WO2024120370A1

WO2024120370A1 - Damping inductor, filtering apparatus, and compressor apparatus

Info

Publication number: WO2024120370A1
Application number: PCT/CN2023/136365
Authority: WO
Inventors: 奚义义; 熊小五; 池上洋; 凌志超; 吴春林
Original assignee: 法雷奥日本株式会社; 奚义义
Priority date: 2022-12-06
Filing date: 2023-12-05
Publication date: 2024-06-13
Also published as: CN118197756A

Abstract

The present disclosure relates to an electronic component, and in particular to a damping inductor for suppressing resonance. The damping inductor comprises: a magnetic conductive core body; and a winding, which is wound around at least a portion of the magnetic conductive core body, wherein the magnetic conductive core body comprises a first magnetic part, the first magnetic part comprises a first magnetic material, the first magnetic material has a first magnetic loss in a first frequency range, the first magnetic material has a second magnetic loss in a second frequency range, any frequency in the first frequency range is higher than any frequency in the second frequency range, and the first frequency range is a frequency range comprising a target resonant frequency. The present disclosure further relates to a damping filtering apparatus comprising the damping inductor, and an EMC filtering apparatus and a compressor.

Description

Damping inductor, filter device and compressor device

This application claims priority to Chinese Patent Application No. 202211556538.1 filed on December 6, 2022. The entire contents of the disclosure of the above-mentioned Chinese patent application are incorporated herein by reference as a part of this application.

Technical Field

The present application relates to electronic components, and in particular to a damping inductor for suppressing resonance, a damping filter device including the same, an EMC filter device and a compressor device.

Background technique

In many applications (e.g., automotive high-voltage applications), ripple immunity is a common requirement of equipment manufacturers and international standardization organizations (e.g., ISO 7637-4 and ISO 21498-2). Therefore, ripple immunity testing is performed before the equipment leaves the factory. However, during the ripple immunity test, EMC filters often burn out due to resonance.

Summary of the invention

In view of the above problems, the present disclosure provides a damping inductor for suppressing resonance, a damping filter device, an EMC filter device and a compressor device including the same.

According to one aspect of the present disclosure, a damping inductor for suppressing resonance is provided, comprising: a magnetic core; and a winding, the winding being wound around at least a portion of the magnetic core; wherein the magnetic core comprises a first magnetic portion, the first magnetic portion comprises a first magnetic material, the first magnetic material has a first magnetic loss within a first frequency range, the first magnetic material has a second magnetic loss within a second frequency range, any frequency within the first frequency range is higher than any frequency within the second frequency range, the first magnetic loss is greater than the second magnetic loss, wherein the first frequency range is a frequency range including a target resonant frequency.

According to an example of the present disclosure, the first magnetic loss is at least ten times greater than the second magnetic loss.

According to an example of the present disclosure, the first frequency range is a frequency range between 1 kHz and 1 MHz.

According to an example of the present disclosure, the second frequency range is a frequency range between 50 Hz and 100 Hz.

According to an example of the present disclosure, the first magnetic material includes silicon steel sheet or electromagnetic pure iron.

According to an example of the present disclosure, the first magnetic part is a plate-shaped structure.

According to an example of the present disclosure, the plate-like structure is formed by stacking a plurality of sheets of the first magnetic material.

According to an example of the present disclosure, the magnetic core further includes a second magnetic portion, and the second magnetic portion includes a second magnetic material.

According to an example of the present disclosure, the second magnetic material has a third magnetic loss within the first frequency range, and the first magnetic loss is at least five times the third magnetic loss.

According to an example of the present disclosure, the second magnetic material includes ferrite or Sendust.

According to an example of the present disclosure, the second magnetic part includes a structure having an opening on at least one side, and the opening is used to cooperate with the first magnetic part.

According to an example of the present disclosure, the second magnetic part includes an E-type structure, a C-type structure, a U-type structure or an H-type structure.

According to an example of the present disclosure, the first magnetic portion is arranged at an opening side of the second magnetic portion and covers two end core columns of the second magnetic portion, so that the first magnetic portion is magnetically coupled with the second magnetic portion.

According to an example of the present disclosure, an air gap is provided between the first magnetic part and the second magnetic part.

According to an example of the present disclosure, the winding is wound around at least a portion of the second magnetic part.

According to an example of the present disclosure, the winding is wound around a middle core leg of the E-type structure, at least one of two end core legs of the E-type structure, or at least a portion of a closed side iron yoke of the E-type structure.

According to an example of the present disclosure, the winding is wound around at least a portion of the first magnetic part.

According to one aspect of the present disclosure, a damping filter device is provided, wherein the damping filter device comprises the above-mentioned damping inductor.

According to another aspect of the present disclosure, an EMC filtering device is provided, comprising: an output-side DC capacitor; and the above-mentioned damping filtering device, connected in series to a DC bus at the front end of the output-side DC capacitor; wherein the target resonant frequency is the resonant frequency of the EMC filtering device.

According to another aspect of the present disclosure, a compressor device is provided, comprising: a DC power input interface; a power circuit for driving a compressor; and the above-mentioned EMC filter device, wherein the EMC filter device is connected between the DC power input interface and the power circuit.

In the above aspects of the present disclosure, by using a part of the magnetic core having higher magnetic loss at the target resonant frequency, the resonance at the target resonant frequency is effectively suppressed, thereby preventing the EMC filter from burning out due to resonance during the ripple immunity test.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the drawings, the same reference numerals generally represent the same components.

FIG1 shows a schematic diagram of a self-damping inductor of the prior art;

FIG2 shows a perspective view of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG3 shows an exemplary expanded view of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG4 shows a schematic diagram of the magnetic flux path of the damping inductor of FIGS. 2 and 3 ;

FIG5( a ) shows an equivalent circuit diagram of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG5( b ) shows a graph of inductance versus frequency of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG5( c ) shows a graph of equivalent AC resistance versus frequency of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG6 shows a structural diagram of a second magnetic portion of a damping inductor for suppressing resonance according to an embodiment of the present disclosure;

FIG7 shows a perspective view of a damping inductor for suppressing resonance according to another embodiment of the present disclosure;

FIG8 shows a schematic diagram of a damping inductor for suppressing resonance according to yet another embodiment of the present disclosure;

FIG9 shows a schematic diagram of a damping inductor for suppressing resonance according to an embodiment of the present disclosure, wherein an air gap is shown;

FIG10 shows a schematic circuit diagram of an EMC filter device according to an embodiment of the present disclosure; and

FIG. 11 shows a schematic diagram of a power supply circuit of a compressor device according to an embodiment of the present disclosure.

Detailed ways

The technical solutions in the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The words "a", "an", and "the" used herein should also include the meanings of "multiple" and "multiple", unless the context clearly indicates otherwise. In addition, the terms "including", "comprising", etc. used herein indicate the presence of the features, steps, operations and/or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

Those skilled in the art will appreciate that ordinal numbers such as the terms "first" and "second" can modify a variety of elements. However, such elements are not limited to the above terms. For example, the above terms do not limit the order and/or importance of the elements. The above terms are only used to distinguish one element from another element. For example, the first element can be referred to as the second element, and similarly, the second element can also be referred to as the first element without departing from the scope of the present disclosure.

All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

FIG1 shows a schematic diagram of a self-damping inductor of the prior art. As shown in FIG1 , the self-damping inductor of the prior art includes a primary winding 10 and a suspended secondary winding 20. The equivalent circuit of the primary winding 10 is composed of an inductor L1, a series resistor (AC resistor ACR plus DC resistor DCR) and a parallel resistor _RP , wherein the resistor _RP is a parallel resistor at both ends of the winding that depends on the frequency, including an ohmic part and a frequency-sensitive part induced at both ends of the inductor. In order to pursue a high inductance value and an extremely low DC resistance, the primary winding is designed to have a high quality factor. Current flows through the inductor L1 of the primary winding 10, thereby inducing a current in the inductor L2 in the secondary winding 20 (i.e., generating an equivalent eddy current), and the frequency response resistor _Rf in the secondary winding 20 consumes the equivalent eddy current to suppress the current of a specific frequency (e.g., a resonant frequency) input by the primary winding 10. In other words, the damping effect is mainly achieved by the frequency response resistor _Rf of the secondary winding 20. However, on the one hand, such a damping inductor requires two windings; on the other hand, due to the power consumption through the secondary winding, the heat dissipation performance is poor and the heat dissipation design is difficult. In addition, similar problems also exist in other existing damping filter designs, and in high-voltage applications, the damping filter also has a high-voltage isolation problem.

FIG. 2 shows a perspective view of a damping inductor for suppressing resonance according to an embodiment of the present disclosure. As shown in Fig. 2, the damping inductor 100 for suppressing resonance according to the embodiment of the present disclosure comprises a magnetic core and a winding 102, wherein the magnetic core comprises a first magnetic part 101 and a second magnetic part 103. In the embodiment of the present disclosure, the magnetic core can be any material capable of conducting magnetism.

According to an embodiment of the present disclosure, the winding 102 is wound around at least a portion of the magnetic core. When current passes through the winding 102, a magnetic flux is formed in the magnetic core. When the magnetic flux passes through the first magnetic portion 101 and the second magnetic portion 103, magnetic loss is generated thereon. The theoretical calculation formula for the power loss per unit mass of silicon steel sheet is shown in the following formula (1):
P＝P _h +P _c +P _e =K _h f(B _m ) ² +K _c (fB _m ) ² +K _e (fB _m ) ^1.5 (1)

Wherein, P represents the total power loss per unit mass of the magnetic core, _Ph represents the hysteresis loss, _Pc represents the additional loss, _Pe represents the eddy current core loss, f represents the frequency, _Bm represents the amplitude of the AC magnetic induction intensity component, _Kh represents the hysteresis core loss coefficient, _Ke represents the eddy current core loss coefficient, and _Kc represents the additional loss coefficient.

In this article, the term "eddy current loss" refers to the fact that when there is an alternating magnetic field in a conductor, according to the law of electromagnetic induction, an induced current will be generated in the conductor. This current flows in the conductor to generate Joule heat, causing the conductor to heat up and cause losses. In this article, the term "hysteresis loss" refers to the loss caused by friction during the high-speed rotation of the magnetic domains inside the magnetic core, which is ultimately manifested as heat energy.

The inventors recognize that, according to formula (1), the power loss at different frequencies is mainly affected by the core loss coefficient. In view of this, the present disclosure proposes that, unlike the conventional damping inductor, the first magnetic part 101 of the damping inductor 100 includes a first magnetic material, the first magnetic material has a first magnetic loss in a first frequency range and a second magnetic loss in a second frequency range, wherein any frequency in the first frequency range is higher than any frequency in the second frequency range, and the first magnetic loss is greater than the second magnetic loss, and the first frequency range is a frequency range including the target resonant frequency. In an embodiment of the present disclosure, the second frequency range is the normal operating frequency range of the circuit to which the damping inductor 100 is applied, and the target resonant frequency is the possible resonant frequency of the applied circuit. By setting the magnetic material of the first magnetic part 101 to have a lower magnetic loss in the normal operating frequency range of the applied circuit, the circuit performance will not be affected by the large amount of power consumed by the damping inductor when the circuit is operating normally, and the damping inductor has a larger magnetic loss at the target resonant frequency, which increases the power loss of the inductor at the target resonant frequency, thereby effectively suppressing the resonance.

In some embodiments of the present disclosure, the first magnetic loss may be at least ten times the second magnetic loss. Those skilled in the art should understand that it is desirable that the magnetic loss of the magnetic core of the damping inductor 100 is as small as possible at the normal operating frequency of the circuit to which the damping inductor 100 is applied, and as large as possible at the possible resonant frequency of the applied circuit, so as to consume more power and better suppress resonance.

In some embodiments of the present disclosure, the first frequency range may be a frequency range between 1 kHz and 1 MHz. Those skilled in the art will appreciate that the first frequency range may be set to different ranges according to specific application requirements, in particular, the upper limit of the first frequency range may be set to be greater than 1 MHz, and the lower limit of the first frequency range may be set to be less than 1 kHz. In some embodiments of the present disclosure, the second frequency range may be a frequency range between 50 Hz and 100 Hz. Those skilled in the art will appreciate that the second frequency range may be set according to the normal operating frequency of the specific application circuit of the damping inductor.

In some embodiments of the present disclosure, the first magnetic material may include silicon steel sheets or electromagnetic pure iron, such as DT4 steel, etc. Those skilled in the art should understand that the first magnetic material may also include any other magnetic conductive material suitable for use in low frequency applications but not suitable for use in higher frequency applications.

The following describes an example implementation of the present disclosure in conjunction with FIGS. 3-4 and 6-9. FIG. 3 shows an exemplary expansion diagram of a damping inductor for suppressing resonance according to an embodiment of the present disclosure. As shown in FIG. 3, the second magnetic part 103 may have an E-type structure, which has two end core columns 103a and 103b and an intermediate core column 103c, and the winding 102 is wound around a portion of the intermediate core column 103c. The first magnetic part 101 is arranged on the open side of the E-type structure of the second magnetic part 103 and cooperates with the second magnetic part 103. It should be understood that although the intermediate core column 103c shown in FIG. 3 is a cylinder and the inner sides of the two end core columns 103a and 103b are arc-shaped, the embodiment of the present disclosure is not limited thereto. According to the embodiment of the present disclosure, the inner sides of the intermediate core column and the two end core columns may be other shapes, for example, the intermediate core column may be a rectangular parallelepiped or a polygonal column, and the inner sides of the two end core columns may be a planar structure or a multi-faceted structure composed of multiple planes.

FIG4 shows a schematic diagram of the magnetic flux path of the damping inductor of FIG2 and FIG3. As shown in FIG4, the first magnetic part 101 covers the two end core columns 103a and 103b and the middle core column 103c of the second magnetic part 103, so that the first magnetic part 101 is magnetically coupled with the second magnetic part 103. Specifically, since the winding 102 is wound around a portion of the middle core column 103c of the second magnetic part 103, the current I in the current direction shown in FIG4 flows through the winding 102, generating a magnetic flux Φ in the middle core column 103c. As shown in FIG4, the magnetic flux Φ passes through the middle core column 103c, the closed side iron yoke of the second magnetic part 103, the two end core columns 103a or 103b of the second magnetic part 103, and the first magnetic part 101, forming a closed path. Since the magnetic permeability in the air is low, the magnetic flux Φ mainly exists in the first magnetic part 101 and the second magnetic part 103.

In some embodiments of the present disclosure, the winding 102 may alternatively be wound around at least a portion of the first magnetic portion 101 .

In some embodiments of the present disclosure, the winding 102 may alternatively surround the second magnetic portion 103. At least a portion of one of the two end core columns 103a and 103b of the E-type structure is wound, or at least a portion of the closed side yoke of the E-type structure is wound around the second magnetic part 103. Such an arrangement and the arrangement shown in FIG4 both form a closed magnetic flux path through the first magnetic part 101 and the second magnetic part 103, and the difference from the arrangement shown in FIG4 lies in the magnetic flux distribution, which may result in different magnetic resistances depending on the length of the magnetic flux path and the different magnetic permeabilities of the magnetic conductive materials in the magnetic flux path.

In some embodiments of the present disclosure, alternatively, the two ends of the second magnetic part 103 may also be connected together, and the inner sides of the two ends form a complete external circular structure. For example, the middle core column of the second magnetic part 103 and the external circular structure may be concentric circles.

Fig. 5(a) shows an equivalent circuit diagram of a damping inductor for suppressing resonance according to an embodiment of the present disclosure. In Fig. 5(a), the equivalent circuit of the damping inductor includes an inductance L _ac , an equivalent AC resistance R _ac caused by core loss, and a parasitic capacitance C of the inductor, wherein the inductance L _ac is connected in series with the equivalent AC resistance R _ac and then connected in parallel with the parasitic capacitance C, wherein the parasitic capacitance C is very small and can be ignored.

The equivalent AC resistance R _ac of the damping inductor can be calculated according to the following formula (2):

Wherein, P represents the power loss per unit mass of the magnetic core, I _ac represents the alternating current, and M _core represents the weight of the magnetic core.

In addition, the alternating current I _ac and the magnetic induction intensity component B _m have a relationship defined by the following formula (3):

in, It represents the magnetic resistance of the magnetic circuit, N represents the number of turns of the coil winding, and Ae represents the cross-sectional area of the magnetic core.

Substituting formula (1)-(2) into formula (3), we can derive the calculation formula (4) of the equivalent AC resistance R _ac as follows:

According to the above formula (4), the equivalent AC resistance R _ac of the inductor depends on the loss factor of the magnetic core, the number of winding turns N and the weight of the magnetic core.

FIG5(b) shows a graph of the inductance of a damping inductor for suppressing resonance relative to frequency according to an embodiment of the present disclosure. In FIG5(b), the horizontal axis is the frequency and the vertical axis is the inductance value. As the frequency increases, the inductance does not decrease significantly. FIG5(c) shows a graph of the equivalent AC resistance R _ac of a damping inductor for suppressing resonance relative to frequency according to an embodiment of the present disclosure. In FIG5(c), the horizontal axis is the frequency and the vertical axis is the equivalent AC resistance value. As the frequency increases, the equivalent AC resistance R _ac increases significantly. This is because the first magnetic part 101 uses a magnetic material with a large loss coefficient of the magnetic core. According to formula (4), the greater the frequency, the greater the equivalent AC resistance of the first magnetic part 101.

In an embodiment of the present disclosure, the second magnetic part 103 includes a second magnetic material. The second magnetic material has a third magnetic loss in a first frequency range (e.g., a higher frequency range), and the first magnetic loss is at least five times the third magnetic loss. In other words, the loss coefficient of the second magnetic material is small, and the magnetic loss of the second magnetic part 103 does not increase significantly with the increase of the frequency. In some embodiments of the present disclosure, the second magnetic material includes ferrite, sendust or any other material suitable for use in high frequency applications. In such an embodiment, the power consumption of suppressing resonance is mainly achieved by the first magnetic part 101, and the second magnetic part 103 does not generate excessive heat at the resonant frequency of the application circuit.

Referring again to FIGS. 2 to 4 , in an embodiment of the present disclosure, the first magnetic part 101 may be a plate-like structure. Since the power loss at the resonant frequency is mainly realized by the magnetic loss of the first magnetic part 101, the first magnetic part 101 is configured as a plate-like structure, and the large surface area of the plate-like structure is utilized to facilitate heat dissipation and cooling. In some embodiments of the present disclosure, an additional heat dissipation device, such as a heat dissipation fin, may be provided on the opposite side where the first magnetic part 101 and the second magnetic part 103 are joined. Due to the specific power consumption mode and good heat dissipation design of the damping inductor 100, the damping inductor 100 can be applied to high-power applications.

In addition, in the embodiment where the winding 102 is not wound around the first magnetic part, since the first magnetic part 101 in the damping inductor 100 is not electrically coupled to the winding 102, there is no high voltage isolation problem for the first magnetic part 101 in high voltage applications. In some embodiments of the present disclosure, the plate-like structure is formed by stacking a plurality of sheets of first magnetic materials, as shown in FIGS. 3 , 4 and 7 .

In some embodiments of the present disclosure, the second magnetic part 103 includes a structure having an opening on at least one side, and the opening is used to cooperate with the first magnetic part 101. Those skilled in the art should understand that in some embodiments of the present disclosure, the second magnetic part 103 can be other structures with openings different from the E-type structure illustrated in Figures 2 to 4, such as the C-type structure, U-type structure or H-type structure shown in Figure 6.

FIG7 shows a stereoscopic view of a damping inductor for suppressing resonance according to another embodiment of the present disclosure. In FIG7 , the second magnetic part 103 has a C-shaped structure, and the first magnetic part 101 is arranged on the open side of the C-shaped structure of the second magnetic part 103, and cooperates with the second magnetic part 103. Specifically, the two end core columns 103a and 103b of the second magnetic part 103 are engaged with the first magnetic part 103, so that the first magnetic part 101 can be magnetically coupled with the second magnetic part 103. The coil 102 surrounds a portion of the closed side yoke of the second magnetic part 103. Current flows through the coil 102, resulting in a magnetic flux generated in the closed side yoke of the second magnetic part 103, and the magnetic flux passes through the closed side yoke, one end core column 103a or 103b, the first magnetic part 101, and the other end core column 103b or 103a, forming a closed magnetic flux path.

In the embodiments illustrated in FIGS. 2 to 4 and FIGS. 6 and 7, the second magnetic part has an opening, which is used to cooperate with the first magnetic part. The first magnetic material is a magnetic material suitable for high-frequency occasions but not for higher-frequency occasions, and the second magnetic part is set to be a magnetic material suitable for high-frequency occasions. This opening design and the plate-shaped design of the first magnetic material are conducive to heat dissipation.

FIG8 shows a schematic diagram of a damping inductor for suppressing resonance according to another embodiment of the present disclosure. As shown in FIG8 , the first magnetic part 101 and the second magnetic part 103 of the damping inductor 100 can be designed as an E-type structure, the opening sides of the two are relatively matched, the first magnetic part 101 and the second magnetic part 103 are made of different magnetic materials, and the winding is wound around a part of the second magnetic part 103. In this embodiment, the heat is still mainly generated and dissipated by the first magnetic part 101. In some embodiments of the present disclosure, the winding is wound around the middle core column of the second magnetic part 103 in FIG8 .

Optionally or alternatively, in some embodiments of the present disclosure, the second magnetic part can be set to a magnetic material suitable for low-frequency applications but not suitable for high-frequency applications, such as the first magnetic material. This embodiment can still use only a single inductor to suppress the resonance of its application circuit, but all magnetic cores will generate a large power consumption at the resonant frequency, resulting in more heat generated by the first magnetic part and the second magnetic part.

In addition, in some embodiments of the present disclosure, an air gap is provided between the first magnetic part 101 and the second magnetic part 103. FIG9 shows a schematic diagram of a damping inductor for suppressing resonance according to an embodiment of the present disclosure, in which an air gap is shown. As shown in FIG9, two end core columns 103a and 103b of the second magnetic part 103 are in direct contact with the first magnetic part 101, and an air gap 104 is provided between the middle core column 103c of the second magnetic part 103 and the first magnetic part 101.

When there is a small air gap in the magnetic flux path, the reluctance of the air gap It can be calculated by the following formula (5):

Wherein, l _g represents the air gap length of the air gap 104, u ₀ represents the vacuum magnetic permeability, and Ae represents the cross-sectional area of the magnetic core.

Those skilled in the art should understand that in some embodiments of the present disclosure, the middle core column 103c of the second magnetic part 103 can be connected to the first magnetic part 101, and the air gap 104 is set between the two end core columns 103a and/or 103b of the first magnetic part 101 and the second magnetic part 103.

In the embodiment of the present disclosure, the air gap is a non-magnetic part, that is, a material with very low magnetic conductivity or almost no magnetic conductivity, forming a separation layer between the first magnetic part 101 and the second magnetic part 103. Such an air gap has high magnetic resistance. In the embodiment of the present disclosure, the air gap can be filled with non-magnetic materials, such as gas, plastic, wood, etc. According to the above formulas (4) and (5), the equivalent AC resistance R _ac of the inductor is The value of R ac depends not only on the loss factor of the magnetic core, but also on the air gap length l _g . By adjusting the air gap length l _g, the equivalent AC resistance R _ac of the inductor can be adjusted.

In addition, those skilled in the art should understand that the above formula (5) is based on a vacuum air gap as an example, where _u0 represents the vacuum magnetic permeability. When different materials are filled in the air gap, the magnetic permeability in formula (5) can be replaced by the magnetic permeability of the different materials. In other words, the equivalent AC resistance R _ac of the inductor also depends on the type of the air gap filling material.

In the embodiments of the present disclosure, the damping filter device composed of the damping inductor of the present disclosure can be used to replace the traditional damping filter device that needs to be composed of multiple inductors and resistors. Since only a single damping inductor is used, the damping filter device has the advantage of small size; in addition, the damping inductor also brings the advantage of good heat dissipation performance.

FIG10 shows a schematic circuit diagram of an EMC filter device 200 according to an embodiment of the present disclosure. As shown in FIG10 , the EMC filter device 200 includes an output-side DC capacitor Cdc and an input-side DC capacitor C1, and a damping inductor 100, which is connected in series to a DC bus bar at the front end of the output-side DC capacitor Cdc. By designing the damping inductor 100 so that its target resonant frequency is the resonant frequency of the EMC filter device 200, the resonance of the EMC filter device 200 during the ripple test is effectively suppressed.

When the EMC filter device 200 operates at its non-resonant frequency, the magnetic material selected by the damping inductor 100 has a low magnetic resistance at the non-resonant frequency, so that the equivalent resistance of the damping inductor 100 is low, thereby not affecting the normal filtering performance of the EMC filter device 200. On the contrary, when the EMC filter device 200 operates at its resonant frequency, the magnetic resistance of the magnetic material of the damping inductor 100 at the resonant frequency is very high, so that the equivalent resistance of the damping inductor 100 is reduced, thereby playing the effect of suppressing the resonance of the EMC filter device 200.

FIG11 shows a schematic diagram of a power supply circuit of a compressor device 400 according to an embodiment of the present disclosure. As shown in FIG11 , the compressor device 400 includes a DC power input interface, which is connected to a high voltage DC power supply 500. The compressor device 400 also includes an EMC filter device 420, a power circuit 430, and a compressor 440. The EMC filter device 420 and the power circuit 430 are similar to the above-mentioned EMC filter device 200 and the power circuit 300. The power circuit 430 is used to drive the compressor 440, and the EMC filter device 420 is connected between the DC power input interface and the power circuit 430 for EMC filtering. By using the EMC filter device 420 with the damping inductor of the present disclosure in the compressor device 400, EMC filtering of the power supply of the compressor 440 is achieved, and the EMC filter device can suppress its own resonance.

The compressor 440 in FIG. 11 is an air conditioning compressor used in automobiles, also known as an electric compressor. It should be understood that the EMC filter device 200 can be used for other automotive electrical equipment, especially high voltage (e.g., 400V, 800V, etc.) electrical equipment such as PTC heaters.

The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and/or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

A damping inductor for suppressing resonance, comprising:

A magnetically conductive core; and

A winding, the winding being wound around at least a portion of the magnetically conductive core;

The magnetic core includes a first magnetic part, the first magnetic part includes a first magnetic material, the first magnetic material has a first magnetic loss in a first frequency range, the first magnetic material has a second magnetic loss in a second frequency range, any frequency in the first frequency range is higher than any frequency in the second frequency range, and the first magnetic loss is greater than the second magnetic loss.

Wherein, the first frequency range is a frequency range including the target resonant frequency.
The damping inductor of claim 1, wherein the first magnetic loss is at least ten times greater than the second magnetic loss.
The damping inductor according to claim 1 or 2, wherein the first frequency range is a frequency range between 1 kHz and 1 MHz.
The damping inductor according to claim 1 or 2, wherein the second frequency range is a frequency range between 50 Hz and 100 Hz.
The damping inductor according to claim 1 or 2, wherein the first magnetic material comprises silicon steel sheet or electromagnetic pure iron.
The damping inductor according to claim 1 or 2, wherein the first magnetic portion is a plate-like structure.
The damping inductor according to claim 6, wherein the plate-like structure is formed by stacking a plurality of sheets of the first magnetic material.
The damping inductor according to claim 1 or 2, wherein the magnetically conductive core further comprises a second magnetic portion, and the second magnetic portion comprises a second magnetic material.
The damped inductor of claim 8, wherein the second magnetic material has a third magnetic loss in the first frequency range, and the first magnetic loss is at least five times the third magnetic loss.
The damping inductor of claim 8, wherein the second magnetic material comprises ferrite or Sendust.
The damping inductor according to claim 8, wherein the second magnetic portion comprises a structure having an opening on at least one side, the opening being used to cooperate with the first magnetic portion.
The damping inductor according to claim 11, wherein the second magnetic portion comprises E Type structure, C-type structure, U-type structure or H-type structure.
The damping inductor according to claim 11, wherein the first magnetic portion is arranged on an open side of the second magnetic portion and covers both end cores of the second magnetic portion, so that the first magnetic portion is magnetically coupled with the second magnetic portion.
The damping inductor according to claim 13, wherein an air gap is provided between the first magnetic portion and the second magnetic portion.
The damping inductor of claim 8, wherein the winding is wound around at least a portion of the second magnetic portion.
The damping inductor of claim 12, wherein the winding is wound around a middle core leg of the E-type structure, at least one of two end core legs of the E-type structure, or at least a portion of a closed side iron yoke of the E-type structure.
The damping inductor according to claim 1 or 2, wherein the winding is wound around at least a portion of the first magnetic portion.
A damping filter device, wherein the damping filter device comprises the damping inductor according to any one of claims 1 to 17.
An EMC filtering device, comprising:

Output side DC capacitor; and

The damping filter device according to claim 18 is connected in series to the DC bus at the front end of the output-side DC capacitor;

Wherein, the target resonant frequency is the resonant frequency of the EMC filter device.
A compressor device, comprising:

DC power input interface;

a power circuit for driving a compressor; and

According to the EMC filtering device of claim 19, the EMC filtering device is connected between the DC power input interface and the power circuit.