JP2024025514A - Power conversion device, manufacturing method of power conversion device - Google Patents

Abstract

The present invention provides a power converter device and a method for manufacturing the power converter device that achieve both low noise and low cost. A power conversion device includes a power module having a switching element that converts DC power into AC power, the DC bus bar supplying the DC power to the switching element, and a metal bus bar housing the switching element. The device includes a casing and a capacitor that connects the DC bus bar and the casing, and the capacitor and the casing are electrically connected by a first connecting member that is a conductive adhesive. [Selection diagram] Figure 5

Description

The present invention relates to a power conversion device and a method for manufacturing the power conversion device.

In the power conversion device, large common mode noise leaks into the battery system due to resonance of the Y capacitor mounted thereon. This may result in the problem of not being able to meet EMC regulations (noise standards). As a countermeasure for such problems, for example, in Patent Document 1 below, by having a configuration in which an inductor is connected to a waterway through a conductive sheet, the capacitance of the insulating layer and the inductance of the inductor are adjusted to reduce noise. A semiconductor device in which the number of semiconductor devices is reduced is disclosed.

Japanese Patent Application Publication No. 2015-223010

Conventionally, as a countermeasure against the resonance of the Y capacitor, in order to have a large resistance, it was necessary to change the physical properties of the Y capacitor connection member, such as increasing the low efficiency, or to insert a damping resistor in series. Even if measures were taken to reduce noise, the use of a PCB board to mount the resistor caused problems such as increased costs. Further, even if there is no damping resistor, the GND terminal of the Y capacitor is connected to the casing via a welding fitting, and there is a concern that the cost of welding fittings and mounting will increase.

An object of the present invention is to provide a power conversion device and a method for manufacturing the power conversion device that achieve both low noise and low cost.

A power conversion device including a power module having a switching element that converts DC power to AC power, the DC bus bar supplying the DC power to the switching element, and a metal casing housing the switching element. A capacitor connecting the DC bus bar and the casing is provided, and the capacitor and the casing are electrically connected by a first connecting member that is a conductive adhesive.
Further, the power conversion device of the present invention includes a DC bus bar that supplies the DC power to a switching element that converts DC power into AC power, a metal casing that houses the switching element, and a metal casing that includes the DC bus bar and the casing. a capacitor connected to the housing, a step portion protruding upward is formed in the casing, and the capacitor and the step portion are filled in a first adhesive container, which is a thermosetting resin and conductive. a second connecting member that is electrically connected to the capacitor and the casing by a first connecting member that is a static adhesive, and that is filled in a filling part formed in a part of the casing that is different from the stepped part; A manufacturing method is adopted in which the first connecting member and the second connecting member are electrically connected by heating the first connecting member and the second connecting member simultaneously.

According to the present invention, it is possible to provide a power conversion device and a method for manufacturing the power conversion device that achieve both low noise and low cost.

Explanatory diagram of the power converter installed in the vehicle and other components related to drive Functional block diagram of the power conversion device in Figure 1 Configuration diagram of a filter circuit included in the power conversion device of FIG. 2 An explanatory diagram of a filter circuit according to an embodiment of the present invention AA sectional view in Figure 4 An explanatory diagram of a resin lid provided in a filter circuit according to an embodiment of the present invention Modified example of the first connecting material container according to an embodiment of the present invention Diagram applying Figure 7 to a filter circuit First modification Second modification Third modification Fourth modification

Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are examples for explaining the present invention, and are omitted and simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless specifically limited, each component may be singular or plural.

The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

(One embodiment of the present invention and overall configuration of the device)
(Figure 1)
The vehicle is equipped with a power converter 200, a battery system 136, a motor generator MG, and a transmission TM. Power conversion device 200 includes filter circuit 1, smoothing capacitor 500, power module 150, driver circuit 174, and control circuit section 172 inside.

The battery system 136 stores electrical energy necessary for running the vehicle, and supplies DC power to the power conversion device 200. DC connector 138 is a connector used to input DC power from battery system 136 to power converter 200.

Filter circuit 1 filters noise generated in power converter 200 and prevents noise from entering battery system 136. The smoothing capacitor 500 smoothes the DC power from the battery system 136, thereby supplying stable DC power to the inverter circuit section included in the power module 150.

The inverter circuit section included in the power module 150 includes a switching element that converts DC power into AC power. The control circuit section 172 receives commands from a higher-level control device (not shown) via the control connector 430, and transmits a drive signal to the driver circuit 174 on the driver board. The driver circuit 174 drives the power module 150 based on a signal from the control circuit section 172 on the control board. Thereby, the switching element of the inverter circuit section included in power module 150 is activated and outputs alternating current to motor generator MG.

AC terminal 420 transmits three-phase AC output from power module 150 to motor generator MG. Power generated by motor generator MG is transmitted to tires via transmission TM.

(Figure 2)
Current sensor 180 is installed near AC bus bar 421 to detect the AC current output from power module 150 to motor generator MG. The current value detected by the current sensor 180 is input to the control circuit section 172 and used for feedback processing. Motor control connector 420a receives a signal from motor generator MG1, and transmits the signal to control circuit section 172 through motor control wiring 435.

(Figure 3)
The filter circuit 1 includes a Y capacitor 4 connected to a positive bus bar 5a that supplies DC power to the switching element, a Y capacitor 4 connected to a negative bus bar 5b, and connects each Y capacitor 4 to a housing 104. It has a first connecting member 7. Y capacitor 4 has a role as a noise removal capacitor of power conversion device 200.

(Figure 4, Figure 5)
The filter circuit 1 includes a DC bus bar 5 that supplies DC power to a switching element, a metal housing 104 that houses the switching element, and a Y capacitor 4 that connects the DC bus bar 5 and the housing 104. The Y capacitor 4 and the housing 104 are electrically connected by a first connecting member 7 that is a conductive adhesive.

The Y capacitor 4 has a GND terminal 9 (first terminal) and an HV terminal 6 (second terminal). The HV terminal 6 of one Y capacitor 4 is connected to a positive bus bar 5a of an HV bus bar (DC bus bar), and the HV terminal 6 of the other Y capacitor 4 is connected to a negative bus bar 5b. The GND terminals 9 of the Y capacitors 4 are connected to the first connection members 7, respectively. The first connecting member 7 is a conductive adhesive, and is filled in the first adhesive container 10.

The housing 104 has a stepped portion 104a projecting upward. The bottom surface of the first adhesive container 10 is in contact with the stepped portion 104a. The first adhesive container 10 is non-conductive and has a through hole through which the GND terminal 9 of the Y capacitor 4 and the positioning pin 8 of the housing 104 pass. The positioning pin 8 passes through a through hole in the first adhesive container 10 and is connected to the stepped portion 104a. As a result, while the return current to the housing 104 flows from the GND terminal 9 to the positioning pin 8 inside the first connection member 7, it spreads from the positioning pin 8 to the entire housing 104 and becomes a noise source (switching source). The current returning to has a component in the opposite direction. As a result, the magnetic fields can be canceled by each other's currents, and the inductance can be reduced. As a result, noise can be reduced.

By filling the first adhesive container 10 with the first connecting member 7 which is a conductive adhesive, the positioning pin 8 and the GND terminal 9 are electrically connected. Thereby, the noise of the positive bus bar 5a and the negative bus bar 5b can be bypassed to the housing 104, and the noise can be filtered. Furthermore, this allows both the positioning of the adhesive container 10 in the housing 104 and the connection between the first connecting member 7 and the housing 104 to be achieved.

The casing 104 is also connected to the Y capacitor 4 at a portion other than the stepped portion 104a, and is connected to the bottom surface of the Y capacitor 4 (lower surface in FIG. 5) by the second connecting member 7a. Thereby, the Y capacitor 4 is fixed to the housing 104.

The first connecting member 7 filled in the first adhesive container 10 has resistance by being electrically connected between the GND terminal 9 and the casing 104. By adjusting the filling amount of the first connecting member 7, a desired damping resistance value that does not deteriorate noise performance can be obtained. This is because the first connecting member 7 has a material-specific resistivity as a conductive adhesive, and this can be used to adjust the damping resistance to a desired value. Furthermore, by filling the container 10 with the first connecting member 7, the first connecting member 7 is prevented from adhering to unnecessary portions of the casing 104.

The first connecting member 7 may be formed by mixing two types of liquids. That is, after positioning the first adhesive container 10 in the housing 104, the first connecting member 7 can be formed by mixing two types of adhesives within the container 10. Therefore, the process of mixing two types of first connecting members 7 in advance and then filling them into the container 10 is no longer necessary, and the degree of freedom of the entire process is improved, and productivity is improved.

The present invention also provides a DC bus bar 5 composed of a positive bus bar 5a and a negative bus bar 5b that supply DC power to a switching element that converts DC power into AC power, and a metal housing 104 that houses the switching element. , and a Y capacitor 4 that connects the DC bus bar 5 and the housing 104. As a manufacturing process of this device, a step part 104a protruding upward is formed in the casing 104, and the Y capacitor 4 and the step part 104a are filled in the first adhesive container 10 using a thermosetting resin and conductive resin. The Y capacitor 4 and the casing 104 are electrically connected by the first connecting member 7, which is an adhesive, and the Y capacitor 4 is electrically connected to the casing 104 using a second adhesive, which is filled in a filling part 19 formed in a part of the casing 104 that is different from the stepped part 104a. A process is adopted in which electrical connection is made by the connecting member 7a and the first connecting member 7 and the second connecting member 7a are heated simultaneously.

By employing such a manufacturing process, the resin curing process by heating only needs to be performed once, so that the assembly time can be prevented from increasing. For example, FIPG (Formed In Place Gasket) is used as the second connection member 7a. The second connection member 7a can use the same conductive adhesive as the first connection member 7 instead of a different type of adhesive from the first connection member 7, so that costs can be reduced.

According to the configuration of the present invention, there is no need for welding fittings for the GND terminal 9, which were conventionally used for the Y capacitor 4. Furthermore, by mounting the Y capacitor 4 on the housing 104 at low cost, resonance can be attenuated. Thereby, it is possible to provide the power conversion device 200 that achieves both low noise and low cost.

(Figure 6)
The first adhesive container 10 may have a resin lid 12 on the top thereof as a lid for the container 10 to prevent contamination, so that the first connecting member 7 is sealed inside the container 10. Moreover, this can prevent the first connecting member 7 from leaking or scattering from the container 10. Furthermore, the vibration resistance of the container 10 is improved, and the adhesion to the GND terminal 9 and the positioning pin 8 is maintained.

In addition, by placing the first adhesive container 10 on the reference line 11 (on a plane) formed by the upper surface of the Y capacitor 4 and the upper surface of the stepped portion 104a, the arrangement of the first adhesive container 10 can be improved. Not only can this be limited on the casing 104, but also the first connecting member 7 in the container 10 is filled so as to accumulate on a flat surface, so that it does not accumulate unevenly. Thereby, the positioning pin 8 and the GND terminal 9 can be bonded to each other at the same height within the container 10 by the first connecting member 7. Moreover, the stress of the first connecting member 7 due to vibration is also dispersed, and an improvement in vibration resistance can be expected.

(Figure 7, Figure 8)
As illustrated, the first adhesive container 10 has a plurality of internal walls 10b, and the first connecting member 7 is folded back along the plurality of internal walls 10b within the first adhesive container 10. It may also be configured to be filled with. In this way, in order to adjust the damping resistance value depending on the filling amount of the first connecting member 7 into the container 10, the damping resistance value can be adjusted depending on the length of the filled portion in the container 10 while considering both an increase in resistance and a low inductance. You may adjust the value. Furthermore, with such a configuration, the currents flowing through the first connecting member 7 are directed in opposite directions at the folded portion of the container 10, thereby canceling the magnetic flux and contributing to reducing inductance. That is, it is possible not only to adjust the resistance value but also to achieve both an increase in resistance and a low inductance.

It is shown in the figure that the first adhesive container 10 is provided with a through hole 13 through which the positioning pin 8 for fixing to the housing 104 described above is inserted, and a through hole 14 for the GND terminal 9. ing. By providing two through holes 13 and 14 in the container 10, the first adhesive container 10 can be positioned in the housing 104, and mounting can be facilitated. In addition, in order to intentionally leak the first connecting member 7 inside the adhesive container 10 to the lower part of the adhesive container 10 and fix the adhesive container 10 to the housing 104 and the Y capacitor 4 over a larger area, the through hole 13 The diameter of the positioning pin 8 may be larger than the diameter of the positioning pin 8 by 2 mm or more. This improves the vibration resistance of the container 10.

(First modification)
(Figure 9)
In the filter circuit 1, the first terminal 9 of the Y capacitor 4 is inserted into the through hole of the first adhesive container 10, and the second terminal 6 is inserted into the through hole of the first adhesive container 10, and the second terminal 6 is inserted into the second adhesive container connected to the DC bus bar 5. It is inserted into a through hole formed in 10a. At this time, the second terminal 6 and the DC bus bar 5 are electrically connected by the first connecting member 7 filled in the second adhesive container 10a. In this way, by providing the first connecting member 7 and the container 10a for the connection between the HV terminal 6 and the DC bus bars 5a, 5b, welding is not required for the connection between the HV terminal 6 and the DC bus bars 5a, 5b.

Further, the second adhesive container 10a may be formed as a part of the resin 15 that molds the DC bus bars 5a, 5b, thereby reducing the cost of newly manufacturing the second adhesive container 10a. This makes it possible to reduce costs.

(Second modification)
(Figure 10)
A fixing member 17 is disposed between the first adhesive container 10 and the stepped portion 104a of the housing 104. If the position of the container 10 is determined by something other than the positioning pin 8 of the housing 104, the positioning pin 8 may be replaced with a screw 16 and fixed to the stepped portion 104a. This further improves the fixation of the first adhesive container 10 to the housing 104.

(Third modification)
(Figure 11)
The housing 104 may have a configuration including a connection member filling portion 19 that fills the first connection member 7. The GND terminal 9 of the Y capacitor 4 is electrically connected to the housing 104 through the first connecting member 7 because the housing 104 has only a recess that can store (fill) the conductive first connecting member 7. and fixed. Furthermore, the housing 104 has minute irregularities 18 . If it is desired to adjust the damping resistance by increasing or decreasing the resistance value between the GND terminal 9 and the housing 104, this can be achieved by increasing or decreasing the surface area by increasing or decreasing the minute unevenness portions 18. In this way, even with the configuration without the adhesive container 10, noise from the DC bus bars 5a and 5b can be released.

(Fourth modification)
(Figure 12)
The GND terminal 9 and the HV terminal 6 of the Y capacitor 4 may be bent into an L-shaped (key-shaped) GND terminal 9a and HV terminal 6a. Thus, for example, when this L-shaped Y capacitor 4 is applied in the configuration shown in FIG. 11, the welding area between the positive bus bar 5a and the HV terminal 6 can be increased. Furthermore, since the GND terminal 9a is closer to the housing 104, it is possible to reduce the number of first connecting members 7. Furthermore, the Y capacitor 4 in the housing 104 is strong against shaking in the horizontal direction in the drawing.

When this L-shaped Y capacitor 4 is applied to the configuration shown in FIGS. 4 and 5, the through hole of the adhesive container 10 need only be made large enough for the GND terminal 9 to pass through, and it is not necessary to use a straight terminal. , the structure is perpendicular to the vibration direction, which improves vibration resistance against stress generated by vertical or horizontal vibration.

According to the embodiment of the present invention described above, the following effects are achieved.

(1) A power conversion device 200 including a power module 150 having a switching element that converts DC power to AC power, which includes a DC bus bar 5 that supplies DC power to the switching element, and a metal casing that houses the switching element. The Y capacitor 4 connects the DC bus bar 5 and the housing 104, and the Y capacitor 4 and the housing 104 are electrically connected by a first connecting member 7 that is a conductive adhesive. Ru. By doing so, it is possible to provide the power conversion device 200 that achieves both low noise and low cost.

(2) The first connecting member 7 is filled into the first non-conductive adhesive container 10. By doing this, it is possible to adjust the damping resistance to a desired value.

(3) The housing 104 has a stepped portion 104a that protrudes upward, and the first adhesive container 10 is placed on the reference line 11 formed by the upper surface of the Y capacitor 4 and the upper surface of the stepped portion 104a. The bottom of the is installed. By doing so, the first connecting member 7 can be filled in the container 10 on a flat surface without being biased, and the vibration resistance can be improved.

(4) The bottom surface of the first adhesive container 10 is in contact with the stepped portion 104a. By doing so, it is possible to achieve low inductance and low noise.

(5) The first adhesive container 10 has a through hole 13 through which the positioning pin 8 for fixing to the housing 104 is inserted. By doing this, implementation can be facilitated.

(6) The diameter of the through hole 13 is larger than the diameter of the positioning pin 8 by 2 mm or more. By doing so, it is possible to improve fixation and vibration resistance.

(7) The Y capacitor 4 has a first terminal 9 and a second terminal 6, the first terminal 9 is inserted into the through hole 14 of the first adhesive container 10, and the second terminal 6 is connected to the DC bus bar. The second terminal 6 and the DC bus bar 5 are connected to each other by the first connecting member 7 filled in the second adhesive container 10a. electrically connected. This eliminates the need for welding.

(8) The second adhesive container 10a is formed as a part of the resin 15 that molds the DC bus bar 5. By doing so, the number of adhesive containers 10 can be reduced and costs can be reduced.

(9) The first adhesive container 10 has a resin lid 12 on its upper part. By doing this, it is possible to take measures against contamination.

(10) The first adhesive container 10 has a plurality of internal walls 10b, and the first connecting member 7 is filled so as to be folded back along the plurality of internal walls 10b within the first adhesive container 10. be done. By doing so, inductance can be reduced.

(11) The first adhesive container 10 is fixed to the stepped portion 104a with the screw 16. By doing this, vibration countermeasures can be implemented.

(12) The housing 104 has a connecting member filling portion 19 that fills the first connecting member 7. By doing so, the number of containers 10 can be reduced and costs can be reduced.

(13) The power converter 200 includes a DC bus bar that supplies DC power to a switching element that converts DC power into AC power, a metal housing 104 that houses the switching element, a DC bus bar 5, and a housing 104. and a Y capacitor 4 for connecting. Then, a stepped portion 104a protruding upward is formed in the casing 104, and the Y capacitor 4 and the stepped portion 104a are attached to a first adhesive container 10 filled with a thermosetting resin and conductive adhesive. The first connecting member 7 electrically connects the Y capacitor 4 and the housing 104, and the second connecting member 7a filled in a filling part 19 formed in a part of the housing 104 different from the stepped part 104a connects the Y capacitor 4 and the housing 104 electrically. The first connecting member 7 and the second connecting member 7a are heated simultaneously. By employing such a method of manufacturing the power conversion device 200, the process can be simplified, and both low noise and low cost can be achieved.

(14) In the first adhesive container 10, the first connecting member 7 is formed by mixing two types of liquids. By doing this, the type of adhesive for the first connecting member 7 can be limited, and the degree of freedom in the assembly process is improved.

Note that the present invention is not limited to the above-described embodiments, and various modifications and other configurations can be combined without departing from the scope of the invention. Furthermore, the present invention is not limited to having all the configurations described in the above embodiments, but also includes configurations in which some of the configurations are deleted.

1 Filter circuit 4 Y capacitor 5 HV bus bar 5a Positive bus bar 5b Negative bus bar 6 HV terminal (second terminal)
6a L-shaped HV terminal 7 First connection member 7a Second connection member 8 Positioning pin 9 GND terminal (first terminal)
9a L-shaped GND terminal 10 First adhesive container 10a Second adhesive container 10b Internal wall 11 Reference line 12 Resin lid 13 Locating pin hole 14 GND terminal hole 15 Molded resin 16 Screw 17 Fixing member 18 Micro Uneven part 19 Connection member filling part 104 Housing 104a Step part

Claims (14)

A power conversion device comprising a power module having a switching element that converts DC power to AC power,
A DC bus bar that supplies the DC power to the switching element, a metal housing that houses the switching element, and a capacitor that connects the DC bus bar and the housing,
The capacitor and the casing are electrically connected by a first connecting member that is a conductive adhesive. A power conversion device. The power conversion device according to claim 1,
The first connecting member is filled in a first non-conductive adhesive container. The power conversion device. The power conversion device according to claim 2,
The casing has a stepped portion projecting upward,
A power conversion device, wherein a bottom surface of the first adhesive container is placed on a reference line formed by an upper surface of the capacitor and an upper surface of the stepped portion. The power conversion device according to claim 3,
The bottom surface of the first adhesive container is in contact with the stepped portion. The power conversion device. The power conversion device according to claim 2,
The first adhesive container has a through hole through which a positioning pin for fixing to the housing is inserted. The power conversion device. The power conversion device according to claim 5,
The diameter of the through hole is 2 mm or more larger than the diameter of the positioning pin. The power conversion device according to claim 5,
The capacitor has a first terminal and a second terminal,
the first terminal is inserted into the through hole of the first adhesive container,
The second terminal is inserted into a through hole formed in a second adhesive container connected to the DC bus bar,
The second terminal and the DC bus bar are electrically connected by the first connecting member filled in the second adhesive container. The power converter. The power conversion device according to claim 7,
The second adhesive container is formed as a part of resin that molds the DC bus bar. Power conversion device. The power conversion device according to claim 2,
The first adhesive container has a resin lid on its upper part. Power conversion device. The power conversion device according to claim 2,
the first adhesive container has a plurality of internal walls;
The first connecting member is filled in the first adhesive container so as to be folded back along the plurality of internal walls. The power conversion device according to claim 3,
The first adhesive container is fixed to the stepped portion with a screw. The power conversion device. The power conversion device according to claim 1,
The casing has a connection member filling part that fills the first connection member. The power conversion device. A DC bus bar that supplies the DC power to a switching element that converts DC power into AC power, a metal casing that houses the switching element, and a capacitor that connects the DC bus bar and the casing. ,
forming a step portion projecting upward in the casing;
electrically connecting the capacitor and the stepped portion with a first connecting member that is a thermosetting resin and conductive adhesive filled in a first adhesive container;
electrically connecting the capacitor and the casing by a second connecting member filled in a filling part formed in a part of the casing different from the step part;
A method for manufacturing a power conversion device, comprising heating the first connection member and the second connection member at the same time. A method for manufacturing a power conversion device according to claim 13, comprising:
A method for manufacturing a power conversion device, wherein the first connecting member is formed by mixing two types of liquids in the first adhesive container.

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