WO2014132710A1

WO2014132710A1 - Power conversion device

Info

Publication number: WO2014132710A1
Application number: PCT/JP2014/051437
Authority: WO
Inventors: 順平楠川; 央上妻; 中津　欣也; 佐々木　康二; 佐藤　俊也
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2013-03-01
Filing date: 2014-01-24
Publication date: 2014-09-04
Also published as: JP2014171284A; JP5852975B2

Abstract

The invention addresses the problem of improving the speed of developing power conversion devices. A power conversion device of the present invention comprises: a film capacitor covered with an insulating outer cover and having a pair of terminals projecting from the insulating outer cover; and a base to which the film capacitor is fixed. The base has: a base-side capacitor housing recess which is a recess recessed from the surface on the opposite side to the bottom surface toward the bottom surface and on which the film capacitor is disposed; and a pair of terminal through-holes passing through from a bottom portion of the base-side capacitor housing recess to the bottom surface. The film capacitor is fixed to the base by an insulation sealing material filled in the space between a first recess and the film capacitor while partially touching the base-side capacitor housing recess. The pair of terminals projects from the bottom surface to the outside of the base through the pair of terminal through-holes and are electrically connected to a conductive sheet circuit.

Description

Power converter

The present invention relates to a film capacitor and a power conversion device such as an inverter device using the film capacitor.

The power conversion device represented by the inverter device is applied and deployed to various home appliances, industrial equipment, power equipment, automobile equipment such as a hybrid vehicle (HEV), and an electric vehicle (EV). Inverter devices used in HEVs and EVs are required to have higher voltage and smaller size and higher density in order to reduce fuel consumption, reduce power consumption, and reduce space. These inverter devices are composed of components such as a capacitor for smoothing DC power, in addition to a power semiconductor module incorporating a power semiconductor element such as IGBT, a bus bar, and a coil. In particular, as a capacitor for HEV and EV inverter devices, the voltage used is as high as several hundred volts, so a high withstand voltage film capacitor is mainly used in many cases.

A film capacitor is a film capacitor element having a wound body in which two organic dielectric films deposited with metal are stacked and wound, and current collecting electrodes (metallicon electrodes) formed on both end faces of the wound body, and And a pair of terminals respectively connected to the collecting electrodes at both ends. In HEV and EV inverter devices, the film capacitor element with the terminal connected as described above is housed in a resin case, and the space between the resin case and the film capacitor element is sealed with an insulating sealing resin (potting resin). The capacitor module is manufactured (see Patent Document 1).

JP 2012-161242 A

It is necessary to prepare various inverter devices depending on the vehicle type and output capacity. In addition, it is necessary to design a resin case for storing the film capacitor element exclusively for each inverter model, and to manufacture a capacitor module dedicated to each model. For this reason, the development speed of the inverter device is difficult to improve, and the cost may increase.

A power conversion device according to claim 1 smoothes a power semiconductor module that converts DC power into AC power, and DC power that is covered with an insulating sheath and has a pair of terminals protruding from the insulating sheath. Film capacitor, a plate-like conductor plate on which a circuit for electrically connecting the power semiconductor module and the film capacitor is formed, a pedestal to which the film capacitor is fixed, and a power semiconductor housing portion for housing the power semiconductor module And a housing-side capacitor housing portion for housing a film capacitor fixed to the pedestal, the power semiconductor module is fixed, and the conductor plate and the pedestal in a state where the plate surface of the conductor plate and the bottom surface of the pedestal face each other. The pedestal is a recess recessed from the surface opposite to the bottom surface toward the bottom surface. And a pair of terminal through holes penetrating from the bottom to the bottom of the base-side capacitor housing recess, and the film capacitor is partly in contact with the base-side capacitor housing recess. In the state, it is fixed to the pedestal by an insulating sealing material filled in the space between the first recess, and the pair of terminals protrudes from the bottom surface to the outside of the pedestal through the pair of terminal through-holes to form a circuit on the conductor plate. It is electrically connected.

According to the present invention, the development speed of the power converter can be improved.

It is a perspective view which shows the external appearance of the power converter device (inverter device) of 1st Embodiment. It is an exploded view of an inverter apparatus. It is an external appearance perspective view of a film capacitor. It is sectional drawing which shows typically the attachment state to the housing | casing of a conductor plate, a base, a film capacitor, and a power semiconductor module. It is the perspective view of the base seen from the upper surface side of the base. It is the perspective view of the base seen from the bottom face side of the base. It is sectional drawing which shows typically the attachment state to the housing | casing of the conductor plate of the 2nd Embodiment, a base, a film capacitor, and a power semiconductor module. It is a perspective view of the base of 2nd Embodiment seen from the upper surface side of the base. It is the perspective view of the base of 2nd Embodiment seen from the bottom face side of the base. It is sectional drawing which shows typically the attachment state to the housing | casing of the conductor plate of a 3rd Embodiment, a base, a film capacitor, and a power semiconductor module. It is a perspective view of the base of 3rd Embodiment seen from the upper surface side of the base. It is the perspective view of the base of 3rd Embodiment seen from the bottom face side of the base. 5 is a diagram showing a cross-sectional structure of a main circuit portion of a power conversion device according to Comparative Example 1. FIG. 6 is a diagram illustrating a cross-sectional structure of a main circuit portion of a power conversion device according to Comparative Example 2. FIG. It is a figure which shows the result of a vibration analysis. It is a figure which shows the result of a vibration analysis. It is a figure which shows the result of a moisture resistance test.

--- First embodiment ---
A first embodiment of a power converter according to the present invention will be described with reference to FIGS. The power conversion device of the present embodiment can be applied not only to a hybrid vehicle (HEV) but also to a power conversion device mounted on a vehicle such as a plug-in hybrid vehicle (PHEV) or an electric vehicle (EV). The present invention can also be applied to power conversion devices used for vehicles such as construction machines.

FIG. 1 is a perspective view showing an external appearance of a power conversion device (inverter device) 100 according to the present embodiment, and FIG. 2 is an exploded view of the inverter device 100. The inverter device 100 includes an upper lid 110, an AC bus bar 120, a gate / control board 130, a DC bus bar 140, a board base 150, and a conductor plate 160. The inverter device 100 includes a pedestal 10, a plurality of film capacitors 1, a water channel / case (housing) 20, a power semiconductor module 21, and a lower lid 170.

In the inverter device 100, each part constituting the inverter device 100 is housed in an inverter case having an upper lid 110, a water channel / case 20, and a lower lid 170. The water channel / case 20 is a case for accommodating the film capacitor 1 and the power semiconductor module 21 as described later. In the following description, the water channel / case 20 is simply referred to as a housing 20. The upper lid 110 is an upper lid of the housing 20. The lower lid 170 is a lower lid of the housing 20, to which a water channel partition plate 171 that partitions a water channel through which a refrigerant (for example, water) for cooling the power semiconductor module 21 flows is attached. 172 is provided. The material of the upper lid 110, the water channel / case 20, and the lower lid 170 is, for example, aluminum.

The power semiconductor module 21 is a module that incorporates a series circuit of upper and lower arms of an inverter circuit constituted by power semiconductor elements, and is provided corresponding to three phases of AC power U phase, V phase, and W phase. . The film capacitor 1 is a capacitor for smoothing DC power, and is fixed to the housing 20 together with the pedestal 10 while being fixed to the pedestal 10. The film capacitor 1 and the housing 20 will be described in detail later.

The conductor plate 160 is a laminated bus bar in which a positive electrode conductor plate and a negative electrode conductor plate (not shown) are laminated via a sheet-like insulating member (insulating paper or resin). Note that the positive electrode conductor plate and the negative electrode conductor plate (not shown) are formed of wide plate conductors. Thus, by making a positive electrode conductor plate and a negative electrode conductor plate having a large area into a laminated structure, the resistance value and inductance of the conductor plate 160 can be reduced. The conductor plate 160 is fixed above the housing 20 and the base 10 fixed to the housing 20.

The substrate base 150 is an aluminum plate sandwiched between the casing 20 and the upper lid 110 and plays a role of releasing heat generated in the gate / control board 130 to the refrigerant through the casing 20. The DC bus bar 140 is a bus bar connected to the conductor plate 160 and connected to an external secondary battery (not shown). The AC bus bar 120 is a bus bar connected to the AC terminal of the power semiconductor module 21 and is connected to an external motor generator (not shown). The gate / control board 130 is a board in which the control circuit and driver circuit of the inverter device 100 are built. The control circuit calculates whether a motor generator (not shown) is operated as a motor or a generator, generates a control pulse based on the calculation result, and supplies the control pulse to the driver circuit. The driver circuit generates a drive pulse for controlling the inverter circuit based on the supplied control pulse.

--- About film capacitor 1 used in this embodiment ---
In conventional HEV and EV inverter devices, a capacitor module in which a film capacitor element is stored in advance in a dedicated resin case prepared for each inverter model is used. On the other hand, as shown in FIG. 3, the film capacitor 1 used in the present embodiment is a capacitor having a pair of

terminals

2 and 2 attached to a film capacitor element 1a and covered with an insulation sheath 3. It is a single part. In FIG. 3, reference numeral 1b denotes a current collecting electrode (metallicon electrode) of the film capacitor element 1a.

The film capacitor element 1a has a rounded rectangular shape (that is, a shape composed of two parallel lines of two equal lengths and two semicircles) in which two organic dielectric films on which metal is deposited are stacked and wound. And a current collecting electrode (metallicon electrode) formed on both end faces of the wound body. Thus, since the cross section of the film capacitor element 1a has a rounded rectangular shape, the cross sectional shape of the film capacitor 1 covered with the insulating outer covering 3 also has a rounded rectangular shape. For convenience of description, in the following description, the surface of the film capacitor 1 on which the two

electrodes

2 and 2 are provided is called an end surface of the film capacitor 1 and is a plane portion extending in the same direction as the terminal 2 between the both end surfaces. Is called the side surface of the film capacitor 1.

3 are directly electrically connected to the conductor plate 160. The

terminals

2 and 2 of the film capacitor 1 shown in FIG. However, when mounted on a vehicle such as HEV, PHEV, or EV as in the inverter device 100 of the present embodiment, the vibration of the vehicle is transmitted to the film capacitor 1. For this reason, only the electrical and mechanical connection between the

terminals

2 and 2 of the film capacitor 1 and the conductor plate 160 is not sufficient in the connection portion (A portion in FIG. 3) between the film capacitor element 1a and the terminal 2 or in FIG. There is a possibility that the connecting portion (B portion in FIG. 3) between the illustrated conductor plate 160 and the

terminals

2 and 2 is broken.

Further, as described above, the film capacitor element 1a is covered with the insulating outer sheath 3. However, moisture penetrates from the interface between the

terminals

2, 2 and the resin of the insulating outer sheath 3, and the film capacitor element 1a is metallized. The thin film electrode of the film may be oxidized, resulting in a decrease in capacity. Furthermore, since it is necessary to position and electrically connect the plurality of film capacitors 1 to the conductor plate 160 one by one, there is a risk of hindering productivity.

Therefore, in the present embodiment, the above-described concerns are eliminated by fixing the film capacitor 1 to the base 10 in advance. This will be specifically described below.

--- About the pedestal 10 ---
FIG. 4 is a cross-sectional view schematically showing how the conductor plate 160, the pedestal 10, the film capacitor 1, and the power semiconductor module 21 are attached to the housing 20. FIG. 5 is a perspective view of the pedestal 10 viewed from the top surface 10a side of the pedestal 10, and FIG. 6 is a perspective view of the pedestal 10 viewed from the bottom surface 10b side of the pedestal 10. In the pedestal 10 of the present embodiment, pedestal-side capacitor accommodating recesses (accommodating recesses) 11 for accommodating one film capacitor 1 are provided at six locations.

The housing recess 11 is a recess that is recessed from the top surface 10 a toward the bottom surface 10 b, and has a pair of terminal through

holes

14, 14, a protrusion 15, and an insulating sealing material insertion port 16. As shown in FIG. 6, a bottom surface recess 12 is provided on the bottom surface 10 b of the base 10. In addition, the pedestal 10 is provided with a bolt hole 10c for fixing to the casing 20 together with the conductor plate 160 by bolting, as will be described later.

The accommodating recess 11 is, for example, a recess that is recessed in a semi-cylindrical shape obtained by vertically dividing a cylinder into two equal parts. Regarding the shape of the housing recess 11, the curvature radius of the curved surface corresponding to the surface of the cylinder is larger than the curvature radius in the cross section of the semicircular portion of the film capacitor 1 having a rounded rectangular cross section. In the housing recess 11, a pair of terminal through

holes

14 and 14 are provided in the vicinity of the boundary between the wall surface corresponding to both end faces of the cylinder and the curved surface corresponding to the surface of the cylinder.

The pair of through

holes

14 and 14 are holes through which the pair of

terminals

2 and 2 are inserted when the film capacitor 1 is disposed in the housing recess 11. The protrusions 15 are protrusions that protrude from the bottom of the housing recess 11, and two protrusions 15 are provided, for example, spaced from each other in the longitudinal direction of the cylinder for each housing recess. The insulating sealing material insertion port 16 is, for example, a groove-like portion provided on the wall surface corresponding to the end surface of the cylinder of the housing recess 11 as shown in FIG.

The bottom surface recess 12 is a recess provided so as to surround the periphery of the opening on the bottom surface side of the terminal through hole 14, and is provided for all the terminal through holes 14.

--- Fixing the film capacitor 1 to the base 10 ---
The film capacitor 1 is fixed to the pedestal 10 thus configured as follows. First, the pair of

terminals

2 and 2 of the film capacitor 1 are inserted through the terminal through

holes

14 and 14 formed in the housing recess 11 of the base 10, and the film capacitor 1 is disposed in the housing recess 11 of the base 10. When the film capacitor 1 is disposed in the housing recess 11, the pair of

terminals

2 and 2 are inserted through the pair of terminal through

holes

14 and 14, respectively, and protrude from the bottom surface 10b.

In addition, when the film capacitor 1 is disposed in the housing recess 11, the portion between the pair of terminals 2 of the film capacitor 1 comes into contact with the protrusion 15, so that the film capacitor 1 is separated from the curved surface of the housing recess 11 (particularly, the housing is stored A gap is formed apart from the bottom of the recess 11 by an amount defined by the height of the protrusion 15.

Next, an epoxy-based insulating sealing resin (second insulating sealing material 18) having a resin viscosity of about 85,000 mPa · s is poured into the bottom recess 12 formed on the bottom surface 10b of the base 10 to solidify the resin. As described above, the bottom surface recess 12 is a recess provided in the bottom surface 10b and surrounds the periphery of the terminal 2 protruding toward the conductor plate 160 disposed to face the bottom surface 10b as described later. Is formed. Therefore, the base 10 and the film capacitor 1 can be temporarily fixed by solidifying the second insulating seal 18 poured into the bottom recess 12, and the gap between the terminal through hole 14 and the terminal 2 is filled. Thus, by filling the gap between the terminal through hole 14 and the terminal 2 with the second insulating seal 18, the first insulating sealing material described later flows out from the gap between the terminal through hole 14 and the terminal 2. To prevent.

Next, an epoxy insulating resin (first insulating sealing material 17) having a resin viscosity of, for example, about 800 mPa · s is poured into the insulating sealing material insertion port 16 formed in the housing recess 11 of the base 10. Since the viscosity of the first insulating sealing material 17 is sufficiently low, the first insulating sealing material 17 also flows into the gap between the bottom portion of the housing recess 11 formed by the protrusion 15 and the film capacitor 1. The first insulating sealing material 17 is filled up to a height near the boundary between the semicircular portion and the straight portion of the film capacitor 1 having a rounded rectangular cross section.

After filling the first insulating sealing material 17, the pedestal 10 on which the film capacitor 1 is placed is placed in a high-temperature bath, the first insulating sealing material 17 is cured, and the pedestal 10 and the film capacitor 1 are first insulated. Fix with the sealing material 17.

Thereafter, the pedestal 10 to which the film capacitor 1 is fixed and the power semiconductor module 21 are respectively arranged on the housing 20. As shown in FIGS. 2 and 4, the housing 20 is provided with a capacitor / pedestal accommodating portion 20 </ b> A for accommodating the film capacitor 1 and the pedestal 10, and a power semiconductor module accommodating portion 20 </ b> B for accommodating the power semiconductor module 21. It has been. The power semiconductor module housing portion 20B is configured such that the refrigerant entering and exiting from the refrigerant inlet / outlet 172 passes therethrough.

The pedestal 10 to which the film capacitor 1 is fixed is disposed in the capacitor / pedestal housing portion 20A, and the power semiconductor module 21 is disposed in the power semiconductor module housing portion 20B. The pedestal 10 to which the film capacitor 1 is fixed is disposed in the capacitor / pedestal storage portion 20A with the film capacitor 1 fixed to the storage recess 11 facing the housing 20 side.

Thereafter, the conductor plate 160 is disposed so as to face the bottom surface 10 b of the base 10, and the conductor plate 160 and the base 10 are fixed to the housing 20 with the bolts 24. Then, the conductor plate 160 and the terminal 2 of the film capacitor 1, and the conductor plate 160 and the terminal 22 of the power semiconductor module are electrically connected, for example, by welding. Thereby, the main circuit part of the inverter apparatus 100 is completed.

Further, the AC bus bar 120 and the DC bus bar 140, the substrate base 150, and the gate / control substrate 130 are attached, electrically connected, covered with the upper lid 110, and fixed with bolts (not shown), and the inverter device 100 is completed.

The inverter device 100 according to the present embodiment has the following operational effects.
(1) A film capacitor 1 as a component in which a pair of

terminals

2 and 2 are attached to a film capacitor element 1a and covered with an insulating exterior coating 3 is placed on a pedestal 10 having a housing recess 11, and a first insulating sealing material 17 and fixed. Then, the pedestal 10 to which the film capacitor 1 was fixed was fixed to the housing 20 with bolts 24 together with the conductor plate 160.

As a result, there is no risk of breakage at the connection portion between the terminal 2 and the film capacitor element 1a or the conductor plate 160 due to the vibration of the vehicle, and moisture that has entered from the boundary surface between the

terminals

2 and 2 and the insulation sheath 3 There is no risk of oxidation of the thin film electrode of the metallized film of the film capacitor element 1a. Furthermore, positioning of the plurality of film capacitors 1 with respect to the conductor plate 160 is facilitated, contributing to productivity. Accordingly, the film capacitor 1 as a component in which the pair of

terminals

2 and 2 are attached to the film capacitor element 1a and the insulating sheath 3 is covered can be directly mounted on the conductor plate 160. This can improve development speed and reduce costs.

(2) The bottom surface 10 b of the pedestal 10 and the conductor plate 160 were disposed facing each other, and the terminal 2 of the film capacitor 1 protruding from the pedestal 10 was directly connected to the conductive plate 160. Thereby, the terminal 2 can be directly connected to the conductor plate 160, the wiring length can be shortened, and the inductance can be reduced, so that the loss is reduced.

(3) The projection 15 is provided on the bottom of the housing recess 11. Thereby, when the film capacitor 1 is disposed in the housing recess 11, the film capacitor 1 is separated from the bottom of the housing recess 11 by an amount defined by the height of the protrusion 15, thereby forming a gap. Accordingly, since the first insulating sealing material 17 having a low viscosity flows into the gap between the film capacitor 1 and the curved surface of the housing recess 11, it is possible to prevent the insulating exterior coating 3 from being peeled off at the interface with the terminal 2. Thereby, since moisture does not enter from the boundary surface between the terminal 2 and the insulating exterior coating 3, it is possible to prevent a decrease in the capacity of the film capacitor 1 and improve durability. Further, the fixing strength between the film capacitor 1 and the base 10 can be sufficiently secured, and the durability of the inverter device 100 against vibration can be improved.

(4) The second insulating sealing material 18 having a high resin viscosity is poured into the bottom surface recess 12 formed on the bottom surface 10b of the base 10 to solidify the resin. Thereby, the fixing strength between the terminal 2 and the base 10 is improved. Therefore, it is possible to suppress an undesired stress from acting on the connection portion between the terminal 2 and the conductive plate 160 and to improve the reliability and durability of the connection portion between the terminal 2 and the conductive plate 160. Further, since the gap between the terminal through hole 14 and the terminal 2 is filled with the second insulating seal 18, the first insulating sealing material can be prevented from flowing out from the gap between the terminal through hole 14 and the terminal 2. Productivity in the process of fixing 1 to the base 10 can be improved.

--- Second Embodiment ---
A second embodiment of the power conversion device according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. This embodiment is different from the first embodiment mainly in that the protrusion 15 is not provided.

FIG. 7 is a cross-sectional view schematically showing how the conductor plate 160, the pedestal 10, the film capacitor 1, and the power semiconductor module 21 are attached to the housing 20 in the present embodiment. FIG. 8 is a perspective view of the pedestal 10 viewed from the upper surface 10a side of the pedestal 10, and FIG. 9 is a perspective view of the pedestal 10 viewed from the bottom surface 10b side of the pedestal 10. In the pedestal 10 of the present embodiment, the protrusion 15 is not provided.

In the pedestal 10 of the present embodiment, the capacitor terminal proximal-side concave portion that is a concave portion provided in the vicinity of the opening at the bottom of the accommodating concave portion 11 of each terminal through-hole 14 so as to surround the periphery of the opening. (Terminal base side recesses) 13 are respectively provided. About another point, there is no change point in the base 10 of 1st Embodiment, and the base 10 of this Embodiment.

--- Fixing the film capacitor 1 to the base 10 ---
The film capacitor 1 is fixed to the pedestal 10 of the present embodiment configured as described above as follows. First, the pair of

terminals

2 and 2 of the film capacitor 1 are inserted through the terminal through

holes

terminals

2 and 2 are inserted through the pair of terminal through

holes

14 and 14, respectively, and protrude from the bottom surface 10b.

In the present embodiment, since the protrusion 15 is not provided, when the film capacitor 1 is disposed in the housing recess 11, the portion between the pair of terminals 2 of the film capacitor 1 comes into contact with the bottom of the housing recess 11. However, as described above, the curvature radius of the curved surface forming the accommodating recess 11 is larger than the curvature radius of the semicircular portion of the film capacitor 1 having a rounded rectangular cross section. Therefore, when the film capacitor 1 is disposed in the housing recess 11, the film capacitor 1 is separated from the curved surface of the housing recess 11 (except for the vicinity of the deepest bottom of the housing recess 11) to form a gap.

Next, the second insulating sealing material 18 having a resin viscosity of about 85,000 mPa · s is poured into the bottom recess 12 formed on the bottom surface 10b of the base 10 to solidify the resin. The effect obtained by filling the bottom recess 12 with the second insulating sealing material 18 is the same as that of the first embodiment.

Next, an epoxy insulating resin (first insulating sealing material 17) having a resin viscosity of, for example, about 500 mPa · s is poured into the insulating sealing material insertion port 16 formed in the housing recess 11 of the base 10. Since the viscosity of the first insulating sealing material 17 is sufficiently low, the first insulating sealing material 17 also flows into the gap between the housing recess 11 and the film capacitor 1 and the terminal proximal end recess 13. The first insulating sealing material 17 is filled up to a height near the boundary between the semicircular portion and the straight portion of the film capacitor 1 having a rounded rectangular cross section. Further, the viscosity (about 500 mPa · s) of the first insulating sealing material 17 of the present embodiment is lower than the viscosity (about 800 mPa · s) of the first insulating sealing material 17 of the first embodiment. It may be equivalent to the viscosity (about 800 mPa · s) of the first insulating sealing material 17 of the first embodiment.

After filling with the first insulating sealing material 17, the base 10 on which the film capacitor 1 is arranged is placed in a high-temperature tank, and the first insulating sealing material 17 is cured, as in the first embodiment. 10 and the film capacitor 1 are fixed by a first insulating sealing material 17. In addition, the process etc. which arrange | position the base 10 with which the film capacitor 1 fixed after this, and the power semiconductor module 21 in the housing | casing 20 are each performed are the same as 1st Embodiment.

Inverter device 100 of the present embodiment has the following operational effects in addition to the operational effects of the first embodiment.
(1) The terminal base end side concave portion 13 is provided in the vicinity of the opening of the terminal through hole 14 at the bottom of the housing concave portion 11. Thereby, even if the protrusion 15 is not provided, the first insulating sealing material 17 filled in the terminal proximal-side concave portion 13 has the base end of the terminal 2 protruding from the insulating coating 3 (the terminal of the film capacitor 1). 2). Therefore, there is no risk of breakage at the connecting portion between the terminal 2 and the film capacitor element 1a due to the vibration of the vehicle, and the film capacitor element 1a due to moisture entering from the boundary surface between the

terminals

2, 2 and the insulating exterior coating 3 is eliminated. There is no risk of oxidation of the thin film electrode of the metallized film.

(2) Since the protrusion 15 is not provided, the insertion depth of the film capacitor 1 into the housing recess 11 is deeper than that of the first embodiment by the height of the protrusion 15. Therefore, similarly to the first embodiment, even if the first insulating sealing material 17 is filled up to a height near the boundary between the semicircular portion and the straight portion of the film capacitor 1 having a rounded rectangular cross section. The amount of the first insulating sealing material 17 required for filling can be reduced, which contributes to cost reduction.

--- Third embodiment ---
A third embodiment of the power conversion device according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first and second embodiments. This embodiment is different from the first and second embodiments mainly in that the bottom surface recess 12 is not provided on the bottom surface 10b of the base 10.

FIG. 10 is a cross-sectional view schematically showing how the conductor plate 160, the pedestal 10, the film capacitor 1, and the power semiconductor module 21 are attached to the housing 20 in the present embodiment. FIG. 11 is a perspective view of the pedestal 10 viewed from the upper surface 10a side of the pedestal 10, and FIG. 12 is a perspective view of the pedestal 10 viewed from the bottom surface 10b side of the pedestal 10. In the pedestal 10 of the present embodiment, as described above, the bottom surface recess 12 is not provided on the bottom surface 10b of the pedestal 10 (FIG. 12).

--- Fixing the film capacitor 1 to the base 10 ---
The film capacitor 1 is fixed to the pedestal 10 thus configured as follows. First, prior to disposing the film capacitor 1 in the housing recess 11, the boundary portion between the terminal 2 of the film capacitor 1 and the exterior insulation coating 3, that is, the base end portion of the terminal 2 protruding from the insulation exterior coating 3 (film capacitor An epoxy insulating resin (second insulating sealing material 18) having a resin viscosity of, for example, about 150,000 mPa · s is applied to the base portion of the terminal 2 of 1.

Thereafter, the pair of

terminals

2 and 2 of the film capacitor 1 are inserted through the terminal through

holes

14 and 14 formed in the housing recess 11 of the base 10, and the film capacitor 1 is disposed in the housing recess 11 of the base 10. The second insulating sealing material 18 is solidified. In this way, by applying the second insulating sealing material 18 in advance to the base end portion of the terminal 2 protruding from the insulating outer covering film 3 and solidifying the second insulating sealing material 18 after the film capacitor 1 is arranged. The same operational effects as when the second insulating sealing material 18 is poured into the bottom recess 12 in the first embodiment and solidified are produced.

Further, in the present embodiment, the protrusion 15 is formed in the housing recess 11. Therefore, when the film capacitor 1 is disposed in the housing recess 11, the portion between the pair of terminals 2 of the film capacitor 1 comes into contact with the projection 15, and the film capacitor 1 is projected from the curved surface of the housing recess 11. A gap is formed by being separated by an amount defined by the height of.

After filling with the first insulating sealing material 17, the base 10 on which the film capacitor 1 is arranged is placed in a high-temperature tank, and the first insulating sealing material 17 is cured, as in the first embodiment. 10 and the film capacitor 1 are fixed by a first insulating sealing material 17.

The subsequent steps of placing the base 10 to which the film capacitor 1 is fixed and the power semiconductor module 21 and the power semiconductor module 21 are respectively performed in the housing 20 are the same as those in the first embodiment.

In the present embodiment, when the pedestal 10 to which the film capacitor 1 is fixed is disposed in the housing 20, a resin, such as the first insulating sealing material 17, is previously placed in the capacitor / pedestal housing portion 20 </ b> A of the housing 20. A thermosetting insulating resin having a low viscosity may be poured. Then, the pedestal 10 to which the film capacitor 1 is fixed is disposed in the capacitor / pedestal housing portion 20A, and the power semiconductor module 21 is disposed in the power semiconductor module housing portion 20B.

In this case, thereafter, the conductor plate 160 is disposed so as to face the bottom surface 10 b of the base 10, and the conductor plate 160 and the base 10 are fixed to the housing 20 with the bolts 24. Then, these are put in a high-temperature tank, the insulating resin poured into the capacitor / pedestal housing portion 20A is cured, and the housing 20 and the film capacitor 1 are fixed with the insulating resin. Then, the conductor plate 160 and the terminal 2 of the film capacitor 1, and the conductor plate 160 and the terminal 22 of the power semiconductor module are electrically connected, for example, by welding.

As described above, the insulating resin poured into the capacitor / pedestal housing portion 20A may be cured, and the casing 20 and the film capacitor 1 may be fixed with the insulating resin. In addition to the present embodiment, in the first and second embodiments, the housing 20 and the film capacitor 1 may be fixed with an insulating resin. It is not essential to fix the housing 20 and the film capacitor 1 with an insulating resin.

Inverter device 100 of the present embodiment has the following operational effects in addition to the operational effects of the first and second embodiments.
(1) Prior to disposing the film capacitor 1 in the housing recess 11, for example, the second insulating sealing material 18 is applied to the boundary portion between the terminal 2 of the film capacitor 1 and the exterior insulating coating 3. Thereby, it can prevent that the insulation exterior coating 3 peels at the interface with the terminal 2. Thereby, since moisture does not enter from the boundary surface between the terminal 2 and the insulating exterior coating 3, it is possible to prevent a decrease in the capacity of the film capacitor 1 and improve durability.

(2) Fixing strength between the casing 20 and the film capacitor 1 by fixing the end opposite to the end of the film capacitor 1 fixed by the pedestal 10 to the capacitor / pedestal accommodating portion 20A with an insulating resin. Can be further improved. This further eliminates the possibility of breakage at the connection portion between the terminal 2 and the film capacitor element 1a or the conductor plate 160 due to the vibration of the vehicle, and enters from the boundary surface between the

terminals

2 and 2 and the insulating exterior coating 3. The possibility of oxidation of the thin film electrode of the metallized film of the film capacitor element 1a due to moisture is further eliminated. Therefore, the durability of the inverter device 100 can be further improved.

--- Comparative Example 1 ---
FIG. 13 is a diagram showing a cross-sectional structure of the main circuit portion of the power conversion device in which the film capacitor 1 used as the comparative example 1 is directly connected to the conductor plate 160. In Comparative Example 1, the base 10 in the first to third embodiments does not exist.

--- Fixing of film capacitor 1 ---
In the power converter of Comparative Example 1, the film capacitor 1 is fixed as follows. First, the pair of

terminals

2 and 2 of the film capacitor 1 are arranged at predetermined positions on the conductor plate 160, and the pair of

terminals

2 and 2 are connected to the conductor plate 160 by welding. The film capacitor 1 is supported on the conductor plate 160 only by the connection portion with the pair of terminals 2.

The power semiconductor module 21 is disposed in the power semiconductor module housing portion 20B. Thereafter, the conductor plate 160 to which the film capacitor 1 is attached is disposed. As a result, the film capacitor 1 is disposed in the capacitor housing portion 20 </ b> C provided in the housing 20.

Thereafter, the conductor plate 160 is fixed to the housing 20 with the bolts 24. And the conductor board 160 and the terminal 22 of a power semiconductor module are electrically connected by welding. Thereby, the main circuit part of the power converter device of the comparative example 1 is completed.

--- Comparative Example 2 ---
FIG. 14 is a diagram showing a cross-sectional structure of the main circuit portion of the power conversion device in which the film capacitor 1 used as the comparative example 1 is directly connected to the conductor plate 160. In Comparative Example 2, as in Comparative Example 1, the base 10 in the first to third embodiments does not exist.

--- Fixing of film capacitor 1 ---
In the power converter of Comparative Example 2, the film capacitor 1 is fixed as follows. First, as in Comparative Example 1, the pair of

terminals

2 and 2 are connected to the conductor plate 160 by welding, respectively.

Then, the epoxy adhesive 26 is applied between the conductor plate 160 and the pair of

elements

2 and 2, and the base end portion of the terminal 2 protruding from the insulating outer coating 3 and the conductor plate 160 are bonded with the epoxy adhesive 26. Fix it. The film capacitor 1 is supported on a conductor plate 160 by a connection portion between the pair of

terminals

2 and 2 and an epoxy adhesive 26.

Thereafter, the conductor plate 160 is fixed to the housing 20 with the bolts 24. And the conductor board 160 and the terminal 22 of a power semiconductor module are electrically connected by welding. Thereby, the main circuit part of the power converter device of the comparative example 2 is completed.

--- Vibration analysis ---
In order to verify the effect of the present invention with respect to the power converters of the first to third embodiments and Comparative Examples 1 and 2, the inventors made a connection between the film capacitor element 1a and the terminal 2 during vibration. (A part in FIG. 3) and the stress analysis concerning the connection part (B part in FIG. 3) of the conductor plate 160 and the

terminals

2 and 2 were implemented.

FIG. 15 shows a connection portion between the film capacitor element 1a and the terminal 2 when a vibration in a frequency range of 0 to 2000 Hz is applied in the power conversion devices of the first to third embodiments and Comparative Examples 1 and 2 (FIG. It is a figure which shows the analysis result of the maximum stress which acts on the A section in FIG. In FIG. 15, the vertical axis indicates the stress ratio when the stress in the X direction in the film capacitor 1 of Comparative Example 1 is 1 (reference). Note that the X direction refers to the horizontal direction of the paper surface in FIGS. 13 and 14, the Y direction refers to the depth direction of the paper surface in FIGS. 13 and 14, and the Z direction refers to the vertical direction of the paper surface in FIGS.

In Comparative Example 1, since the film capacitor 1 is supported only by the welded portion between the pair of terminals 2 and the conductor plate 160, the film capacitor 1 is greatly shaken when vibration is applied, and the film capacitor element 1a and the terminal 2 A large stress is generated at the joint. In Comparative Example 2, since the film capacitor 1 is fixed to the conductor plate 160 by the welded portion between the pair of terminals 2 and the conductor plate 160 and the epoxy adhesive 26, the Y direction and Z Directional stress is suppressed. However, since the film capacitor 1 is supported only in the vicinity of the terminal 2 of the film capacitor element 1 a via the pair of

terminals

2, 2 and the insulation sheath 3, the stress in the X direction is still high.

The film capacitor 1 according to the first and second embodiments is fixed to the conductor plate 160 at a welded portion between the pair of terminals 2 and the conductor plate 160, and through a portion filled with the first insulating sealing material 17. It is fixed to the base 10. In this case, vibration is suppressed in all directions of X, Y, and Z, and stress applied to the joint portion between the film capacitor element 1a and the terminal 2 can be suppressed.

FIG. 16 also shows the effect on the joint between the terminal 2 of the film capacitor 1 and the conductor plate 160 when vibration is applied in the range of 0 to 2000 Hz in the first to third embodiments and the comparative examples 1 and 2. It is an analysis result of maximum stress to be performed. The stress acting on the joint between the terminal 2 of the film capacitor 1 and the conductor plate 160 is also different from that of Comparative Examples 1 and 2 in the first to third embodiments in that the film capacitor 1 is formed by the base 10 and the insulating sealing material 17. Since it is fixed, vibration is suppressed and stress can be reduced.

---- Moisture resistance test ---
In order to verify the effect of the present invention on the power converters of the first to third embodiments and Comparative Examples 1 and 2, the inventors conducted a moisture resistance test of the film capacitor 1. FIG. 17 is a diagram showing the results of the moisture resistance evaluation. The power converters of the first and second embodiments and Comparative Example 1 are placed in a high-temperature and high-humidity tank of 85 ° C./85% RH, and predetermined. It is the result of having measured the capacity | capacitance of the film capacitor 1 for every time.

In FIG. 17, the horizontal axis represents the time of exposure to an atmosphere of 85 ° C./85% RH, and the vertical axis represents the rate of change in capacitance when the initial capacitor capacity before the test is 1. When the value on the vertical axis is a negative value, the capacitance of the capacitor is lower than the initial value.

As can be seen from FIG. 17, in Comparative Example 1, the capacity tends to decrease with time. This is presumably because moisture entered from the boundary surface between the outer insulation coating 3 of the film capacitor 1 and the terminal 2 and the thin film electrode of the metallized film of the film capacitor element 1a was oxidized.

In contrast to Comparative Example 1, in the first and second embodiments, the boundary portion between the outer insulating coating 3 and the terminal 2 of the film capacitor 1 (the base end portion of the terminal 2 protruding from the insulating outer coating 3) is the base 10. And since it is covered with the insulating sealing material 26, moisture absorption can be suppressed, and a decrease in capacity can be suppressed.

---- Modifications ----
(1) In 3rd Embodiment mentioned above, although the bottom face recessed part 12 is not provided in the bottom face 10b of the base 10, this invention is not limited to this, In 3rd Embodiment, the bottom face of the base 10 A bottom recess 12 may be provided on 10b. Then, as in the first and second embodiments, the second insulating sealing material 18 may be poured into the bottom recess 12 to solidify the resin.

(2) In the above description, each insulating sealing material is described with specific resin viscosities, but the numerical values of these resin viscosities are examples, and the present invention is not limited thereto. Moreover, you may use not only an epoxy-type insulating resin but various resin which has electrical insulation.

(3) In the above description, the number of film capacitors 1 fixed to the base 10 is six, but the present invention is not limited to this. The number of film capacitors 1 fixed to the pedestal 10 may be, for example, one or two or more arbitrary plural depending on the required capacity.

(4) In the above description, the film capacitor 1 has a rounded rectangular cross section, but the present invention is not limited to this. For example, a cylindrical capacitor having a circular cross section may be used.
(5) You may combine each embodiment and modification which were mentioned above, respectively.

Note that the present invention is not limited to the above-described embodiment, and a power semiconductor module that converts DC power into AC power and a pair of terminals that are covered with the insulating outer sheath and are covered with the insulating outer sheath. A film capacitor for smoothing the projecting DC power, a plate-like conductor plate on which a circuit for electrically connecting the power semiconductor module and the film capacitor is formed, a pedestal on which the film capacitor is fixed, and a power semiconductor It has a power semiconductor housing part for housing the module and a housing side capacitor housing part for housing the film capacitor fixed to the pedestal. The power semiconductor module is fixed and the plate surface of the conductor plate and the bottom surface of the pedestal face each other. And a housing for fixing the conductive plate and the pedestal in a state where the pedestal is recessed from the surface opposite to the bottom surface toward the bottom surface. And a pair of terminal through holes penetrating from the bottom portion to the bottom surface of the pedestal-side capacitor housing recess. The film capacitor is identical to the pedestal-side capacitor housing recess. The part is fixed to the pedestal by an insulating sealing material filled in a space between the first recess and the part, and the pair of terminals protrudes from the bottom to the outside of the pedestal through the pair of terminal through holes. It includes power converters of various structures, characterized in that they are electrically connected to the circuit of the conductor plate.

1 film capacitor, 1a film capacitor element, 2 terminal, 3 insulation sheathing, 10 pedestal, 11 pedestal side capacitor housing recess (housing recess), 12 bottom surface recess, 13 capacitor terminal proximal recess (terminal proximal recess), 14 Terminal through hole, 15 protrusion, 16 insulating sealing material insertion port, 17 epoxy insulating resin (first insulating sealing material), 18 epoxy insulating sealing resin (second insulating sealing material), 20 water channel / Case (housing), 21 power semiconductor module, 100 power conversion device (inverter device), 160 conductor plate

Claims

A power semiconductor module that converts DC power into AC power; and
A film capacitor for smoothing DC power covered with an insulating sheath and having a pair of terminals protruding from the insulating sheath;
A plate-like conductor plate on which a circuit for electrically connecting the power semiconductor module and the film capacitor is formed;
A pedestal to which the film capacitor is fixed;
A power semiconductor housing portion for housing the power semiconductor module; a housing-side capacitor housing portion for housing the film capacitor fixed to the base; and fixing the power semiconductor module; and a plate surface of the conductor plate; A housing for fixing the conductor plate and the pedestal in a state where the bottom surface of the pedestal faces each other;
The pedestal is a recess that is recessed from the surface opposite to the bottom surface toward the bottom surface, and a pedestal-side capacitor housing recess in which the film capacitor is disposed, and from the bottom of the pedestal-side capacitor housing recess to the bottom surface A pair of terminal through-holes penetrating,
The film capacitor is fixed to the pedestal by an insulating sealing material filled in a space between the first concave portion in a state where a part of the film capacitor is in contact with the pedestal side capacitor accommodating concave portion,
The pair of terminals protrudes from the bottom surface to the outside of the pedestal through the pair of terminal through holes, and is electrically connected to the circuit of the conductor plate.
The power conversion device according to claim 1,
The pedestal further includes a bottom surface recessed portion formed on the bottom surface and surrounding the terminal protruding from the bottom surface toward the conductor plate,
The power converter according to claim 1, wherein the bottom recess is filled with an insulating sealing material.
In the power converter device according to claim 1 or 2,
The pedestal further has a protrusion protruding from the bottom of the pedestal-side capacitor housing recess,
The power converter according to claim 1, wherein the film capacitor is fixed to the pedestal in a state in which the film capacitor is in contact with the protruding portion and is separated from a bottom portion of the pedestal-side capacitor receiving recess by a protruding distance of the protruding portion.
In the power converter device according to claim 1 or 2,
The pedestal further has a concave portion recessed from the bottom portion of the pedestal side capacitor housing concave portion toward the bottom surface, and is formed so as to surround the periphery of the proximal side of the terminal. ,
The capacitor terminal proximal end concave portion is filled with an insulating sealing material.
In the power converter according to any one of claims 1 to 4,
The pedestal is fixed to the housing with the surface opposite to the bottom surface facing the housing-side capacitor housing portion,
The power conversion device according to claim 1, wherein the film capacitor is fixed to a bottom surface of the housing-side capacitor housing portion by an insulating resin.