CN113794456A

CN113794456A - Multistage filtering structure, motor controller and vehicle

Info

Publication number: CN113794456A
Application number: CN202111106861.4A
Authority: CN
Inventors: 刘蕾; 杨洋; 张伟; 吴鸿信
Original assignee: Jee Automation Equipment Shanghai Co ltd
Current assignee: Jee Automation Equipment Shanghai Co ltd
Priority date: 2021-09-22
Filing date: 2021-09-22
Publication date: 2021-12-14

Abstract

The invention discloses a multi-stage filtering structure, a motor controller and a vehicle, wherein the multi-stage filtering structure is fixed at a DC end in a controller shell, the head end of the DC end is a high-voltage bus, and the tail end of the DC end is a thin film capacitor; the input end of the high-voltage bus is correspondingly connected with the positive and negative input ends of the first-stage filtering fixing seat assembly; the positive and negative output ends of the first-stage filtering fixing seat assembly are respectively and correspondingly connected with the positive and negative input ends of the second-stage filtering fixing seat assembly; and the positive and negative output ends of the secondary filtering fixing seat assembly are respectively and correspondingly connected with the positive and negative input ends of the thin film capacitor. A plurality of filter devices are integrated together through an integrated and modular design, and the EMC capability of the DC end of the controller can be guaranteed to be improved to the maximum extent in a limited space.

Description

Multistage filtering structure, motor controller and vehicle

Technical Field

The invention relates to the technical field of motor controllers, in particular to a multi-stage filtering structure, a motor controller with the multi-stage filtering structure and a vehicle with the motor controller.

Background

Electromagnetic compatibility (EMC) refers to the ability of equipment or a system to work normally in the electromagnetic environment and not to bear electromagnetic disturbance to anything in the environment. According to the EMC definition, the electronic device needs to meet EMC design specifications, on one hand, it needs to ensure that the electronic device has a certain degree of immunity to electromagnetic interference existing in the environment, and on the other hand, it is required that the electromagnetic interference generated by the electronic device in the operating process to the environment cannot exceed a specified limit value.

An automotive motor controller is a typical electronic device on which electronic components such as a connection harness, a PCB, a power module, and a capacitor module are laid out. When the EMC scheme is designed, a general design idea is to add filter devices such as a magnetic ring and a magnetic buckle at a direct current end and a three-phase end, and add filter capacitors, a shielding case, a grounding design and other measures on a filter PCB on a transmission path. In order to meet EMC design criteria, more filter devices are arranged in a limited space as much as possible to increase the level of filtering.

When the controller DC end (DC end) EMC is designed, the traditional design method is to add a plurality of filter elements such as filter capacitors, magnetic rings, magnetic buttons, and filter circuit boards in the current transmission path. However, the conventional EMC design method has two disadvantages: on the one hand, since these filter elements are separate bodies, a part of the space fixing elements is left out at the time of installation. When the filter elements are enough, the space of the DC end of the controller for accommodating the filter module is amplified, the design space of the DC/AC end is compressed, and the design difficulty is obviously improved; on the other hand, the filtering element is independent individual, the integration degree of the filtering module is low, the installation process is complicated, the production beat of the controller product is enlarged, and the production efficiency is obviously reduced.

Disclosure of Invention

In view of at least one of the above-mentioned technical problems, the present invention is directed to: the utility model provides a no filter circuit board structure in multistage filtering structure, motor controller and vehicle, second grade filtering fixing base subassembly, the structure is simplified. Replace the magnetic core with the magnetic ring simultaneously, realize that one-level filtering fixing base subassembly and second grade filtering fixing base subassembly unite two into one, adopt modular design, novel structure. A plurality of filter devices are integrated together through an integrated and modular design, and the EMC capability of the DC end of the controller can be guaranteed to be improved to the maximum extent in a limited space.

The technical scheme of the invention is as follows:

one of the objectives of the present invention is to provide a multi-stage filtering structure, which is fixed at a DC end in a controller housing, wherein the head end of the DC end is a high-voltage bus, and the tail end of the DC end is a thin-film capacitor, the multi-stage filtering structure includes a first-stage filtering fixed base assembly and a second-stage filtering fixed base assembly, and the first-stage filtering fixed base assembly and the second-stage filtering fixed base assembly are arranged in the controller housing;

the input end of the high-voltage bus is correspondingly connected with the positive and negative input ends of the primary filtering fixing seat assembly; the positive and negative output ends of the first-stage filtering fixing seat assembly are respectively and correspondingly connected with the positive and negative input ends of the second-stage filtering fixing seat assembly;

and the positive and negative output ends of the secondary filtering fixing seat assembly are respectively and correspondingly connected with the positive and negative input ends of the film capacitor.

Optionally, the primary filter fixing seat assembly includes a first injection molded part housing and a first filter device; a first positive copper bar, a first negative copper bar and a first groove are arranged in the first injection molding piece shell; the first filter device comprises a first magnetic core and a filter circuit, and the first magnetic core is fixed in the first groove;

the second-stage filtering fixing seat assembly comprises a second injection molding part shell and a second filtering device; a second positive copper bar, a second negative copper bar, a grounding copper bar and a plurality of second grooves are arranged in the second injection molding piece shell;

the second filter device comprises a magnetic ring, a second magnetic core, four second Y capacitors and a second X capacitor;

the second magnetic core is positioned among the four second Y capacitors; the magnetic ring is fixed in the second groove on one side, close to the primary filtering fixing seat assembly, of the second injection molding piece shell.

Optionally, two first via holes are formed in the upper portion of the first magnetic core, and the two first via holes respectively penetrate through the first positive copper bar and the first negative copper bar;

two second through holes are formed in the upper portion of the second magnetic core and penetrate through the second positive copper bar and the second negative copper bar respectively;

and the middle part of the magnetic ring is provided with a magnetic ring via hole which penetrates through the second positive copper bar and the second negative copper bar.

Optionally, the first magnetic core is composed of an E-type magnetic core and an I-type magnetic core;

the second magnetic core is composed of an E-shaped magnetic core and an I-shaped magnetic core.

Optionally, the first magnetic core is fixed in the first groove on the side of the first injection-molded part shell far away from the secondary filter fixing seat assembly through potting;

the magnetic ring is fixed on one side, close to the first-stage filtering fixing seat assembly, of the second injection molding piece shell in a glue pouring or glue dispensing and sealing cover mode; and/or

The second magnetic core is fixed in the second groove on the side, far away from the primary filter fixing seat assembly, of the second injection molding part shell through potting.

Optionally, the input end of the high-voltage bus is in locking connection with the positive and negative input ends of the first-stage filtering fixing seat assembly through screws;

the positive and negative output ends of the first-stage filtering fixing seat assembly are respectively in locking connection with the positive and negative input ends of the second-stage filtering fixing seat assembly through screws;

and the positive and negative output ends of the secondary filter fixing seat assembly are respectively in locking connection with the positive and negative input ends of the thin film capacitor through screws.

Optionally, the filter circuit includes a circuit board, and two first X capacitors and two first Y capacitors disposed on the circuit board;

four mounting holes are formed in the periphery of the circuit board, two holes are power taking ends, the other two holes are grounding ends, and the power taking ends are correspondingly lapped with the first positive electrode copper bar and the first negative electrode copper bar and are used for taking power for two electrodes of the first X capacitor and the first level of the first Y capacitor; the grounding end is lapped with the controller shell and is grounded at the other pole of the first Y capacitor.

The two first X capacitors are arranged at intervals, and the two first Y capacitors are symmetrically arranged on two sides of one first X capacitor.

Optionally, the four second Y capacitors and the one second X capacitor are encapsulated in remaining second trenches in the second injection molded part housing, two second Y capacitors are arranged side by side on a side of the second injection molded part housing away from the primary filter holder assembly, and two remaining second Y capacitors and the one second X capacitor are arranged side by side on a side of the second injection molded part housing close to the primary filter holder assembly and close to the magnetic ring;

electricity taking welding pins are respectively led out of the second positive electrode copper bar and the second negative electrode copper bar, and ground welding pins are led out of the ground copper bar and are welded and fixed with electricity taking pins on the second X capacitor and the second Y capacitor to take electricity for the second X capacitor and the second Y capacitor; and the grounding welding foot is welded and fixed with the grounding pin on the second Y capacitor and is used for grounding the second Y capacitor.

It is another object of the present invention to provide a motor controller including the multi-stage filter structure of any one of the above.

It is a further object of the present invention to provide a vehicle including the motor controller described above.

Compared with the prior art, the invention has the advantages that:

according to the multi-stage filtering structure, the structure of the filtering circuit board is not arranged in the two-stage filtering fixing seat assembly, and the structure is simplified. Replace the magnetic core with the magnetic ring simultaneously, realize that one-level filtering fixing base subassembly and second grade filtering fixing base subassembly unite two into one, adopt modular design, novel structure. A plurality of filter devices are integrated together through an integrated and modular design, and the EMC capability of the DC end of the controller can be guaranteed to be improved to the maximum extent in a limited space.

Drawings

The invention is further described with reference to the following figures and examples:

fig. 1 is a schematic diagram of an installation structure of a multistage filtering structure in a controller housing according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a first-stage filter fixing base assembly of a multi-stage filter structure according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of the first magnetic core or the second magnetic core of the first-stage filter fixing base assembly of the multi-stage filter structure according to the embodiment of the invention;

FIG. 4 is a schematic structural diagram of a filter circuit of a first-stage filter fixing base assembly of a multi-stage filter structure according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a two-stage filter fixing base assembly of a multi-stage filter structure according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a magnetic ring of a two-stage filter fixing base assembly with a multi-stage filter structure according to an embodiment of the invention.

Wherein: 1. a first-stage filtering fixed seat component; 2. a secondary filtering fixed seat component; 3. a first positive input terminal; 4. a first negative input; 5. a first positive output end; 6. a first negative output terminal; 7. a second positive input terminal; 8. a second negative input terminal; 9. a second positive output end; 10. a second negative output terminal; 11a, a first magnetic core; 11b, a second magnetic core; 12. a filter circuit; 13. a magnetic ring; 14. a power taking end; 15. a ground terminal; 16. taking a power-taking welding leg; 17. a ground leg; 18. an E-shaped magnetic core; 19. a type I magnetic core; 20a, a first X capacitor; 20b, a second X capacitor; 21a, a first Y capacitor; 21b, a second Y capacitor; 22. a controller housing; 23. a high voltage bus; 24. and (3) a thin film capacitor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

Example (b):

referring to fig. 1 to 6, in the multi-stage filtering structure according to the embodiment of the present invention, a DC terminal, i.e., a direct current terminal, is fixed in a controller housing 22, a head end of the DC terminal, i.e., a right side of an upper end shown in fig. 1, is a high voltage bus 23, and a tail end, i.e., a lower end shown in fig. 1, is a thin film capacitor 24. The multistage filtering structure comprises a first-stage filtering fixing seat assembly 1 and a second-stage filtering fixing seat assembly 2. The primary filter mount assembly 1 and the secondary filter mount assembly 2 are arranged laterally within the controller housing 22. As shown in fig. 1, the left side of the controller housing 22 is the first-stage filter fixing seat assembly 1, the right side of the controller housing 22 is the second-stage filter fixing seat assembly 2, and the first-stage filter fixing seat assembly and the second-stage filter fixing seat assembly are transversely arranged left and right, so that the design space of the DC end EMC can be well controlled.

The input end of the high-voltage bus 23 is correspondingly connected with the positive and negative input ends of the first-stage filtering fixing seat assembly 1. The positive and negative output ends of the first-stage filtering fixing seat assembly 1 are respectively and correspondingly connected with the positive and negative input ends of the second-stage filtering fixing seat assembly 2. The positive and negative output ends of the secondary filter fixing seat assembly 2 are respectively and correspondingly connected with the positive and negative input ends of the thin film capacitor 24. Specifically, as shown in fig. 1, the input end of the high-voltage bus 23 is connected to the positive and negative input ends of the first-stage filtering fixing seat assembly 1 through screws in a locking manner. The positive and negative output ends of the first-stage filtering fixing seat assembly 1 are respectively in locking connection with the positive and negative input ends of the second-stage filtering fixing seat assembly 2 through screws. And the positive and negative output ends of the secondary filter fixing seat assembly 2 are respectively in locking connection with the positive and negative input ends of the thin film capacitor 24 through screws.

As shown in fig. 2 to 4, the first-stage filter holder assembly 1 includes a first injection-molded housing and a first filter element. The first injection molding piece shell is approximately square, and a first positive copper bar, a first negative copper bar and a plurality of first grooves (not shown in the figure) are arranged in the first injection molding piece shell. The two ends of the first positive electrode copper bar are respectively the positive input end and the positive output end of the first-stage filtering fixed base assembly 1, and the two ends of the first negative electrode copper bar are respectively the negative input end and the negative output end of the first-stage filtering fixed base assembly 1. For convenience of description and distinction, the positive input terminal and the positive output terminal of the first-stage filter holder assembly 1 are described as the first positive input terminal 3 and the first positive output terminal 5, respectively, and the negative input terminal and the negative output terminal of the first-stage filter holder assembly 1 are described as the first negative input terminal 4 and the first negative output terminal 6, respectively. As shown in fig. 2, the first positive input terminal 3 and the first negative input terminal 4 are arranged side by side at the front end of the right side of the first injection molded part housing, and the first positive output terminal 5 and the first negative output terminal 6 are arranged side by side at the front end of the left side of the first injection molded part housing.

First filter includes a first magnetic core 11a and a filter circuit 12, and the embedment of first magnetic core 11a is fixed in first slot and has two first via holes on it, and first positive copper bar and first negative pole copper bar are passed respectively to two first via holes. Differential mode or common mode interference can be effectively inhibited. As shown in fig. 2, the first magnetic core 11a is disposed at the middle rear end of the first injection molded part housing, and the first filter circuit 12 is disposed at the left end of the first injection molded part housing and at the rear ends of the first positive output terminal 5 and the first negative output terminal 6. As shown in fig. 3, the first core 11a is composed of an E-core 18 and an I-core 19, and the E-core 18 is fixed to the I-core 19 with its open end facing downward. In this embodiment, the circuit board is an existing conventional PCBA, that is, a printed circuit board or a printed circuit board.

More specifically, the filter circuit 12 includes a circuit board, and two first X capacitors 20a and two first Y capacitors 21a disposed on the circuit board, where the two first X capacitors 20a are disposed at intervals, and the two first Y capacitors 21a are symmetrically disposed on two sides of one of the first X capacitors 20 a. As shown in fig. 4, the circuit board is a square circuit board, one first X capacitor 20a with a larger size is disposed on the right rear side of the circuit board, another first X capacitor 20a with a smaller size is disposed on the left front side of the circuit board and has a space with the another first X capacitor 20a, and two first Y capacitors 21a are symmetrically disposed on the left and right sides of the first X capacitor 20a with a smaller size. Four mounting holes are formed around the circuit board, two holes of two sides of the first X capacitor 20a with large size are power taking ends 14, the other two grounding ends 15 are connected with the power taking ends 14, the power taking ends 14 are in corresponding lap joint with the first positive copper bar and the first negative copper bar, and the two poles of the first X capacitor 20a and the first level of the first Y capacitor 21a are used for taking power. The grounding terminal 15 is connected with the controller shell 22 in a lap joint mode, and the other pole of the Y capacitor is grounded. The first X capacitor 20a can effectively suppress differential mode interference, and the first Y capacitor 21a can effectively suppress common mode interference.

In some preferred embodiments, the first magnetic core 11a is fixed by potting in a first groove on the side of the first injection-molded housing remote from the second-stage filter holder assembly 2, i.e., on the left side of the first injection-molded housing as shown in fig. 2.

As shown in fig. 5-6, the two-stage filter mount assembly includes a second injection molded housing and a second filter element. The second injection molded part housing extends transversely, i.e., in the left-right direction as shown in fig. 1 and 5, and the second injection molded part housing has a second positive copper bar, a second negative copper bar, a ground copper bar and a plurality of second grooves (not shown). The two ends of the second positive electrode copper bar are respectively the positive input end and the positive output end of the second-stage filtering fixing base assembly 2, and the two ends of the second negative electrode copper bar are respectively the negative input end and the negative output end of the second-stage filtering fixing base assembly 2. For convenience of description and distinction, the positive input terminal and the positive output terminal of the secondary filter holder assembly 2 are described as the second positive input terminal 7 and the second positive output terminal 9, respectively, and the negative input terminal and the negative output terminal of the secondary filter holder assembly 2 are described as the second negative input terminal 8 and the second negative output terminal 10, respectively. As shown in fig. 5, the second positive input terminal 7 and the second negative input terminal 8 are arranged side by side in front and back on the left side of the second injection molded part housing, and the second positive output terminal 9 and the second negative output terminal 10 are arranged side by side in left and right on the front end of the right side of the second injection molded part housing.

The second filter device includes a magnetic ring 13, a second magnetic core 11b, four second Y capacitors 21b, and a second X capacitor 20 b. As shown in fig. 5 and 6, the magnetic ring 13 is an elliptical magnetic ring 13, a through hole of the magnetic ring 13 is formed in the middle of the elliptical magnetic ring 13, and the through hole of the magnetic ring 13 penetrates through the second positive electrode copper bar and the second negative electrode copper bar. As shown in fig. 5, magnetic ring 13 is fixed in a second groove (not shown) on the side of the second injection-molded housing close to first-stage filter holder assembly 1, i.e., on the left side of fig. 5, and the second groove is an elliptical groove matched with magnetic ring 13.

The second magnetic core 11b is encapsulated in the second injection molding shell and is provided with two second through holes, and the two second through holes respectively penetrate through the second positive copper bar and the second negative copper bar. Differential mode or common mode interference can be effectively inhibited. The second core 11b is also composed of an E-core 18 and an I-core 19, and the open end of the E-core 18 faces downward and is fixed to the I-core 19, similarly to the first core 11 a.

Four second Y capacitors 21b and one second X capacitor 20b are potted in the remaining second trenches in the second injection molded housing. Specifically, as shown in fig. 5, two second Y capacitors 21b are arranged side by side in front and back on the side of the second injection molded part housing away from the primary filter fixed seat assembly 1, that is, on the right side of the second injection molded part housing shown in fig. 5, and the other two second Y capacitors 21b and one second X capacitor 20b are arranged side by side in front, in middle, and back on the side of the second injection molded part housing close to the primary filter fixed seat assembly 1 and close to the magnetic ring 13, that is, on the left side of the second injection molded part housing shown in fig. 5, that is, on the right side of the magnetic ring 13.

As shown in fig. 5, the second magnetic core 11b is located between the four second Y capacitors 21b, specifically, is disposed at a middle position of the second injection-molded housing.

And the second positive copper bar and the second negative copper bar are respectively led out with a power taking welding pin 16, the grounding copper bar is led out with a grounding welding pin 17, and the power taking welding pin 16 is welded and fixed with the power taking pins on the second X capacitor 20b and the second Y capacitor 21b to take power for the second X capacitor 20b and the second Y capacitor 21 b. The grounding pin 17 is welded to the grounding pin of the second Y capacitor 21b, and is grounded to the second Y capacitor 21 b. The second X capacitor 20b can effectively suppress differential mode interference, and the second Y capacitor 21b can effectively suppress common mode interference.

In some preferred embodiments, the magnetic ring 13 is fixed on the side of the second injection-molded housing close to the primary filter holder assembly 1, i.e., on the left side of the second injection-molded housing as shown in fig. 5, by means of potting or dispensing with a sealing cap.

In some preferred embodiments, the second magnetic core 11b is fixed by potting in a second groove on the side of the second injection-molded housing remote from the first-stage filter holder assembly 1, i.e., in the middle of the second injection-molded housing as shown in fig. 5.

In the embodiment of the invention, the structure of the filter circuit board is not arranged in the second-stage filter fixing seat component 2, so that the structure is simplified. Replace the magnetic core with magnetic ring 13 simultaneously, realize that one-level filtering fixing base subassembly 1 and second grade filtering fixing base subassembly 2 unite two into one, adopt the modularized design, novel structure.

According to the multi-stage filtering structure provided by the embodiment of the invention, a plurality of filtering devices are integrated together through an integrated and modular design, so that the EMC (electro magnetic compatibility) capability of the DC end of the controller can be ensured in a limited space to the greatest extent. The multi-stage filtering structure provided by the embodiment of the invention can meet different grade requirements of EMC grade 3, grade 4, grade 5 and the like by adding or deleting the filtering capacitor, the magnetic ring 13, the magnetic core and the filtering circuit board according to customer or cost requirements.

The embodiment of the invention also provides a motor controller which comprises the multistage filtering structure of the embodiment. Other structures and operating principles of the motor controller are not described or limited in detail herein, and are conventional structures.

The embodiment of the invention also provides a vehicle which comprises the motor controller of the embodiment.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.

Claims

1. A multi-stage filtering structure is fixed at a DC end in a controller shell (22), and is characterized in that the head end of the DC end is a high-voltage bus (23), the tail end of the DC end is a thin-film capacitor (24), the multi-stage filtering structure comprises a first-stage filtering fixed base assembly (1) and a second-stage filtering fixed base assembly (2), and the first-stage filtering fixed base assembly (1) and the second-stage filtering fixed base assembly (2) are arranged in the controller shell (22);

the input end of the high-voltage bus (23) is correspondingly connected with the positive and negative input ends of the primary filtering fixing seat assembly (1); the positive and negative output ends of the first-stage filtering fixing seat assembly (1) are respectively and correspondingly connected with the positive and negative input ends of the second-stage filtering fixing seat assembly (2);

and the positive and negative output ends of the secondary filter fixing seat assembly (2) are respectively and correspondingly connected with the positive and negative input ends of the thin film capacitor (24).

2. A multistage filter structure as claimed in claim 1, characterized in that said first stage filter holder assembly (1) comprises a first injection-molded housing and a first filter element; a first positive copper bar, a first negative copper bar and a first groove are arranged in the first injection molding piece shell; said first filter element comprising a first magnetic core (11a) and a filter circuit (12), said first magnetic core (11a) being fixed in said first trench;

the second-stage filtering fixing seat assembly (2) comprises a second injection molding piece shell and a second filtering piece; a second positive copper bar, a second negative copper bar, a grounding copper bar and a plurality of second grooves are arranged in the second injection molding piece shell;

the second filter device comprises a magnetic ring (13), a second magnetic core (11b), four second Y capacitors (21b) and a second X capacitor (20 b);

the second magnetic core (11b) is positioned among four second Y capacitors (21 b); the magnetic ring (13) is fixed in one second groove on one side, close to the primary filtering fixing seat assembly (1), of the second injection molding part shell.

3. The multistage filtering structure according to claim 2, wherein two first via holes are arranged at the upper part of the first magnetic core (11a), and the two first via holes respectively pass through the first positive copper bar and the first negative copper bar;

two second via holes are formed in the upper portion of the second magnetic core (11b), and penetrate through the second positive copper bar and the second negative copper bar respectively;

and a magnetic ring via hole is formed in the middle of the magnetic ring (13), and penetrates through the second positive copper bar and the second negative copper bar.

4. A multi-stage filter structure according to claim 2, characterized in that said first core (11a) is composed of an E-core (18) and an I-core (19);

the second magnetic core (11b) is composed of an E-shaped magnetic core (18) and an I-shaped magnetic core (19).

5. A multistage filter structure according to claim 2, wherein said first magnetic core (11a) is fixed by potting in said first groove of the side of said first injection-molded housing remote from said second stage filter holder assembly (2);

the magnetic ring (13) is fixed on one side, close to the first-stage filtering fixing seat assembly (1), of the second injection molding piece shell in a glue pouring or dispensing and sealing manner; and/or

The second magnetic core (11b) is fixed in the second groove of the side, far away from the primary filter fixing seat component (1), of the second injection molding shell through potting.

6. The multistage filtering structure of claim 1, wherein the input end of the high-voltage bus bar (23) is in locking connection with the positive and negative input ends of the first-stage filtering fixing seat assembly (1) through screws;

the positive and negative output ends of the first-stage filtering fixing seat assembly (1) are respectively in locking connection with the positive and negative input ends of the second-stage filtering fixing seat assembly (2) through screws;

and the positive and negative output ends of the secondary filter fixing seat assembly (2) are respectively in locking connection with the positive and negative input ends of the thin film capacitor (24) through screws.

7. A multistage filtering structure according to claim 2, wherein said filtering circuit (12) comprises a circuit board and two first X capacitors (20a) and two first Y capacitors (21a) arranged on said circuit board;

four mounting holes are formed in the periphery of the circuit board, two holes are power taking ends (14), the other two holes are grounding ends (15), the power taking ends (14) are correspondingly connected with the first positive electrode copper bar and the first negative electrode copper bar in an overlapping mode, and the power taking ends are used for taking power for two poles of the first X capacitor (20a) and the first Y capacitor (21 a); the grounding end (15) is lapped with the controller shell (22) and is grounded at the other pole of the first Y capacitor (21 a);

the two first X capacitors (20a) are arranged at intervals, and the two first Y capacitors (21a) are symmetrically arranged on two sides of one first X capacitor (20 a).

8. A multi-stage filter structure according to claim 2, wherein the four second Y capacitors (21b) and the one second X capacitor (20b) are embedded in the remaining second trenches in the second injection-molded housing, wherein two second Y capacitors (21b) are arranged side by side on the side of the second injection-molded housing away from the first-stage filter holder assembly (1), and the remaining two second Y capacitors (21b) and the one second X capacitor (20b) are arranged side by side on the side of the second injection-molded housing close to the first-stage filter holder assembly (1) and close to the magnetic ring (13);

electricity taking welding pins (16) are respectively led out of the second positive electrode copper bar and the second negative electrode copper bar, a grounding welding pin (17) is led out of the grounding copper bar, and the electricity taking welding pins (16) are welded and fixed with electricity taking pins on the second X capacitor (20b) and the second Y capacitor (21b) to take electricity for the second X capacitor (20b) and the second Y capacitor (21 b); and the grounding welding foot (17) is welded and fixed with a grounding pin on the second Y capacitor (21b) and is grounded for the second Y capacitor (21 b).

9. A motor controller comprising a multi-stage filter structure according to any of claims 1-8.

10. A vehicle characterized by comprising the motor controller of claim 9.