CN111697844A

CN111697844A - Motor inverter

Info

Publication number: CN111697844A
Application number: CN201910197189.0A
Authority: CN
Inventors: 陈恺达; 姚通; 刘文俊; 王震宇
Original assignee: Suzhou Gala Tech Power Co ltd
Current assignee: Jiangsu galatech Microelectronics Co.,Ltd.
Priority date: 2019-03-15
Filing date: 2019-03-15
Publication date: 2020-09-22

Abstract

A motor inverter for cooperation with an electric motor, the motor inverter comprising: the direct current capacitor is in a rectangular cuboid shape and comprises a top surface, a bottom surface and four side surfaces, wherein the side surfaces comprise a first side surface and three second side surfaces; three groups of transistor groups are arranged on the second side surface respectively, and two adjacent transistor groups are vertical to each other; the high-voltage connector is arranged close to the first side face and is connected with the direct-current capacitor; and the asynchronous motor is connected with the direct current capacitor. Therefore, the dc transistor groups in the present invention are located on the three second sides of the dc capacitors, and the adjacent two dc capacitors are at right angles therebetween. And the high-voltage connector is positioned on the first side surface of the direct-current capacitor, so that the electric distribution structure is compact, the three phases are vertical to each other, the energy density is high, the electric performance is good, the electromagnetic interference is small, the three-phase electric balance is good, and the efficiency is higher.

Description

Motor inverter

Technical Field

The present invention relates to a motor inverter, and more particularly, to a motor inverter having high power.

Background

An inverter is an electronic device that converts direct current into alternating current using a high-frequency bridge circuit, and its purpose is opposite to that of a rectifier. In the existing electric vehicle, the inverter is also generally used for controlling the motor of the vehicle and providing power for the operation of the vehicle.

However, the arrangement of capacitors, transistors, etc. in the conventional inverter is often not too tight, resulting in problems such as too high inductance of the high-frequency circuit, or a reduction in service life due to improper heat transfer.

Therefore, it is necessary to design a motor inverter having a better arrangement structure.

Disclosure of Invention

In order to solve the above problems, the present invention provides a motor inverter for cooperation with an electric motor, the motor inverter including: the direct current capacitor is in a rectangular cuboid shape and comprises a top surface, a bottom surface and four side surfaces, wherein the side surfaces comprise a first side surface and three second side surfaces; three groups of transistor groups are arranged on the second side surface respectively, and two adjacent transistor groups are vertical to each other; the high-voltage connector is arranged close to the first side face and is connected with the direct-current capacitor; and the asynchronous motor is connected with the direct current capacitor.

As a further improvement of the present invention, the transistor group includes bipolar transistors arranged in sequence, and the dc capacitor includes: the positive electrode bus board comprises a positive electrode connecting end and a positive electrode wiring end, the positive electrode connecting end is close to the first side face and is connected with the high-voltage connector, and the positive electrode wiring ends are arranged close to the second side face and are connected with the bipolar transistor; the negative electrode wiring board comprises a negative electrode connecting end and a negative electrode wiring end, the negative electrode connecting end is connected with the high-voltage connector, and the negative electrode wiring end is connected with the bipolar transistor; the phase-level junction boards are arranged at intervals, each phase-level junction board comprises a phase-level connection end and a phase-level wiring end, the phase-level connection ends are connected with the asynchronous motor, and the phase-level wiring ends are connected with the bipolar transistors.

As a further improvement of the present invention, the thickness of the positive electrode connecting end is greater than that of the positive electrode terminal, the thickness of the negative electrode connecting end is greater than that of the negative electrode terminal, and the thickness of the phase connection end is greater than that of the phase terminal.

As a further improvement of the present invention, the dc capacitor includes a housing, a first receiving space is formed in the housing, the positive bus bar and the negative bus bar are both partially disposed in the first receiving space, and the phase bus bar is disposed outside the receiving space and on the upper side of the negative bus bar.

As a further improvement of the present invention, the positive bus bar includes a positive main body formed by bending along an inner surface of the housing, and the positive connection end and the positive terminal are disposed on the positive main body; the negative electrode wiring board comprises a square negative electrode main body and a negative electrode terminal seat extending from three sides of the negative electrode main body, and the negative electrode wiring terminal is arranged on the negative electrode terminal seat; the phase pole bus board comprises a phase pole main body and a phase pole terminal base extending from the phase pole main body, and the phase pole wiring terminal is arranged on the phase pole terminal base; the motor inverter further includes an insulating layer disposed between the phase terminal block and the negative terminal block.

As a further improvement of the present invention, the positive electrode main body is formed by bending along an inner surface of the casing, the negative electrode main body is plate-shaped and covers the positive electrode main body, and a second accommodating space is formed between the negative electrode main body and the positive electrode main body; the direct current capacitor further comprises a plurality of thin film capacitor units, and the thin film capacitor units are arranged in the second accommodating space.

As a further improvement of the present invention, the motor inverter further includes two Y capacitors, and the Y capacitors are disposed near the first side surface; and the positive connecting end and the negative connecting end are respectively connected with the two Y capacitors.

As a further improvement of the invention, the positive electrode connecting end comprises a positive electrode wide end and a positive electrode narrow end bent and extended from the positive electrode wide end, and the negative electrode connecting end comprises a negative electrode wide end and a negative electrode narrow end bent and extended from the negative electrode wide section; the positive wide end and the negative wide end are connected with the high-voltage connector, and the negative wide end and the negative narrow end are respectively connected with the two Y capacitors.

As a further improvement of the present invention, the transistor group includes a strip-shaped heat sink, and the bipolar transistors are symmetrically attached to two opposite sides of the heat sink.

As a further improvement of the present invention, the motor inverter further includes a discharge resistor disposed at an end of the heat sink and disposed near the first side surface.

The invention has the beneficial effects that: the direct current transistor groups are positioned on three second sides of the direct current capacitors, and a right angle is formed between two adjacent direct current capacitors. And the high-voltage connector is positioned on the first side surface of the direct-current capacitor, so that the electric distribution structure is compact, the three phases are vertical to each other, the energy density is high, the electric performance is good, the electromagnetic interference is small, the three-phase electric balance is good, and the efficiency is higher.

Drawings

Fig. 1 is a schematic perspective view of a motor inverter according to the present invention;

FIG. 2 is a schematic perspective view of the DC capacitor of the present invention at one angle;

FIG. 3 is a schematic perspective view of a DC capacitor according to another embodiment of the present invention;

FIG. 4 is an enlarged schematic view of the circled portion in FIG. 3;

FIG. 5 is a schematic perspective view of a transistor array according to the present invention;

fig. 6 is a schematic perspective view of the positive electrode bus bar according to the present invention;

fig. 7 is a schematic perspective view of a negative electrode bus bar according to the present invention;

fig. 8 is a schematic perspective view of a phase bus plate according to the present invention;

fig. 9 is a schematic perspective view of a housing of the dc capacitor of the present invention;

fig. 10 is a schematic perspective view of a support plate in the dc capacitor of the present invention.

100-a motor inverter; 10-a direct current capacitor; 1-a shell; 11-a first side; 12-a second side; 13-a first housing space; 14-a support plate; 141-a cross beam; 142-a first blind hole; 143-second blind hole; 2-positive pole bus plate; 21-a positive electrode body; 211-a first base plate; 212-a first side panel; 213-a first capacitance connection plate; 22-positive electrode connecting end; 221-positive wide end; 222-positive pole narrow end; 23-positive terminal; 3-negative pole bus board; 31-a negative body; 32-negative terminal base; 321-negative terminal; 33-a second capacitive connecting plate; 34-a negative electrode connection end; 341-negative wide end; 342-negative narrow end; 4-phase pole bus plate; 41-phase body; 42-phase terminal base; 421-phase terminal; 43-phase pole connection end; 70-transistor group; 90-drive circuit board; 71-a heat sink; 72-a bipolar transistor; 81-discharge resistance.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Moreover, repeated reference numerals or designations may be used in various embodiments. These iterations are merely for simplicity and clarity of describing the present invention, and are not intended to represent any correlation between the different embodiments or configurations discussed.

As shown in fig. 1 to 10, the present invention provides a motor inverter 100 for cooperation with an electric motor, the motor inverter 100 including:

the direct current capacitor 10 is a rectangular cuboid and comprises a top surface, a bottom surface and four side surfaces, wherein the side surfaces comprise a first side surface 11 and three second side surfaces 12;

three groups of transistor groups 70 are arranged on the second side surface 12, and two adjacent transistor groups 70 are perpendicular to each other;

the high-voltage connector is arranged close to the first side surface 11 and is connected with the direct current capacitor 10;

an asynchronous motor (not shown) is connected to the dc capacitor 10.

The motor inverter 100 further includes a driving circuit board 90, wherein the driving circuit board 90 is disposed on the upper side of the dc capacitor 10, and is electrically connected to both the dc capacitor 10 and the transistor group 70, so as to achieve the driving control function.

Therefore, as shown in fig. 1 and fig. 2, the dc transistor groups 70 in the present invention are located on the three second sides 12 of the dc capacitors 10, and a right angle is formed between two adjacent dc capacitors 10. And the high-voltage connector is positioned on the first side surface 11 of the direct current capacitor 10, so that the electrical distribution structure is compact, and three phases are vertical to each other, therefore, the energy density is high, the electrical performance is good, the electromagnetic interference is small, the three-phase electrical balance is good, and the efficiency is higher.

For convenience of description, the direction of the first side surface 11 relative to the other second side surfaces 12 is referred to as forward, and the opposite direction is referred to as backward; the direction of the first bottom surface away from the side surface is downward, and the opposite direction is upward.

As shown in fig. 5, the transistor group 70 includes a strip-shaped heat spreader 71 and bipolar transistors 72 symmetrically attached TO two opposite sides of the heat spreader 71, and the bipolar transistors 72 are formed by packaging the insulated gate bipolar transistors 72 with TO-247. The pins of the bipolar transistors 72 are all arranged upward and are all connected to the dc capacitor 10. The distance between the bipolar transistors 72 in each transistor group 70 is as small as possible, thereby reducing the high frequency circuit loop in the motor inverter 100 and correspondingly reducing the high frequency circuit loop inductance. The number of bipolar transistors 72 in the three transistor group 70 may be varied, depending on the power requirements of the motor inverter 100.

As shown in fig. 3 to 4, the dc capacitor 10 further includes a discharge resistor 81, and the discharge resistor 81 is disposed on the heat sinks 71 of the two transistor groups 70 and is disposed near the first side surface 11. That is, the discharge resistor 81 is disposed on the front side of the heat sink 71, and the bipolar transistors 72 are symmetrically arranged on the left and right sides of the heat sink 71. The transistor groups 70 are provided in three groups, and are respectively adjacent to the three second sides 12 of the dc capacitor 10. The discharging resistor 81 is a fast discharging resistor, and a joint thereof is connected with the driving circuit board 90 and directly attached to the heat sink 71. The heat generated in the discharging process can be quickly led out through the radiator 71, so that the heat dissipation in the quick discharging process is ensured, and the installation is simplified.

The dc capacitor 10 specifically includes: the solar cell comprises a shell 1, a positive electrode bus plate 2 and a negative electrode bus plate 3 which are arranged in the shell 1, and a phase electrode bus plate 4 which is arranged on the negative electrode bus plate 3, wherein the shell 1 is made of epoxy resin. Specifically, the following is a detailed description.

As shown in fig. 9, a case 1 is formed of epoxy resin and has a substantially rectangular square shape, the case 1 constitutes a housing of the dc capacitor 10, and a first receiving space 13 having a substantially rectangular square shape is formed in the case 1. And the bottom of the housing 1 is provided with a fin structure, thereby enlarging the surface area of the housing 1 and helping the heat dissipation of the direct current capacitor 10.

As shown in fig. 6, the positive electrode bus bar 2 is partially accommodated in the first accommodation space 13. The positive electrode bus bar 2 is bent along the inner surface of the housing 1 to form a positive electrode main body 21, a positive electrode connecting terminal 22 connected to the positive electrode main body 21, and a positive electrode terminal 23 in contact with the bipolar transistors 72 of the transistor group 70. The positive electrode main body 21 includes a first bottom plate 211 and a first side plate 212 extending from the first bottom plate 211 along a direction close to the three second side surfaces 12, and the positive electrode terminals 23 are arranged on the upper side of the first side plate 212 and extend upward out of the housing 1. The positive electrode main body 21 further includes a first capacitor connecting plate 213 extending upward from a side of the first bottom plate 211 close to the first side surface 11, and the positive electrode connecting end 22 is bent and extends forward from the first capacitor connecting plate 213.

The positive connection end 22 includes a positive wide end 221 extending forward from the first capacitor connection plate 213 and a positive narrow end 222 bent forward from the positive wide end 221, and the positive narrow end 222 is bent horizontally and outwardly and then extends forward. The thickness of the positive electrode connection terminal 22 is greater than that of the positive electrode terminal 23. The anode wide end 221 is connected to the high voltage connector.

In the positive power bus plate 2, the material thickness of the positive terminal 23 connected to the transistor group 70 and the drive circuit board 90 is thin, thereby facilitating the soldering with the transistor group 70 and the soldering with the drive circuit board 90. In the positive bus bar 2, the positive wide end 221 connected to the high-voltage connector is thicker, so that the strength of the interface is increased. In addition, the use of the positive electrode bus bar 2 with a large thickness reduces power loss of the dc capacitor 10 during use, reduces the heat generation amount of the dc capacitor 10 during operation, and thus increases the service life of the dc capacitor 10.

As shown in fig. 7, in the negative bus bar 3, the negative bus bar 3 includes a square negative body 31 and a negative terminal base 32 extending from three sides of the negative body 31 near the second side 12, the negative bus bar 3 further includes a plurality of negative terminals 321 disposed on the negative terminal base 32, the negative terminals 321 are arranged along a side of the negative terminal base 32, pins of the negative terminals 321 face upward and protrude from the negative body 31, and a portion of the pins is electrically connected to the driving circuit board 90 and the phase bus bar 4. The negative electrode bus bar 3 further includes a second capacitor connecting plate 33 extending downward from a side of the negative electrode main body 31 close to the first side surface 11, and the negative electrode bus bar 3 further includes a negative electrode connecting end 34 extending forward from the second capacitor connecting plate 33. A row of through holes are further formed in the inner side of the negative terminal base 32 for the positive terminal 23 and the bipolar transistor 72 to pass through.

The negative connection terminal 34 includes a negative wide end 341 extending forward from the second capacitor connection plate 33 and a negative narrow end 342 bent forward from the negative wide end 341, and the negative narrow end 342 is bent horizontally and outwardly and then extends forward. The negative narrow end 342 extends in a horizontal direction opposite to the positive narrow end 222. The thickness of the negative terminal 34 is greater than the thickness of the negative terminal 321. The negative wide end 341 is connected to the high voltage connector.

In the negative electrode bus bar 3, the material thickness of the negative electrode terminal 321 connected to the transistor group 70 and the drive circuit board 90 is thin, thereby facilitating the soldering with the transistor group 70 and the soldering with the drive circuit board 90. In the negative electrode bus bar 3, the negative electrode wide end 341 connected to the high voltage connector is thicker, so that the strength of the interface is increased. In addition, the use of the negative electrode bus plate 3 with a large thickness reduces the power loss of the dc capacitor 10 in use, reduces the heat generation amount of the dc capacitor 10 during operation, and thus increases the service life of the dc capacitor 10.

When the positive bus bar 2 and the negative bus bar 3 are installed, the negative body 31 is covered on the positive body 21 in a plate shape, a second accommodating space (not numbered) is formed between the negative body 31 and the positive body 21, and the dc capacitor further includes a plurality of thin film capacitor units (not shown) arranged in the second accommodating space. The first capacitor connecting plate 213 is connected to the bottom of the thin film capacitor unit, and the second capacitor connecting plate 33 is electrically connected to the top of the thin film capacitor unit. Specifically, in this embodiment, the thin film capacitor units have a total of six and are sequentially arranged horizontally. The thin film capacitor unit is horizontally arranged, so that the welding connection with a bus board is simplified, the equivalent series resistance of the thin film capacitor unit is reduced, and the loss of the inverter in the operation process is reduced. Of course, the number and volume of the thin film capacitor units can be adjusted according to the required capacitance value and the volume of the dc capacitor housing 1.

As shown in fig. 8, three phase pole busbars 4 are arranged and spaced from each other, each of the phase pole busbars 4 includes a phase pole main body 41 and a phase pole terminal seat 42 extending from the phase pole main body 41, and phase pole terminals 421 are arranged on the phase pole terminal seats 42. The phase terminal 421 is provided with two columns of phase terminals 421, and one column near the outer side and the negative terminal 321 are positioned on the same column and are in butt joint with the bipolar transistor 72 near the outer side in the transistor group 70; the inner row of the phase terminals 421 is located in the same row as the positive terminal 23 and is connected to the inner bipolar transistor 72 of the transistor group 70. Further, a row of phase terminals 421 on the inner side are extended to be connected to the driving circuit board 90.

The phase-pole bus board 4 further includes a phase-pole connecting end 43 bent and extending upward from the phase-pole main body 41, the phase-pole connecting end 43 is used for connecting with a three-phase asynchronous motor, and the three phase-pole bus boards 4 respectively correspond to three phases in the three-phase asynchronous motor and also respectively correspond to the three transistor groups 70 in the motor inverter 100. The thickness of the phase connecting end 43 of the phase bus bar 4 connected to the three-phase asynchronous motor is thicker than that of the phase terminal 421, and the width is wider, so that the strength of the interface can be enhanced, and the current strength bearing capacity of the phase bus bar 4 can be further enhanced. And the resistance values of the three phase-level bus plates are similar, so that the current imbalance in the operation process of the inverter is reduced, and the electrical balance of the motor inverter 100 is improved.

Three phases of the three-phase asynchronous motor respectively correspond to the three phase pole bus plates 4, and also respectively correspond to the three transistor groups 70 in the motor inverter 100.

As shown in fig. 10, the dc capacitor 10 further includes a support plate 14, the support plate 14 is located below the negative bus bar 3, and the support plate 14 is used to support the phase bus bar 4. The tapered structure is densely arranged at the bottom of the support plate 14, so that the support plate 14 can be fixed in the shell 1. The top of the support plate 14 is provided with a cross beam 141 and a first blind hole 142 with the same height as the cross beam 141, and the first blind hole 142 can support the stationary phase pole busbar 4 by using a self-tapping screw in a matching manner. In addition, the second blind hole 143 at the top of the supporting plate 14 can support and fix the driving circuit board 90 by fitting a self-tapping screw, and the height of the second blind hole 143 is greater than that of the first blind hole 142.

The support plate 14 is fixed in the housing 1, and thus can support not only the phase collector 4 but also the drive circuit board 90. Thereby, the structural stability of the phase bus plate 4 and the drive circuit board 90 can be enhanced while reducing the overall volume of the motor inverter 100. In addition, the phase electrode bus plate 4 is disposed on the upper side of the supporting plate 14 and is not disposed inside the housing 1, which can help the heat dissipation of the phase electrode bus plate 4 during the use of the dc capacitor 10, and the heat of the phase electrode bus plate 4 cannot be transferred to the thin film capacitor unit.

Therefore, the positive bus bar 2, the negative bus bar 3, and the phase bus bar 4 in the dc capacitor 10 are configured such that each of the bipolar transistors 72 in the transistor group 70 is closest to the thin film capacitor unit electrically, and each of the bipolar transistors 72 is also closest to each of the joints of the three-phase asynchronous motor electrically, so that the bipolar transistors 72 of each phase share a good current, the risk of damage due to an excessive current pressure of a single transistor group 70 is reduced, and the service life of the motor inverter 100 is prolonged. In addition, the high-frequency circuit loop path formed by the bipolar transistor 72, the thin-film capacitor unit, the positive electrode bus plate 2, the negative electrode bus plate 3 and the phase electrode bus plate 4 is short, so that the parasitic inductance in the motor inverter 100 can be further reduced, and the motor inverter has better electrical performance.

As shown in fig. 3 to 4, the motor inverter 100 further includes two Y capacitors 82, the two Y capacitors 82 are disposed near the first side surface 11, and the positive narrow end 222 of the positive connection end 22 and the negative narrow end 342 of the negative connection end 34 are respectively connected to the two Y capacitors 82. And, the positive wide end 221 of the positive connection terminal 22 is connected to the positive electrode of the high voltage connector, the positive narrow end 222 is connected to the Y capacitor 82, the negative wide end 341 of the negative connection terminal 34 is connected to the negative electrode of the high voltage connector, and the negative narrow end 342 is connected to the Y capacitor 82, so that the electrical paths of the two Y capacitors 82 to the high voltage positive electrode and the high voltage negative electrode, respectively, are short.

The Y capacitor 82 can be conducted with the housing ground of the motor inverter 100 through a Y capacitor ground bus plate (not shown) and a metal bolt, so that the length of the Y capacitor ground bus plate is short, the electrical distance between the Y capacitor 82 and the motor is short, the impedance between the Y capacitor 82 and the motor housing is reduced, and the electromagnetic interference of the motor inverter 100 is small. In addition, the two Y capacitors 82 are accommodated in the Y capacitor fixing frame 821, and the Y capacitor fixing frame 821 extends outward and partially covers the positive connection end 22 and the negative connection end 34, so that a better insulation effect is achieved.

Therefore, in summary, the motor inverter 100 includes the dc capacitors 10 in a rectangular cube and the transistor groups 70 distributed on three sides of the dc capacitors 10, so that the motor inverter 100 has a compact electrical distribution structure and three phases perpendicular to each other, and thus has high energy density, good electrical performance, small electromagnetic interference, good three-phase electrical balance and higher efficiency.

It should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art will be able to make the description as a whole, and the embodiments may be appropriately combined to form other embodiments as will be appreciated by those skilled in the art.

The above detailed description is merely illustrative of possible embodiments of the present invention and is not intended to limit the scope of the invention, which is intended to include all equivalent embodiments or modifications within the scope of the present invention without departing from the technical spirit of the present invention.

Claims

1. A motor inverter for cooperation with an electric motor, the motor inverter comprising:

the direct current capacitor is in a rectangular cuboid shape and comprises a top surface, a bottom surface and four side surfaces, wherein the side surfaces comprise a first side surface and three second side surfaces;

three groups of transistor groups are arranged on the second side surface respectively, and two adjacent transistor groups are vertical to each other;

the high-voltage connector is arranged close to the first side face and is connected with the direct-current capacitor;

and the asynchronous motor is connected with the direct current capacitor.

2. The motor inverter of claim 1, wherein the transistor group comprises bipolar transistors arranged in series, and the dc capacitor comprises:

the positive electrode bus board comprises a positive electrode connecting end and a positive electrode wiring end, the positive electrode connecting end is close to the first side face and is connected with the high-voltage connector, and the positive electrode wiring ends are arranged close to the second side face and are connected with the bipolar transistor;

the negative electrode wiring board comprises a negative electrode connecting end and a negative electrode wiring end, the negative electrode connecting end is connected with the high-voltage connector, and the negative electrode wiring end is connected with the bipolar transistor;

the phase-level junction boards are arranged at intervals, each phase-level junction board comprises a phase-level connection end and a phase-level wiring end, the phase-level connection ends are connected with the asynchronous motor, and the phase-level wiring ends are connected with the bipolar transistors.

3. The motor inverter of claim 2, the positive connection end having a thickness greater than a thickness of the positive terminal, the negative connection end having a thickness greater than a thickness of the negative terminal, the phase connection end having a thickness greater than a thickness of the phase terminal.

4. The motor inverter according to claim 2, wherein the dc capacitor includes a housing, a first receiving space is formed in the housing, the positive bus bar and the negative bus bar are partially disposed in the first receiving space, and the phase bus bar is disposed outside the receiving space and on the upper side of the negative bus bar.

5. The motor inverter of claim 2, the positive bus bar including a positive body bent along an inner surface of the housing, the positive connection end and the positive terminal being disposed on the positive body;

the negative electrode wiring board comprises a square negative electrode main body and a negative electrode terminal seat extending from three sides of the negative electrode main body, and the negative electrode wiring terminal is arranged on the negative electrode terminal seat;

the phase pole bus board comprises a phase pole main body and a phase pole terminal base extending from the phase pole main body, and the phase pole wiring terminal is arranged on the phase pole terminal base;

the motor inverter further includes an insulating layer disposed between the phase terminal block and the negative terminal block.

6. The motor inverter according to claim 5, wherein the positive electrode body is formed by bending along an inner surface of the case, the negative electrode body is plate-shaped and covers the positive electrode body, and a second receiving space is formed between the negative electrode body and the positive electrode body; the direct current capacitor further comprises a plurality of thin film capacitor units, and the thin film capacitor units are arranged in the second accommodating space.

7. The motor inverter of claim 2, further comprising two Y capacitors, the Y capacitors being disposed proximate the first side; and the positive connecting end and the negative connecting end are respectively connected with the two Y capacitors.

8. The motor inverter of claim 7, the positive connection end comprising a positive wide end and a positive narrow end extending from the positive wide end, the negative connection end comprising a negative wide end and a negative narrow end extending from the negative wide section; the positive wide end and the negative wide end are connected with the high-voltage connector, and the negative wide end and the negative narrow end are respectively connected with the two Y capacitors.

9. The motor inverter of claim 2, the transistor stack comprising a strip-shaped heat sink, the bipolar transistors being symmetrically attached to opposite sides of the heat sink.

10. The motor inverter according to claim 9, further comprising a discharge resistor disposed at an end of the heat sink and disposed proximate to the first side.