Power conversion device

Abstract

To provide a power conversion device in which a low-voltage circuit can operate properly even in an environment affected by noise or heat.SOLUTION: A power conversion device includes: a power conversion circuit 1 housed in the housing AH and configured to convert power; and a cooling plate 2 housed in the housing AH and configured to cool the power conversion circuit 1 with a cooling fluid. The power conversion circuit 1 has a high-voltage region X in which a high-voltage electronic component 14 through which high-voltage electric power flows is disposed, and a low-voltage region Y in which a low-voltage electronic component 15 through which lower-voltage electric power than that of the high-voltage electronic component 14 flows is disposed, and a shield 11 is branched from the cooling plate 2 and protruding is disposed between the high-voltage region X and the low-voltage region Y in the power conversion circuit 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power conversion device. [Background technology]

[0002] Patent Document 1 describes a DC-DC converter mounted on an automobile that obtains driving force from an electric motor, which has a first wall separating a low-voltage circuit section and a high-voltage circuit section. Specifically, as shown in Figure 12 of the document, the document discloses a configuration in which a first wall (120) is disposed between a first space (150) that houses the high-voltage circuit section and a second space (151) that houses the low-voltage circuit section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-131371 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle that runs on the driving force of an electric motor, it has been considered to provide a power conversion device that controls the power supplied to the electric motor in a housing that accommodates the electric motor, reduction gear, etc.

[0005] Vehicles that run on the driving force of an electric motor often require a charging circuit that performs voltage transformation and rectification to enable charging of the battery that supplies power to the electric motor from an externally supplied commercial power source. Furthermore, a DC-DC converter circuit that converts battery power into low-voltage power may also be required to supply power to the vehicle's air conditioning system and operate meters, car navigation systems, etc. Therefore, it has been considered to configure a power conversion device that combines the charging circuit, DC-DC converter circuit, etc. into a single package and house this power conversion device in a housing.

[0006] However, in a configuration in which a power conversion device configured as a single package is housed in a housing that also houses an electric motor, there is concern that, for example, noise from other power conversion circuits or heat from other circuits may act on the low-voltage DC-DC converter circuit, leading to malfunction.

[0007] For these reasons, there is a demand for a power conversion device in which low-voltage circuits can operate properly even in an environment affected by noise and heat. [Means for solving the problem]

[0008] A characteristic configuration of a power conversion device according to the present invention includes a housing, a power conversion circuit housed in the housing and configured to convert electric power, and a cooling plate housed in the housing and configured to cool the power conversion circuit with a cooling fluid, the power conversion circuit including a high-voltage electronic component through which high-voltage electric power flows. and, A low-voltage electronic component to which low-voltage power flows from the high-voltage electronic component and A shielding body that branches out and protrudes from the cooling plate is provided in the power conversion circuit. The high-voltage electronic component and the low-voltage electronic component The point is that it is located between

[0009] According to this configuration, High-voltage electronic components and Low-voltage electronic components Since a shield is placed between , high Heat and noise from voltage electronic components , low This suppresses the phenomenon that affects the voltage electronic components, and therefore, a power conversion device is configured in which the low-voltage circuit can operate properly even in an environment affected by noise and heat. [Brief explanation of the drawings]

[0010] [Figure 1] 10 is a cross-sectional view showing the positional relationship between a shield, a parallel shielding portion, and an OBC substrate. FIG. [Figure 2] FIG. 2 is a plan view of an OBC substrate. [Figure 3] FIG. 10 is a perspective view showing the positional relationship between the shield, the parallel shielding portion, and the OBC substrate. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a power conversion device according to the present invention will be described with reference to the drawings. The present embodiment is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0012] [Basic configuration] 1 shows a partial cross section of a vehicle drive device A that transmits the driving force of a drive motor M to wheels (not shown). The vehicle drive device A accommodates the drive motor M, a gear mechanism (not shown) that reduces the driving force of the drive motor M and transmits it to the drive wheels (not shown), and a power conversion device B in an internal space AS of a housing AH.

[0013] The vehicle drive device A is provided on the vehicle in the up-down relationship shown in FIG. 1, and therefore in this embodiment, the up-down relationship will be described based on the up-down direction shown in FIG.

[0014] The power conversion device B includes a charging OBC circuit 1 (an example of a power conversion circuit) that converts AC power from an AC power source (basically a commercial power source) supplied from outside the vehicle into high-voltage DC power and charges the battery (not shown), a DC-DC converter that steps down the battery's DC power to a voltage used by on-board devices and outputs it, and a voltage conversion unit that steps down the battery power to the voltage of the commercial power source and outputs it as AC power. The OBC in the OBC circuit mentioned above is an abbreviation for On Board charger.

[0015] This power conversion device B is provided in a vehicle having a power configuration similar to that of a plug-in hybrid electric vehicle (PHEV). Note that the vehicle is not limited to a plug-in hybrid vehicle, but may also be a hybrid electric vehicle (HEV), a battery electric vehicle (BEV), or a fuel cell electric vehicle (FCEV).

[0016] As shown in Fig. 1, power conversion device B has a structure in which an OBC circuit 1 is arranged at the top as a power conversion circuit, a cooling plate 2 is arranged in the middle in the vertical direction, and a filter circuit board 3 is arranged at the bottom end, all of which are connected by multiple connecting frames 4. This power conversion device B includes the DC-DC converter, voltage conversion unit, etc., and is arranged close to the side of the traction motor M in the internal space AS of the housing AH.

[0017] The filter circuit board 3 includes a plurality of electronic elements, a plurality of coil modules, a plurality of AC filters, and the like.

[0018] The cooling plate 2 functions to lower the temperature of both the front and back surfaces of the cooling plate 2 by flowing a cooling fluid supplied from the outside through an internal flow path. This cooling plate 2 can use, as the cooling fluid, cooling water such as long-life coolant (LLC), insulating oil such as paraffin, or refrigerant such as hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO), but in this embodiment, cooling water such as long-life coolant (LLC) containing ethylene glycol or propylene glycol is used.

[0019] The cooling plate 2 is connected to the filter circuit board 3 below by multiple connecting frames 4, and is configured so that as the temperature of the connecting frames 4 drops, heat is removed from the filter board via the connecting frames 4. Furthermore, the electronic elements and the like mounted on the filter circuit board 3 are arranged close to or in contact with the underside of the filter circuit board 3. This allows the cooling plate 2 to directly remove heat generated by the electronic elements and the like mounted on the filter circuit board 3, thereby suppressing temperature increases.

[0020] A transformer 6 (voltage transformer) is disposed in a position adjacent to the upper side of the cooling plate 2, and the cooling plate 2 is provided with a cooling wall 10 that protrudes upward on the side opposite the traction motor M with respect to the transformer 6. The cooling plate 2 also has a plate-shaped shield 11 that protrudes upward on the side adjacent to the traction motor M. The shield 11 is disposed between the traction motor M and the power conversion device B, adjacent to the OBC circuit 1.

[0021] Furthermore, a shield plate 7 is disposed above the transformer 6, with both ends supported by a cooling wall 10 and a shield 11. The shield plate 7 is made of a metal material that blocks electromagnetic noise.

[0022] The cooling wall 10 and the shield 11 are not structured to allow a cooling fluid to flow through them, but function to lower the ambient temperature by reducing the temperature through thermal conduction. The cooling wall 10 and the shield 11 are made of a metal material with high thermal conductivity, but a conductive resin material or a resin with high thermal conductivity may also be used. When a metal material or a conductive resin material is used for the shield 11, a configuration is adopted in which these are electrically connected to the ground side of the power conversion device B.

[0023] 1 and 2, the OBC circuit 1 (power conversion circuit) includes electronic elements, such as capacitors and other electronic elements, that enable voltage conversion on the underside of an OBC substrate 1a (an example of a power conversion substrate). The OBC substrate 1a includes, as electronic elements, a plurality of high-voltage electronic components 14 and a plurality of low-voltage electronic components 15 (the arrangement of these electronic elements will be described later).

[0024] The OBC substrate 1a (power conversion substrate) of this OBC circuit 1 is connected to the cooling plate 2 by multiple connecting frames 4, which also enables heat dissipation via the connecting frames 4. In particular, the upright portion 11a, which is the extending end of the upper end of the shielding body 11, is connected to the OBC substrate 1a, and the parallel shielding portion 12, which is integrally formed in the shape of a balcony at the upper end of this shielding body 11, is positioned so as to extend toward the driving motor M in a position along the underside of the OBC substrate 1a.

[0025] As shown in Figures 1 and 3, the end of the parallel shielding portion 12 and the erected portion 11a at the upper end of the shielding body 11 are connected to the OBC substrate 1a by a plurality of screws 13. This configuration transfers heat from the electronic elements of the OBC circuit 1 to the screws 13, parallel shielding portion 12, and shielding body 11, enabling cooling by the cooling plate 2. Note that bolts or rivets may be used to connect the end of the parallel shielding portion 12 to the upper end of the shielding body 11. Furthermore, if the parallel shielding portion 12 and the shielding body 11 are made of metal, they may be fixed to the ground side of the OBC substrate 1a by soldering or brazing.

[0026] The entire shield 11 functions as an upright portion 11a rising from the plate end portion 2E, but in this embodiment, the shield 11 is referred to as a structure that is connected at its base end to the cooling plate 2 and branches off from the cooling plate 2 to protrude upward. The upright portion 11a is described as a connecting portion at the upper end of the shield 11, located along the area C (the boundary in this embodiment) between the high-voltage region X and the low-voltage region Y in plan view.

[0027] [Noise countermeasures] The direction of the motor axis P, along which the rotor of the travel motor M rotates, is set as shown in Figure 1. The OBC substrate 1a, the cooling plate 2, and the filter circuit board 3 are arranged in a manner that aligns with the motor axis P, and that the OBC substrate 1a, the cooling plate 2, and the filter circuit board 3 are arranged in a manner that is parallel to one another.

[0028] A substrate end 1E of the OBC substrate 1a (power conversion substrate) that is close to the outer periphery of the travel motor M protrudes beyond a plate end 2E of the cooling plate 2 that is close to the outer periphery of the travel motor M. As a result, a triangular dead space DS is formed between the underside of the OBC substrate 1a and the outer periphery of the travel motor M when viewed in a direction along the motor axis P. In other words, an inverted triangular dead space DS is formed above the plate end 2E of the cooling plate 2 that is close to the travel motor M, and below the area of the OBC circuit 1 that is arranged above the travel motor M.

[0029] As shown in FIG. 2, the OBC substrate 1a is disposed such that a substrate end 1E overlaps the upper side of the traveling motor M, and the parallel shielding portion 12 overlaps the upper side of the traveling motor M.

[0030] On the OBC substrate 1a of the OBC circuit 1, a high-voltage area X is arranged at a position away from the drive motor M, and a low-voltage area Y is arranged at a position close to the drive motor M. High-voltage electronic components 14 (such as switching elements and capacitors for charging and discharging the high-voltage battery) that control the high voltage are arranged in the high-voltage area X, and low-voltage electronic components 15 (such as switching elements and capacitors for charging and discharging the low-voltage battery) that control the low voltage are arranged in the low-voltage area Y.

[0031] The OBC board 1a is positioned so that a portion of the outer edge of the low-voltage area Y overlaps the upper side of the traction motor M. This positioning is determined by circuit design based on the positional relationship with other boards, the size of the board, the rational placement of electronic elements, etc.

[0032] The traction motor M generates heat during operation and generates electromagnetic noise. On the OBC board 1a, the low-voltage electronic components 15 used in the low-voltage region Y are more susceptible to temperature and noise than the high-voltage electronic components 14 used in the high-voltage region X. Furthermore, the low-voltage electronic components 15 may also be affected by noise and heat generated in the high-voltage region X. The high-voltage electronic components 14 are not limited to the high-voltage electronic components 14 mounted on the OBC substrate 1a, but also include the transformer 6 and the coil module that constitutes the filter circuit substrate 3. Therefore, the high-voltage region X includes the high-voltage electronic components 14, the transformer 6, the coil module, etc. mounted on the OBC substrate 1a.

[0033] For this reason, as shown in Figure 1, in the vertical area adjacent to the dead space DS, a shielding body 11 is arranged along the space C between the high voltage area X and the low voltage area Y in a planar view, and inside the dead space DS, a parallel shielding portion 12 is arranged along the underside of the portion of the OBC substrate 1a that is arranged above the driving motor M.

[0034] 1 and 3, the upright portion 11a at the upper end of the shield 11 is disposed on the OBC substrate 1a at a position (boundary) that overlaps with the area C between the high-voltage area X and the low-voltage area Y in a plan view, thereby separating the high-voltage area X from the low-voltage area Y. The parallel shielding portion 12 is disposed at a position spaced a set distance downward from the underside of the OBC substrate 1a. As a result, the parallel shielding portion 12 covers the underside of the low-voltage electronic components 15 on the OBC substrate 1a.

[0035] Due to this positional relationship, the shielding body 11 and the parallel shielding part 12 block the heat and electromagnetic noise acting from the driving motor M and the heat and electromagnetic noise acting from the high-voltage area X, thereby suppressing malfunction in the low-voltage area Y. Furthermore, because the shielding body 11 can block the heat and electromagnetic noise acting from the driving motor M, it also suppresses malfunction in the high-voltage area X.

[0036] [Another embodiment] The present invention may be configured as follows in addition to the above-described embodiments (common numbers and symbols as in the embodiments are used to designate components having the same functions as in the embodiments).

[0037] (a) Not limited to the OBC substrate 1a, High-voltage electronic components 14 High voltage region X and , having low-voltage electronic components 15 In a power control circuit having a low voltage region Y, a high voltage region X High-voltage electronic components arranged in 14 and the low voltage region Y Low-voltage electronic components arranged in 15 A shield 11 may be disposed between the electrodes C. As partially described in the embodiment, the shield 11 can be made of a material having at least one of good electromagnetic shielding properties and good thermal conductivity.

[0038] In the (b) embodiment, a cooling fluid is configured to flow through the shield 11. By configuring in this way, the shield 11 can also actively remove heat from the electronic components, enabling good heat dissipation.

[0039] (c) The substrate constituting the power conversion circuit may have electronic components arranged on either the top or bottom surface, or on both the top and bottom surfaces. That is, for example, for a substrate having a high-voltage region X with high-voltage electronic components 14 on the top surface and a low-voltage region Y with low-voltage electronic components 15, shield 11 may be arranged from the underside of the substrate toward space C between them, with upright portion 11a of shield 11 being close to them, and parallel shielding portion 12 may be arranged along the bottom surface of the substrate.

[0040] In another embodiment (c), electronic components are arranged on both sides of the board that constitutes the electric control circuit. High-voltage electronic components 14 High voltage region X and Low voltage electronic components 15 It is also possible to form a low voltage region Y and place the erected portion 11a of the shield 11 close to the space C between them.

[0041] (d) The power control circuit may be configured such that a unit having a high-voltage area X equipped with high-voltage electronic components 14 and a unit having a low-voltage area Y equipped with low-voltage electronic components 15 are arranged adjacent to each other.

[0042] In the configuration of this alternative embodiment (d), if a gap exists between a unit having a high-voltage region X and a unit having a low-voltage region Y, it is possible to place the shield 11 in the gap. Also, even if no gap exists, it is possible to place the shield 11 in a position close to the gap C.

[0043] (e) In the above-described embodiment, the upright portion 11a at the upper end of the shield 11 is disposed at a position (boundary) of the OBC substrate 1a that overlaps the area C between the high-voltage area X and the low-voltage area Y in a plan view. High-voltage electronic components arranged in 14 and the low voltage region Y Low-voltage electronic components arranged in 15 Instead, the upright portion 11a at the upper end of the shield 11 may be arranged slightly closer to the high voltage region X or the low voltage region Y than the boundary between the high voltage region X and the low voltage region Y in a plan view. High-voltage electronic components14 and the low voltage region Y Low voltage electronic components15 It is placed between.

[0044] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention.

[0045] In the above-described embodiment, the following configurations are envisioned. (1) A power converter circuit (OBC circuit 1) is provided in the housing AH, and the power converter circuit (OBC circuit 1) is housed in the housing AH and converts electric power. The power converter circuit (OBC circuit 1) is provided with a cooling plate 2 that is housed in the housing AH and cools the power converter circuit (OBC circuit 1) with a cooling fluid. The power converter circuit (OBC circuit 1) includes high-voltage electronic components 14 through which high-voltage electric power flows. and, A low-voltage electronic component 15 to which low-voltage power flows from a high-voltage electronic component 14 and The shield 11 that branches out and protrudes from the cooling plate 2 is a part of the power conversion circuit (OBC circuit 1). High-voltage electronic components 14 and low-voltage electronic components 15 It is located at point C between and.

[0046] According to this, High-voltage electronic components 14 and Low-voltage electronic components 15 Since the shielding body 11 is placed between , high Heat and noise from the voltage electronics 14 , low The phenomenon acting on the voltage electronic component 15 is suppressed.

[0047] (2) In the power conversion device B of (1), it is preferable that the device further includes a traction motor M housed in a housing AH, and that a shield 11 is disposed between the traction motor M and the power conversion circuit (OBC circuit 1).

[0048] This makes it possible for the shield 11 to block noise or heat generated by the traction motor M, thereby suppressing malfunction of the power conversion circuit (OBC circuit 1) due to the influence of such noise or heat.

[0049] (3) In the power conversion device B of (1) or (2), the power conversion board (OBC board 1a) on which the power conversion circuit (OBC circuit 1) is mounted and the cooling plate 2 are positioned parallel to each other along the motor axis P of the driving motor M, and the board end 1E of the power conversion board (OBC board 1a) on the outer periphery of the driving motor M protrudes more than the plate end 2E of the cooling plate 2 on the outer periphery of the driving motor M, thereby forming a triangular dead space DS between the power conversion board (OBC board 1a) and the outer periphery of the driving motor M when viewed in the direction along the motor axis P, and it is preferable that the shielding body 11 has a standing portion 11a that rises from the plate end 2E toward the power conversion board (OBC board 1a) at a position adjacent to the dead space DS.

[0050] As a result, a triangular dead space DS is formed between the power conversion board (OBC board 1a) and the outer periphery of the driving motor M when viewed in the direction along the motor axis P, and by effectively utilizing this dead space DS to place a shielding body 11 adjacent to the dead space DS, the shielding body 11 can be placed naturally, and even if, for example, part of the shielding body 11 has a shape that protrudes in the direction of the dead space DS, it can be easily placed.

[0051] (4) In any one of the power conversion devices B of (1) to (3), it is preferable that the shielding body 11 has a parallel shielding portion 12 formed at the extending end of the upright portion 11a on the side of the power conversion board (OBC board 1a) and oriented along the power conversion board (OBC board 1a) toward the dead space DS.

[0052] With this, since the parallel shielding portion 12 is formed in a position along the power conversion board (OBC board 1a) at the end on the extending side of the shielding body 11, this parallel shielding portion 12 can block noise and heat radiated from the driving motor M toward the power conversion board (OBC board 1a) and suppress malfunction of electronic components on the power conversion board (OBC board 1a). Also, since the parallel shielding portion 12 is formed toward the dead space DS, there is no need to change the design to ensure space for placement.

[0053] (5) In the power conversion device B of (1), it is preferable that the power conversion circuit (OBC circuit 1) has a high-voltage area X in which high-voltage electronic components 14 are arranged, and a low-voltage area Y in which low-voltage electronic components 15 are arranged.

[0054] According to this, the power conversion circuit (OBC circuit 1) can be configured with a high-voltage area X where high-voltage electronic components 14 are arranged and a low-voltage area Y where low-voltage electronic components 15 are arranged.

[0055] (6)(5) In the power converter B, the high voltage region X is larger than the low voltage region Y. Housed in Housing AH It is disposed at a position separated from the driving motor M, The shield 11 is From the plate end 2E on the outer periphery of the cooling plate 2, the driving motor M The power conversion circuit (OBC circuit 1) has a standing portion 11a that stands up toward a power conversion substrate (OBC substrate 1a) on which the power conversion circuit (OBC circuit 1) is mounted, It is preferable that the standing portion 11a is disposed at a position that separates the high voltage region X and the low voltage region Y.

[0056] According to this, noise and heat acting from the high voltage area X to the low voltage area Y can be reliably blocked by the standing portion 11a arranged at a position separating the high voltage area X and the low voltage area Y. [Industrial Applicability]

[0057] The present invention can be used in a power conversion device. [Explanation of symbols]

[0058] 1: OBC circuit (power conversion circuit), 1a: OBC board (power conversion board), 1E: board edge, 2: cooling plate, 2E: plate edge, 11: shield, 11a: standing portion, 14: high-voltage electronic component, 15: low-voltage electronic component, AH: housing, B: power conversion device, C: gap (boundary), DS: dead space, M: driving motor, P: motor shaft core, X: high-voltage area, Y: low-voltage area

Claims

1. Housing and a power conversion circuit housed in the housing and configured to convert electric power; a cooling plate accommodated in the housing and configured to cool the power conversion circuit with a cooling fluid, the power conversion circuit has a high-voltage region in which high-voltage electronic components are arranged to allow high-voltage power to flow, and a low-voltage region in which low-voltage electronic components are arranged to allow low-voltage power to flow from the high-voltage electronic components, a shield branching out from the cooling plate and projecting from the cooling plate, the shield being disposed between the high-voltage region and the low-voltage region of the power conversion circuit;

2. The vehicle further includes a traction motor housed in the housing, The power conversion device according to claim 1 , wherein the shield is disposed between the traction motor and the power conversion circuit.

3. the power conversion board on which the power conversion circuit is mounted and the cooling plate are positioned parallel to each other along the motor axis of the traction motor, a substrate end portion of the power conversion board that is on the outer periphery side of the travel motor protrudes further than a plate end portion of the cooling plate that is on the outer periphery side of the travel motor, thereby forming a triangular dead space between the power conversion board and the outer periphery of the travel motor when viewed in a direction along the motor shaft core, The power conversion device according to claim 2 , wherein the shield has an upright portion that rises from the end of the plate toward the power conversion board at a position adjacent to the dead space.

4. The power conversion device according to claim 3 , wherein the shielding body has a parallel shielding portion formed at an extending end of the upright portion on the side of the power conversion board, the parallel shielding portion being oriented along the power conversion board toward the dead space.

5. the high voltage region is disposed at a position farther from the traction motor than the low voltage region, The power conversion device according to claim 4 , wherein the standing portion is disposed at a position that separates the high voltage region from the low voltage region.

Images