Capacitor busbar with telescopic low-inductance magnetic ring for reducing electromagnetic interference

Abstract

The invention discloses a capacitor busbar with telescopic low-inductance magnetic rings for reducing electromagnetic interference, and relates to the field of electromagnetic interference suppression. The capacitor busbar comprises a busbar, and a plurality of capacitor cores are wrapped in the busbar; the terminals comprise a first terminal and a second terminal, a filter capacitor is connected between the first terminal and the second terminal, the first terminal and the second terminal are telescopically sleeved with the two magnetic rings respectively, at least one part of the two magnetic rings are connected to achieve synchronous telescopic movement, a telescopic body is fixedly connected to the busbar on one side of the magnetic rings, the telescopic body is connected with the two magnetic rings, and the telescopic body is connected with the two magnetic rings. And the driving module is used for driving the magnet ring to stretch up and down to change the coverage area of the magnet ring to the terminal. Compared with a traditional electromagnetic interference suppression device, the capacitor busbar is more effective and flexible, the magnetic rings can be telescopically adjusted, heat dissipation is efficient, electromagnetic interference can be suppressed under different working condition requirements, inductance is reduced, system performance is improved, and potential safety hazards are avoided.

Description

Technical Field

[0001] The invention belongs to the field of electromagnetic interference suppression, and in particular relates to a capacitor busbar with a low-inductance magnetic ring that can be retracted to reduce electromagnetic interference. Background Art

[0002] Nowadays, new energy vehicles are developing rapidly, and the increase of electromagnetic interference in new energy vehicles is an inevitable problem compared with traditional vehicles. The motor drive controller is the main source of electromagnetic interference. The rapid opening and closing of power devices in the motor controller will generate high-frequency voltage and current, which will flow in the line, thereby generating electromagnetic interference; the current of the inductive load will not change transiently after the power is cut off. Due to this characteristic, a reverse voltage pulsation will be caused when the switch is disconnected, forming a current in the circuit, forming electromagnetic interference to the system; PWM signals, devices with high-frequency parameters, etc. will cause certain electromagnetic interference to the system. In addition, inductance will also be generated in the motor controller. Unreasonable inductance will also generate electromagnetic interference and generate a lot of heat, which will affect the surrounding components and even the life of the system. Electromagnetic interference will affect the normal operation of the system. The electromagnetic waves generated by electromagnetic interference will affect the signals of the transmission line and the receiver, causing distortion and interruption of the control signal, resulting in the controller being unable to accurately execute instructions. In addition, the signal distortion and interruption caused by electromagnetic interference will cause the controller to be unable to detect the fault of the motor, which will bring serious safety hazards. Therefore, in order to ensure the normal operation of the motor controller and avoid safety hazards, it is very important to reduce the inductance and suppress electromagnetic interference.

[0003] Most of the existing electromagnetic interference suppression devices are special filters. Adding filters after the power supply or capacitor increases the weight and cost of the controller. On the other hand, the interference suppression frequency band is small, and it is difficult to suppress electromagnetic interference outside its fixed frequency band. When some electromagnetic interference is suppressed by magnetic rings, the method is single and cannot cope with the different degrees of electromagnetic interference generated under different working conditions. Moreover, these devices cannot achieve the effect of reducing inductance. In addition, some adjustment devices have slow response and low precision, and generate heat during the operation of the interference suppression equipment. The existing devices also lack effective heat dissipation capabilities.

[0004] In view of the above problems existing in the prior art, it is necessary to propose a capacitor busbar device which can reduce inductance, has a retractable magnetic ring to suppress electromagnetic interference and has efficient heat dissipation, so as to suppress electromagnetic interference under different working conditions, reduce inductance, improve system performance and avoid safety hazards. Summary of the invention

[0005] The purpose of the present invention is to provide a capacitor busbar with a low inductance magnetic ring that can be retracted to reduce electromagnetic interference, so as to solve the problems existing in the prior art, such as the small number of electromagnetic interference suppression frequency bands, the lack of accurate suppression of electromagnetic interference under different working conditions, the filter increasing the cost and volume of the motor controller, the low response speed, and the low heat dissipation efficiency.

[0006] To achieve the above object, the present invention provides a capacitor busbar with a low inductance magnetic ring that can be retracted to reduce electromagnetic interference, comprising:

[0007] Busbar;

[0008] Capacitor cores, a plurality of the capacitor cores are wrapped in the busbar;

[0009] Terminals, the terminals are led out from the capacitor core, the terminals include terminal 1 and terminal 2, and a filter capacitor is connected between the terminal 1 and the terminal 2;

[0010] Magnetic rings, wherein the two magnetic rings can be telescopically sleeved outside the first terminal and the second terminal respectively, and at least a part of the two magnetic rings are connected to achieve synchronous telescopic movement;

[0011] The telescopic body is fixedly connected to the busbar on the side of the magnetic ring and connected to the two magnetic rings, and is used to drive the magnetic ring to stretch up and down to change the coverage area of ​​the magnetic ring on the terminal.

[0012] The above structure aims to propose a capacitor busbar with reduced inductance, retractable magnetic ring to suppress electromagnetic interference and efficient heat dissipation, so as to suppress electromagnetic interference under different working conditions, reduce inductance, improve system performance and avoid safety hazards.

[0013] Preferably, the magnetic ring comprises magnetic ring one, magnetic ring two and magnetic ring three which are telescopically sleeved in sequence, and the two magnetic rings one located outside the two terminals are connected in an 8-shape.

[0014] Preferably, a current sensor is installed at a middle position where the two magnetic rings are connected, and the current sensor is electrically connected to a control board, and the control board is electrically connected to the telescopic body.

[0015] Preferably, a plurality of heat sinks are circumferentially distributed in the annular internal gap of the magnetic ring, and the gap is filled with a phase change material in contact with the heat sink.

[0016] Preferably, a plurality of annular flanges are protruded from the outer peripheral side of the heat sink.

[0017] Preferably, the material of the magnetic ring is at least one of manganese-zinc ferrite and nickel-zinc ferrite.

[0018] Preferably, the telescopic body includes a telescopic outer rod and a telescopic inner rod axially slidably sleeved together, and a servo motor driving the telescopic inner rod to move axially, and one end of the telescopic inner rod away from the telescopic outer rod is fixedly connected to a connecting rod, and one end of the connecting rod away from the telescopic inner rod is connected to the top of the magnetic ring through an annular body.

[0019] Preferably, the telescopic outer rod has an inner cavity for accommodating the insertion of the telescopic inner rod, the inner cavity has a baffle, the baffle and the insertion end of the telescopic inner rod are connected with a spring, and the servo motor is connected to the insertion end of the telescopic inner rod to drive the telescopic inner rod to move axially.

[0020] Preferably, the gap between the capacitor core and the busbar is fixed by adding a filler, and the filler is epoxy resin.

[0021] Preferably, a plurality of circular holes are formed on the side and bottom of the busbar.

[0022] The present invention discloses the following technical effects:

[0023] The present invention provides a more effective, flexible and adjustable suppression structure than the traditional electromagnetic interference suppression device. The magnetic ring and the filter capacitor are installed together on the capacitor busbar to suppress different types of electromagnetic interference. At the same time, according to the different currents fed back in the circuit under different working conditions, the telescopic rod is driven to move, so as to change the area of ​​the busbar terminal covered by the magnetic ring, thereby suppressing electromagnetic interference under different frequency bands and working conditions. In view of the problems existing in the prior art, the present invention can detect the current through a high-precision sensor and use a servo motor to realize active telescopic and flexible, accurate and rapid change of the busbar area covered by the magnetic ring, so as to accurately suppress electromagnetic interference of different degrees, reduce inductance, and have efficient heat dissipation capabilities, thereby improving the performance of the motor control system and avoiding safety hazards. It has a certain reference value for the research on improving the working performance and service life of the motor controller and the design of the electromagnetic interference suppression structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the connection between the busbar and the terminal in an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of a magnetic ring in an embodiment of the present invention;

[0028] Figure 4 A top view of a magnetic ring 1 in an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of a current sensor in a magnetic ring 1 of the present invention;

[0030] Figure 6 It is a schematic diagram of the structure of the heat sink in the magnetic ring 1 of the present invention;

[0031] Figure 7 It is a structural schematic diagram of a telescopic body in an embodiment of the present invention;

[0032] Figure 8 1 is a diagram showing the internal structure of the telescopic outer rod in an embodiment of the present invention.

[0033] In the figure: 1. terminal; 11. terminal one; 12. terminal two; 2. magnetic ring; 21. magnetic ring one; 22. magnetic ring two; 23. magnetic ring three; 24. current sensor; 25. heat sink; 26. phase change material; 3. busbar; 4. capacitor core; 5. telescopic body; 51. telescopic outer rod; 52. telescopic inner rod; 53. connecting rod; 54. annular body; 55. spring; 56. baffle; 57. servo motor; 6. filter capacitor. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figures 1 to 8As shown, the present invention provides a low-inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference, comprising a busbar 3, a capacitor core 4, a terminal 1, a magnetic ring 2, a filter capacitor 6, a telescopic body 5 and a control board for controlling the operation of the system; wherein a plurality of capacitor cores 4 are wrapped in the busbar 3 to achieve upper and lower connection conduction, each capacitor core 4 leads to a group of terminals 1, the terminals 1 are fixed on the busbar 3 by welding, so that they are parallel and overlapped, which is conducive to reducing inductance; each group of terminals 1 includes a terminal 11 and a terminal 2 12, the terminal 1 11 and the terminal 2 12 are input terminals 1 and output terminals 1 respectively, and the filter capacitor 6 is connected to the electronic one and Between the terminals 2 and 12, the magnetic ring 2 and the filter capacitor 6 are combined to achieve comprehensive suppression of common-mode and differential-mode electromagnetic interference, and the parallel overlapping distribution of the busbar 3 terminals 1 reduces the capacitor inductance; the gap between the capacitor core 4 and the busbar 3 is fixed by adding fillers; the magnetic ring 2 adopts a retractable structure, and the magnetic ring 2 adopts a double-ring structure, which is respectively sleeved on the outside of the terminal 1 11 and the terminal 2 12 to cover the two terminals 1 respectively; the telescopic body 5 is fixed to the busbar 3 on the side of the magnetic ring 1 21, and its extended end is connected to the top of the magnetic ring 2, which is used to drive the magnetic ring 2 to move up and down, thereby realizing the change of the area of ​​the terminal 1 covered by the magnetic ring 2.

[0037] The above structure adopts a telescopic variable magnetic ring 2 structural design. The telescopic rod is controlled by the control panel to accurately control the extension and retraction of the magnetic ring 2, thereby changing the area covering the busbar 3 terminal 1, realizing the interference characteristics under different working conditions and conditions, and achieving precise suppression.

[0038] Further optimization scheme, such as Figures 3 to 6 As shown, the magnetic ring 2 includes a magnetic ring 1 21, a magnetic ring 22 and a magnetic ring 3 23, and the magnetic ring 1 21, the magnetic ring 22 and the magnetic ring 3 23 are telescopically sleeved in sequence, wherein the two magnetic rings 1 21 located outside the two terminals 1 are connected in an 8-shaped manner, and the two can be integrally formed, the two magnetic rings 22 are independently telescopically sleeved in the two magnetic rings 1 21, and the two magnetic rings 3 23 are independently telescopically sleeved in the two magnetic rings 22, and the tops of the two magnetic rings 3 23 are connected to the telescopic body 5, and move with the up and down movement of the telescopic body 5 to change the adjustment of the coverage area of ​​the terminal 1 11 and the terminal 2 12. The use of the 8-shaped magnetic ring 2 structure can achieve the purpose of separate suppression, and the terminals 1 at the input and output ends are separately suppressed.

[0039] Further optimization scheme, such as Figure 4 and Figure 5 As shown, a high-precision current sensor 24 is installed in the middle position where the two magnetic rings 21 are connected. The current sensor 24 is used to detect the current in the system and feed back the current signal received by the sensor to the control board. The control board calculates the area of ​​the terminal 1 covered by the magnetic ring 2 according to the current situation and transmits the adjustment signal to the servo motor 57.

[0040] Further optimization scheme, such as Figure 4 As shown, multiple heat sinks 25 are circumferentially distributed in the annular internal gaps of magnetic ring 1 21, magnetic ring 22 and magnetic ring 3 23 to increase the heat dissipation area, and phase change material 26 is filled in the annular internal gaps. The phase change material 26 is in full contact with the heat sink 25, and the two cooperate to achieve a more efficient heat dissipation effect.

[0041] Further optimization scheme, such as Figure 5 As shown, the outer periphery of the heat sink 25 is protruded with a plurality of annular flanges to increase the contact area with the phase change material 26 and thus improve the heat dissipation effect.

[0042] In some other embodiments, the heat sink 25 is a spherical heat sink.

[0043] Further optimization scheme, such as Figure 7 As shown, the telescopic body 5 includes a telescopic outer rod 51, a telescopic inner rod 52, a connecting rod 53, an annular body 54 and a servo motor 57 for driving the telescopic inner rod 52 to slide back and forth along the inner cavity of the telescopic outer rod 51; wherein the telescopic outer rod 51 has an inner cavity for accommodating the axial insertion of the telescopic inner rod 52, and a baffle 56 is provided in the inner cavity, a spring 55 is connected between the baffle 56 and the end surface of the telescopic inner rod 52, and the servo motor 57 is arranged in the inner cavity; the connecting rod 53 is used to connect the magnetic ring 3 23 and the telescopic inner rod 52, The top of the magnetic ring three 23 is connected to an annular body 54, and the annular body 54 is fixedly connected to one end of the connecting rod 53. The other end of the connecting rod 53 is fixedly connected to the end of the telescopic inner rod 52 and is perpendicular to the telescopic inner rod 52. The servo motor 57 is covered with a line, and the other end of the line is connected to the telescopic inner rod 52. The servo motor 57 drives the axial movement of the telescopic rod through the cooperation of the line and the spring 55. The servo motor 57 can greatly improve the accuracy and speed of the telescopic adjustment and accurately control the position of the magnetic ring 2.

[0044] To further optimize the solution and achieve common suppression of interference in different frequency bands, the magnetic ring 2 uses one of the two materials, manganese-zinc ferrite or nickel-zinc ferrite, or a combination of the two materials, and the interior of the magnetic ring 2 is filled with a phase change material 26, which is combined with the heat sink 25 to achieve efficient heat dissipation.

[0045] To further optimize the solution, the magnetic ring 2 can be manufactured by using an investment casting sintering process.

[0046] According to a further optimization scheme, in the telescopic body 5, the spring 55 is manufactured by a hot rolling process, and the telescopic rod is manufactured by cutting, welding and other processes.

[0047] To further optimize the solution, in order to facilitate the injection of epoxy resin and the heat dissipation of the clamping block, a number of circular holes are opened on the side and bottom of the busbar 3.

[0048] In some embodiments, the filler of the gap between the capacitor core 4 and the busbar 3 is epoxy resin.

[0049] In some embodiments, the busbar 3 and the terminal 1 are made of a tube, the capacitor core 4 is made of a polypropylene film, and the magnetic ring 2 is made of a ferrite material.

[0050] When assembling the capacitor busbar of the above embodiment, the structural assembly of the telescopic body 5 is completed first, and then the magnetic ring 2 is assembled, and then the busbar 3 and the capacitor core 4 are assembled, and finally the internal gap is poured with a filler.

[0051] The working principle of the embodiment of the present invention is as follows:

[0052] Power devices, inductive loads, etc. will generate high-frequency current in the circuit, thereby forming electromagnetic interference. The magnetic ring 2 is a high-frequency impedance element mounted on the terminal 1. When high-frequency noise passes through the magnetic ring 2, it is suppressed by the high impedance characteristics, thereby reducing the conduction and radiation of electromagnetic interference. The current sensor 24 is placed in the hole in the middle of the magnetic ring 21 to detect the current in the system and feed back the current signal received by the sensor to the control board. The control board calculates the area of ​​the terminal 1 covered by the magnetic ring 2 according to the current situation, and transmits the adjustment signal to the servo motor 57. The servo motor 57 can achieve fast and accurate driving according to the size of the current, and combines with the spring 55 to achieve the up and down movement of the telescopic rod, and drives the magnetic ring 2 to move telescopically through the connecting rod 53, so as to accurately control the position of the magnetic ring 2, so as to achieve accurate suppression according to the interference characteristics under different working conditions and conditions, and combine with the filter capacitor 6 to achieve comprehensive suppression of differential mode interference and common mode interference, and reduce the inductance through the parallel overlapping distribution of the terminals 1, improve the performance of the system, and avoid safety hazards.

[0053] It should be understood that, in practical applications, the servo motor 57 may also be other drive structures or mechanical devices capable of realizing linear motion functions / rotational motion / telescopic motion, for example, it may be a telescopic motor, a hydraulic cylinder, an electric cylinder, and the like.

[0054] Compared with the prior art, the embodiments of the present invention at least disclose the following beneficial effects:

[0055] 1. The low inductance magnetic ring of the present invention can be retracted to reduce the electromagnetic interference of the capacitor busbar, and a special heat dissipation ball is used to increase the heat dissipation area, and is combined with the phase change material 26 to achieve efficient heat dissipation of the suppression device.

[0056] 2. The low-inductance magnetic ring of the present invention can be retracted to reduce the capacitor busbar of electromagnetic interference. The advanced servo motor 57 is used to drive the telescopic rod to accurately control the extension and retraction of the magnetic ring, and the area of ​​the terminal 1 covered by the magnetic ring 2 is accurately changed to realize the interference characteristics under different working conditions and conditions, and achieve accurate suppression.

[0057] 3. The low inductance magnetic ring of the present invention can be retracted to reduce the capacitor busbar of electromagnetic interference, and the "8"-shaped magnetic ring 2 is used to achieve the respective suppression of the input and output ends, and the terminals 1 on the busbar 3 are parallel and overlapped to reduce the inductance of the capacitor.

[0058] 4. The low-inductance magnetic ring of the present invention can be retracted to reduce the capacitor busbar of electromagnetic interference. The magnetic ring 2 and the filter capacitor 6 are combined to achieve comprehensive suppression of common-mode and differential-mode electromagnetic interference, replace additional filters to suppress electromagnetic interference, and improve the integration of the motor controller.

[0059] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0060] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do 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 understood as a limitation on the present invention.

[0061] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A low inductance magnetic ring that can be retracted to reduce electromagnetic interference capacitor busbar, characterized in that: include: Busbar (3); A capacitor core (4), wherein a plurality of the capacitor cores (4) are wrapped in the busbar (3); Terminals (1), the terminals (1) being led out from the capacitor core (4), the terminals (1) comprising a first terminal (11) and a second terminal (12), a filter capacitor (6) being connected between the first terminal (11) and the second terminal (12); A magnetic ring (2), wherein the two magnetic rings (2) are respectively telescopically sleeved outside the first terminal (11) and the second terminal (12), and at least a portion of the two magnetic rings (2) are connected to achieve synchronous telescopic movement; The telescopic body (5) is fixedly connected to the busbar (3) on one side of the magnetic ring (2), connected to the two magnetic rings (2), and is used to drive the magnetic ring (2) to stretch up and down, so as to change the coverage area of ​​the magnetic ring (2) on the terminal (1).

2. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 1 is characterized in that: The magnetic ring (2) comprises a magnetic ring one (21), a magnetic ring two (22) and a magnetic ring three (23) which are telescopically sleeved in sequence, and the two magnetic rings one (21) located outside the two terminals (1) are connected in an 8-shaped manner.

3. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 2 is characterized in that: A current sensor (24) is installed at the middle position where the two magnetic rings (21) are connected. The current sensor (24) is electrically connected to a control board, and the control board is electrically connected to the telescopic body (5).

4. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 2 is characterized in that: A plurality of heat sinks (25) are distributed circumferentially in the annular internal space of the magnetic ring (2), and the space is filled with a phase change material (26) in contact with the heat sink (25).

5. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 4 is characterized in that: The outer peripheral side of the heat sink (25) is protruded with a plurality of annular flanges.

6. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 1, characterized in that: The material of the magnetic ring (2) is at least one of manganese-zinc ferrite and nickel-zinc ferrite.

7. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 1, characterized in that: The telescopic body (5) comprises a telescopic outer rod (51) and a telescopic inner rod (52) which are axially slidably sleeved, and a servo motor (57) which drives the telescopic inner rod (52) to move axially, and one end of the telescopic inner rod (52) away from the telescopic outer rod (51) is fixedly connected with a connecting rod (53), and one end of the connecting rod (53) away from the telescopic inner rod (52) is connected to the top of the magnetic ring (2) through an annular body (54).

8. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 7, characterized in that: The telescopic outer rod (51) has an inner cavity for accommodating the insertion of the telescopic inner rod (52), and the inner cavity has a baffle (56). The baffle (56) and the insertion end of the telescopic inner rod (52) are connected with a spring (55). The servo motor (57) is connected to the insertion end of the telescopic inner rod (52) to drive the telescopic inner rod (52) to move axially.

9. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 1, characterized in that: The gap between the capacitor core (4) and the busbar (3) is fixed by adding a filler, and the filler is epoxy resin.

10. The low inductance magnetic ring retractable capacitor busbar for reducing electromagnetic interference according to claim 9, characterized in that: The side and bottom of the busbar (3) are provided with a plurality of circular holes.

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