Protection structure based on fuse and filter capacitor

Abstract

The utility model relates to a protection structure based on a fuse and a filter capacitor. The protection structure comprises a base plate, the fuse, the filter capacitor, a PDU wire harness, a common mode inductor, a copper bar positive electrode, a copper bar negative electrode and a connecting sheet. One end of the PDU wire harness is respectively connected with the connecting sheet and the negative electrode of the copper bar, the other end of the PDU wire harness passes through the common mode inductor (4), and the positive electrode of the copper bar, the negative electrode of the copper bar and the connecting sheet are all arranged on the bottom plate. According to the utility model, the fuse and the filter capacitor are organically combined together, so that the fuse can effectively suppress electromagnetic interference and improve the overall performance of the motor controller while realizing circuit protection, a traditional fuse can only cut off a circuit when current is overloaded, while the product has accurate overcurrent protection capability and can effectively prevent electromagnetic interference when the current is overloaded. And the problem of electromagnetic interference can be effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of electrical protection technology, and in particular to a protection structure based on fuses and filter capacitors. Background Technology

[0002] Inverters are core components of electric and hybrid vehicles, responsible for current conversion and vehicle control. During operation, motor controllers not only generate electromagnetic interference (EMI) that adversely affects surrounding electronic equipment and communication systems, but they are also highly susceptible to external electromagnetic interference, leading to control signal distortion, system instability, and even malfunctions. Therefore, good electromagnetic compatibility (EMC) is crucial for the normal and reliable operation of motor controllers.

[0003] Meanwhile, circuit protection plays an indispensable role in motor controllers. As a commonly used circuit protection component, a fuse can quickly disconnect the circuit when overloads or short circuits occur, preventing excessive current from damaging the motor controller and other related equipment, effectively avoiding safety accidents such as fires. At the moment of motor startup, the current typically spikes dramatically in a short period. Without effective fuse protection, the electronic components in the motor controller may burn out due to excessive current.

[0004] However, traditional EMC design and FUSE design are often independent and separate. This separate design not only leads to a complex internal structure and large space occupation of the motor controller, increasing the system size and cost, but also makes it difficult to fully utilize their respective functional advantages during actual operation due to the lack of effective coordination between the two, failing to meet the urgent needs of modern motor systems for high performance, high reliability, and miniaturization. Therefore, conducting research on FUSE design that integrates EMC functions, organically combining EMC functions with the circuit protection functions of the FUSE, has extremely important practical significance.

[0005] Chinese patent application CN111490323B discloses an integrated busbar EMC filtering structure, including a DC high-voltage busbar, a busbar mounting base, positive and negative copper busbars, a grounding copper busbar, a common-mode magnetic ring, a differential-mode magnetic ring, a filter capacitor, positive and negative leads, and fastening screws. The busbar mounting base includes mounting holes, threaded insert holes, a common-mode magnetic ring cavity, a differential-mode magnetic ring cavity, and a filter capacitor cavity. The positive and negative copper busbars pass through the differential-mode magnetic ring cavity. The grounding copper busbars are placed on the bottom surface of the mounting holes of the busbar mounting base. The common-mode magnetic ring is installed in the common-mode magnetic ring cavity, the differential-mode magnetic ring is installed in the differential-mode magnetic ring cavity, and the filter capacitor is installed in the filter capacitor cavity. The common-mode magnetic ring and the differential-mode magnetic ring are arranged horizontally in parallel, and the common-mode magnetic ring, the differential-mode magnetic ring, and the filter capacitor are stacked vertically. The DC high-voltage busbar passes through the common-mode magnetic ring. The fastening screws connect the DC high-voltage busbar and the positive and negative copper busbars. Although this patent achieves EMC filtering function, it does not demonstrate the function of fuse breaking.

[0006] Therefore, providing a protection structure that can simultaneously provide fuse protection and EMC functionality is an urgent problem to be solved. Utility Model Content

[0007] The purpose of this invention is to overcome the defects of the existing technology and provide a protection structure based on fuses and filter capacitors.

[0008] The objective of this utility model can be achieved through the following technical solutions:

[0009] According to one aspect of the present invention, a protection structure based on a fuse and a filter capacitor is provided, the protection structure comprising a base plate, a fuse, a filter capacitor, a PDU harness, a common-mode inductor, a positive copper busbar, a negative copper busbar, and a connecting piece.

[0010] The connecting piece is connected to the negative terminal of the copper busbar through a filter capacitor, and the positive terminal of the copper busbar is connected to the connecting piece through a fuse. One end of the PDU harness is connected to the connecting piece and the negative terminal of the copper busbar respectively, and the other end of the PDU harness passes through a common mode inductor. The positive terminal of the copper busbar, the negative terminal of the copper busbar, and the connecting piece are all mounted on the base plate.

[0011] As a preferred technical solution, the protection structure further includes a fuse mounting hole, in which the fuse is installed.

[0012] As a preferred technical solution, the fuse mounting hole is installed between the positive electrode of the copper busbar and the connecting piece.

[0013] As a preferred technical solution, the fuse and the connecting piece are provided in a one-to-one correspondence.

[0014] As a preferred technical solution, the protective structure further includes a mounting column, which is mounted on the base plate.

[0015] As a preferred technical solution, the mounting post is connected to the positive terminal of the copper busbar.

[0016] As a preferred technical solution, the protection structure further includes a grounding nest, which is mounted on the base plate.

[0017] As a preferred technical solution, the protection structure further includes an input hole, which is installed on the positive and negative terminals of the copper busbar, respectively.

[0018] As a preferred technical solution, the filter capacitor is an X-type filter capacitor.

[0019] As a preferred technical solution, the filter capacitor is a Y-type filter capacitor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This utility model organically combines a fuse and a filter capacitor, enabling the fuse to effectively suppress electromagnetic interference while protecting the circuit and improving the overall performance of the motor controller. Traditional fuses can only cut off the circuit when the current is overloaded, while this product can effectively deal with electromagnetic interference while having precise overcurrent protection capabilities.

[0022] 2. This utility model organically combines fuses and filter capacitors, reducing the number of components and space occupied on the circuit board, which is conducive to the miniaturization design of electronic devices and provides more flexibility for circuit board layout.

[0023] 3. This invention also incorporates a common-mode inductor, which, in conjunction with a filter capacitor and a common-mode choke, further bypasses high-frequency interference signals. The capacitor exhibits low impedance at high frequencies, diverting high-frequency noise to ground, significantly reducing electromagnetic interference and substantially improving the electromagnetic compatibility of the equipment—a feat unmatched by traditional fuses. Attached Figure Description

[0024] Figure 1 This is an overall structural diagram of the present invention;

[0025] Figure 2 This is a disassembly diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the voltage distribution of this utility model;

[0027] 1. Filter capacitor; 2. Fuse mounting hole; 3. PDU harness; 4. Common mode inductor; 5. Input hole; 6. Positive copper busbar; 7. Negative copper busbar; 8. Connecting piece; 9. Mounting post; 10. Grounding nest. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model.

[0029] To address the aforementioned issues, this invention breaks away from the traditional mindset that EMC design and FUSE design are independent, organically integrating the two to propose a novel integrated design concept. This concept emphasizes the synergistic effect of EMC and circuit protection functions. Through optimized design, the FUSE can effectively suppress electromagnetic interference while providing circuit protection, thereby improving the overall performance of the motor controller.

[0030] This invention provides a protection structure based on a fuse and a filter capacitor. By organically combining the fuse and the filter capacitor, this invention enables the fuse to effectively suppress electromagnetic interference while providing circuit protection, thus improving the overall performance of the motor controller. Traditional fuses can only cut off the circuit when there is an overload, while this product provides precise overcurrent protection and effectively addresses electromagnetic interference. This invention reduces the number of components and the space occupied on the circuit board, which is beneficial for the miniaturization of electronic devices and provides more flexibility in circuit board layout. This invention also incorporates a common-mode inductor, which, in conjunction with the filter capacitor and the common-mode choke, further bypasses high-frequency interference signals. The capacitor exhibits low impedance at high frequencies, diverting high-frequency noise to ground, greatly reducing electromagnetic interference and significantly improving the electromagnetic compatibility of the equipment—a feature unmatched by traditional fuses.

[0031] like Figures 1-3 As shown, a protection structure based on a fuse and a filter capacitor is provided. The protection structure includes a base plate, a fuse, a filter capacitor 1, a PDU harness 3, a common mode inductor 4, a copper busbar positive terminal 6, a copper busbar negative terminal 7, and a connecting piece 8.

[0032] The connecting piece 8 is connected to the negative copper busbar 7 via the filter capacitor 1, and the positive copper busbar 6 is connected to the connecting piece 8 via a fuse. One end of the PDU harness 3 is connected to the connecting piece 8 and the negative copper busbar 7 respectively, and the other end of the PDU harness 3 passes through the common mode inductor 4. The positive copper busbar 6, the negative copper busbar 7, and the connecting piece 8 are all mounted on the base plate.

[0033] The protective structure also includes a fuse mounting hole 2, in which the fuse is installed.

[0034] The fuse mounting hole 2 is installed between the positive electrode 6 of the copper busbar and the connecting piece 9.

[0035] The fuses and connecting pieces 9 are configured in a one-to-one correspondence.

[0036] The protective structure also includes a mounting column 9, which is mounted on the base plate.

[0037] The mounting post 9 is connected to the positive copper busbar 6. The mounting post 9 is connected to the positive copper busbar 6 via a fuse, meaning that a fuse is also installed between the mounting post 9 and the positive copper busbar 6.

[0038] In this embodiment, the present invention adopts a structure with three fuses. The technical principle of the present invention is as follows:

[0039] After the DC power from the battery pack is filtered, the positive and negative terminals are input through the positive terminal 6 and negative terminal 7 of the copper busbar, respectively. The positive terminal 6 of the copper busbar is input to the FUSE (i.e., fuse). The FUSE is installed at the fuse mounting hole 2. A nut is riveted to the copper busbar of the positive terminal 6 of the copper busbar. The two mounting feet of the FUSE are installed on the nut riveted to the positive terminal 6 of the copper busbar and the nut on the connecting piece 8, respectively. At this time, the polarity of the nut on the connecting piece 8 is the same as the polarity of the positive terminal 6 of the copper busbar, which is the positive terminal. Overcurrent protection is achieved by controlling the current magnitude.

[0040] After the DC current from the battery pack is filtered, it needs to be filtered again before output to meet EMC requirements after passing through fuse mounting hole 2. Here, a filter capacitor 1 and a common-mode inductor 4 are added for EMC shielding. The filter capacitor 1 is integrated with the FUSE structure, and the positive and negative terminals of the two mounting pins of the filter capacitor 1 utilize the positive terminal 6 and the negative terminal 7 of the copper busbar for filtering.

[0041] The PDU harness 3 structure has two positive and negative copper lugs 3+ and 3- secured to the connecting piece 8 and the negative copper busbar 7. The PDU harness 3 outputs to PTC, AC, etc., and passes through a common-mode inductor 4 again before output to achieve EMC functionality. A high-voltage distribution box, abbreviated as PDU (Power Distribution Unit).

[0042] The protective structure also includes a grounding nest 10, which is mounted on the base plate.

[0043] The protective structure also includes an input port 5, which is respectively installed on the positive terminal 6 and the negative terminal 7 of the copper busbar. The filter capacitor 1 is an X-type filter capacitor 1. The filter capacitor 1 is a Y-type filter capacitor 1.

[0044] In this embodiment, the filter capacitor 1 can be selected as an X / Y capacitor according to the requirements. Here, an X capacitor is shown. Both the positive and negative terminals use the FUSE structure. When a Y capacitor is selected, only one polarity of the copper busbar can be used. The grounding part uses the grounding nest 10 nest to realize the filtering function.

[0045] This structure saves space on the copper busbar required for welding the filter capacitor. The filter capacitor 1 part is welded using the FUSE copper busbar to filter high-frequency noise. At the same time, the common-mode inductor before the output effectively suppresses electromagnetic interference.

[0046] Fuse (fuse wire section): High-purity, low-resistance alloy material is selected as the fuse wire to ensure that the heat generated under normal operating current is minimized. The fuse wire is designed with a flat shape to increase the heat dissipation area and improve overload capacity.

[0047] Common-mode inductor 4 (i.e., the common-mode choke section): A high-permeability, low-loss core material, such as manganese-zinc ferrite, is selected. Two windings are evenly wound on the core, using multi-strand fine copper wire to reduce the skin effect and improve high-frequency performance. The number of turns and wire diameter of the windings are optimized based on the required inductance and rated current.

[0048] Filter capacitor 1: A multilayer ceramic capacitor is selected as the filter capacitor, which has the advantages of small size, stable capacitance value, and good high-frequency characteristics. The filter capacitor is directly soldered near the pin of the FUSE and connected with the shortest possible lead to reduce parasitic inductance and resistance and improve the filtering effect.

[0049] Similar to a traditional fuse, the circuit is cut off by the heat generated by the current blowing the fuse wire. In this design, a filter capacitor is added inside the fuse, working in conjunction with a common-mode choke (i.e., common-mode inductor 4). The filter capacitor 1 can bypass high-frequency interference signals, further reducing electromagnetic interference. By appropriately selecting the capacitor value and layout, it has low impedance to interference signals within the operating frequency range, effectively filtering out high-frequency noise. After passing through the filter capacitor, the PDU harness 3 passes through the magnetic ring of the common-mode inductor 4. When common-mode current passes through, the magnetic fields generated by the two windings superimpose, thus presenting high impedance to the common-mode current and suppressing common-mode interference. For differential-mode current, the magnetic fields generated by the two windings cancel each other out, having a smaller impact on the differential-mode current.

[0050] Traditional fuses only provide overcurrent protection, while fuses with integrated EMC functionality offer dual protection against both overcurrent and electromagnetic interference (EMI) suppression. In the event of an overcurrent condition, the fuse quickly cuts off the circuit, protecting the equipment from excessive current damage. Simultaneously, during normal operation, it continuously suppresses EMI, maintaining stable equipment operation. Compared to the single overcurrent protection of traditional fuses, this provides more comprehensive protection.

[0051] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A protection structure based on a fuse and a filter capacitor, characterized in that, The protection structure includes a base plate, a fuse, a filter capacitor (1), a PDU harness (3), a common mode inductor (4), a copper busbar positive electrode (6), a copper busbar negative electrode (7), and a connecting piece (8). The connecting piece (8) is connected to the negative copper busbar (7) through the filter capacitor (1), and the positive copper busbar (6) is connected to the connecting piece (8) through the fuse. One end of the PDU harness (3) is connected to the connecting piece (8) and the negative copper busbar (7) respectively. The other end of the PDU harness (3) passes through the common mode inductor (4). The positive copper busbar (6), the negative copper busbar (7) and the connecting piece (8) are all mounted on the base plate.

2. The protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The protective structure also includes a fuse mounting hole (2), in which the fuse is installed.

3. The protection structure based on a fuse and a filter capacitor according to claim 2, characterized in that, The fuse mounting hole (2) is installed between the positive electrode (6) of the copper busbar and the connecting piece (8).

4. The protection structure based on a fuse and a filter capacitor according to claim 2, characterized in that, The fuses and connecting pieces (8) are set in a one-to-one correspondence.

5. The protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The protective structure also includes a mounting column (9), which is mounted on the base plate.

6. A protection structure based on a fuse and a filter capacitor according to claim 5, characterized in that, The mounting post (9) is connected to the positive copper busbar (6).

7. The protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The protective structure also includes a grounding nest (10), which is mounted on the base plate.

8. The protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The protective structure also includes an input hole (5), which is installed on the positive electrode (6) and the negative electrode (7) of the copper busbar, respectively.

9. A protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The filter capacitor (1) is a filter capacitor (1) using an X capacitor.

10. A protection structure based on a fuse and a filter capacitor according to claim 1, characterized in that, The filter capacitor (1) is a filter capacitor (1) using a Y capacitor.

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