Capacitor module integrating EMC boosting, fuse and four-stage EMC filtering functions

Abstract

The invention discloses a capacitor module integrating EMC boosting, fuse and four-stage EMC filtering functions, and relates to the technical field of capacitors. A capacitor module integrating EMC boosting, fuse and four-stage EMC filtering functions is used for an electric automobile motor control circuit and comprises a frame body, two capacitor cores are arranged in the frame body side by side, one capacitor core is a filtering capacitor C1, the other capacitor core is a direct-current supporting thin-film capacitor C2, and the other capacitor core is a direct-current supporting thin-film capacitor C2. An EMC (Electro Magnetic Compatibility) boosting module, a fuse module and a four-stage EMC filtering module are integrated; through the design of high integration, four-stage EMC filtering, an anti-circulation circuit, double fusing protection, heat dissipation performance optimization, easy installation and maintenance and the like, the performance, reliability and stability of the system are remarkably improved, and the overall cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of capacitors, and particularly relates to a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions. Background Art

[0002] DC support film capacitors have two functions in the motor control circuit of electric vehicles. One is that the capacitor provides ripple current when the upper arm of the inverter is turned off and the lower arm is turned on, avoiding adverse effects such as motor torque pulsation and current sampling distortion caused by large voltage fluctuations. The other is that the capacitor provides a loop for the high-frequency current generated by the system, reduces the loop impedance, and reduces switching losses and voltage spikes.

[0003] Traditional capacitor modules have single functions and usually require external boost circuits, fuses, and multi-stage filtering modules, resulting in a large system volume, complex connections, and low reliability. In the prior art, EMC filtering mostly adopts a two-stage or three-stage structure, and the ability to suppress high-frequency interference is limited; the fuse and the boost module are independently designed, and the fault response speed is slow. In addition, the heat dissipation performance of existing modules is insufficient and it is difficult to adapt to high-load or high-temperature environments. Therefore, there is an urgent need for a highly integrated, performance-optimized, and reliable capacitor module. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions that can overcome or at least partially solve the above problems.

[0005] To solve the above technical problem, the basic concept of the technical solution adopted by the present invention is: a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions for an electric vehicle motor control circuit. The capacitor module includes a frame body, and two capacitor cores are arranged in parallel in the frame body. One is a filtering capacitor C1, and the other is a DC support film capacitor C2, and it is integrated with: an EMC boost module for raising the input power supply voltage to a preset value; a fuse module including a fast fuse K1 and a DC-DC fuse K2; a four-stage EMC filtering module composed of a first-stage to a fourth-stage EMC filtering circuit connected in sequence; an anti-circulation circuit is provided between the second-stage EMC filtering circuit and the third-stage EMC filtering circuit, and the anti-circulation circuit is composed of a filtering capacitor C1, a filtering inductor L2, and a fast fuse K1; positive and negative copper bars and a grounding copper bar are provided in the frame body, and the positive and negative copper bars are provided with installation parts, and both ends of the grounding copper bar extend outside the frame.

[0006] Preferably, the filtering capacitor C1 and the DC support film capacitor C2 are arranged in parallel, corresponding to the fourth-stage filtering circuit and the anti-circulation circuit in the four-stage EMC filtering module respectively.

[0007] Preferably, the four - stage EMC filtering module specifically includes: a first - stage EMC filtering circuit: including a differential - mode capacitor CX1, common - mode capacitors CY1 and CY2; a second - stage EMC filtering circuit: including a differential - mode capacitor CX2, common - mode capacitors CY3 and CY4, and a differential - mode inductor L1; a third - stage EMC filtering circuit: including common - mode capacitors CY5 and CY6; a fourth - stage EMC filtering circuit: including common - mode capacitors CY7, CY8, CY9, CY10, CY11, CY12, and the DC - supporting thin - film capacitor C2.

[0008] Preferably, the fast - melting fuse K1 is arranged in the anti - circulating current circuit, and the DC - DC fuse K2 is arranged at the high - voltage input end and works in cooperation with the contactor and the pre - charge circuit; a plurality of EMC capacitor mounting positions are provided at the bottom and side of the frame body, and the interior is filled with an epoxy resin or polyurethane sealing and filling layer.

[0009] Preferably, the filtering inductor L2 is composed of a magnetic ring arranged inside the frame body, and the positive and negative copper bars pass through the magnetic ring to form an inductor structure; the grounding copper bar forms a multi - point grounding structure through the extended part of the frame body.

[0010] Preferably, an open - type mounting cavity is provided on the side of the frame body, and the common - mode capacitors CY1, CY2, CY3, and CY4 are fixed in the open - cavity body through a potting process and are directly welded to the extended end of the grounding copper bar.

[0011] Preferably, the mounting part of the positive and negative copper bars includes a standardized interface, and an insulating isolation groove is provided at the interface. The positive and negative pins of the DC - supporting thin - film capacitor C2 are connected to the copper - bar interface through laser welding.

[0012] Preferably, the magnetic ring is made of nanocrystalline alloy material, the inner diameter of which has a gap of 0.5 - 1 mm with the cross - section of the positive and negative copper bars. The outer surface of the magnetic ring is coated with a silica - gel buffer layer and is fixed to the inner wall of the frame body through a snap - fit structure.

[0013] After adopting the above - mentioned technical solution, the present invention has the following beneficial effects compared with the prior art: Through designs such as highly integrated, four - stage EMC filtering, anti - circulating current circuit, dual - fuse protection, optimized heat - dissipation performance, and easy installation and maintenance, the present invention significantly improves the performance, reliability, and stability of the system and reduces the overall cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the drawings: Figure 1Structural schematic of a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions proposed by the present invention Figure 1 ; Figure 2 Structural schematic of a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions proposed by the present invention Figure 2 ; Figure 3 Circuit diagram of a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions proposed by the present invention.

[0015] In the figure: 1. Frame main body; 2. Installation part; 3. Positive and negative copper busbar group; 4. Inductor; 5. Sealing filling layer; 6. Grounding copper busbar; 7. Capacitor core; 8. Magnetic ring; 9. EMC capacitor. Specific implementation manner

[0016] The following further describes the present invention in detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0017] It should be understood that terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0018] In the description of the present invention, the orientation or positional relationship indicated by terms such as "transverse", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0019] Example 1: Refer to Figures 1 - 3, a capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions, is used in the electric vehicle motor control circuit. The capacitor module includes a frame body, and two capacitor cores are arranged in parallel in the frame body. One of them is a filtering capacitor C1, and the other is a DC support film capacitor C2. It also integrates: an EMC boost module for raising the input power supply voltage to a preset value; a fuse module including a fast fuse K1 and a DC-DC fuse K2; a four-stage EMC filtering module composed of first-stage to fourth-stage EMC filtering circuits; an anti-circulation circuit is provided between the second-stage EMC filtering circuit and the third-stage EMC filtering circuit, and this anti-circulation circuit is composed of a filtering capacitor C1, a filtering inductor L2, and a fast fuse K1; positive and negative copper bars and a grounding copper bar are provided in the frame body, and the positive and negative copper bars are provided with mounting parts, and both ends of the grounding copper bar extend to the outside of the frame; the filtering capacitor C1 and the DC support film capacitor C2 are arranged in parallel, corresponding to the fourth-stage filtering circuit and the anti-circulation circuit in the four-stage EMC filtering module respectively; the four-stage EMC filtering module specifically includes: the first-stage EMC filtering circuit: including a differential-mode capacitor CX1, common-mode capacitors CY1, CY2; the second-stage EMC filtering circuit: including a differential-mode capacitor CX2, common-mode capacitors CY3, CY4, and a differential-mode inductor L1; the third-stage EMC filtering circuit: including common-mode capacitors CY5, CY6; the fourth-stage EMC filtering circuit: including common-mode capacitors CY7, CY8, CY9, CY10, CY11, CY12, and the DC support film capacitor C2.

[0020] In the present invention, the EMC boost module is composed of a boost transformer and a switching tube, and is used to raise the voltage of the input power supply to a preset value; the fuses K1 and K2 use fuse wires, and their rated current values are 75A to 135A, and are used to fuse when an overcurrent or short-circuit fault occurs in the circuit to cut off the circuit; the four-stage EMC filtering module includes four filtering units, namely the first-stage EMC filtering circuit, the second-stage EMC filtering circuit, the third-stage EMC filtering circuit, and the fourth-stage EMC filtering circuit, which are connected in series. Specifically, the first-stage filtering unit (primary EMC filtering circuit) consists of a differential-mode capacitor CX1, common-mode capacitors CY1 and CY2. The capacitance value of the differential-mode capacitor CX1 is 1 nF to 47 nF, and the withstand voltage value is 275 VAC to 305 VAC. The capacitance values of the common-mode capacitors CY1 and CY2 are 33 nF to 68 nF, and the withstand voltage value is 275 VAC to 305 VAC. The inductance value of the differential-mode inductor L1 is 30 μH to 75 μH @ 10 KHz, 15 μH to 45 μH @ 100 KHz. One end of the differential-mode capacitor CX1 is connected to one end of the common-mode capacitor CY1. The other end of the common-mode capacitor CY1 is connected to one end of the differential-mode inductor L1. The other end of the differential-mode inductor L1 is connected to one end of the common-mode capacitor CY2. The other end of the common-mode capacitor CY2 is connected to the other end of the differential-mode capacitor CX1 to form an LC filtering network. The primary EMC filtering circuit is located at the front end of the power input to filter out most of the conducted interference (common-mode interference and differential-mode interference) on the power line. The large capacitor bypasses the low-frequency differential-mode interference, and the inductor suppresses the high-frequency interference from entering the subsequent circuit. The second-stage filtering unit (secondary EMC filtering circuit) consists of a differential-mode capacitor CX1, common-mode capacitors CY3 and CY4, and a differential-mode inductor L1. The capacitance values of the common-mode capacitors CY3 and CY4 are 68 nF to 150 nF, and the withstand voltage value is 275 VAC to 305 VAC. The inductance value of the differential-mode inductor L1 is 30 μH to 75 μH @ 10 KHz, 15 μH to 45 μH @ 100 KHz. One end of the common-mode capacitor CY3 is connected to one end of the differential-mode inductor L1. The other end of the differential-mode inductor L1 is connected to one end of the common-mode capacitor CY4. The other end of the common-mode capacitor CY4 is connected to the other end of the common-mode capacitor CY3 to form a π-type filtering network. The secondary EMC filtering circuit further filters out the residual interference on the basis of the primary filtering, especially has a better suppression effect on the high-frequency band interference, and reduces the interference entering the subsequent circuit. The third-stage filtering unit (tertiary EMC filtering circuit) is located after the anti-circulation circuit and consists of common-mode capacitors CY5 and CY6. The capacitance values of the common-mode capacitors CY5 and CY6 are 1 nF to 33 nF, and the withstand voltage value is 275 VAC to 305 VAC. One end of the common-mode capacitor CY5 is connected to the filtering capacitor C1. The other end of the common-mode capacitor CY5 is connected to one end of the common-mode capacitor CY6. The other end of the common-mode capacitor CY6 is connected to the other end of the filtering capacitor C1 to form a π-type filtering network. The tertiary EMC filtering circuit is close to the input port of the sensitive circuit and uses fine components to filter out the subtle interference remaining after the first two stages to protect the sensitive circuit from electromagnetic interference. The fourth-stage filtering unit (four-stage EMC filtering circuit) consists of common-mode capacitors CY7, CY8, CY9, CY10, CY11, CY12 and a DC support film capacitor C2; the capacitance value of the DC support film capacitor C2 is 250 μF to 650 μF, and the withstand voltage value is 400 VDC to 900 VDC; the capacitance values of the common-mode capacitors CY7, CY8, CY9, CY10, CY11, CY12 are 1 nF to 33 nF, and the withstand voltage values are 275 VAC to 305 VAC. One end of the DC support film capacitor C2 is connected to one end of the common-mode capacitor CY7, the other end of the common-mode capacitor CY7 is connected to one end of the common-mode capacitor CY8, the other end of the common-mode capacitor CY8 is connected to one end of the common-mode capacitor CY9, the other end of the common-mode capacitor CY9 is connected to one end of the common-mode capacitor CY10, the other end of the common-mode capacitor CY10 is connected to one end of the common-mode capacitor CY11, the other end of the common-mode capacitor CY11 is connected to one end of the common-mode capacitor CY12, and the other end of the common-mode capacitor CY12 is connected to the other end of the DC support film capacitor C2 to form a complex π-type filtering network; the four-stage EMC filtering circuit performs the final fine processing on the signal to further suppress specific frequency interference or common-mode interference and ensure that the output signal meets the electromagnetic compatibility requirements; Furthermore, an anti-circulation current circuit is formed by a filtering capacitor C1, a filtering inductor L2 and a fast-fusing fuse K1. Compared with the traditional anti-circulation current circuit, the traditional anti-circulation current circuit is generally implemented by two schemes. One is the hardware scheme: using a current-sharing inductor, a current detection resistor or a Hall sensor, etc. in cooperation with a control algorithm; the other is the software scheme: optimizing through PWM modulation. The present invention is composed of a filtering inductor and a filtering capacitor and has the following advantages: (1) Detect the current unevenness problem caused by IGBT parameter differences in multiple parallel circuits, balance the current distribution through LC peak clipping and valley filling, adjust the current of each branch, and avoid device overstress caused by circulating current.

[0021] (2) Reduce the IGBT switching loss. When the upper and lower bridge arms of the inverter switch, the LC filters out the peak voltage and suppresses the instantaneous circulating current caused by dead time or asynchronous drive signals; Among them, the capacitance value of the filtering capacitor C1 is 20 μF to 50 μF, the withstand voltage value is 400 VDC to 900 VDC, and under the current condition of 80 amperes (A), the inductance value of the filtering inductor L2 is 2 microhenries.

[0022] Prevent the current of some modules from being too large due to circulating current. The fast-fusing fuse K1 can respond in milliseconds, protect the IGBT power device single tube from overcurrent damage, reduce the risk of thermal imbalance, and extend the service life of the controller.

[0023] Embodiment 2: Refer to Figures 1 - 3 , which is basically the same as Embodiment 1. Further, a fast-fusing fuse K1 is arranged in the anti-circulation circuit, and a DC-DC fuse K2 is arranged at the high-voltage input end and works in cooperation with the contactor and the pre-charge circuit.

[0024] Furthermore, the fast-fusing fuse K1 and the DC-DC fuse K2 are used to fuse when an overcurrent or short-circuit fault occurs in the circuit to cut off the circuit and protect the equipment from damage. The fast-fusing fuse K1 and the DC-DC fuse K2 in this embodiment both adopt fuse wires, and their rated current values are selected according to the design requirements of the circuit; among them, one end of the DC-DC fuse K2 is connected to the output end of the four-stage EMC filtering circuit, and the other end is connected to loads such as air conditioners, so as to ensure that when an overcurrent or short-circuit fault occurs in the load, the DC-DC fuse K2 can quickly fuse to cut off the circuit and protect the safety of the equipment and the load; and, the fast-fusing fuse K1 and the DC-DC fuse K2 are arranged between the secondary filtering and the circulation circuit, and can quickly fuse when an overcurrent or short-circuit fault occurs in the circuit to cut off the circuit and protect the subsequent circuit and equipment from damage. This setting can also prevent the expansion of the fault and improve the overall stability and reliability of the circuit; Further, the fast-fusing fuse K1 is arranged between the secondary filtering and the anti-circulation circuit, and there are mainly the following advantages: (1) Provide double protection: The secondary filtering circuit mainly undertakes the function of further filtering medium and high-frequency noise on the power line. If a fuse K1 is arranged between it and the anti-circulation circuit, it can not only protect the secondary filtering circuit itself from overcurrent or short-circuit faults, but also protect the faults of the anti-circulation circuit and its subsequent circuits (such as three-stage filtering, DC support capacitors, etc.), forming a double insurance.

[0025] (2) Fault isolation and location: When a fault occurs in the circuit resulting in overcurrent or short circuit, the fuse K1 fuses, isolating the fault area before the secondary filtering circuit or after the anti-circulation circuit. This setting helps to quickly locate the fault range, narrow the troubleshooting area, and improve the maintenance efficiency.

[0026] (3) Prevent the expansion of the fault: The function of the anti-circulation circuit is to prevent current circulation and protect the safety of the circuit and equipment. If an overcurrent or short-circuit fault occurs before the anti-circulation circuit and there is no fuse protection, the fault current may flow through the anti-circulation circuit to the subsequent circuit, causing damage to the subsequent circuit. Setting the fuse K1 can effectively prevent the expansion of the fault and protect the safety of the subsequent circuit.

[0027] (4) Improve circuit reliability: The setting of the fast-fusing fuse K1 enables the circuit to quickly cut off the circuit when an overcurrent or short-circuit fault occurs, preventing the fault from deteriorating further, thereby improving the overall reliability and stability of the circuit.

[0028] Moreover, in the present invention, the DC-DC fuse K2 adopts a DC-DC fuse, which is a fuse specifically designed for DC-DC conversion circuits. Compared with ordinary fuses, it better understands the operating characteristics of DC-DC conversion circuits. DC-DC fuses usually have a lower fusing current and a faster fusing speed. When an overcurrent or short-circuit fault occurs in the circuit, the DC-DC fuse can quickly blow.

[0029] Further, in the above, a four-level EMC filtering circuit is composed of a common-mode capacitor, a differential-mode capacitor, and a differential-mode inductor. In this way, high-voltage and high-frequency switches (such as SiC devices) will generate strong EMI, and four-level progressive filtering can significantly reduce the interference to systems such as on-vehicle chargers and BMS. The general implementation methods of traditional four-level EMC filtering circuits are as follows: The first level is an X capacitor, a common-mode inductor, and a TVS diode; the second level is a magnetic bead and a TVS diode; the third level is a three-phase common-mode choke and a Y capacitor; the fourth level is a low-impedance grounding design of a filtering connector. The four-level EMC filtering circuit in the present invention is composed of a common-mode capacitor, a differential-mode capacitor, and a differential-mode inductor, and has the following advantages: (1) Filter out high-frequency noise introduced from the battery or DC power supply terminal; (2) Interference to control signals, preventing high-frequency noise from coupling to the low-voltage control terminal through the drive line; (3) Suppress the interference generated on the motor side (such as PWM harmonics and motor back EMF noise) from feedback to the controller or power supply line; Reduce the influence of switching noise on motor control accuracy (such as current sampling error and PWM waveform distortion).

[0030] Moreover, a DC-DC fuse K2 is integrated at the high-voltage input end. The fuse on the DC-DC input side cooperates with the contactor and the pre-charge circuit to prevent thermal runaway caused by a short circuit of the high-voltage battery or a DC-DC module failure. When the current exceeds the safety threshold due to a short circuit, component breakdown, or abnormal load, the fuse quickly blows to cut off the circuit and protect the DC-DC converter and its load; The fuse is selected according to 1.4 - 1.8 times the continuous operating current and inrush current of its load air conditioner.

[0031] Embodiment 3: Refer to Figures 1 - 3, which is basically the same as Embodiment 2. Further, a plurality of EMC capacitor mounting positions are provided at the bottom and side of the frame body, and the interior is filled with an epoxy resin or polyurethane sealing and filling layer; the filtering inductor L2 is composed of a magnetic ring arranged in the frame body, and the positive and negative copper bars pass through the magnetic ring to form an inductor structure; the grounding copper bar forms a multi-point grounding structure through the extended part of the frame body; an open mounting cavity is provided on the side of the frame body, and the common-mode capacitors CY1, CY2, CY3, and CY4 are fixed in the open cavity through a potting process and are directly welded to the extended end of the grounding copper bar; the mounting part of the positive and negative copper bars includes a standardized interface, and an insulating isolation groove is provided at the interface. The positive and negative leads of the DC support film capacitor C2 are connected to the copper bar interface through laser welding; the magnetic ring is made of nanocrystalline alloy material, the inner diameter of which has a gap of 0.5-1 mm with the cross-section of the positive and negative copper bars, and the outer surface of the magnetic ring is coated with a silica gel buffer layer and is fixed to the inner wall of the frame body through a snap structure.

[0032] In the present invention, the positive and negative copper bars are integrated into the frame body, reducing the circuit complexity; the grounding copper bar extends outward to ensure the consistency of grounding for all filtering capacitors and reduce the common-mode interference; The magnetic ring serves as the filtering inductor L2, and the positive and negative copper bars pass through the magnetic ring, enhancing the high-frequency noise suppression ability and simplifying the inductor layout; Reference Figure 1 and Figure 2 , the inductor indicated by the reference numeral 4 in the figure is the differential-mode inductor L1; The epoxy resin or polyurethane fills the side opening of the frame, improving the module sealing performance, dust and water resistance, and heat dissipation efficiency; Multiple groups of capacitors (CX1-CX2, CY1-CY12) are distributed at the bottom and side to form a three-dimensional filtering network, covering a wider interference frequency band. All common-mode capacitors (CY1-CY12) are directly connected to the grounding copper bar inside the frame, and the two ends of the copper bar extend to the outside of the module to ensure a short grounding path and consistent impedance, avoiding secondary interference introduced by differences in the ground loop.

[0033] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made. These are all equivalent modifications and evolutions of the above embodiments based on the essential technology of the present invention, and all belong to the protection scope of the present invention.

Claims

1. A capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions, which is used in the motor control circuit of an electric vehicle, and is characterized in that: The capacitor module includes a frame body. Two capacitor cores are arranged in parallel in the frame body. One of them is a filtering capacitor C1, and the other is a DC support film capacitor C2, and it integrates: An EMC boost module for boosting the input power supply voltage to a preset value; A fuse module including a fast fuse K1 and a DC-DC fuse K2; A four-stage EMC filtering module composed of first-stage to fourth-stage EMC filtering circuits connected in sequence; An anti-circulation circuit is provided between the second-stage EMC filtering circuit and the third-stage EMC filtering circuit. The anti-circulation circuit is composed of a filtering capacitor C1, a filtering inductor L2, and a fast fuse K1; Positive and negative copper bars and a grounding copper bar are provided in the frame body. The positive and negative copper bars are provided with installation parts, and both ends of the grounding copper bar extend outside the frame.

2. The capacitor module integrating the functions of EMC boost, fuse and four-stage EMC filtering according to claim 1, wherein, The filtering capacitor C1 and the DC support film capacitor C2 are arranged in parallel, corresponding to the fourth-stage filtering circuit and the anti-circulation circuit in the four-stage EMC filtering module respectively.

3. A capacitor module integrating the functions of EMC boost, fuse and four-stage EMC filtering according to claim 1, characterized in that, The four-stage EMC filtering module specifically includes: The first-stage EMC filtering circuit: includes a differential-mode capacitor CX1, common-mode capacitors CY1, CY2; The second-stage EMC filtering circuit: includes a differential-mode capacitor CX2, common-mode capacitors CY3, CY4, and a differential-mode inductor L1; The third-stage EMC filtering circuit: includes common-mode capacitors CY5, CY6; The fourth-stage EMC filtering circuit: includes common-mode capacitors CY7, CY8, CY9, CY10, CY11, CY12, and the DC support film capacitor C2.

4. The capacitor module integrating the functions of EMC boost, fuse and four-stage EMC filtering according to claim 1, wherein, The fast fuse K1 is arranged in the anti-circulation circuit, and the DC-DC fuse K2 is arranged at the high-voltage input end and works in cooperation with the contactor and the pre-charge circuit; A plurality of EMC capacitor installation positions are provided at the bottom and side of the frame body, and an epoxy resin or polyurethane sealing and filling layer is filled inside.

5. The capacitor module integrating the functions of EMC boost, fuse and four-stage EMC filtering according to claim 1, characterized in that The filtering inductor L2 is composed of a magnetic ring arranged in the frame body, and the positive and negative copper bars pass through the magnetic ring to form an inductor structure; The grounding copper bar forms a multi-point grounding structure through the extended part of the frame body.

6. The capacitor module integrating the functions of EMC boost, fuse and four-stage EMC filtering according to claim 4, wherein, An open installation cavity is provided on the side of the frame body. The common-mode capacitors CY1, CY2, CY3, CY4 are fixed in the open cavity through a potting process, and are directly welded to the extended end of the grounding copper bar.

7. A capacitor module integrating EMC boost, fuse, and four-stage EMC filtering functions, characterized in that, The installation part of the positive and negative copper bars includes a standardized interface, and an insulating isolation groove is provided at the interface. The positive and negative pins of the DC support film capacitor C2 are connected to the copper bar interface through laser welding.

8. The capacitor module integrating EMC boost, fuse and four-stage EMC filtering functions according to claim 5, characterized in that, The magnetic ring is made of nanocrystalline alloy material. The inner diameter of the magnetic ring has a gap of 0.5 - 1 mm with the cross-section of the positive and negative copper bars. The outer surface of the magnetic ring is coated with a silica gel buffer layer and is fixed to the inner wall of the frame body through a snap structure.

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