A capacitor with a perforated cooling plate

Abstract

The present invention relates to a capacitor (1) which is included in a motor drive that enables the electric motor to be operated by converting the energy stored as DC in the vehicle battery into AC current; and enables the cooling process to be performed from its large surface wherein the busbars (3) are located.

Description

[0001] DESCRIPTION

[0002] A CAPACITOR WITH A PERFORATED COOLING PLATE

[0003] Technical Field

[0004] The present invention relates to a capacitor which is included in a motor drive that enables the electric motor to be operated by converting the energy stored as DC in the vehicle battery into AC current; and enables the cooling process to be performed from its large surface wherein the busbars are located.

[0005] Background of the Invention

[0006] The energy collected as DC current in vehicle batteries must be converted into AC current when operating the electric motor. Therefore, the energy stored in the battery goes through a cycle that includes a motor drive unit in order to drive the electric motor. High-speed electronic load switching is performed inside the motor drive. In the absence of a capacitor between the motor and the battery, these currents will be drawn from the battery and therefore generate an intense electromagnetic noise. For this reason, today, there is a need for a DC link capacitor which is compatible with the mechanical design of the inverter in order for the high amplitude currents in the motor drive to be drawn from an intermediate component instead of the battery so as to avoid the said noise.

[0007] On the other hand, the capacitor needs cooling as it heats up during operation. A cooling surface specific to the system is defined in order to provide cooling. The HV lines included in the capacitor, the unit cooling channel, the mechanical design of the unit should be taken into consideration during the creation of this surface and a thermal analysis should be performed according to the unit operating conditions. Furthermore, the most common method during capacitor production is to place capacitor elements and busbars in the mold and to apply epoxy filler over the large surface. In order for the capacitors produced by this method to have the desired flatness and tolerance of the epoxy filling surface, the production process must be in two stages, which adversely affects the production time and cost. Therefore, today, a method which will both enable the formation of a flat surface and will not adversely affect production time and cost is required.

[0008] The Chinese patent document no. CN106376215, an application included in the state of the art, discloses a DC link capacitor with integrated cooling. The DC link capacitor comprises an inverter that converts the voltage of the direct current provided by the high-voltage battery of the electric vehicle into alternating current. In the said invention, there is a cold plate used with the inverter of the electric vehicle and the cold plate makes a physical contact by covering the DC link capacitor. By means of the cooling plate, the heat generated during the conversion of the current is dissipated by using the cooling plate. In addition, the cooling plate may comprise a filler material that enables the heat to be dissipated.

[0009] Summary of the Invention

[0010] An object of the present invention is to realize a capacitor wherein the instantaneous currents are drawn by instead of the battery and wherein the stray inductances occurring in the transistor and interconnections and the stray resistances occurring in the connection path are minimized via the busbar structure thereof.

[0011] Another object of the present invention is to realize a capacitor which has input busbars designed for minimum cost and optimum cooling, wherein one of the high voltage (HV-High voltage) busbars is not used as a cooling surface.

[0012] A further object of the present invention is to realize a capacitor wherein the process of filling the inner volume with epoxy material is carried out by means of a plate perforated on its wide surface and wherein the busbars are placed in the capacitor body through its wide surface. A further object of the present invention is to realize a capacitor wherein the required tolerances on the cooling surface can be provided by means of the placement of the perforated plate on the prongs in the body and flatness thereof.

[0013] Detailed Description of the Invention

[0014] “A Capacitor with a Perforated Cooling Plate” realized to fulfd the objectives of the present invention is shown in the figures attached, in which:

[0015] Figure 1 is a perspective view of an inventive capacitor with a perforated cooling plate.

[0016] Figure 2 is a view wherein the epoxy material filling surface of an inventive capacitor with a perforated cooling plate is shown.

[0017] The components illustrated in the figures are individually numbered, where the numbers refer to the following:

[0018] 1. Capacitor

[0019] 2. Body

[0020] 3. Busbar

[0021] 31. First Lug

[0022] 32. Second Lugs

[0023] 33. Connection Hole

[0024] 4. Cooling Plate

[0025] 5. Gap

[0026] 6. Tab

[0027] An inventive capacitor (1) which enables the electric motor to be operated by converting the energy stored as DC in the vehicle batteries of electric vehicles into AC current and the stray inductors and stray resistances in the connection path to be minimized during operation comprises at least one body (2) which has a rectangular prism shape and has an internal volume wherein the capacitor elements are positioned; at least two busbars (3) which are located on the body (2) on any surface of the body (2) that is wider than the other surfaces thereof and comprise a first lug (31) protruding outward from the body (2) when positioned on the body (2) and a plurality of second lugs (32) extending toward the body (2) and shorter than the first lug (31); at least one cooling plate (4) which is located on the large surface of the body (2) wherein the busbars (3) are located; comprises a plurality of gaps (5) in order for epoxy material to be filled; and enables an epoxy layer to be formed on the large surface upon epoxy filling and enables cooling to be realized from the said surface.

[0028] The body (2) included in an inventive capacitor (1) is in the shape of a rectangular prism wherein the busbars (3) are located on one of its surfaces that is wider than the other surfaces and on which there are lugs (31, 32) used for connection to the motor driver with holes. The body (2) comprises a cooling plate (4) that is located on the surface wherein the busbars (3) are located and that enables an epoxy layer to be obtained by filling the epoxy material therein. There is a plurality of gaps (5) located on the cooling plate (4). While the gaps (5) near the edges of the cooling plate (4) are semicircular, the gaps (5) inside are full circular.

[0029] The body (2) comprises an opening on its large surface wherein only the epoxy is filled, and a cooling plate (4) with a plurality of gaps (5) is placed in the said opening. Epoxy material is filled in a single step through the opening in the body (2) following the placement of the capacitor elements and then the cooling plate (4). In this way, the opening of the body (2) is used both as an element placement and as a cooling surface; on the other hand, while the application time reduces, the costs of parts are also reduced. The busbar (3) included in an inventive capacitor (1) comprises a first lug (31) and four second lugs (32) that are shorter than the first lug (31) facing in opposite directions with respect to each other for minimum cost and optimum cooling. When the busbar (3) is positioned on the body (2), the second lugs (32) extend towards one of the large surfaces of the body (2). And the first lug (31) extends upwards from the body (2). The busbar (3) is located on one of the wide surfaces of the body (2) and does not exit to the surface of any of the large surfaces of the body (2). In this way, it is not needed to use one of the busbars (3) as a cooling surface.

[0030] The cooling plate (4) included in an inventive capacitor (1) comprises a plurality of gaps (5) in order to fill the body (2) with epoxy. The capacitor elements are placed into the body (2) through the said opening before the cooling plate (4) is placed into the opening of the body (2). The cooling plate (4) is fixed to the body (2) via the prongs located on the body (2). The cooling plate (2) also has a flat surface. In this way, the desired tolerances on the cooling surface can be provided. After the elements are placed in the body (2), the cooling plate (4) is placed, and the epoxy fills into the body through the gaps (5) and enables a cooling layer to be formed on the surface of the body (2).

[0031] Industrial Application of the Invention

[0032] The inventive capacitor (1) meets the instantaneous high current requirement between the electric motor and the battery in electric vehicles by being used in the motor drive. In this way, less electromagnetic noise is generated than in applications wherein the capacitor (1) is not used. On the other hand, the stray inductance that occurs in the interconnections and the transistor used and the stray resistances that occur in the connection path are minimized due to the busbar (3) structure. Within these basic concepts; it is possible to develop various embodiments of the inventive “A Capacitor (1) with a Perforated Cooling Plate (4)”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

Claims

CLAIMS1. A capacitor (1) which enables the electric motor to be operated by converting the energy stored as DC in the vehicle batteries of electric vehicles into AC current and the stray inductors and stray resistances in the connection path to be minimized during operation; characterized by at least one body (2) which has a rectangular prism shape and has an internal volume wherein the capacitor elements are positioned; at least two busbars (3) which are located on the body (2) on any surface of the body (2) that is wider than the other surfaces thereof and comprise a first lug (31) protruding outward from the body (2) when positioned on the body (2) and a plurality of second lugs (32) extending toward the body (2) and shorter than the first lug (31); at least one cooling plate (4) which is located on the large surface of the body (2) wherein the busbars (3) are located; comprises a plurality of gaps (5) in order for epoxy material to be filled; and enables an epoxy layer to be formed on the large surface upon epoxy filling and enables cooling to be realized from the said surface.

2. A capacitor (1) according to Claim 1; characterized by the body (2) which is in the shape of a rectangular prism wherein the busbars (3) are located on one of its surfaces that is wider than the other surfaces and on which there are lugs (31, 32) used for connection to the motor driver with holes.

3. A capacitor (1) according to Claim 1 or 2; characterized by the body (2) which comprises a cooling plate (4) that is located on the surface wherein the busbars (3) are located and that enables an epoxy layer to be obtained by filling the epoxy material therein.

4. A capacitor (1) according to any one of the preceding claims; characterized by the cooling plate (4) whose gaps (5) near the edges are semicircular while the gaps (5) on the inside are full circular5. A capacitor ( 1 ) according to any one of the preceding claims ; characterized by the body (2) which comprises an opening on its large surface wherein only the epoxy is filled, and a cooling plate (4) with a plurality of gaps (5) is placed in the said opening.

6. A capacitor ( 1 ) according to any one of the preceding claims ; characterized by the busbar (3) which comprises a first lug (31) and four second lugs (32) that are shorter than the first lug (31) facing in opposite directions with respect to each other for minimum cost and optimum cooling.

7. A capacitor ( 1 ) according to any one of the preceding claims ; characterized by the second lugs (32) which extend towards one of the wide surfaces of the body (2) when the busbar (3) is positioned on the body (2).

8. A capacitor ( 1 ) according to any one of the preceding claims ; characterized by the first lug (31) which extends upwards from the body (2).

9. A capacitor ( 1 ) according to any one of the preceding claims ; characterized by the cooling plate (4) which is fixed to the body (2) via the prongs located on the body (2).

10. A capacitor (1) according to any one of the preceding claims, which meets the instantaneous high current requirement between the electric motor and the battery in electric vehicles by being used in the motor drive.

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