; each column of switching devices includes one or more switching devices connected in parallel; At least one input copper bus and one output copper bus are fixed on the aluminum substrate; An input copper busbar is electrically connected to a column of the aforementioned switching devices, and all columns of switching devices are electrically connected to an output copper busbar. In the first direction, an output copper busbar is arranged in the middle of all column switching devices, and an input copper busbar is arranged on the side of each column switching device opposite to the output copper busbar. In the second direction, all input copper busbars are arranged on one side of all column switching devices, and the output copper busbars are arranged on the other side of all column switching devices; The first direction and the second direction are perpendicular.

[0009] Preferably, the number of input copper busbars is the same as the number of columns of the switching devices, and the number of columns of the switching devices is one or an even number of columns; When the number of columns of the switching devices is one, in the first direction, one input copper busbar and one output copper busbar are respectively arranged on both sides of the column of switching devices; in the second direction, one input copper busbar is arranged on one side of the column of switching devices, and the output copper busbar is arranged on the other side of the column of switching devices. When the number of columns of the switching devices is even, in the first direction, one output copper busbar is arranged in the middle of all columns of switching devices, and an input copper busbar is arranged on the side of each column of switching devices away from the output copper busbar; in the second direction, all input copper busbars are arranged on one side of all columns of switching devices, and the output copper busbars are arranged on the other side of all columns of switching devices.

[0010] Preferably, the switching devices include a first column of switching devices and a second column of switching devices arranged side by side along a first direction, and the input copper busbar includes a first input copper busbar and a second input copper busbar. The first column of switching devices is electrically connected to the first input copper busbar, and the second column of switching devices is electrically connected to the second input copper busbar. The output copper busbar is arranged between the first column of switching devices and the second column of switching devices.

[0011] Preferably, the first input copper busbar is arranged outside the first column of switching devices, and the second input copper busbar is arranged outside the second column of switching devices.

[0012] This application also provides a vehicle including the aforementioned on-board power supply DC-DC device.

[0013] The beneficial effects of this application are as follows: By changing the traditional single-sided copper busbar input and output configuration of the low-voltage output side of the DC-DC power supply to a double-sided copper busbar input and output configuration, the current path of each switching device is optimized, so that the current of each switching device is basically shared, avoiding the problem of uneven heating of the switching devices, thereby improving the reliability of the product. Attached Figure Description

[0014] Figure 1 A schematic diagram of the copper busbar input and output wiring arrangement for a DCDC device in an existing vehicle power supply. Figure 2 This is a schematic diagram of the copper busbar input and output wiring arrangement scheme and routing distance for the DCDC device of the vehicle power supply in the prior art; Figure 3 This is a schematic diagram of the copper busbar input and output wiring arrangement of the DCDC device for vehicle power supply in the embodiments of this application; Figure 4 This is a schematic diagram showing the routing distance of the copper busbars of the DC-DC device for the vehicle power supply in this embodiment of the application. Detailed Implementation

[0015] Reference Figure 3 and Figure 4This application provides a DC-DC power supply device for vehicles, comprising: a housing; an aluminum substrate 1 fixed on the housing; at least one row of switching devices 3 fixed on the aluminum substrate 1; at least one input copper busbar 2 and one output copper busbar 4 fixed on the aluminum substrate 1; one input copper busbar 2 is electrically connected to one row of switching devices 3, and all rows of switching devices 3 are electrically connected to one output copper busbar 4. In a first direction, one output copper busbar 4 is arranged in the middle of all rows of switching devices 3, and each row of switching devices 3 has one input copper busbar 2 arranged on the side opposite to the output copper busbar 4. In the second direction, all input copper busbars 2 are arranged on one side of all column switching devices 3, and the output copper busbars 4 are arranged on the other side of all column switching devices 3; The first direction and the second direction are perpendicular.

[0016] In the embodiments of this application, the number of columns of the switching device 3 is one column or an even number of columns.

[0017] Wherein, when the number of columns of the switching devices 3 is one column, in the first direction, one of the input copper busbars 2 and the output copper busbars 4 are respectively arranged on both sides of the column of switching devices 3; in the second direction, one of the input copper busbars 2 is arranged on one side of the column of switching devices 3, and the output copper busbars 4 are arranged on the other side of the column of switching devices 3. When the number of columns of the switching devices 3 is even, in the first direction, one output copper busbar 4 is arranged in the middle of all columns of switching devices 3, and an input copper busbar 2 is arranged on the side of each column of switching devices 3 away from the output copper busbar 4; in the second direction, all input copper busbars 2 are arranged on one side of all columns of switching devices 3, and the output copper busbar 4 is arranged on the other side of all columns of switching devices 3. The first direction and the second direction are perpendicular.

[0018] Combination Figure 3 and Figure 4 The "one side" and "the other side" mentioned above refer to opposite sides of the aluminum substrate 1; for example, one side refers to the upper side in the figure, and the other side refers to the lower side. In other embodiments, if the arrangement direction of the switching device 3 changes, one side and the other side may also be the left and right sides of the aluminum substrate. The first direction and the second direction mentioned above refer to two directions that are parallel to and perpendicular to each other on the surface of the aluminum substrate 1. For example, in the figure, the first direction refers to... Figure 3 and Figure 4 The left and right directions, the second direction refers to Figure 3 and Figure 4 The second direction.

[0019] In this embodiment, by changing the traditional single-sided copper busbar input / output method of the low-voltage output side of the vehicle power supply's DC-DC device to a double-sided copper busbar input / output method, the current path of each switching device 3 is optimized, so that each switching device 3 has basically equal current, avoiding the problem of uneven heating of the switching device 3, thereby improving the reliability of the product.

[0020] In this embodiment, the number of input copper busbars 2 is the same as the number of columns of switching devices 3, that is, one row of switching devices 3 is electrically connected to one input copper busbar 2.

[0021] Reference Figure 4 In a specific example of an embodiment of this application, the switching device 3 includes a first column of switching devices 31 and a second column of switching devices 32, the input copper busbar 2 includes a first input copper busbar 21 and a second input copper busbar 22, the first column of switching devices 31 is electrically connected to the first input copper busbar 21, and the second column of switching devices 32 is electrically connected to the second input copper busbar 22; the output copper busbar 4 is arranged between the first column of switching devices 31 and the second column of switching devices 32.

[0022] Reference Figure 4 In this embodiment of the application, the first input copper busbar 21 is arranged outside the first column of switching devices 31, and the second input copper busbar 22 is arranged outside the second column of switching devices 32.

[0023] Since the large current flows in from one side of the aluminum substrate 1 and out from the other side, the trace length flowing through each switching device 3 is approximately equal (specific current path). Figure 4 (As indicated by the middle arrow), the trace lengths of each current path specifically satisfy: L1' = a1 + b1 + c1; L2' = a2 + b2 + c2; L3'=a3+b3+c3.

[0024] Where L1' represents the current path flowing through the first switching device in the first column of switching devices 31, a1 represents the current path from the first input copper busbar 21 to the first switching device in the first column of switching devices 31, b1 represents the current path within the first switching device in the first column of switching devices 31, and c1 represents the current path from the first switching device in the first column of switching devices 31 to the output copper busbar 4; L2' represents the current path flowing through the second switching device in the first column of switching devices 31, and a2 represents the current path from the first input copper busbar 21 to the second switching device in the first column of switching devices 31. In the diagram, b2 represents the current path in the second switching device in the first column of switching devices 31, and c2 represents the current path from the second switching device in the first column of switching devices 31 to the output copper busbar 4; L3' represents the current path through the third switching device in the first column of switching devices 31, a3 represents the current path from the first input copper busbar 21 to the third switching device in the first column of switching devices 31, b3 represents the current path in the third switching device in the first column of switching devices 31, and c3 represents the current path from the third switching device in the first column of switching devices 31 to the output copper busbar 4, and L1'≈ L2'≈L3'. It can be seen that the above scheme avoids the current sharing problem caused by inconsistent path lengths, makes the heat generation of the switching device 3 uniform, and improves the reliability of the product.

[0025] This application also provides a vehicle including the aforementioned on-board power supply DC-DC device.

[0026] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A DC-DC device for vehicle power supply, characterized in that, include: case; Aluminum substrate (1) fixed on the housing; At least one column of switching devices (3) is fixed on the aluminum substrate (1); each column of switching devices (3) includes one or more switching devices connected in parallel; At least one input copper busbar (2) and one output copper busbar (4) are fixed on the aluminum substrate (1); An input copper busbar (2) is electrically connected to a column of switching devices (3), and all columns of switching devices (3) are electrically connected to the output copper busbar (4); In the first direction, an output copper busbar (4) is arranged in the middle of all column switching devices (3), and an input copper busbar (2) is arranged on the side of each column switching device (3) away from the output copper busbar (4). In the second direction, all input copper busbars (2) are arranged on one side of all column switching devices (3), and the output copper busbars (4) are arranged on the other side of all column switching devices (3); The first direction and the second direction are perpendicular.

2. The DCDC device for vehicle power supply according to claim 1, characterized in that, The number of input copper busbars (2) is the same as the number of columns of the switching device (3), and the number of columns of the switching device (3) is one column or an even number of columns; When the number of columns of the switching devices (3) is one column, in the first direction, one of the input copper busbars (2) and the output copper busbars (4) are respectively arranged on both sides of the column of the switching devices (3); in the second direction, one of the input copper busbars (2) is arranged on one side of the column of the switching devices (3), and the output copper busbars (4) are arranged on the other side of the column of the switching devices (3); When the number of columns of the switching devices (3) is even, in the first direction, one output copper busbar (4) is arranged in the middle of all columns of switching devices (3), and one input copper busbar (2) is arranged on the side of each column of switching devices (3) away from the output copper busbar (4); in the second direction, all input copper busbars (2) are arranged on one side of all columns of switching devices (3), and the output copper busbar (4) is arranged on the other side of all columns of switching devices (3).

3. The DCDC device for vehicle power supply according to claim 2, characterized in that, The switching device (3) includes a first column of switching devices (31) and a second column of switching devices (32) arranged side by side along a first direction. The input copper busbar (2) includes a first input copper busbar (21) and a second input copper busbar (22). The first column of switching devices (31) is electrically connected to the first input copper busbar (21), and the second column of switching devices (32) is electrically connected to the second input copper busbar (22). The output copper busbar (4) is arranged between the first column of switching devices (31) and the second column of switching devices (32).

4. The DCDC device for vehicle power supply according to claim 3, characterized in that, The first input copper busbar (21) is arranged outside the first column of switching devices (31), and the second input copper busbar (22) is arranged outside the second column of switching devices (32).

5. A vehicle, characterized in that, The DC-DC device includes the vehicle power supply as described in any one of claims 1-4.

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