Power conversion device

1. A power conversion device comprising:

a power module unit including a plurality of semiconductor elements arranged in a first direction, a power body portion storing the plurality of semiconductor elements separately in a plurality of portions or collectively in one portion, and a plurality of power terminals respectively connected to the plurality of semiconductor elements and protruding from the power body portion toward one side in a second direction perpendicular to the first direction, the plurality of power terminals being arranged in the first direction; and

a capacitor module including a capacitor element, a capacitor case storing the capacitor element with capacitor sealing resin interposed, and a capacitor busbar connected to the capacitor element, wherein

the capacitor busbar has

a flat-plate portion formed in a plate shape of which a width in the first direction is greater than a width in the second direction, the flat-plate portion being exposed to outside from the capacitor sealing resin,

a plurality of power terminal connection portions extending toward another side in the second direction from the flat-plate portion and arranged in the first direction, the plurality of power terminal connection portions being respectively connected to the plurality of power terminals,

a power supply connection portion connected to the flat-plate portion and connected to a DC power supply, and

a plurality of element connection portions connected to the flat-plate portion and located on the one side in the second direction relative to the flat-plate portion, the plurality of element connection portions being arranged in the first direction and connected to the capacitor element,

an element-connection-portion position range which is a position range in the first direction between two element connection portions located at both ends in the first direction among the plurality of element connection portions, and a power-terminal-connection-portion position range which is a position range in the first direction between two power terminal connection portions located at both ends in the first direction among the plurality of power terminal connection portions, are within a position range in the first direction where the flat-plate portion is located,

a length of the element-connection-portion position range and a length of the power-terminal-connection-portion position range are equivalent to each other,

a center position of the element-connection-portion position range and a center position of the power-terminal-connection-portion position range are equivalent to each other, and

as seen in a direction where the element connection portions are arranged, along the second direction, the power terminal connection portions are arranged at an opposite side of the flat-plate portion than are the element connection portions.

2. The power conversion device according to claim 1 , wherein

as seen in the second direction,

80% or more of the element-connection-portion position range overlaps the power-terminal-connection-portion position range, and

80% or more of the power-terminal-connection-portion position range overlaps the element-connection-portion position range.

3. The power conversion device according to claim 1 , wherein

as the capacitor busbar, a first capacitor busbar connected to a first electrode of the capacitor element and a second capacitor busbar connected to a second electrode of the capacitor element are provided, and

a first flat-plate portion which is the flat-plate portion of the first capacitor busbar and a second flat-plate portion which is the flat-plate portion of the second capacitor busbar are located so as to be opposed to each other.

4. The power conversion device according to claim 3 , further comprising a spacer having insulating property and provided between the first flat-plate portion and the second flat-plate portion.

5. The power conversion device according to claim 4 , wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply,

the DC path portion has a support portion extending from the DC path portion into the capacitor sealing resin, and

the spacer has an opposed portion held between the first flat-plate portion and the second flat-plate portion, and a spacer support portion extending in a direction of the DC path portion from the opposed portion and extending into the capacitor sealing resin along the support portion.

6. The power conversion device according to claim 5 , wherein

the spacer support portion has a tubular portion formed in a tubular shape surrounding a periphery of the support portion, and

the tubular portion extends into the capacitor sealing resin.

7. The power conversion device according to claim 3 , wherein

as seen in a third direction perpendicular to the first direction and the second direction,

an area of the first electrode that overlaps the element connection portions of the first capacitor busbar is smaller than an area of the first electrode that does not overlap the element connection portions of the first capacitor busbar, and

an area of the second electrode that overlaps the element connection portions of the second capacitor busbar is smaller than an area of the second electrode that does not overlap the element connection portions of the second capacitor busbar.

8. The power conversion device according to claim 1 , wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply,

the DC path portion extends toward the one side in the second direction from a part of the flat-plate portion that is positioned on the one side in the second direction on one side or another side in the first direction, and

the DC path portion is located so as to overlap the capacitor sealing resin, as seen in a third direction perpendicular to the first direction and the second direction.

9. The power conversion device according to claim 1 , further comprising a ground-side capacitor element connected between the capacitor busbar and a ground, wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply, and

the DC path portion is located so as to at least partially overlap the ground-side capacitor element, as seen in a third direction perpendicular to the first direction and the second direction.

10. The power conversion device according to claim 1 , wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply,

the power conversion device further comprises a ground-side capacitor element connected between the DC path portion and a ground and stored in the capacitor case with the capacitor sealing resin interposed,

the capacitor case is formed in a bottomed tubular shape, and

the ground-side capacitor element is located on an opened side opposite to a bottom wall side of the capacitor case.

11. The power conversion device according to claim 1 , wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply, and

the DC path portion has a support portion extending from the DC path portion into the capacitor sealing resin.

12. The power conversion device according to claim 11 , further comprising a ground-side capacitor element stored in the capacitor case with the capacitor sealing resin interposed, wherein

the support portion is connected to one electrode of the ground-side capacitor element, and another electrode of the ground-side capacitor element is connected to a ground.

13. The power conversion device according to claim 11 , wherein

the DC path portion has a plurality of the support portions.

14. The power conversion device according to claim 11 , wherein

the support portion is located on the flat-plate portion side relative to the DC connection portion side at the DC path portion.

15. The power conversion device according to claim 11 , wherein

the DC path portion is formed in a plate shape, and

the DC connection portion and the support portion are provided at the same side surface of the DC path portion, as seen in a third direction perpendicular to the first direction and the second direction.

16. The power conversion device according to claim 11 , wherein

the support portion is formed in a plate shape, and

the support portion has, at a part extending into the capacitor sealing resin, one or both of a part cut out inward from a side surface and a part protruding toward the capacitor sealing resin side from a side surface.

17. The power conversion device according to claim 1 , further comprising a ground-side capacitor module including a ground-side capacitor element connected between the capacitor busbar and a ground, and a ground-side capacitor case storing the ground-side capacitor element with ground-side capacitor sealing resin interposed, wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply, and

the DC path portion is located so as to at least partially overlap the ground-side capacitor module, as seen in a third direction perpendicular to the first direction and the second direction.

18. The power conversion device according to claim 17 , further comprising a housing storing the power module unit, the capacitor module, and the ground-side capacitor module, wherein

the capacitor case and the ground-side capacitor case are each formed in a bottomed tubular shape,

the housing has a first surface to which the power module unit is thermally connected and a second surface to which the capacitor module and the ground-side capacitor module are thermally connected, and a coolant path for cooling the first surface is provided on a back side of the first surface,

the second surface faces toward one side in a third direction perpendicular to the first direction and the second direction and is located on the one side in the second direction of the first surface and on another side in the third direction relative to the first surface, and the housing has a step portion between the first surface and the second surface,

the coolant path is located on the other side in the second direction of the step portion, and

in one or both of the capacitor module and the ground-side capacitor module, an opened side opposite to a bottom wall side of each of the capacitor case and the ground-side capacitor case is opposed to the step portion.

19. The power conversion device according to claim 18 , wherein

the step portion, and one or both of the capacitor sealing resin and the capacitor busbar, are thermally connected to each other.

20. The power conversion device according to claim 1 , wherein

the power supply connection portion has a DC path portion which is a part exposed to outside from the capacitor sealing resin and connected to the flat-plate portion, and a DC connection portion which is a part connected to the DC path portion and connected to the DC power supply,

the DC path portion is formed in a plate shape, and

a thickness of the DC path portion is greater than a thickness of the flat-plate portion.

21. The power conversion device according to claim 1 , wherein

the element connection portion has a protrusion protruding toward the capacitor element, at an end on the capacitor element side, and

the capacitor element and the protrusion are connected to each other.

22. The power conversion device according to claim 1 , further comprising:

a housing storing the power module unit and the capacitor module; and

a control board for controlling the power module unit, wherein

the housing has a first surface to which the power module unit is thermally connected and a second surface to which the capacitor module is thermally connected,

the capacitor case is formed in a bottomed tubular shape that opens toward the other side in the second direction, a part of a peripheral wall thereof on the second surface side contacts with the second surface, and the capacitor case has a bush protruding toward an outer peripheral side, at a part of the peripheral wall on a side opposite to the second surface, and

the control board is fixed to the bush by a screw.