A film capacitor with integrated online detection EMC and BOOST boost function

Abstract

The present invention discloses a film capacitor with integrated online detection type EMC and BOOST boosting functions, belonging to the technical field of capacitors. A film capacitor with integrated online detection type EMC and BOOST boosting functions, including a shell and several groups of capacitor cores arranged inside the shell, and also including: a positive copper bar and a negative copper bar electrically connected to the capacitor core, the positive copper bar and the negative copper bar are designed as laminated busbars; a polysilicon magnetic ring wrapped on the positive copper bar and the negative copper bar; a Y2 capacitor group, electrically connected to the positive copper bar and the negative copper bar, the Y2 capacitor group and the polysilicon magnetic ring form an LC passive filter; the present invention can filter the electromagnetic interference transmitted by batteries, motors, electronic controls, etc. through power lines and other circuit signal lines at high and low frequencies, and at the same time test whether the filtered data meets the standard requirements.

Description

Technical Field

[0001] The invention relates to the technical field of capacitors, and in particular to a film capacitor integrating online detection type EMC and BOOST boosting functions. Background Art

[0002] The function of film capacitors in motor controllers is BOOST boost. In the circuit topology, the BOOST boost module is composed of inductor L, switch device K and diode D, which can increase the voltage of battery B from V0 to nV0 and apply it to the load R. When the switch K is closed, the current flowing through the inductor L increases, and the electricity is converted into magnetism and stored in the inductor. When the switch K is turned on, the magnetism instantly becomes electricity, and high voltage appears at both ends of the inductor. The current is released from the inductor and flows to the output capacitor C through the diode D. If the current of the inductor L increases linearly at a certain ratio, the discharge path of the inductor is only in the direction of the diode and charges the output capacitor. After multiple switching cycles, the voltage of the output capacitor increases, and the output voltage increases from V0 to nV0.

[0003] Film capacitors with BOOST boost function are generally used in topology circuits where electric vehicle motor controllers need to boost lower battery voltages (such as 300VDC-500VDC) to high voltages (such as 700VDC-900VDC).

[0004] EMC testing mainly includes two aspects. One is electromagnetic interference testing, including radiation testing (electromagnetic waves radiated by the test equipment to the outside world) and conduction testing (electromagnetic interference transmitted by the test equipment through the power line or signal line). The other is electromagnetic immunity testing, such as the test equipment's tolerance to electrostatic discharge, fast transient pulses, surge voltage, etc. The online detection EMC function of the film capacitor with a boost function disclosed in this patent can filter the high and low frequencies of electromagnetic interference transmitted by batteries, motors, electronic controls, etc. through power lines and other circuit signal lines, and at the same time test whether the filtered data meets the standard requirements. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to propose a film capacitor with integrated online detection EMC and BOOST boost functions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The invention comprises a shell and several groups of capacitor cores arranged inside the shell, and also comprises: a positive copper bar and a negative copper bar electrically connected to the capacitor core, wherein the positive copper bar and the negative copper bar are designed as laminated busbars; a polycrystalline silicon magnetic ring wrapped on the positive copper bar and the negative copper bar; a Y2 capacitor group electrically connected to the positive copper bar and the negative copper bar, wherein the Y2 capacitor group and the polycrystalline silicon magnetic ring form an LC passive filter; and the inductance between the positive copper bar and the negative copper bar and the polycrystalline silicon magnetic ring is:

[0008]

[0009] in, ——Inductance value

[0010] ——Magnetic permeability in vacuum, 4π×10 −7 Henry / meter

[0011] ——Relative magnetic permeability of magnetic ring

[0012] ——Equivalent turns of busbar

[0013] ——Cross-sectional area of ​​busbar

[0014] ——Average length of busbar.

[0015] Preferably, it also includes: an integrated wiring harness electrically connected to the Y2 capacitor group, the positive copper busbar and the negative copper busbar.

[0016] Preferably, an insulating film is provided between the positive copper busbar and the negative copper busbar.

[0017] Preferably, the positive copper busbar and the negative copper busbar are low stray inductance wavy laminated busbar designs, comprising two or more wavy laminates passing through the polysilicon magnetic ring.

[0018] Preferably, the wavy stack formed by the positive copper busbar and the negative copper busbar is a triangular wavy line.

[0019] Preferably, the wavy stack formed by the positive copper bar and the negative copper bar is a smooth semicircular wavy line.

[0020] Preferably, the wavy stack formed by the positive copper bar and the negative copper bar is a trapezoidal wavy line.

[0021] Furthermore, the wavy laminated positive copper bar and negative copper bar include two or more wavy laminates passing through the polysilicon magnetic ring, wherein the wavy laminates at both ends are large waves, and the wavy laminates in the middle are small waves, and the wave height relationship between the large waves and the small waves is:

[0022]

[0023]

[0024] in: ——Wave height ratio between large waves and small waves

[0025] ——Big wave height

[0026] ——Small wave height

[0027] ——Increase rate of the ratio of large wave height to small wave height, value range: 0.1-0.12

[0028] ——When the number of small waves in the middle is 0, the height ratio of the large wave to a certain reference inner wave, value: 1

[0029] ——The number of small waves in the middle.

[0030] Preferably, epoxy resin or polyurethane is used to fill the capacitor core in the housing, and the film capacitor is vacuum packaged.

[0031] Compared with the prior art, the present invention provides a film capacitor integrating online detection EMC and BOOST boosting functions, which has the following beneficial effects:

[0032] 1. The film capacitor with integrated online detection EMC and BOOST boost function forms an LC passive filter through a Y2 capacitor group and a polysilicon magnetic ring. The inductor and capacitor are connected in series to filter out the main (3rd, 5th, 7th) harmonics.

[0033] 2. The film capacitor with integrated online detection EMC and BOOST boost function adopts low stray inductance wavy laminated busbar design of positive copper busbar and negative copper busbar, which includes two or more wavy laminated layers passing through polysilicon magnetic ring, so that the overlapping surface is as large as possible, so as to achieve the effect of canceling out the noise of positive and negative signals on the DC bus.

[0034] 3. The film capacitor with integrated online detection EMC and BOOST boost function connects one end of the integrated wiring harness to the positive copper bus and the negative copper bus, and the other end to the EMC comprehensive tester. When the capacitor is installed on the motor controller and powered on, the EMC comprehensive tester can extract the noise signal on the capacitor bus and monitor the electromagnetic compatibility effect in real time. This function can realize system debugging in the product development stage and real-time EMC monitoring in the market application stage.

[0035] The parts not involved in the film capacitor with integrated online detection EMC and BOOST boost function are the same as the existing technology or can be implemented by using the existing technology. The present invention can filter the high and low frequencies of electromagnetic interference transmitted by batteries, motors, electronic controls, etc. through power lines and other circuit signal lines, and test whether the filtered data meets the standard requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the overall structure of a film capacitor with integrated online detection EMC and BOOST boost functions proposed by the present invention;

[0037] Figure 2 The internal structure of a film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 1 ;

[0038] Figure 3 The internal structure of a film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 2 ;

[0039] Figure 4 This is a structural schematic diagram of the polysilicon magnetic ring part of a film capacitor with integrated online detection EMC and BOOST boosting functions proposed by the present invention;

[0040] Figure 5 The structure of the positive copper bar and the negative copper bar of the film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 1 ;

[0041] Figure 6 The present invention proposes a film capacitor with integrated online detection EMC and BOOST boost function. Figure 5 The enlarged structural diagram of part A in the middle;

[0042] Figure 7 The structure of the positive copper bar and the negative copper bar of the film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 2 ;

[0043] Figure 8 The structure of the positive copper bar and the negative copper bar of the film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 3 ;

[0044] Fig. 9The structure of the positive copper bar and the negative copper bar of the film capacitor with integrated online detection EMC and BOOST boost function proposed by the present invention is shown in FIG. Figure 4 ;

[0045] Fig.10 A film capacitor with integrated online detection EMC and BOOST boost functions proposed by the present invention;

[0046] Fig.11 This is a circuit topology diagram inside a film capacitor with integrated online detection EMC and BOOST boost functions proposed by the present invention.

[0047] In the figure: 1. Shell; 2. Integrated wiring harness; 3. Polysilicon magnetic ring; 4. Positive copper busbar; 5. Negative copper busbar; 6. Capacitor core; 7. Y2 capacitor group; 8. Insulating film. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0049] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0050] Reference Figure 1-Figure 11 , including a housing 1 and a plurality of groups of capacitor cores 6 arranged inside the housing 1, and also including: a positive copper bar 4 and a negative copper bar 5 electrically connected to the capacitor core 6, the positive copper bar 4 and the negative copper bar 5 are designed as laminated busbars; a polycrystalline silicon magnetic ring 3 wrapped around the positive copper bar 4 and the negative copper bar 5; a Y2 capacitor group 7, electrically connected to the positive copper bar 4 and the negative copper bar 5, the Y2 capacitor group 7 and the polycrystalline silicon magnetic ring 3 form an LC passive filter; the inductance between the positive copper bar 4 and the negative copper bar 5 and the polycrystalline silicon magnetic ring 3 is:

[0051]

[0052] in, ——Inductance value

[0053] ——Magnetic permeability in vacuum, 4π×10 −7 Henry / meter

[0054] ——Relative magnetic permeability of magnetic ring

[0055] ——Equivalent turns of busbar

[0056] ——Cross-sectional area of ​​busbar

[0057] ——Average length of busbar.

[0058] In the present invention, the film capacitor is internally integrated with an EMC (electromagnetic compatibility) filter module, which is implemented by two parts. One is an LC filter composed of two groups of Y2 capacitors and a polysilicon magnetic ring 3, and the other is a DC busbar positive and negative busbar low stray inductance laminated busbar design, so that the surface overlaps and passes through the magnetic ring, and the noise of the positive and negative pole signals on the busbar can be offset. When the capacitor is mounted on the motor controller and powered on, the noise conducted and radiated by the battery, motor, electronic control, etc., the EMC filter module can filter out the high and low frequency bands to meet the national standard requirements;

[0059] The Y2 capacitor group 7 includes two groups of Y2 capacitors, the two groups of Y2 capacitors are connected in series, and each group of Y2 capacitors includes two Y2 capacitors connected in parallel;

[0060] By calculating the inductance between the positive copper bus 4, the negative copper bus 5 and the polysilicon magnetic ring 3, the noise cancellation effect and filtering effect of the positive and negative signals can be evaluated, and the functional adjustment and operation stability maintenance of the film capacitor can be achieved by adjusting the current and voltage in real time.

[0061] Reference Figure 1-Figure 11 , and also includes: an integrated wiring harness 2 electrically connected to the Y2 capacitor group 7, the positive copper bar 4 and the negative copper bar 5; an insulating film 8 is provided between the positive copper bar 4 and the negative copper bar 5.

[0062] In the present invention, the integrated wiring harness 2 is an integrated voltage acquisition wiring harness, one end of which is connected to the positive and negative poles of the busbar (i.e., the positive copper busbar 4 and the negative copper busbar 5), and the other end is connected to the EMC comprehensive tester. When the capacitor is mounted on the motor controller and powered on, the EMC comprehensive tester can extract the noise signal on the capacitor busbar and monitor the electromagnetic compatibility effect in real time. This function can realize system debugging in the product development stage and real-time EMC monitoring in the market application stage.

[0063] Reference Figure 1-Figure 11 The positive copper busbar 4 and the negative copper busbar 5 are low stray inductance wavy laminated busbar designs, comprising two or more wavy laminated layers passing through the polysilicon magnetic ring 3 .

[0064] In the present invention, the wavy design helps to reduce the stray inductance generated during the flow of current. The stray inductance is unnecessary inductance in the current path, which will cause energy loss and electromagnetic interference. Through the wavy laminated design, the current path is optimized, so that the inductance value is reduced, thereby improving the efficiency and stability of the system; the laminated design not only increases the surface area of ​​the copper busbar, which is beneficial to heat dissipation, but also makes the current distribution more uniform. In the polycrystalline silicon magnetic ring 3, this laminated structure can better interact with the magnetic ring to improve the electromagnetic conversion efficiency. In addition, the polycrystalline silicon magnetic ring 3 has good magnetic permeability and magnetic saturation characteristics, and can effectively guide and control the magnetic field. When the wavy laminated busbar passes through the polycrystalline silicon magnetic ring 3, the magnetic ring can enhance or change the magnetic field distribution around the busbar, thereby further optimizing the electromagnetic performance; such a low stray inductance design helps to reduce electromagnetic radiation and electromagnetic interference, and improve the electromagnetic compatibility of the entire system;

[0065] The wavy shape can increase the contact area between the copper bars, thereby improving the tightness and stability of the connection. A larger contact area helps reduce contact resistance and improve current transmission efficiency. The wavy design can reduce the gap between the copper bars to a certain extent, reducing the electromagnetic interference and stray inductance caused by the gap. The wavy shape can increase the surface area of ​​the copper bar, which is beneficial to heat dissipation. During the current transmission process, the copper bar will generate a certain amount of heat. Good heat dissipation performance helps to maintain the stable operation of the system.

[0066] Reference Figure 8 The wavy stack formed by the positive copper bar 4 and the negative copper bar 5 is a triangular wavy line.

[0067] In the present invention, the triangular wave line has sharp peaks and troughs, which may produce a strong electromagnetic concentration effect locally. In situations where the local magnetic field or heat dissipation effect needs to be enhanced, the triangular wave line design may be more effective; the BOOST boost function is an important feature of this film capacitor, which can increase the battery voltage to a higher level to meet the power supply requirements of motors and other equipment in new energy vehicles. The triangular wave design may help to form a more complex electric and magnetic field distribution inside the capacitor, which may be beneficial to improving the efficiency and stability of the BOOST boost.

[0068] refer to Figure 7 The wavy stack formed by the positive copper bar 4 and the negative copper bar 5 is a smooth semicircular wavy line.

[0069] In the present invention, the semicircular arc shape design makes the copper busbar surface smooth and continuous, reducing right angles and sharp parts. This design helps to reduce electromagnetic radiation and interference because the smooth surface reduces the scattering of electromagnetic waves. At the same time, the semicircular arc shape also helps to improve the heat dissipation efficiency because the smooth surface is conducive to air flow and heat transfer.

[0070] refer to Fig. 9 The wavy stack formed by the positive copper bar 4 and the negative copper bar 5 is a trapezoidal wavy line.

[0071] In the present invention, the trapezoidal wave line presents a trapezoidal change in cross section, with a gradually increasing width or height, and this design can provide different inductance values ​​and electromagnetic shielding effects at different positions; due to the change in the trapezoidal cross section, the current may generate an uneven magnetic field distribution during transmission, and this unevenness may help optimize the filtering effect or electromagnetic compatibility;

[0072] refer to Figure 1-Figure 11 Furthermore, the wavy laminated positive copper bar 4 and the negative copper bar 5 include two or more wavy laminates passing through the polysilicon magnetic ring 3, wherein the wavy laminates at both ends are large waves, and the wavy laminates in the middle are small waves, and the wave height relationship between the large waves and the small waves is:

[0073]

[0074]

[0075] in: ——Wave height ratio between large waves and small waves

[0076] ——Big wave height

[0077] ——Small wave height

[0078] ——Increase rate of the ratio of large wave height to small wave height, value range: 0.1-0.12

[0079] ——When the number of small waves in the middle is 0, the height ratio of the large wave to a certain reference inner wave, value: 1

[0080] ——The number of small waves in the middle.

[0081] Specifically, the two triangles at the edge of the triangular wavy line are the largest, and the several triangles in the middle are smaller than the two large triangles at the edge, such as Figure 8As shown, setting the two triangular waves at the edge to the maximum can more effectively guide the electromagnetic field to form a stronger concentration effect at the edge of the capacitor. This design helps to form a "barrier" at the edge of the capacitor, making the electromagnetic field more inclined to circulate inside the capacitor rather than radiate directly outward; at the same time, setting the middle waves to the minimum can reduce the interference and obstruction of these areas to the electromagnetic field. The design of small waves makes the current flow more smoothly in these areas, reducing the mutation and fluctuation of the electromagnetic field, thereby helping to maintain the stability and orderliness of the electromagnetic field;

[0082] Moreover, the large waves at the edge can not only guide the electromagnetic field, but also serve as a part of the electromagnetic shielding. They can block or weaken the radiation of the electromagnetic field inside the capacitor to the external space, thus improving the electromagnetic shielding performance of the capacitor.

[0083] The same is true for semicircular wavy lines and trapezoidal wavy lines.

[0084] By designing the positive copper busbar 4 and the negative copper busbar 5 as low stray inductance wavy laminated busbars, the wavy line design can increase the surface area of ​​the copper busbar, thereby reducing resistance and energy loss, which helps to improve current transmission efficiency and reduce heat generation; the wavy line shape design helps to increase the contact area between the copper busbar and the surrounding environment and improve the heat dissipation efficiency, especially in high-power transmission occasions, this advantage is particularly obvious; by optimizing the shape and size of the wavy line, the electromagnetic characteristics of the copper busbar can be adjusted, thereby reducing the electromagnetic radiation and interference level, which helps to improve the electromagnetic compatibility of the entire system; the wavy line design can increase the rigidity and toughness of the copper busbar and improve its stability under mechanical stress and vibration environments, which is of great significance for ensuring the long-term stable operation of the DC busbar; the wavy line design can be adjusted and optimized according to actual needs to adapt to different layouts and space constraints, which helps to achieve a more compact and efficient electrical system design.

[0085] In one embodiment, reference Fig.11 , the internal circuit topology of the film capacitor, the DC current is output from P(in) and P(out), output from N(in) and N(out), and the ripple current is input and output from C. The present application adopts the design of independent routing of the DC bus P(in)-P(out), N(in)-N(out) and the capacitor welding busbar and then merging, which can reduce the temperature rise of the capacitor core 6 when the DC busbar is over-current. At the same time, the two nuts on the DC busbar copper bar are made of T2 copper, and brazing is filled at the connection between the nut and the busbar. High-frequency welding technology is adopted to enable the nut to have the function of fixed installation and large current flow;

[0086] The value range of the components in this circuit topology diagram is:

[0087] 45μF≤C≤200μF

[0088] 11μH≤L≤30μH

[0089] 0.001μF≤CY1=CY2≤0.1μF

[0090] 0.1μF≤CY3=CY4≤0.47μF.

[0091] Reference Figure 1-Figure 11 The capacitor core 6 in the housing 1 is filled with epoxy resin or polyurethane, and the film capacitor is vacuum packaged.

[0092] In the present invention, epoxy resin or polyurethane materials are used to fill the capacitor core 6 of the film capacitor and vacuum package it, which can significantly improve the insulation performance, mechanical strength, thermal stability and electrical performance of the capacitor, which is crucial to ensure the long-term stable operation and reliability of the capacitor.

[0093] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A film capacitor integrating online detection type EMC and BOOST boosting functions, comprising a housing (1) and a plurality of groups of capacitor cores (6) arranged inside the housing (1), characterized in that: Also includes: A positive copper busbar (4) and a negative copper busbar (5) electrically connected to the capacitor core (6), wherein the positive copper busbar (4) and the negative copper busbar (5) are of laminated busbar design; A polycrystalline silicon magnetic ring (3) wrapped around the positive copper busbar (4) and the negative copper busbar (5); A Y2 capacitor group (7) is electrically connected to the positive copper busbar (4) and the negative copper busbar (5), and the Y2 capacitor group (7) and the polysilicon magnetic ring (3) form an LC passive filter; The inductance between the positive copper bar (4) and the negative copper bar (5) and the polysilicon magnetic ring (3) is: Among them, L——inductance value μ0——Magnetic permeability in vacuum, 4π×10-7 Henry / meter μ r ——Relative magnetic permeability of magnetic ring N——Equivalent turns of busbar S——Cross-sectional area of ​​busbar l——average length of busbar; The positive copper busbar (4) and the negative copper busbar (5) are low stray inductance wavy laminated busbar designs, comprising two or more wavy laminated layers passing through the polycrystalline silicon magnetic ring (3); The wavy laminated positive copper bar (4) and negative copper bar (5) comprise two or more wavy laminates passing through the polysilicon magnetic ring (3), wherein the wavy laminates at both ends are large waves, and the wavy laminates in the middle are small waves, and the wave height relationship between the large waves and the small waves is: R=a·N+b Where: R——Ratio of wave height between large waves and small waves A——Height of big wave B——Height of small wave a——Increase rate of the ratio of large wave height to small wave height, value range: 0.1-0.12 b——When the number of small waves in the middle is 0, the height ratio of the large wave to a certain reference inner wave, value: 1 N——The number of small waves in the middle.

2. The film capacitor with integrated online detection EMC and BOOST boosting functions according to claim 1, characterized in that: It also includes: an integrated wiring harness (2) electrically connected to the Y2 capacitor group (7), the positive copper busbar (4) and the negative copper busbar (5).

3. The film capacitor with integrated online detection EMC and BOOST boost function according to claim 1, characterized in that: An insulating film (8) is provided between the positive electrode copper busbar (4) and the negative electrode copper busbar (5).

4. The film capacitor with integrated online detection EMC and BOOST boost function according to claim 1, characterized in that: The wavy stack formed by the positive copper busbar (4) and the negative copper busbar (5) is a triangular wavy line.

5. The film capacitor with integrated online detection EMC and BOOST boosting functions according to claim 1, characterized in that: The wavy stack formed by the positive copper busbar (4) and the negative copper busbar (5) is a smooth semicircular wavy line.

6. The film capacitor with integrated online detection EMC and BOOST boosting functions according to claim 1, characterized in that: The wavy stack formed by the positive electrode copper busbar (4) and the negative electrode copper busbar (5) is a trapezoidal wavy line.

7. The film capacitor with integrated online detection EMC and BOOST boosting functions according to claim 1, characterized in that: The capacitor core (6) in the housing (1) is filled with epoxy resin or polyurethane, and the film capacitor is vacuum packaged.

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