Filter circuit and structure for vehicle motor controller

Abstract

The invention provides a filter circuit and structure for a vehicle motor controller. The filter circuit comprises a first magnetic ring, a differential mode capacitor module, a common mode capacitor module and a second magnetic ring, the input end of the first magnetic ring is connected with a high-voltage direct-current power supply bus side of a vehicle motor controller; the differential mode capacitor module is connected in parallel with the output end of the first magnetic ring; the common-mode capacitor module comprises a first capacitor and a second capacitor; the first end of the first capacitor is connected with the positive electrode of the output end of the first magnetic ring, the second end of the first capacitor and the first end of the second capacitor are connected to the ground, and the second end of the second capacitor is connected with the negative electrode of the output end of the first magnetic ring; the input end of the second magnetic ring is connected with the output end of the first magnetic ring, and the output end of the second magnetic ring is the output end of the filter. The structure comprises a shell, and the shell is used for packaging the circuit.

Description

Technical Field

[0001] The present application relates to the field of filter technology, and in particular to a filter circuit and structure for a vehicle motor controller. Background Art

[0002] With the increasing penetration rate of new energy vehicles, major OEMs are continuously improving the integration of the three-electric system (electric drive, BMS, PDU). Active devices, passive devices, motor eddy currents, and the on and off of switches interfere with the entire three-electric system. The interference of the three-electric system affects other automotive electronic power-consuming equipment, air conditioning, display, and navigation stability. Mainstream manufacturers are paying more and more attention to EMC. New energy electric vehicles are becoming more and more popular, and 800V high-voltage SiC platforms are increasing. The anti-interference ability and stability of electric vehicle controllers are becoming increasingly the focus. The 800V high-voltage, high-power density electric drive controller represented by the third-generation wide-bandgap silicon carbide (SiC) power semiconductor has been widely used due to its high switching frequency, low loss, and good temperature resistance. However, it also brings more serious electromagnetic interference (EMI) problems. When the SiC power semiconductor devices in the electric drive controller perform high-speed switching, they will generate very high du / dt voltage change rate and di / dt current change rate, generating electromagnetic interference (EMI); from this electric drive DC filter, filter group, and AC filter core are widely used to suppress electromagnetic interference (EMC), filter IGBT, SiC high-frequency noise, and improve signal quality and system stability.

[0003] The filter is mainly used to suppress the electromagnetic interference of the IGBT switching noise inside the controller to the high-voltage system, thereby protecting the receiver inside and outside the vehicle and meeting the enterprise standards of the components and the regulatory announcement tests of the whole vehicle. The filter circuit for the vehicle is mainly composed of magnetic rings and RC capacitors, and the structure is mainly composed of copper bars connecting various components and the filter housing.

[0004] The researchers found that the existing filter circuits and mechanisms have the following technical disadvantages: The filter circuit is not provided with a differential mode capacitor module and a common mode capacitor module, and cannot filter out differential mode noise and common mode noise.

[0005] Ferrite magnetic rings are commonly used, which cannot obtain sufficient inductance and have low magnetic permeability.

[0006] The use of a large number of copper bars for connection and fastening is a very complicated operation in assembly. Too many fastening screws and a variety of materials make the assembly time-consuming and labor-intensive, and the cost increases. A large amount of metal-to-metal contact occurs during the fastening process, and it is also easy to cause insulation and voltage failure problems.

[0007] The filter adopts an integrated single-ended outlet and can only be installed and used on one side. It cannot fully arrange the space of the electric drive axle electric control box, and cannot achieve lightweight and cost reduction.

[0008] Therefore, the filter circuits and mechanisms on the market cannot meet the needs of automotive filters. It is necessary to design a filter that adapts to current needs, filter out differential and common mode noise, ensure the inductance and permeability of the magnetic ring, simplify the installation of the copper busbar, achieve lightweight and reduce costs. Summary of the invention

[0009] In order to solve the many problems existing in the existing filter circuits and structures in vehicle filtering, such as the inability to filter out differential-mode and common-mode noise, insufficient magnetic ring inductance, low magnetic permeability, complex copper busbar assembly, high risk of withstand voltage failure, and insufficient space utilization of the electric drive axle electric control box; thereby achieving the purpose of filtering out differential-mode and common-mode noise, ensuring sufficient magnetic ring inductance and high magnetic permeability, simplifying the installation of the copper busbar, and achieving the effect of lightweight and cost reduction while meeting the requirements of vehicle filtering, the present application provides a filter circuit and structure for a vehicle motor controller.

[0010] The above-mentioned invention objective of the present application is achieved through the following technical solutions: A filter circuit and structure for a vehicle motor controller, the circuit comprising a first magnetic ring, a differential mode capacitor module, a common mode capacitor module, and a second magnetic ring; The input end of the first magnetic ring is connected to the high-voltage DC power bus side of the vehicle motor controller; the differential mode capacitor module is connected in parallel to the output end of the first magnetic ring; the common mode capacitor module includes a first capacitor and a second capacitor; the first end of the first capacitor is connected to the positive pole of the output end of the first magnetic ring, the second end of the first capacitor and the first end of the second capacitor are connected to the ground, and the second end of the second capacitor is connected to the negative pole of the output end of the first magnetic ring; the input end of the second magnetic ring is connected to the output end of the first magnetic ring, and its output end is the output end of the filter.

[0011] Furthermore, the differential mode capacitor module is composed of a plurality of capacitors connected in parallel.

[0012] Furthermore, the first magnetic ring is a nanocrystalline magnetic ring.

[0013] Furthermore, the second magnetic ring is a ferrite magnetic ring.

[0014] A filter structure for a vehicle motor controller comprises a shell, the shell is used to encapsulate the filter circuit, the shell is provided with a first cavity portion, a second cavity portion, a third cavity portion and a PCB board mounting portion; positive and negative copper bars which are fastened and connected are mounted between the first cavity portion, the second cavity portion and the third cavity portion; a PCB circuit board is mounted on the PCB board mounting portion, and a grounding end of the PCB circuit board is connected to the shell.

[0015] Furthermore, the first magnetic ring can be freely embedded in the first cavity part or the second cavity part according to the filter installation method.

[0016] Furthermore, the second magnetic ring is embedded in the third cavity portion.

[0017] Furthermore, the PCB circuit board is provided with the differential mode capacitor module and the common mode capacitor module and is packaged and fixed.

[0018] Furthermore, the gaps between the first magnetic ring and the second magnetic ring and the cavity portion, and the gap between the PCB board mounting portion and the PCB circuit board, are filled and cured by curing silicone rubber.

[0019] Furthermore, the shell is made of tin-plated aluminum plate.

[0020] In summary, this application includes the following beneficial technical effects: 1. The filter circuit is equipped with a differential mode capacitor module and a common mode capacitor module, which can filter the differential mode and common mode noise of the filter; 2. The magnetic ring adopts the method of matching nanocrystalline magnetic ring and ferrite magnetic ring, so that while ensuring the low cost of the magnetic ring, sufficient inductance is obtained and high magnetic permeability is achieved; 3. The positive and negative copper bars are installed on the shell with fastened connection to avoid metal-to-metal contact, thus reducing a lot of assembly time, material cost and complex machining process; 4. The first magnetic ring can be installed in the first cavity part or the second cavity part according to the needs, and can be installed on both sides to fully arrange the space of the electric control box of the electric drive axle, thereby achieving lightweight and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a filter circuit for a vehicle motor controller of the present application.

[0022] Figure 2 It is the simulation analysis waveform of the filter circuit.

[0023] Figure 3 This is the structural diagram of the positive and negative copper bars of the filter.

[0024] Figure 4 This is the structural diagram of the first magnetic ring of the filter.

[0025] Figure 5 This is the structural diagram of the filter's PCB circuit board.

[0026] Figure 6 This is the first assembly diagram of the filter.

[0027] Figure 7 This is the second assembly diagram of the filter.

[0028] Figure 8 This is the third assembly diagram of the filter.

[0029] Fig. 9 This is the fourth assembly diagram of the filter.

[0030] Fig.10 This is the fifth assembly diagram of the filter.

[0031] Fig.11 This is the sixth assembly diagram of the filter. DETAILED DESCRIPTION

[0032] The present application is further described in detail below in conjunction with the accompanying drawings.

[0033] A filter circuit and structure embodiment for a vehicle motor controller A filter circuit and structure for a vehicle motor controller, the circuit comprising a first magnetic ring 10, a differential mode capacitor module 11, a common mode capacitor module 12, and a second magnetic ring 13; like Figure 1 As shown, the input end of the first magnetic ring 10 is connected to the high-voltage DC power supply bus side of the vehicle motor controller; the differential mode capacitor module 11 is connected in parallel to the output end of the first magnetic ring 10; the common mode capacitor module 12 includes a first capacitor C1 and a second capacitor C2; the first end of the first capacitor C1 is connected to the positive pole of the output end of the first magnetic ring 10, the second end of the first capacitor C1 and the first end of the second capacitor C2 are connected to the ground, and the second end of the second capacitor C2 is connected to the negative pole of the output end of the first magnetic ring 10; the input end of the second magnetic ring 13 is connected to the output end of the first magnetic ring 10, and its output end is the output end of the filter.

[0034] Furthermore, the differential mode capacitor module 11 is composed of a plurality of capacitors connected in parallel.

[0035] In the embodiment, the differential mode capacitor module 11 is composed of 6 capacitors connected in parallel, namely a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8; A first end of the third capacitor C3 , a first end of the fourth capacitor C4 , a first end of the fifth capacitor C5 , a first end of the sixth capacitor C6 , a first end of the seventh capacitor C7 and a first end of the eighth capacitor C8 are connected to the positive pole of the output end of the first magnetic ring 10 .

[0036] The second end of the third capacitor C3 , the second end of the fourth capacitor C4 , the second end of the fifth capacitor C5 , the second end of the sixth capacitor C6 , the second end of the seventh capacitor C7 and the second end of the eighth capacitor C8 are connected to the negative electrode of the output end of the first magnetic ring 10 .

[0037] Furthermore, the first capacitor C1 and the second capacitor C2 are 100nF capacitors, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 are 33nF capacitors, and the eighth capacitor C8 is 1uF capacitor.

[0038] Furthermore, the voltage level of the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 is greater than 600V.

[0039] When performing differential-mode interference filtering, the differential-mode interference current generated by the differential-mode interference source signal on the bus side of the high-voltage DC power supply, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8 and the first magnetic ring 10 form a CL circuit to filter the differential-mode interference current; the differential-mode interference current passes through the first magnetic ring 10 and flows through the third capacitor C3 to enter the negative electrode to achieve the first differential-mode filtering, and similarly, is then filtered in turn through the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8.

[0040] When performing common-mode interference filtering, the common-mode interference current generated by the common-mode interference source signal on the high-voltage DC power supply bus side, the first end of the first capacitor C1 receives the common-mode interference current of the positive pole of the output end of the first magnetic ring 10 for filtering, and the second end of the second capacitor C2 receives the common-mode interference current of the negative pole of the output end of the first magnetic ring 10 for filtering.

[0041] Furthermore, the first magnetic ring 10 is a nanocrystalline magnetic ring.

[0042] In this embodiment, the performance requirements of the first magnetic ring 10 are: When the frequency is 10KHz, the initial permeability ranges from 6W to 8W; When the initial magnetic permeability ranges from 3W to 6W and the frequency is 10KHz, the inductance of the first magnetic ring 10 is ≥30uH; When the initial magnetic permeability ranges from 3W to 6W and the frequency is 100KHz, the inductance of the first magnetic ring 10 is ≥25uH; When the initial magnetic permeability ranges from 3W to 6W and the frequency is 250KHz, the inductance of the first magnetic ring 10 is ≥10uH; When the initial permeability ranges from 3W to 6W and the frequency is 500KHz, the inductance of the first magnetic ring 10 is ≥5uH Furthermore, the second magnetic ring 13 is made of a ferrite magnetic ring. In this embodiment, the second magnetic ring 13 is made of ultra-high manganese zinc material; In this embodiment, the performance requirement of the second magnetic ring 13 may be: when the frequency is 10KHz, the initial magnetic permeability is recommended to reach 10KW.

[0043] Furthermore, the input end of the first magnetic ring 10 can receive the signal on the high-voltage DC power bus side of the vehicle motor controller through the passive current probe 106, so that the noise signal is filtered without contact, and then the noise signal is attenuated nonlinearly through the first magnetic ring 10, and then the differential-mode interference current in the noise signal is filtered through the differential-mode capacitor module 11, and the common-mode interference current in the noise signal can be filtered through the common-mode capacitor module 12. A differential-mode and common-mode mixed EMI filter structure is adopted to form a structure with both common-mode filters and differential-mode filters, which can filter differential-mode interference current and common-mode interference current at the same time, improve the filter's suppression and filtering of interference signals, and improve the filter's power density. The effects of differential-mode and common-mode filtering are achieved on the high-voltage DC power bus side of the vehicle motor controller, thereby overcoming the defect that the EMI suppression effect in the prior art is difficult to satisfy the simultaneous differential-mode filtering and common-mode filtering.

[0044] The first magnetic ring 10 adopts a nanocrystalline magnetic ring. The nanocrystalline magnetic ring can obtain sufficient inductance, high magnetic permeability, and can maintain stable performance in a wide frequency range. The high-frequency loss is low, which can effectively reduce signal distortion and improve the working efficiency and stability of the circuit. At the same time, since the high-voltage DC power supply bus side of the vehicle motor controller generates high current and high heat due to high voltage during operation, and within a certain temperature change range, the nanocrystalline magnetic ring used in the first magnetic ring 10 has a small change in magnetic properties, ensuring that the first magnetic ring 10 can still work normally under harsh working environment temperatures.

[0045] The second magnetic ring 13 is a ferrite magnetic ring, which has low cost and good chemical stability. It can withstand the acid and alkali environment at the rear end of the filter and prevent the magnetic ring from being corroded, thereby ensuring the normal operation of the equipment. At the same time, the ferrite magnetic ring can effectively absorb and suppress high-frequency electromagnetic interference and meet the filtering requirements of electromagnetic interference in the filter.

[0046] By matching nanocrystalline magnetic rings with ferrite magnetic rings, the cost can be effectively controlled under the premise of meeting the requirements of filtering performance. Nanocrystalline magnetic rings are used at the input end of filters with high filtering accuracy requirements, while ferrite magnetic rings are used at the output end of filters with a wide frequency range and low filtering accuracy requirements. Optimize the cost structure and improve the cost performance of the entire filtering system.

[0047] like Figure 2As shown, in this embodiment, the signal on the high-voltage DC power bus side of the vehicle motor controller exceeds the standard at 30MHz, and is filtered through a filter circuit and simulated and analyzed. When no filtering is performed, the resonance point of the simulation curve is at 10MHz. After filtering through the filter, the resonance point of the curve is adjusted to around 30MHz and the insertion loss is close to 40dB, which meets the GB / T18655 conducted emission limit requirements of the vehicle motor controller.

[0048] A filter structure for a vehicle motor controller includes a shell 100, the shell 100 is used to encapsulate a filter circuit, the shell 100 is provided with a first cavity portion 101, a second cavity portion 102, a third cavity portion 103 and a PCB board mounting portion 104; positive and negative copper bars 105 are mounted between the first cavity portion 101, the second cavity portion 102 and the third cavity portion 103, and the PCB board mounting portion 104 is mounted with a PCB circuit board, and the grounding end of the PCB circuit board is connected to the shell 100.

[0049] The positive and negative copper busbars 105 are firmly connected and embedded in the shell 100 and are integrally injection molded. The positive and negative copper busbars 105 have positive and negative lead-out ports in the first cavity portion 101, the second cavity portion 102, and the third cavity portion 103. The positive and negative copper busbars 105 are connected to the passive current probe 106 at the positive and negative ports in the first cavity portion 101 and the second cavity portion 102. The passive current probe 106 can be connected to the high-voltage DC power supply bus side of the vehicle motor controller; the positive and negative copper busbars 105 are connected to the rear end of the filter circuit at the positive and negative ports in the third cavity portion 103.

[0050] like Figure 3 As shown, in this embodiment, the size of a single copper bar of the positive and negative copper busbars 105 is 271mm*25mm*5mm, which can carry a current of 300A.

[0051] The positive and negative copper busbars 105 are integrally embedded in the injection molding process to avoid metal-to-metal contact, thereby reducing a large amount of assembly time, material costs, and complex machining processes.

[0052] The positive and negative copper busbars 105 are integrally embedded in the injection mold. Through the injection molding process, direct contact between metal and metal is effectively avoided, thereby significantly reducing the electrochemical corrosion and increased resistance caused by metal contact, greatly improving the stability and safety of the product; at the same time, from the perspective of time cost, the connection and assembly between metal parts in traditional processes often takes a lot of time, while this technology directly eliminates many tedious assembly steps through one-time injection molding of the positive and negative copper busbars 105, and a lot of assembly time is saved; in terms of cost, traditional processes may require the use of various connectors, insulating materials, etc. to achieve the connection and insulation of metal parts, but after adopting the overall embedded injection molding technology, the use of these additional materials is greatly reduced, thereby reducing material costs.

[0053] like Figure 4 As shown, further, the first magnetic ring 10 can be freely embedded in the first cavity portion 101 or the second cavity portion 102 according to the filter installation method.

[0054] The first magnetic ring 10 is installed on both sides. In terms of space utilization, the traditional magnetic ring installation method is often relatively fixed, resulting in a waste of some space in the electric drive axle electric control box. The first magnetic ring 10 adopts a double-sided installation technology, which can make full use of the internal space of the electric drive axle electric control box and make the layout of each component more reasonable and compact. By reasonably planning the installation position of the first magnetic ring 10, not only can the overall structure be optimized, but more space can also be reserved for other key components, further improving the integration of the entire electric control box.

[0055] From the perspective of lightweighting, more reasonable space utilization means that a more compact and lightweight shell design can be selected, reducing the use of unnecessary materials, thereby achieving lightweighting of the electric drive axle electric control box. For weight-sensitive application scenarios such as vehicle motors, this can effectively improve energy utilization efficiency and extend driving range.

[0056] In this embodiment, the first magnetic ring 10 has a height H ≥ 30 mm and a thickness T ≥ 10 mm.

[0057] Furthermore, the second magnetic ring 13 is embedded in the third cavity portion 103, the positive and negative copper bars 105 are connected to the rear end of the filter circuit through the carbon steel nuts 107 on the positive and negative ports 108 of the third cavity portion 103, and two NZ-M8-4-ZC carbon steel nuts 107 are riveted on the positive and negative ports.

[0058] NZ-M8-4-ZC carbon steel nut 107 is made of carbon steel with high strength and hardness, and can withstand large loads to ensure the stability of the back-end connection of the filter circuit; at the same time, carbon steel has low cost, which can effectively reduce costs and improve efficiency; at the same time, after surface treatment such as galvanizing, it has good corrosion resistance, can resist external erosion and extend service life; it has a high degree of compatibility with corresponding bolts and other connectors, and is simple and convenient to install, which can improve assembly efficiency and reduce installation difficulty and labor costs; in addition, the use of NZ-M8-4-ZC carbon steel nut 107 has stable physical properties to ensure the reliability and durability of the connection.

[0059] In this embodiment, the second magnetic ring 13 has a height H ≥ 45 mm and a thickness T ≥ 12 mm.

[0060] The first magnetic ring 10 and the second magnetic ring 13 are combined with the positive and negative magnetic cores to form an inductor structure, thereby filtering the differential mode interference current and the common mode interference current.

[0061] like Figure 5 As shown, further, the PCB board mounting portion 104 is mounted with a PCB circuit board, and the PCB circuit board is provided with a differential mode capacitor module 11 and a common mode capacitor module 12 and is packaged and fixed.

[0062] The two lead pins of the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7 and the eighth capacitor C8 should be connected to the positive and negative copper busbars 105 at the shortest possible overlapping distance.

[0063] The lead pins of the first end of the first capacitor C1 and the second end of the second capacitor C2 and the lead points of the positive and negative copper busbars 105 should be kept at the shortest possible overlap distance; the pins of the second end of the first capacitor C1 and the first end of the second capacitor C2 and the connection points of the housing 100 should be grounded over a large area and the overlap distance should be kept as short as possible.

[0064] Furthermore, the gaps between the first magnetic ring 10 and the second magnetic ring 13 and the cavity portion, and the gap between the PCB board mounting portion 104 and the PCB circuit board are filled and cured by curing silicone rubber.

[0065] In this embodiment, room temperature curing silicone rubber GO-1704-1 is used for filling.

[0066] Furthermore, the housing 100 is made of tin-plated aluminum plate.

[0067] In this embodiment, the thickness of the housing 100 is 2 mm; Furthermore, the housing 100 is provided with an electromagnetic protection connector for positive and negative cables.

[0068] In this embodiment, the installation sequence of the relevant components of the filter structure is as follows: Step 1: Fix the positive and negative copper bars 105 to the housing 100. Step 2: embed the second magnetic ring 13 into the third cavity 103, such as Figure 6 As shown; Step 3: freely embed the first magnetic ring 10 in the first cavity 101 or the second cavity 102 according to the filter installation method, such as Figure 7 As shown; Step 4: Fill and cure the gaps between the first magnetic ring 10 and the second magnetic ring 13 and the cavity portion by curing silicone rubber, such as Figure 8 As shown; Step 5: The positive and negative copper bars 105 are grounded to the positive and negative terminals of the third cavity 103 and the housing 100, and two NZ-M8-4-ZC carbon steel nuts 107 are riveted. Fig. 9 As shown; Step 6: After the differential mode capacitor module 11 and the common mode capacitor module 12 are fixed on the PCB, the PCB is placed on the PCB mounting portion, and after being fixed, the silicone rubber is filled and cured. Fig.10 As shown; Step 7: According to the position of the first magnetic ring 10, the positive and negative copper bars 105 are led out of the first cavity 101 or the second cavity 102 and connected to the corresponding passive current probes 106. Fig.11 As shown; Step 8: Connect the positive and negative copper bars 105 to the rear end of the filter circuit through the carbon steel nuts 107 on the positive and negative ports of the third cavity portion 103 .

[0069] The present application includes the following beneficial technical effects: the filter circuit is provided with a differential mode capacitor module and a common mode capacitor module, which can filter the differential mode noise and common mode noise of the filter; the magnetic ring adopts a nanocrystalline magnetic ring and a ferrite magnetic ring that are matched with each other, so that while ensuring the low cost of the magnetic ring, sufficient inductance is obtained to achieve high magnetic permeability; the positive and negative copper bars are installed in the shell with a tight connection to avoid metal-to-metal contact, thereby reducing a lot of assembly time, material costs and complex machining processes; the first magnetic ring can be installed in the first cavity part or the second cavity part according to needs, and can be installed on both sides to fully arrange the space of the electric drive bridge electric control box, thereby achieving lightweight and reducing costs.

[0070] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0071] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0072] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0073] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A filter circuit for a vehicle motor controller, characterized in that: The circuit comprises: A first magnetic ring, the input end of which is connected to the high-voltage DC power bus side of the vehicle motor controller; A differential mode capacitor module, connected in parallel to the output end of the first magnetic ring; A common mode capacitor module, comprising a first capacitor and a second capacitor; a first end of the first capacitor is connected to the positive electrode of the first magnetic ring output end, a second end of the first capacitor and a first end of the second capacitor are connected to the ground, and a second end of the second capacitor is connected to the negative electrode of the first magnetic ring output end; The second magnetic ring has an input end connected to the output end of the first magnetic ring, and an output end of the second magnetic ring is the output end of the filter.

2. A filter circuit for a vehicle motor controller according to claim 1, characterized in that: The differential mode capacitor module is composed of a plurality of capacitors connected in parallel.

3. A filter circuit for a vehicle motor controller according to claim 1, characterized in that: The first magnetic ring is a nanocrystalline magnetic ring.

4. The filter circuit for a vehicle motor controller according to claim 1, characterized in that: The second magnetic ring is a ferrite magnetic ring.

5. A filter structure for a vehicle motor controller, comprising a housing, wherein the housing is used to encapsulate the filter circuit for a vehicle motor controller according to any one of claims 1 to 4, characterized in that: The shell is provided with a first cavity portion, a second cavity portion, a third cavity portion and a PCB board mounting portion; positive and negative copper bars are installed between the first cavity portion, the second cavity portion and the third cavity portion, which are fastened together; a PCB circuit board is installed on the PCB board mounting portion, and the grounding end of the PCB circuit board is connected to the shell.

6. A filter structure for a vehicle motor controller according to claim 5, characterized in that: The first magnetic ring can be freely embedded in the first cavity part or the second cavity part according to the filter installation method.

7. A filter structure for a vehicle motor controller according to claim 6, characterized in that: The second magnetic ring is embedded in the third cavity portion.

8. The filter structure for a vehicle motor controller according to claim 5, characterized in that: The PCB circuit board is provided with the differential mode capacitor module and the common mode capacitor module and is packaged and fixed.

9. The filter structure for a vehicle motor controller according to claim 7, characterized in that: The gaps between the first magnetic ring and the second magnetic ring and the cavity portion, and the gap between the PCB board mounting portion and the PCB circuit board are filled and cured by curing silicone rubber.

10. The filter structure for a vehicle motor controller according to claim 5, characterized in that: The shell is made of tin-plated aluminum plate.

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