Filter circuit, filter and inverter system

Abstract

The utility model relates to a filter circuit, a filter and an inverter system. The filter circuit comprises a positive busbar, a negative busbar, a first-stage common-mode filter module, a second-stage common-mode filter module, a third-stage common-mode filter module, a fourth-stage common-mode filter module, a first-stage differential-mode filter module, a second-stage differential-mode filter module and a third-stage differential-mode filter module, wherein the first-stage common-mode filtering module, the second-stage common-mode filtering module, the third-stage common-mode filtering module and the fourth-stage common-mode filtering module are connected in parallel through a positive busbar and a negative busbar; and the first-stage differential mode filtering module, the second-stage differential mode filtering module and the third-stage differential mode filtering module are connected in parallel through the positive busbar and the negative busbar. By adopting the filter circuit, the electromagnetic interference generated by the inversion module of the motor controller is subjected to four times of common-mode filtering and three times of differential-mode filtering, so that the electromagnetic interference of the motor controller can be reduced to be very low, and the suppression effect on electromagnetic radiation is improved.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle technology, and in particular to a filter circuit, a filter, and an inverter system. Background Art

[0002] With the booming development of the new energy vehicle industry, sales of pure electric vehicles and hybrid vehicles are increasing. For these vehicles, the electric control unit uses batteries and motor controllers to transmit power and recover kinetic energy from the rotation of the motor to reverse charge the battery.

[0003] Traditionally, motor controllers incorporate an inverter module to convert the battery's DC power into the motor's AC power. The inverter module's frequent switching generates significant electromagnetic interference, affecting both radio receivers and other onboard electrical components. Furthermore, this excessive electromagnetic noise can cause the motor controller to fail to meet electromagnetic compatibility (EMC) standards, ultimately causing the entire vehicle to fail to meet these limits.

[0004] Therefore, how to reduce the electromagnetic radiation of the motor controller is a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] Based on this, it is necessary to provide a filter circuit, filter and inverter system that can reduce the electromagnetic radiation of the motor controller to address the above technical problems.

[0006] In a first aspect, the present application provides a filter circuit, characterized in that the filter circuit includes: a positive busbar, a negative busbar, a first-stage common-mode filter module, a second-stage common-mode filter module, a third-stage common-mode filter module, a fourth-stage common-mode filter module, a first-stage differential-mode filter module, a second-stage differential-mode filter module, and a third-stage differential-mode filter module;

[0007] Among them, the first-stage common-mode filter module, the second-stage common-mode filter module, the third-stage common-mode filter module and the fourth-stage common-mode filter module are all connected in parallel through the positive busbar and the negative busbar; the first-stage differential-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module are all connected in parallel through the positive busbar and the negative busbar;

[0008] The first-stage common-mode filter module is composed of common-mode capacitors, and the second-stage common-mode filter module, the third-stage common-mode filter module and the fourth-stage common-mode filter module include at least one common-mode filter module composed of common-mode inductors.

[0009] In one embodiment, a first end of the first-stage common-mode filter module is connected to the positive busbar, a second end of the first-stage common-mode filter module is connected to the negative busbar, and a third end of the first-stage common-mode filter module is grounded;

[0010] The first input terminal and the first output terminal of the second-stage common-mode filter module are both connected to the positive busbar, and the second input terminal and the second output terminal of the second-stage common-mode filter module are both connected to the negative busbar;

[0011] A first end of the third-stage common-mode filter module is connected to the positive busbar, a second end of the third-stage common-mode filter module is connected to the negative busbar, and a third end of the third-stage common-mode filter module is grounded;

[0012] A first end of the fourth-stage common-mode filter module is connected to the positive busbar, a second end of the fourth-stage common-mode filter module is connected to the negative busbar, and a third end of the fourth-stage common-mode filter module is grounded.

[0013] In one embodiment, the first-stage common-mode filtering module includes a first common-mode capacitor and a second common-mode capacitor, one end of the first common-mode capacitor is connected to the positive busbar, and the other end of the first common-mode capacitor is grounded; one end of the second common-mode capacitor is connected to the negative busbar, and the other end of the second common-mode capacitor is grounded.

[0014] In one embodiment, the second-stage common-mode filtering module includes a common-mode inductor, the positive input terminal and the positive output terminal of the common-mode inductor are both connected to the positive busbar, and the negative input terminal and the negative output terminal of the common-mode inductor are both connected to the negative busbar.

[0015] In one embodiment, the third-stage common-mode filtering module includes a third common-mode capacitor and a fourth common-mode capacitor, one end of the third common-mode capacitor is connected to the positive busbar, and the other end of the third common-mode capacitor is grounded; one end of the fourth common-mode capacitor is connected to the negative busbar, and the other end of the fourth common-mode capacitor is grounded.

[0016] In one embodiment, the fourth-stage common-mode filtering module includes a fifth common-mode capacitor and a sixth common-mode capacitor, one end of the fifth common-mode capacitor is connected to the positive busbar, and the other end of the fifth common-mode capacitor is grounded; one end of the sixth common-mode capacitor is connected to the negative busbar, and the other end of the sixth common-mode capacitor is grounded.

[0017] In one embodiment, the first end of the first-stage differential mode filter module is connected to the positive busbar, and the second end of the first-stage differential mode filter module is connected to the negative busbar;

[0018] The first end of the second-stage differential mode filter module is connected to the positive busbar, and the second end of the second-stage differential mode filter module is connected to the negative busbar;

[0019] The first end of the third-stage differential-mode filter module is connected to the positive busbar, and the second end of the third-stage differential-mode filter module is connected to the negative busbar.

[0020] In one embodiment, the first-stage differential mode filtering module includes a first differential mode capacitor, the second-stage differential mode filtering module includes a second differential mode capacitor, and the third-stage differential mode filtering module includes a third differential mode capacitor.

[0021] In a second aspect, the present application further provides a filter, which includes a supporting capacitor housing, a filter housing, and the filter circuit in the first aspect;

[0022] The first-stage common-mode filter module and the first-stage differential-mode filter module in the filter circuit are arranged in the supporting capacitor housing; the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module in the filter circuit are arranged in the filter housing.

[0023] In a third aspect, the present application further provides an inverter system, which includes an inverter module, a supporting capacitor housing, a filter housing, and the filter circuit in the first aspect;

[0024] The first-stage common-mode filter module and the first-stage differential-mode filter module in the filter circuit are arranged in the supporting capacitor housing; the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module in the filter circuit are arranged in the filter housing to constitute a filter.

[0025] The filter circuit, filter, and inverter system described above include: a positive busbar, a negative busbar, a first-stage common-mode filter module, a second-stage common-mode filter module, a third-stage common-mode filter module, a fourth-stage common-mode filter module, a first-stage differential-mode filter module, a second-stage differential-mode filter module, and a third-stage differential-mode filter module; wherein the first-stage common-mode filter module, the second-stage common-mode filter module, the third-stage common-mode filter module, and the fourth-stage common-mode filter module are all connected in parallel via the positive busbar and the negative busbar; and the first-stage differential-mode filter module, the second-stage differential-mode filter module, and the third-stage differential-mode filter module are all connected in parallel via the positive busbar and the negative busbar. Using this filter circuit, the electromagnetic interference generated by the inverter module of the motor controller undergoes four common-mode filtering and three differential-mode filtering, which can reduce the electromagnetic interference of the motor controller to a very low level, thereby improving the suppression effect of electromagnetic radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 1 is a schematic structural diagram of a filter circuit in one embodiment;

[0028] Figure 2 1 is a schematic diagram of the circuit structure of a filter circuit in one embodiment;

[0029] Figure 3 1 is a schematic diagram of a filtering process of a filtering circuit in one embodiment;

[0030] Figure 4 is a schematic diagram of measurement results of electromagnetic radiation of an electric drive system without a filter circuit in one embodiment;

[0031] Figure 5 In one embodiment, there is Figure 2 Schematic diagram of the measurement results of electromagnetic radiation of the electric drive system of the filter circuit shown;

[0032] Figure 6 is a schematic structural diagram of a filter including a filtering circuit in one embodiment;

[0033] Figure 7 is a schematic structural diagram of a filter including a filtering circuit in one embodiment;

[0034] Figure 8 is a schematic structural diagram of a filter including a filtering circuit in one embodiment;

[0035] Figure 9 FIG. 4 is a schematic structural diagram of a filter including a filtering circuit in an embodiment.

[0036] Description of reference numerals:

[0037] 101: positive busbar; 102: negative busbar; 103 (C1, C2): first-stage common-mode filter module;

[0038] 104 (L): second stage common mode filter module; 105 (C3, C4): third stage common mode filter module;

[0039] 106 (C5, C6): fourth-stage common-mode filter module; 107 (C7): first-stage differential-mode filter module;

[0040] 108 (C8): second stage differential mode filter module; 109 (C9): third stage differential mode filter module;

[0041] 110: supporting capacitor housing; 111: filter housing. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0044] It will be understood that the terms "first," "second," etc., used herein may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first capacitor may be referred to as a second capacitor, and similarly, a second capacitor may be referred to as a first capacitor. Both a first capacitor and a second capacitor are capacitors, but they are not the same capacitor.

[0045] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0046] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0047] With the booming development of the new energy vehicle industry, sales of pure electric vehicles and hybrid vehicles are increasing. For these vehicles, the electric control unit uses batteries and motor controllers to transmit power and recover kinetic energy from the rotation of the motor to reverse charge the battery.

[0048] Traditionally, motor controllers incorporate an inverter module to convert the battery's DC power into the motor's AC power. The inverter module's frequent switching generates significant electromagnetic interference, affecting both radio receivers and other onboard electrical components. Furthermore, this excessive electromagnetic noise can cause the motor controller to fail to meet electromagnetic compatibility (EMC) standards, ultimately causing the entire vehicle to fail to meet these limits.

[0049] Therefore, how to reduce the electromagnetic radiation of the motor controller is an urgent problem to be solved by those skilled in the art. As the main means of suppressing electromagnetic interference, the high-voltage filter has gradually become an indispensable part of the motor controller system.

[0050] Based on this, the embodiment of the present application proposes a high-voltage filter for a motor controller of a new energy vehicle to solve the problem of large electromagnetic interference in the motor controller of the current new energy vehicle, thereby reducing the electromagnetic radiation of the motor controller and further reducing the electromagnetic radiation of the entire vehicle system.

[0051] like Figure 1 As shown, it shows a circuit structure of a filter, which includes: a positive busbar 101, a negative busbar 102, a first-stage common-mode filter module 103, a second-stage common-mode filter module 104, a third-stage common-mode filter module 105, a fourth-stage common-mode filter module 106, a first-stage differential-mode filter module 107, a second-stage differential-mode filter module 108, and a third-stage differential-mode filter module 109; wherein the first-stage common-mode filter module 103, the second-stage common-mode filter module 104, the third-stage common-mode filter module 105, and the fourth-stage common-mode filter module 106 are all connected in parallel through the positive busbar 101 and the negative busbar 102; the first-stage differential-mode filter module 107, the second-stage differential-mode filter module 108, and the third-stage differential-mode filter module 109 are all connected in parallel through the positive busbar 101 and the negative busbar 102.

[0052] For example, the positive busbar 101 can be a positive copper busbar, and the negative busbar 102 can be a negative copper busbar; in the embodiment of the present application, there is no limitation on the materials of the positive busbar and the negative busbar. In actual application, it is sufficient to ensure that the positive busbar 101 and the negative busbar 102 serve as conductive elements.

[0053] Exemplarily, for the common-mode filtering module, it can be composed of common-mode capacitors, and the common-mode filtering module can include three connection ends, wherein the first end of the common-mode filtering module can be connected to the positive busbar 101, the second end of the common-mode filtering module can be connected to the negative busbar 102, and the third end of the common-mode filtering module can be grounded, thereby forming a common-mode suppression circuit.

[0054] Exemplarily, for the differential mode filter module, it can be composed of differential mode capacitors, and the differential mode filter module can include two connection ends, wherein the first end of the differential mode filter module can be connected to the positive busbar 101, and the second end of the differential mode filter module can be connected to the negative busbar 102, thereby forming a differential mode suppression circuit.

[0055] In addition, the common-mode filter module can also be composed of a common-mode inductor. When the common-mode filter module includes a common-mode inductor, the common-mode filter module can include a first input terminal, a first output terminal, a second input terminal, and a second output terminal. Based on this, the first input terminal and the first output terminal of the common-mode filter module can both be connected to the positive busbar 101, and the second input terminal and the second output terminal of the common-mode filter module can both be connected to the negative busbar 102. Exemplarily, the common-mode inductor can be a magnetic ring, and the positive busbar 101 and the negative busbar 102 can pass through the magnetic ring. Since the magnetic ring can increase the impedance of the common-mode loop and reduce the current of the common-mode loop, it can attenuate common-mode interference.

[0056] For example, in the filtering circuit in this example, the first-stage common-mode filtering module may be composed of common-mode capacitors, and the second-stage common-mode filtering module, the third-stage common-mode filtering module, and the fourth-stage common-mode filtering module may include at least one common-mode filtering module composed of common-mode inductors.

[0057] It should be noted that, in this example, there is no specific limitation on the number and position of the common-mode filter modules composed of common-mode inductors. For example: when the number of common-mode filter modules composed of common-mode inductors is one, the common-mode filter module composed of common-mode inductors can be a second-stage common-mode filter module, or a third-stage common-mode filter module, or a fourth-stage common-mode filter module. For another example: when the number of common-mode filter modules composed of common-mode inductors is two, the common-mode filter module composed of common-mode inductors can include a second-stage common-mode filter module and a third-stage common-mode filter module, or a second-stage common-mode filter module and a fourth-stage common-mode filter module, or a third-stage common-mode filter module and a fourth-stage common-mode filter module. When the number of common-mode filter modules composed of common-mode inductors is three, the common-mode filter module composed of common-mode inductors can include a second-stage common-mode filter module, a third-stage common-mode filter module and a fourth-stage common-mode filter module.

[0058] In addition, when multiple common-mode filtering modules are included, which are composed of common-mode capacitors, the number and connection method of the common-mode capacitors contained in each common-mode filtering module may be the same or different; when multiple common-mode filtering modules are included, which are composed of common-mode inductors, the number and connection method of the common-mode inductors contained in each common-mode filtering module may be the same or different; similarly, for three-stage differential-mode filtering modules composed of differential-mode capacitors, the number and connection method of the differential-mode capacitors contained in each differential-mode filtering module may be the same or different; the embodiments of the present application do not make specific limitations on this.

[0059] Furthermore, in the embodiment of the present application, there is no specific limitation on the arrangement order of the four-stage common-mode filter module and the three-stage differential-mode filter module in the filter circuit; however, it should be noted that for filter circuits with different arrangement methods, the filtering effects are different, that is, the electromagnetic interference filtering rates are different. For example, from the input end to the output end, the arrangement order can be the first-stage common-mode filter module 103, the first-stage differential-mode filter module 107, the second-stage common-mode filter module 104, the third-stage common-mode filter module 105, the second-stage differential-mode filter module 108, the fourth-stage common-mode filter module 106, and the third-stage differential-mode filter module 109, as shown in FIG. Figure 1 The structure shown in FIG; it may also be a first-stage common-mode filter module 103, a first-stage differential-mode filter module 107, a second-stage common-mode filter module 104, a second-stage differential-mode filter module 108, a third-stage common-mode filter module 105, a fourth-stage common-mode filter module 106, a third-stage differential-mode filter module 109, etc. In practical applications, the arrangement order of the four-stage common-mode filter modules and the three-stage differential-mode filter modules can be adjusted according to different filtering requirements of the filter.

[0060] Exemplarily, the first-stage common-mode filtering module 103 can be configured to filter out common-mode interference within the frequency band of 1MHz to 3MHz, the third-stage common-mode filtering module 105 can be configured to filter out common-mode interference within the frequency band of 6MHz to 13MHz, and the fourth-stage common-mode filtering module 106 can be configured to filter out common-mode interference within the frequency band of 30MHz to 40MHz; in addition, the first-stage differential-mode filtering module 107 can be configured to filter out differential-mode interference within the frequency band of 150kHz to 2MHz, the second-stage differential-mode filtering module 108 can be configured to filter out differential-mode interference within the frequency band of 6MHz to 13MHz, and the third-stage differential-mode filtering module 109 can be configured to filter out differential-mode interference within the frequency band of 30MHz to 40MHz.

[0061] It should be noted that the above common-mode filter frequency band and differential-mode filter frequency band are merely examples and are not intended to limit the common-mode filter frequency band and differential-mode filter frequency band.

[0062] In this embodiment, a filtering circuit is proposed, which includes a four-stage common-mode filtering module and a three-stage differential-mode filtering module. The four-stage common-mode filtering modules are all connected in parallel through the positive busbar and the negative busbar, and the three-stage differential-mode filtering modules are all connected in parallel through the positive busbar and the negative busbar. By using this filtering circuit, the electromagnetic interference generated by the inverter module of the motor controller undergoes four common-mode filtering and three differential-mode filtering, which can reduce the electromagnetic interference of the motor controller to a very low level, thereby improving the suppression effect of electromagnetic radiation.

[0063] In an exemplary embodiment, the first-stage common-mode filter module 103, the third-stage common-mode filter module 105 and the fourth-stage common-mode filter module 106 can be common-mode filter modules composed of common-mode capacitors, and the second-stage common-mode filter module 104 can be a common-mode filter module composed of common-mode inductors; based on this, the connection method of the four-stage common-mode filter modules in parallel through the positive busbar 101 and the negative busbar 102 can be: the first end of the first-stage common-mode filter module 103 is connected to the positive busbar 101, the second end of the first-stage common-mode filter module 103 is connected to the negative busbar 102, and the third end of the first-stage common-mode filter module 103 is grounded; The first input terminal and the first output terminal of the second-stage common-mode filter module 104 are both connected to the positive busbar 101, and the second input terminal and the second output terminal of the second-stage common-mode filter module 104 are both connected to the negative busbar 102; the first end of the third-stage common-mode filter module 105 is connected to the positive busbar 101, the second end of the third-stage common-mode filter module 105 is connected to the negative busbar 102, and the third end of the third-stage common-mode filter module 105 is grounded; the first end of the fourth-stage common-mode filter module 106 is connected to the positive busbar 101, the second end of the fourth-stage common-mode filter module 106 is connected to the negative busbar 102, and the third end of the fourth-stage common-mode filter module 106 is grounded.

[0064] Exemplarily, the first-stage differential mode filter module 107, the second-stage differential mode filter module 108 and the third-stage differential mode filter module 109 can all be differential mode filter modules composed of differential mode capacitors; based on this, the connection method of the three-stage differential mode filter modules in parallel through the positive busbar 101 and the negative busbar 102 can be: the first end of the first-stage differential mode filter module 107 is connected to the positive busbar 101, and the second end of the first-stage differential mode filter module 107 is connected to the negative busbar 102; the first end of the second-stage differential mode filter module 108 is connected to the positive busbar 101, and the second end of the second-stage differential mode filter module 108 is connected to the negative busbar 102; the first end of the third-stage differential mode filter module 109 is connected to the positive busbar 101, and the second end of the third-stage differential mode filter module 109 is connected to the negative busbar 102.

[0065] refer to Figure 2As shown in FIG, which shows a specific circuit structure of a filter circuit. Among them, the first-stage common-mode filter module 103 may include a first common-mode capacitor C1 and a second common-mode capacitor C2. One end of the first common-mode capacitor C1 is connected to the positive busbar 101, and the other end of the first common-mode capacitor C1 is grounded; one end of the second common-mode capacitor C2 is connected to the negative busbar 102, and the other end of the second common-mode capacitor C2 is grounded.

[0066] The second-stage common-mode filter module 104 may include a common-mode inductor L, whose positive input and positive output terminals are both connected to the positive busbar 101 , and whose negative input and negative output terminals are both connected to the negative busbar 102 .

[0067] The third-stage common-mode filter module 105 may include a third common-mode capacitor C3 and a fourth common-mode capacitor C4. One end of the third common-mode capacitor C3 is connected to the positive busbar 101, and the other end of the third common-mode capacitor C3 is grounded; one end of the fourth common-mode capacitor C4 is connected to the negative busbar 102, and the other end of the fourth common-mode capacitor C4 is grounded.

[0068] The fourth-stage common-mode filter module 106 may include a fifth common-mode capacitor C5 and a sixth common-mode capacitor C6, one end of the fifth common-mode capacitor C5 is connected to the positive busbar 101, and the other end of the fifth common-mode capacitor C5 is grounded; one end of the sixth common-mode capacitor C6 is connected to the negative busbar 102, and the other end of the sixth common-mode capacitor C6 is grounded.

[0069] The first-stage differential mode filter module 107 may include a first differential mode capacitor C7, one end of the first differential mode capacitor C7 is connected to the positive busbar 101, and the other end of the first differential mode capacitor C7 is connected to the negative busbar 102; the second-stage differential mode filter module 108 may include a second differential mode capacitor C8, one end of the second differential mode capacitor C8 is connected to the positive busbar 101, and the other end of the second differential mode capacitor C8 is connected to the negative busbar 102; the third-stage differential mode filter module 109 may include a third differential mode capacitor C9, one end of the third differential mode capacitor C9 is connected to the positive busbar 101, and the other end of the third differential mode capacitor C9 is connected to the negative busbar 102.

[0070] That is, the filter circuit includes six common-mode capacitors, namely C1, C2, C3, C4, C5, and C6, and three differential-mode capacitors, namely C7, C8, and C9. Among them, one end of the common-mode capacitors C1, C3, and C5 is connected to the positive busbar 101, and the other end is grounded; one end of the common-mode capacitors C2, C4, and C6 is connected to the negative busbar 102, and the other end is grounded. The common-mode capacitors C1, C2, C3, C4, C5, and C6 can attenuate common-mode interference. Differential-mode capacitors C7, C8, and C9 are respectively connected between the positive busbar 101 and the negative busbar 102, and can attenuate differential-mode interference.

[0071] Continue to refer Figure 2 As shown, in this example, the connection order of the four-stage common-mode filter module and the three-stage differential-mode filter module in the filter circuit is: first-stage common-mode filter module 103, first-stage differential-mode filter module 107, second-stage common-mode filter module 104, third-stage common-mode filter module 105, second-stage differential-mode filter module 108, fourth-stage common-mode filter module 106, and third-stage differential-mode filter module 109.

[0072] refer to Figure 3 As shown, for Figure 2 In the filtering circuit shown, the filtering process of the electromagnetic interference generated by the inverter module of the motor controller can be as follows: first, it is attenuated under the action of the first common-mode capacitor C1 and the second common-mode capacitor C2 of the first-stage common-mode filter module 103, then attenuated under the action of the first differential-mode capacitor C7 of the first-stage differential-mode filter module 107, then attenuated under the action of the common-mode inductor L of the second-stage common-mode filter module 104, then attenuated under the action of the third common-mode capacitor C3 and the fourth common-mode capacitor C4 of the third-stage common-mode filter module 105, then attenuated under the action of the second differential-mode capacitor C8 of the second-stage differential-mode filter module 108, then attenuated under the action of the fifth common-mode capacitor C5 and the sixth common-mode capacitor C6 of the fourth-stage common-mode filter module 106, and then attenuated under the action of the third differential-mode capacitor C9 of the third-stage differential-mode filter module 109; that is, the electromagnetic interference generated by the inverter module of the motor controller can be reduced to a very low level after four common-mode filtering and three differential-mode filtering.

[0073] refer to Figure 4 As shown, it shows the test results of electromagnetic radiation of the electric drive system without the filter circuit, refer to Figure 5 As shown, it shows that there is Figure 2 The test results of the electromagnetic radiation of the electric drive system of the filter circuit of the embodiment shown in FIG. Figure 4 and Figure 5 In the figure, the horizontal axis is the frequency in Hz, and the vertical axis is the conducted emission value in dBuV. Figure 4 L1 is the peak curve, L2 is the average curve, Figure 5 L3 is the peak curve and L4 is the average curve.

[0074] Through Figure 4 and Figure 5By comparison, it can be seen that after the motor system is provided with the filtering circuit proposed in the embodiment of the present application, the electromagnetic radiation can be well suppressed, that is, the common-mode interference and differential-mode interference in the 1MHz to 3MHz frequency band, the 6MHz to 13MHz frequency band, and the 30MHz to 40MHz frequency band are filtered respectively, and the differential-mode interference in the 150kHz to 2MHz frequency band is filtered, so that the electric drive system can meet the Class 3 level of the CISPR25.2016 standard.

[0075] In an exemplary embodiment, a filter is also provided, which may include a filter housing and the filter circuit of any of the above embodiments, wherein the first-stage common-mode filter module 103, the second-stage common-mode filter module 104, the third-stage common-mode filter module 105, the fourth-stage common-mode filter module 106, the first-stage differential-mode filter module 107, the second-stage differential-mode filter module 108 and the third-stage differential-mode filter module 109 in the filter circuit are all arranged in the filter housing of the filter.

[0076] For example, the input end of the filter can be connected to the output end of the inverter in the motor controller, and the output end of the filter can be connected to the power supply (such as a battery) in the new energy vehicle, so that the electromagnetic interference of the current signal output by the inverter can be filtered through the filter, and the filtered current signal is transmitted to the power supply to realize kinetic energy recovery of the motor, thereby reverse charging the power supply.

[0077] The input end of the filter includes the positive input end P11 of the positive busbar 101 and the negative input end P12 of the negative busbar 102, and the output end of the filter includes the positive output end P21 of the positive busbar 101 and the negative output end P22 of the negative busbar 102. In other words, the positive input end P11 of the positive busbar 101 and the negative input end P12 of the negative busbar 102 can be connected to the output end of the inverter, and the positive output end P21 of the positive busbar 101 and the negative output end P22 of the negative busbar 102 can be connected to the input end of the power supply.

[0078] In an exemplary embodiment, a filter is also provided, such as Figure 6 As shown, the filter may include a supporting capacitor housing 103, a filter housing 105 and the filter circuit in any of the above embodiments; wherein, the first-stage common-mode filter module 103 and the first-stage differential-mode filter module 107 in the filter circuit are arranged in the supporting capacitor housing 110; the second-stage common-mode filter module 104, the third-stage common-mode filter module 105, the fourth-stage common-mode filter module 106, the second-stage differential-mode filter module 108 and the third-stage differential-mode filter module 109 in the filter circuit are all arranged in the filter housing 111.

[0079] Among them, the support capacitor is connected between the inverter module and the power supply to stabilize the intermediate DC voltage and ensure the reliability and stability of the power supply. In addition, the support capacitor also provides instantaneous energy exchange and exchanges no power with the power supply and the load.

[0080] For example, for Figure 2 The filtering circuit structure shown can arrange the second-stage common-mode filtering module 104, that is, the part of the circuit before the common-mode inductor L, in the supporting capacitor housing 110; and the second-stage common-mode filtering module 104 and the part of the circuit after the second-stage common-mode filtering module 104, that is, the common-mode inductor L and the part of the circuit after the common-mode inductor L, in the filtering housing 111 of the filter.

[0081] For example, when the first-stage common-mode filter module 103 includes a first common-mode capacitor C1 and a second common-mode capacitor C2, and the first-stage differential-mode filter module 107 includes a first differential-mode capacitor C7, the first common-mode capacitor C1, the second common-mode capacitor C2, and the first differential-mode capacitor C7 can be arranged in the supporting capacitor housing 110. Figure 6 shown.

[0082] It should be noted that, except for the above Figure 2 For other filter circuit structures other than the above, the part of the circuit before the first common-mode inductor L in the filter circuit can be arranged in the supporting capacitor housing 110; and the part of the circuit after the first common-mode inductor L can be arranged in the filter housing 111 of the filter; this can reduce the overall volume of the filter, making the structure of the filter more compact and the overall miniaturization.

[0083] in addition, Figures 6 to 9 The layout structure of each capacitor and magnetic ring in the supporting capacitor housing and the filter housing at different angles is shown.

[0084] Continue to refer Figure 6 As shown, the positive busbar 101 and the negative busbar 102 are located in the supporting capacitor housing 110 and the filter housing 111, and pass through the magnetic ring L; all capacitors and magnetic rings are located in the insulating housing supporting the capacitor and the insulating housing of the filter, and are fixed with a polymer resin insulating material to ensure stability. For example, the material of the magnetic ring L can be nanocrystal or ferrite, and the insulating housing supporting the capacitor and the insulating housing of the filter can both be manufactured using an injection molding process.

[0085] The first common mode capacitor C1, the second common mode capacitor C2 and the first differential mode capacitor C7 are integrated in the supporting capacitor housing 110 and are visible only after the supporting capacitor housing is hidden; for example, refer to Figure 8 and Figure 9As shown, it shows a schematic diagram of the layout structure inside the supporting capacitor housing, including the layout structure of the first common-mode capacitor C1, the second common-mode capacitor C2 and the first differential-mode capacitor C7 inside the supporting capacitor housing.

[0086] In this embodiment, by optimizing and improving the filter structure, the first common-mode capacitor C1, the second common-mode capacitor C2, and the first differential-mode capacitor C7 are integrated into the supporting capacitor, which greatly reduces the space occupied by the high-voltage filter. The high-voltage filter for the motor controller in the new energy vehicle includes a positive busbar for connecting the positive pole of the high-voltage DC bus, a negative busbar for connecting the negative pole of the high-voltage DC bus, a first-level common-mode capacitor C1 and C2, a first-level common-mode inductor L, a third-level common-mode capacitor C3 and C4, a fourth-level common-mode capacitor C5 and C6, a first-level differential-mode capacitor C7, a second-level differential-mode capacitor C8, and a third-level differential-mode capacitor C9, so that the electromagnetic interference generated by the motor controller can be greatly attenuated after four-level common-mode filtering and three-level differential-mode filtering. Therefore, the filter circuit proposed in the embodiment of the present application can solve the problem of large electromagnetic interference in the existing new energy vehicle motor controller while occupying a smaller space, and improve the filtering effect of electromagnetic interference.

[0087] In an exemplary embodiment, an inverter system is also provided, which includes an inverter module, a supporting capacitor housing, a filter housing and the filter circuit of any of the above embodiments; wherein the first-stage common-mode filter module and the first-stage differential-mode filter module in the filter circuit are arranged in the supporting capacitor housing; the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module in the filter circuit are arranged in the filter housing to constitute a filter.

[0088] The layout of the filter circuit in the inverter system can refer to the structural layout of the above filter, that is, refer to the above Figures 6 to 9 The layout structure is not repeated in this example.

[0089] The difference is that, in this example, the inverter system includes an inverter module, a supporting capacitor and a filter, wherein the supporting capacitor includes the first-stage common-mode filter module and the first-stage differential-mode filter module of the above-mentioned filter circuit, and the filter includes the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module of the above-mentioned filter circuit; that is, in this example, the filter in the inverter system is composed of part of the circuit structure of the above-mentioned filter circuit, and the remaining part of the circuit in the filter circuit is integrated in the supporting capacitor; adopting this structure, the volume of the filter can be further reduced, that is, the space occupied by the filter in the inverter can be reduced, thereby realizing the miniaturization design of the filter.

[0090] In addition, it should be noted that in addition to the above Figure 2 In the case of circuit structures other than the filter circuit shown, the portion of the filter circuit before the first common-mode inductor can be integrated into the support capacitor, while the portion of the circuit after the first common-mode inductor can be placed in the filter. Alternatively, depending on the size of the support capacitor, part of the filter circuit structure can be integrated into the support capacitor, while the remaining portion of the circuit can be placed in the filter, thereby increasing the overall compactness and achieving an overall miniaturized design of the inverter.

[0091] For example, the inverter system may further include a magnetic ring, one end of which is connected to the motor controller, the other end of which is connected to the inverter module, the other end of which is connected to the support capacitor, the other end of which is connected to the filter, and the other end of which is connected to the DC power supply. The magnetic ring can filter the AC power output by the motor controller and transmit the filtered AC power to the inverter module, so that the inverter module converts the AC power into DC power for output; then, the DC power is filtered by the support capacitor and the filter, and finally, the DC power, which has been filtered to remove electromagnetic interference, is transmitted to the DC power supply.

[0092] The inverter system in this embodiment can achieve efficient power conversion and transmission between the motor controller and the DC power supply. The inverter system can also filter the electromagnetic interference generated by it, thereby reducing the electromagnetic radiation of the inverter system to meet the EMC standard limits and improve the safety and reliability of the entire vehicle.

[0093] In the description of this specification, the description with reference to the terms "optional embodiment" or "exemplarily" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the exemplary descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0094] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A filter circuit, characterized in that: The filtering circuit includes: a positive busbar, a negative busbar, a first-stage common-mode filtering module, a second-stage common-mode filtering module, a third-stage common-mode filtering module, a fourth-stage common-mode filtering module, a first-stage differential-mode filtering module, a second-stage differential-mode filtering module, and a third-stage differential-mode filtering module; Wherein, the first-stage common-mode filter module, the second-stage common-mode filter module, the third-stage common-mode filter module and the fourth-stage common-mode filter module are all connected in parallel via the positive busbar and the negative busbar; the first-stage differential-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module are all connected in parallel via the positive busbar and the negative busbar; The first-stage common-mode filter module is composed of common-mode capacitors, and the second-stage common-mode filter module, the third-stage common-mode filter module and the fourth-stage common-mode filter module include at least one common-mode filter module composed of common-mode inductors.

2. The filter circuit according to claim 1, wherein: A first end of the first-stage common-mode filter module is connected to the positive busbar, a second end of the first-stage common-mode filter module is connected to the negative busbar, and a third end of the first-stage common-mode filter module is grounded; The first input terminal and the first output terminal of the second-stage common-mode filter module are both connected to the positive busbar, and the second input terminal and the second output terminal of the second-stage common-mode filter module are both connected to the negative busbar; A first end of the third-stage common-mode filter module is connected to the positive busbar, a second end of the third-stage common-mode filter module is connected to the negative busbar, and a third end of the third-stage common-mode filter module is grounded; The first end of the fourth-stage common-mode filter module is connected to the positive busbar, the second end of the fourth-stage common-mode filter module is connected to the negative busbar, and the third end of the fourth-stage common-mode filter module is grounded.

3. The filter circuit according to claim 2, characterized in that: The first-stage common-mode filtering module includes a first common-mode capacitor and a second common-mode capacitor, one end of the first common-mode capacitor is connected to the positive busbar, and the other end of the first common-mode capacitor is grounded; one end of the second common-mode capacitor is connected to the negative busbar, and the other end of the second common-mode capacitor is grounded.

4. The filter circuit according to claim 2, characterized in that: The second-stage common-mode filter module includes a common-mode inductor, a positive input terminal and a positive output terminal of the common-mode inductor are both connected to the positive busbar, and a negative input terminal and a negative output terminal of the common-mode inductor are both connected to the negative busbar.

5. The filter circuit according to claim 2, characterized in that: The third-stage common-mode filtering module includes a third common-mode capacitor and a fourth common-mode capacitor, one end of the third common-mode capacitor is connected to the positive busbar, and the other end of the third common-mode capacitor is grounded; one end of the fourth common-mode capacitor is connected to the negative busbar, and the other end of the fourth common-mode capacitor is grounded.

6. The filter circuit according to claim 2, characterized in that: The fourth-stage common-mode filtering module includes a fifth common-mode capacitor and a sixth common-mode capacitor, one end of the fifth common-mode capacitor is connected to the positive busbar, and the other end of the fifth common-mode capacitor is grounded; one end of the sixth common-mode capacitor is connected to the negative busbar, and the other end of the sixth common-mode capacitor is grounded.

7. The filter circuit according to claim 1, wherein: The first end of the first differential mode filter module is connected to the positive busbar, and the second end of the first differential mode filter module is connected to the negative busbar; The first end of the second-stage differential mode filter module is connected to the positive busbar, and the second end of the second-stage differential mode filter module is connected to the negative busbar; The first end of the third-stage differential-mode filter module is connected to the positive busbar, and the second end of the third-stage differential-mode filter module is connected to the negative busbar.

8. The filter circuit according to claim 7, characterized in that: The first-stage differential mode filtering module includes a first differential mode capacitor, the second-stage differential mode filtering module includes a second differential mode capacitor, and the third-stage differential mode filtering module includes a third differential mode capacitor.

9. A filter, characterized in that: The filter comprises a supporting capacitor housing, a filter housing and a filter circuit according to any one of claims 1 to 8; The first-stage common-mode filter module and the first-stage differential-mode filter module in the filter circuit are arranged in the supporting capacitor housing; the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module in the filter circuit are arranged in the filter housing.

10. An inverter system, characterized in that: The inverter system comprises an inverter module, a supporting capacitor housing, a filter housing and a filter circuit according to any one of claims 1 to 8; The first-stage common-mode filter module and the first-stage differential-mode filter module in the filter circuit are arranged in the supporting capacitor housing; the second-stage common-mode filter module, the third-stage common-mode filter module, the fourth-stage common-mode filter module, the second-stage differential-mode filter module and the third-stage differential-mode filter module in the filter circuit are arranged in the filter housing to constitute a filter.

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