WO2015083476A1

WO2015083476A1 - Electricity conversion device

Info

Publication number: WO2015083476A1
Application number: PCT/JP2014/079281
Authority: WO
Inventors: 建前田; 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: 2013-12-05
Filing date: 2014-11-05
Publication date: 2015-06-11
Also published as: JP2017028747A

Abstract

The problem addressed by the present invention is to provide an electricity conversion device that achieves both an improvement in vibration resistance and an increase in production performance. The electricity conversion device is provided with: a capacitor cell (514); a case (590, 502, 220) that houses the capacitor cell; a conductor plate (800) that is connected to the capacitor cell and transmits DC power; and a lead (560) connecting the capacitor cell and the conductor plate. The lead (560) has a low-rigidity structure for easing the stress imparted on the lead (560), and the case (590) has a lead-holding member (580) for holding the lead (560).

Description

Power converter

The present invention relates to a power converter that converts DC power into AC power or converts AC power into DC power, and more particularly to a power converter that is suitable for being mounted on a vehicle.

Along with the market expansion of hybrid vehicles or electric vehicles, there is a demand for improved productivity of vehicle parts including power conversion devices used in these vehicles. In view of this, technical development has been carried out to reduce costs and improve assembly by simplifying the components of the power converter. Important issues in the simplification of parts include improvement of the fixing method and stress relaxation, and the market demands the same or better performance. In Patent Document 1, in order to suppress displacement stress due to vibration or temperature change, a method of increasing rigidity by fixing a connection portion between a capacitor electrode terminal and a conductor plate with a sealing material is presented.

However, the low-cost and high-quality requirements for power conversion devices in the market require further improvements and simplifications in the shape of the capacitor electrode connection part, the fixing method, and the manufacturing cost.

JP 2010-63355 A

An object of the present invention is to provide a power conversion device that achieves both improved vibration resistance and improved productivity.

A power conversion device according to the present invention comprises a capacitor cell, a case for housing the capacitor cell, a conductor plate connected to the capacitor cell, and a lead for connecting the capacitor cell and the conductor plate, The lead has a low composite structure for relaxing stress applied to the lead, and the case has a holding member for holding the lead.

According to the present invention, the stress generated in the electrical connection portion is relieved, damage due to vibration of the electrical connection portion can be avoided, and the vibration resistance and temperature resistance performance of the power converter is improved.

It is the perspective view which decomposed | disassembled the whole structure of the power converter device 200 into the component. It is the perspective view which decomposed | disassembled the conductor board assembly 800 into the component. 1 is an external perspective view of a capacitor module 500. FIG. It is the perspective view which decomposed | disassembled the capacitor | condenser module 500 into the component. 5 is an enlarged perspective view showing a state where the lead band 580 is mounted. FIG. 3 is an external perspective view of a lead band 580. FIG. 5 is a perspective view showing a joint portion between a lead 560 and a conductor plate 800. FIG. FIG. 6 is a perspective view showing configurations of a capacitor cell storage component 502 and a holding member 590. FIG. 11 is a perspective view showing a state where the capacitor cell 514 is attached to the holding member 590. 6 is a perspective view according to an embodiment in which a capacitor cell 514 is housed in a case 220. FIG. It is the perspective view which decomposed | disassembled the capacitor | condenser module 500 of FIG. 10 into the component. 6 is a perspective view showing another configuration example of the capacitor module 500. FIG. It is a perspective view of the capacitor cell 514 accommodated in the exterior | packing for every cell. 4 is a perspective view showing a shape of a power semiconductor module 300. FIG. FIG. 11 is a perspective view showing another shape example of the lead 560. FIG. 11 is a perspective view showing another shape example of the lead 560.

Hereinafter, embodiments of a power conversion device according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is described about the same element and the overlapping description is abbreviate | omitted.

The power conversion device 200 according to the present embodiment is mainly used for hybrid vehicles and electric vehicles. An example of the vehicle system is described in Japanese Patent Application Laid-Open No. 2010-63355. In addition, the power converter device 200 which concerns on this embodiment may be used for another use in order to achieve the effect. For example, it may be used for a home appliance inverter of a refrigerator or an air conditioner for the purpose of improving productivity and cooling performance. Further, the inverter may be used for an inverter for industrial equipment whose use environment is similar to that for a vehicle inverter.

FIG. 1 is an exploded perspective view illustrating components of the power converter 200 according to the present embodiment in order to explain the overall configuration. The power conversion apparatus 200 includes a circuit board 20, a metal base plate 11, a conductor plate assembly 800, power semiconductor modules 300a to 300c, and a capacitor module 500. These members are attached to the case 220 by a technique such as screw tightening.

The power semiconductor modules 300a to 300c convert DC power into AC power. The capacitor module 500 smoothes DC power. The circuit board 20 is mounted with a drive circuit unit that outputs a drive signal for driving the power semiconductor modules 300a to 300c. In addition, the circuit board 20 includes a control circuit unit that outputs a control signal for controlling the power semiconductor modules 300a to 300c in the drive circuit. An example of these circuit systems is described in Japanese Patent Application Laid-Open No. 2010-63355.

The case 220 forms a flow path forming body through which a coolant for cooling the power semiconductor modules 300a to 300c and the capacitor module 500 flows.

The conductor plate assembly 800 transmits DC power from the capacitor module 500 to the power semiconductor modules 300a to 300c. The electric power converted into alternating current by the power semiconductor modules 300a to 300c is output from the alternating current terminals 804a to 804c.

The power conversion device 200 of this embodiment is configured in a state where a conductor plate (conductor plate assembly 800) that is connected to a capacitor module and transmits DC power is separated from the capacitor module 500. Thus, by providing an air layer between the bus bar assembly 800 and the capacitor module 500, the heat generation of the DC side conductor plate, which is the main factor of heat reception of the capacitor module, is difficult to be transmitted to the capacitor module 500.

The guaranteed temperature of the capacitor cell 514 (see FIG. 4) provided in the capacitor module 500 is lower than other components mounted on the power conversion device 200. When the temperature of the capacitor cell 514 (see FIG. 4) is equal to or higher than the guaranteed temperature, the life of the capacitor cell 514 (see FIG. 4) is drastically reduced, and the function as a smoothing capacitor is not satisfied. Therefore, improving the cooling performance of the capacitor module 500 is an important issue. In the present embodiment, a case 220 that forms a flow path is disposed at the lower part of the capacitor module 500, and the influence of the vertical heat on the capacitor module 500 having a guaranteed temperature lower than that of other components can be suppressed. .

A metal base plate 11 is disposed between the conductor plate assembly 800 and the circuit board 20 to prevent strong electric noise from the capacitor module 500 and the DC side conductor plate from affecting the circuit board 20. . In addition, the heat of the electronic components mounted on the circuit board 20 can be released to the case 220 via the metal base plate 11, thereby reducing the cooling performance and removing the noise while reducing the amount of the metal plate to the minimum necessary. It becomes.

FIG. 2 is a perspective view in which the conductor plate assembly 800 is disassembled into components. The conductor plate assembly 800 includes a positive side conductor plate 801a, a negative side conductor plate 801b, a first holding member 802a, a second holding member 802b, a current sensor 803, AC terminals 804a to 804c, an insulating member 805, and the like. . The insulating member 805 is disposed between the positive electrode side conductor plate 801a and the negative electrode side conductor plate 801b. The positive conductor plate 801a is covered with the first holding member 802a in a state where the surface on the side where the insulating member 805 is disposed is exposed. The negative electrode side conductor plate 801b is covered with the second holding member 802b in a state where the surface on the side where the insulating member 805 is disposed is exposed. The first holding member 802a and the second holding member 802b are formed of, for example, an electrically insulating resin. The AC terminals 804a to 804c are disposed through the through hole of the current sensor 803.

The holding member 802a covering the DC

side conductor plates

801a and 801b is fixed to the case 220 by bolt fastening. By supporting the weight of the conductor plate assembly 800 having the DC

side conductor plates

801a and 801b with the case 220, the connection part between the capacitor module 500 and the DC

side conductor plates

801a and 801b, the power semiconductor modules 300a to 300c, and the DC side conductor are connected. Stress is prevented from concentrating on the connecting portions of the

plates

801a and 801b, and the reliability is improved. For the joining portion, for example, a welding method or the like can be used to reduce the size and the number of parts.

AC terminals 804a to 804c constituting the conductor plate assembly 800 are electrically connected to the power semiconductor modules 300a to 300c. The power semiconductor module 300 has a power module terminal 399, as will be described later with reference to FIG. Power module terminal 399 is connected to AC terminals 804a to 804c.

FIG. 3 shows the external appearance of the capacitor module 500. The capacitor module 500 includes a capacitor housing component 502 having an opening formed on one surface. The capacitor storage component 502 forms a storage space in which a capacitor cell 514 described later is stored. The opening of the capacitor housing component 502 is covered with a sealing material 511. A lead 560 (see FIG. 4) connected to the capacitor cell 514 (see FIG. 4) protrudes from the surface of the sealing material 511 to form a lead protrusion 562. For simplification of the drawing, the shape of the attachment portion to the case 220 formed in the capacitor housing component 502 is not shown in FIG.

FIG. 4 is a perspective view in which the capacitor module 500 is disassembled into components. Capacitor module 500 includes capacitor housing component 502, capacitor cell 514, lead 560, lead holding member 580, and capacitor cell holding member 590. As described above, the capacitor storage component 502 is formed with a storage space, and the capacitor cell 514, the lead 560, the lead band 580, and the capacitor cell holding member 590 are stored in the storage space. It is sealed with a stopper 511.

A plurality of capacitor cells 514 are usually prepared. The capacitor cell 514 used in this embodiment has a substantially flat shape. Capacitor electrodes are formed on one surface of the capacitor cell 514 and the other surface opposite to the one surface. A lead 560 is joined to the capacitor electrode, and a lead-cell junction 561 is formed. The lead-cell joint portion 561 is formed by a method such as soldering or welding.

FIG. 5 is an enlarged perspective view showing a mounted state of the lead band 580 which is a lead holding member. The lead 560 bonded to the capacitor cell 514 is made of a low-rigidity conductive material. Specifically, in this embodiment, the lead 560 is constituted by a plurality of cable-shaped members. By forming the lead 560 using a plurality of cable-shaped members, the shape of the lead 560 can be easily changed. The low-rigidity lead 560 is hooked by the lead holding member 580 in the vicinity of the band attachment portion 592 formed on the capacitor cell holding member 590.

Thus, by using the low-rigidity lead 560, the stress generated in the lead joint portion due to the relative displacement between the conductor plate assembly 800 and the capacitor module 500 can be relieved. In the power conversion device, relative displacement between members can occur due to vibrations generated depending on the environment in which the power conversion device is mounted and differences in thermal expansion coefficients of component materials accompanying temperature changes.

FIG. 6 is an external perspective view of the lead holding member 580. The lead band 580 includes a band holding part 582 and a lead holding part 584. The band holding portion 582 is formed to hook the lead band 580, which is a lead holding member, to the capacitor cell holding member 590. The lead holding portion 584 is formed to hold the lead 560. In this embodiment, the band holding part 582 and the lead holding part 584 are formed in a through-hole shape. The lead band 580 is hooked on the capacitor cell holding member 590 by inserting the band attaching portion 592 of the capacitor cell holding member 590 into the band holding portion 582 having a through hole shape. Similarly, the lead 560 is hooked on the lead band 580 by inserting the lead 560 into the lead holding portion 584 having a through hole shape. The shapes of the band holding portion 582 and the lead holding portion 584 are not limited to the through-hole shape as shown in FIG. 6, and may be any shape that can achieve the functions of the respective members described above. For example, the band holding portion 582 may be formed by forming a recess in the lead band 580, or the lead holding portion 584 may be formed in a clip shape.

FIG. 7 is a perspective view showing a joint portion between the lead 560 and the conductor plate 800. The lead 560 is held by the lead holding portion 584 of the lead band 580 so as to face the corresponding joint portion of the conductor plate assembly 800. As a result, the lead 560 is provisionally determined at the tip position to be a joint portion with the conductor plate assembly 800. The lead 560 forms a lead-conductor plate joint 564 that is a joint with the conductor plate assembly 800, for example, by welding, soldering, or connection using a fixing component at a position temporarily determined on the lead band 580. .

Note that the lead band 580 is a member used to temporarily determine the position of the tip portion of the lead 560 having low rigidity, and thus may be removed after the connection work with the conductor plate assembly 800. For example, the lead band 580 may have a cut shape that is connected to the lead holding portion 584 and can be detached from the lead 560.

As described above, the lead holding member (lead band 580) for holding the low-rigidity lead 560 is provided in the case (capacitor containing component 502 and capacitor cell holding member 590 in this embodiment) that stores the capacitor cell 514. Thus, the connection work with the conductor plate assembly 800 can be facilitated.

When a cable-like member is used as the lead 560 as in this embodiment, the length of the cable is added to the length connecting the lead-cell joint 561 and the lead-conductor plate joint 564 at the shortest distance, and the capacitor module By making the maximum relative displacement difference between 500 and the conductive plate assembly 800 longer than the combined length, the lead 560 is deformed when a displacement occurs, and the effect of stress relaxation can be exhibited.

FIG. 8 is a view showing an assembly arrangement of the capacitor cell holding member 590 and the capacitor housing component 502. As shown in FIG.

Positioning pins

521a and 521b are formed on the bottom forming the storage space for the capacitor storage component 502.

Positioning holes

522a and 522b are formed at the bottom of the capacitor cell holding member 590 corresponding to the

positioning pins

521a and 521b of the capacitor housing component 502. The position of the capacitor cell holding member 590 is determined with respect to the capacitor housing component 502 by fitting the

positioning pins

521a and 521b into the

positioning holes

522a and 522b.

The position of the capacitor module 500 is determined by inserting the positioning bosses 598a and b shown in FIG. As described above, the lead 560 connected to the capacitor cell 514 and the capacitor cell holding member 590 are positioned by the lead band 580. Therefore, since the tip of the lead 560 is disposed in the vicinity of the position where the lead-conductor plate joint 564 is to be formed in the assembly process of the power conversion device, the position adjustment in the connection process with the conductor plate assembly 800 can be performed. It becomes easy.

Also, the capacitor cell holding member 590 can be formed integrally with the capacitor housing component 502. In patent document 1, since the structure which fixes the connection part of a capacitor electrode terminal and a conductor board with a sealing material is used, it fills a sealing material after joining a capacitor cell and a conductor board, and hardens a sealing material. The process to do is performed. The assembly of the capacitor cell and the conductor plate does not have a shape for positioning with the capacitor housing component, and a jig for fixing the conductor plate and the capacitor housing component while positioning each other in the process of curing the sealing material. It is necessary to use it. The jig is used for positioning the capacitor housing component and the inverter case as a reference to suppress the movement of the component due to the flow when the sealing material is hardened and to improve the dimensional accuracy. It was a large jig that was fixed so as to cover the entire shape. Due to the large size of the jig, a large capacity is required to accommodate the limited curing furnace when the manufacturing process is run, and the production is slow due to the large weight and the handling time. Had fallen. Since the jig is large, the manufacturing cost is high. In the present invention, the jig can be eliminated, and the capacitor cell holding member 590 has a necessary positioning function as a substitute.

FIG. 9 is a view showing a state in which the capacitor cell 514 is attached to the capacitor cell holding member 590. Capacitor cell 514 is fixed by capacitor

cell holding portions

594a and 594b which are part of capacitor cell holding member 590.

FIG. 10 shows a state in which the capacitor cell 514 is directly housed in the case 220 and fixed by the sealing material 511. In order to simplify the drawing, the case 220 shows only the shape around the capacitor cell storage portion.

FIG. 11 is a component development view of FIG. In this embodiment, a case 220 is used as a substitute for the capacitor housing component 502. Capacitor cell holding member 590 may be formed as a separate part from case 220 or may be formed integrally as the same part.

FIG. 12 is a diagram showing a form in which a module in which capacitor cells are individually sealed is assembled, unlike the capacitor module of FIG. The capacitor module 500 of the present embodiment uses a plurality of single capacitor cell modules 570 housed in a capacitor module exterior 572 and sealed with a sealing material 511 as shown in FIG. The single capacitor module 570 is housed in the case 220. In the present embodiment, the band attaching portion 592 is formed in a part of the case 220. The single capacitor module 570 positions the tip of the lead 560 by fixing the lead band 580 attached to the lead protrusion 562 protruding from the sealing material 511 to the band attachment portion 592.

According to the capacitor module according to the above-described embodiment, the positioning jig required in the resin sealing process of the capacitor module can be eliminated, the productivity in manufacturing the capacitor module is improved, and the simplified lead terminals of the capacitor module As a result, the connection of the conductor plates is facilitated, and the productivity of the power converter is improved.

FIG. 14 is a perspective view showing the shape of the power semiconductor module 300. The power semiconductor module 300 has a power module terminal 399 connected to the conductor plate of the conductor plate assembly 800. Similarly to the lead 560 of the capacitor module 500, the power module terminal 399 is formed of a low-rigidity member. Therefore, similarly to the capacitor module, the stress caused by the relative displacement between the power semiconductor module 300 and the conductor plate assembly 800 can be relaxed.

15 and 16 are diagrams showing other examples of shapes for forming the lead 560 into a low-rigidity structure. FIG. 15 has a spiral structure like a spring, and the spiral portion is deformed by expansion and contraction, thereby relieving stress generated by relative displacement between the capacitor module 500 and the conductor plate assembly 800. In FIG. 16, the plate-shaped formed body has one or more bent portions, and the same stress relaxation is exhibited by deformation of the bent portions.

11: Metal base plate 20: Circuit board 200: Power converter 220: Case 300: Power semiconductor module 399: Power module terminal 420: Power semiconductor module housing part 500: Capacitor module 502: Capacitor housing part 511: Sealing material 514 : Capacitor cell 521: Positioning pin 522: Positioning hole 560: Lead 561: Lead-cell joint 562: Lead protrusion 564: Lead-conductor plate joint 570: Single capacitor module 572: Capacitor module exterior 580: Lead band 582: Band holding portion 584: Lead holding portion 590: Capacitor cell holding member 592: Band mounting portion 594: Capacitor cell holding portion 598: Positioning boss 800: Conductor plate assembly 801: DC side conductor plate 802 Insulating member 803: current sensor 804: the AC terminal 805: insulating portion

Claims

A capacitor cell;
A case for storing the capacitor cell;
A conductor plate connected to the capacitor cell and transmitting DC power;
A lead for connecting the capacitor cell and the conductor plate;
The lead has a low rigidity structure for relieving stress applied to the lead,
The case is a power conversion device in which the case has a lead holding member for holding the lead.
The power conversion device according to claim 1,
The lead is a power conversion device in which a bent portion is formed to relieve stress applied to the lead.
The power conversion device according to claim 1 or 2,
The lead extends toward the arrangement direction of the conductor plate,
The lead forms a connecting portion connected to the conductor plate at the leading end of the lead in the extending direction;
The lead holding member is a power conversion device arranged so that a projection part of the lead holding member overlaps with a projection part of the connection part when projected from the extending direction of the lead.
The power conversion device according to any one of claims 1 to 3,
The case is a power conversion device in which the case has a capacitor cell holding member that holds the capacitor cell.
The power conversion device according to any one of claims 1 to 4,
The case is a power conversion device having a positioning structure fitted to the conductor plate.
The power conversion device according to any one of claims 1 to 5,
The conductor plate is a power conversion device having a laminate structure in which a positive electrode conductor and a negative electrode conductor are overlapped to face each other.