WO2013061799A1

WO2013061799A1 - Power conversion device

Info

Publication number: WO2013061799A1
Application number: PCT/JP2012/076380
Authority: WO
Inventors: 秀則篠原; 中津　欣也; 芳春山下
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2011-10-27
Filing date: 2012-10-12
Publication date: 2013-05-02
Also published as: JP2013094023A

Abstract

Conventional cooling structures had the issues of only having cooling by direct contact with a side surface of a metal case, no consideration being given to heat transfer in many directions, and more efficient cooling being required.　Heat generated by a magnetic component is efficiently dispersed to a case, by having a transformer and an inductor element positioned in a housing space formed by a rib planted inside the case, and by filling between the transformer and inductor element and the rib, using a resin having radiation and insulation properties.

Description

Power converter

The present invention relates to a power converter such as a DC-DC converter having a magnetic part such as a transformer and / or a coil, and more particularly to a power converter having improved heat resistance.

Electric vehicles and plug-in hybrid vehicles are equipped with an inverter device for driving a motor with a high-voltage storage battery for driving power and a low-voltage storage battery for operating auxiliary equipment such as a vehicle light and radio. Such a vehicle is equipped with a DC-DC converter device that performs power conversion from a high voltage storage battery to a low voltage storage battery or power conversion from a low voltage storage battery to a high voltage storage battery.

In such a vehicle, it is desired to increase the ratio of the room to the total volume of the vehicle as much as possible to improve the comfort. For this reason, it is desired that power converters such as an inverter device and a DC-DC converter device be mounted in a space as small as possible outside the passenger compartment.

Therefore, in order to reduce the size, it is important to efficiently dissipate the heat from the heat generating elements constituting the power conversion device to the outside. Japanese Patent Application Laid-Open No. 2007-173700 discloses a cooling structure for such a power conversion device. (Patent Document 1).

The technology described in Patent Document 1 aims to provide a compact magnetic component by cooling a coil of a magnetic component such as a reactor, and specifically, the first coil portion and the second coil portion of the reactor. The first and second coil portions of the reactor without adding a liquid cooling mechanism by bringing the free flat main surface of the liquid cooling fin of the liquid cooling type inverter device into close contact with each other through a mold resin and a metal case It can be cooled well.

JP 2007-173700 A

By the way, use in a temperature environment, particularly in a high temperature range, can be considered to accelerate the deterioration of the control function of the inverter device and the DC-DC converter device and the deterioration of the structural parts. For this reason, as a cooling mechanism for inverter devices and DC-DC converter devices, the device is generally cooled by a refrigerant composed of a mixture of water, and how to efficiently radiate heat to this cooling mechanism is stable. It is an important technical element to improve the space and save space.

Although the thing of patent document 1 is known as one means for improving this subject, in this technique, the cooling structure is the side of the metal case, and only cooling by the direct contact of the metal case. However, no consideration has been given to heat conduction in various directions, and there has been a problem that more efficient cooling is necessary to ensure further space saving (miniaturization of the apparatus).

A feature of the present invention is a power converter having a DC-DC converter having two or more magnetic parts such as transformers and / or inductor elements and having a step-down circuit and / or a step-up circuit arranged in a case. In addition, a transformer and / or an inductor element is disposed in a storage space formed by ribs planted in the case, and a resin having heat dissipation and insulation is filled between the transformer and / or the inductor element and the rib. Power converter.

According to the present invention, heat generated by a magnetic component such as a transformer and / or an inductor element can be dissipated to the rib and the case via a resin having heat dissipation properties and insulation properties, so that the temperature rise of the magnetic component can be reduced. . Therefore, it is possible to provide a power conversion device that prevents deterioration of the function of the device due to the high temperature environment of the converter device and the progress of deterioration of the components, and suppresses the increase in size.

It is an external appearance perspective view for demonstrating the power converter device which combined the inverter apparatus and the DC-DC converter apparatus. It is the external appearance perspective view which carried out the cross section of the inverter apparatus. It is a circuit diagram which shows the circuit structure of a DC-DC converter apparatus. It is a disassembled perspective view which shows the components arrangement | positioning of a DC-DC converter apparatus. It is an external appearance perspective view for demonstrating a DC-DC converter apparatus. FIG. 3 is an exploded perspective view around a main transformer and an inductor element of a DC-DC converter device. It is a perspective view which shows the inside of a DC-DC converter apparatus. It is sectional drawing which shows the state which has arrange | positioned the main transformer and the inductor element in the case.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

1 and 2 are perspective views showing an external appearance of a power conversion device including an inverter device and a DC-DC converter device. The power conversion device 1 is an integrated DC-DC converter device 100 and inverter device 200. FIG. 1 and 2, the DC-DC converter device 100 and the inverter device 200 are shown in a separated state.

The DC-DC converter device 100 is fixed to the case bottom side of the inverter device 200 by a plurality of bolts (not shown).

The power conversion device 1 is applied to an electric vehicle or the like, and the inverter device 200 drives a traveling motor with electric power from an on-vehicle high voltage storage battery. The vehicle is equipped with a low voltage storage battery for operating auxiliary equipment such as a light and a radio, and the DC-DC converter device 100 converts power from a high voltage storage battery to a low voltage storage battery or a high voltage from a low voltage storage battery. Perform power conversion to storage battery.

A refrigerant flow path through which a refrigerant flows is formed in the side wall of the case 201 of the inverter device 200. The refrigerant flows into the flow path from the inlet pipe 13 and flows out from the outlet pipe 14. On the other hand, the case 101 of the DC-DC converter device 100 faces the bottom surface of the inverter device 200 and is fixed without a gap.

In the fixed state, the DC-DC converter device 100 is also configured to use the refrigerant flow path. In the present embodiment, water is most suitable as the refrigerant, but the refrigerant is not necessarily limited to water and can be used even if it is other than water. Although not shown in FIG. 1, a gasket such as an O-ring is provided in the gap between the case 101 and the case 201 in order to prevent the refrigerant from flowing out of the refrigerant flow path.

Next, the DC-DC converter device 100 will be described. FIG. 3 is a diagram showing a circuit configuration of the DC-DC converter device 100. As shown in FIG. 3, the DC-DC converter device 100 of the present embodiment is compatible with bidirectional DC-DC. Therefore, the step-down circuit (HV circuit) and the step-up circuit (LV circuit) have a synchronous rectification configuration rather than a diode rectification. In addition, in order to achieve high output by HV / LV conversion, large current components are used for the switching elements and the smoothing coil is enlarged.

Specifically, the H bridge type and synchronous rectification switching circuit configurations H1 to H4 using MOSFETs having recovery diodes on both the HV / LV sides. In the switching control, the LC series resonance circuits Cr and Lr are used to perform zero-cross switching at a high switching frequency (100 kHz) to improve the conversion efficiency and reduce the heat loss.

In addition, the active clamp circuits S1 and S2 are provided to reduce the loss due to the circulating current during the step-down operation, and suppress the generation of the surge voltage at the time of switching, thereby reducing the breakdown voltage of the switching element. The device is miniaturized by reducing the breakdown voltage.

Furthermore, in order to secure a high output on the LV side, a full-wave rectification type double current (current doubler) method was adopted. In addition, in order to increase output, high output is ensured by operating a plurality of switching elements simultaneously in parallel.

In the example of FIG. 3, four elements are arranged in parallel such as switching elements SWA1 to SWA4 and SWB1 to SWB4. Further, the high output is achieved by arranging the small reactors L1 and L2 of the switching circuit and the smoothing reactor in parallel so as to have symmetry. As described above, by arranging the small reactors in two circuits, it is possible to reduce the size of the entire DC-DC converter device as compared with the case of arranging one large reactor.

4 to 7 are diagrams for explaining the arrangement of components in the DC-DC converter device 100, FIG. 4 is an exploded perspective view of the DC-DC converter device 100, and FIG. 5 is a top view of the DC-DC converter device 100. FIG. 6 is an exploded perspective view around the main transformer and the inductor element of the DC-DC converter device, and FIG. 7 is a perspective view showing the inside of the DC-DC converter device.

As shown in FIG. 4, the circuit components of the DC-DC converter device 100 are housed in a case 101 made of metal (for example, made of aluminum die casting). A case cover 102 is bolted to the opening of the case 101.

As described above, the case 201 of the inverter device 200 is fixed to the bottom surface side of the case 101. A step-up circuit board on which a main transformer 104, an inductor element 105, a step-down circuit on which switching elements H1 to H4 are mounted, and a switching element SWA1 to SWA4 and SAWB1 to SWB4 (not shown) are mounted on the bottom surface in the case 107 and the like are placed. The main heat generating components are the main transformer 104, the inductor element 105, the power semiconductor module, the switching element, and the like.

When the correspondence with the circuit diagram of FIG. 3 is described, the main transformer 104 corresponds to the transformer Tr, the inductor element 105 corresponds to the reactors L1 and L2 of the current doubler, and the booster circuit board 107 includes the switching element of FIG. S1, S2, etc. are also mounted.

The booster circuit board 107 is mounted on a metal substrate on which switching elements are patterned, and the back surface side of the metal substrate is fixed so as to be in close contact with the bottom surface of the case.

The control circuit board 108 is mounted with a control circuit for controlling switching elements provided in the booster circuit and the step-down circuit. The control circuit board 108 is fixed to a convex portion formed on the upper surface of the metal base plate 109 with a bolt or the like.

The base plate 109 is bolted to a plurality of support portions (not shown) protruding upward from the bottom surface portion of the case 101. As a result, the control circuit board 108 is disposed via the base plate 109 above the heat generating components (the main transformer 104, the inductor element 105, etc.) disposed on the bottom surface of the case.

The base plate 109 has the function of releasing and cooling the heat generated by the control circuit board, and the function of increasing the mechanical resonance frequency of the control circuit board 108. That is, it is possible to dispose screwing portions for fixing the control circuit board 108 to the base plate 109 at short intervals, shorten the distance between the support points when mechanical vibration occurs, and increase the resonance frequency. it can. Since the resonance frequency of the control circuit board 108 can be increased with respect to the vibration frequency transmitted from the engine or the like, it is difficult to be influenced by vibration and the reliability is improved.

Also, the base plate 109 functions as a shielding member for radiant heat from the heat-generating components provided on the bottom surface of the case, and also functions as a shield for shielding switching radiation noise from the switching element.

Further, a case cover 102 is attached to the opening of the case 101, and the inside of the case is sealed.

5A and 5B are perspective views of the DC-DC converter device 100, where FIG. 5A is a perspective view seen from the top, FIG. 5B is a perspective view seen from the bottom, and reference numeral 103 is the bottom of the DC-DC converter device. The refrigerant flow path range is shown. The heat generated by the DC-DC converter device 100 is radiated to the refrigerant flow path range 103. The refrigerant flows in from the inlet pipe 13 of the inverter device 200 and flows out of the outlet pipe 14 in the direction indicated by the arrow.

Next, the arrangement around the main transformer 104 and the inductor element 105 will be described with reference to FIGS.

In FIG. 6,

ribs

101a, 101b, 101c, 101d, and 101e are formed on the case 101. The ribs 101a to 101e are connected to each other, and form a storage space in which the main transformer 104 and the inductor element 105 are stored as described below.

The main transformer 104 and the two inductor elements 105 are disposed on the bottom surface of the case, but the main transformer 104 is disposed in the first storage space A surrounded by the rib 101b and the

ribs

101c and 101d.

The inductance element 105a is disposed in the second storage space B surrounded by the rib 101a and the

ribs

101b and 101c.

The inductance element 105b is disposed in the third storage space C surrounded by the rib 101d and the

ribs

101b and 101e.

The metal plate 110 is a leaf spring, and is made of a stainless spring material. The metal plate 1110 has a function of pressing and fixing the main transformer 104 and the inductor element 105 to the case 101 with a predetermined force.

The AC bus bar 111 is a member that electrically connects the main transformer 104, the

HV side modules

113a and 113b, and the resonance coils 114a and 114b as shown in FIG. The AC bus bar 111 includes

bus bars

111a and 111b and a resin holder 111c, and the

bus bars

111a and 111b are integrally formed with the resin holder 111c. As the material of the resin holder, PPS (polyphenylene sulfide) containing glass or PBT (polybutylene terephthalate) containing glass having excellent dimensional stability and heat resistance is used.

The metal plate 110 and the AC bus bar 111 are fixed to the case 101 with bolts 112a to 112f.

The case 101 has a plurality of support portions 101f to 101k protruding upward. The bolt 112a is the support portion 101f, the bolt 112b is the support portion 101g, the bolt 112c is the support portion 101h, and the bolt 112d. Are fixed to the support portion 101i, the bolt 112e is fixed to the support portion 101j, and the bolt 112f is fixed to the support portion 101k.

Further, the metal plate 110 and the AC bus bar 111 are fastened together by

bolts

112c and 112e, and both are integrated.

The AC bus bar 111a is connected to the terminal 104b of the main transformer and the resonance coil 114a, and the AC bus bar 111b is connected to the terminal 104a of the main transformer and the terminal 113a of the HV module by welding. The HV module terminal 113b and the resonance coil 114b are also connected by welding, and an alternating current flows.

The heat dissipation structure around the main transformer 104 and the inductor element 105, which is a characteristic part of the present invention, will be described with reference to FIG.

FIG. 8 is a cross-sectional view showing a state in which the main transformer 104 and the inductor element 105 are arranged in the case 101. The case 101 is firmly fixed to the case 201 of the inverter device 200, and the main transformer 104 and the inductor element 105 are fixed. Are arranged along the flow of the cooling medium in the direction of the arrow. Thereby, the surface where the main transformer 104 and the inductor element 105 are located is in a stably cooled state.

The main transformer 104 is stored in the first storage space A, the inductor element 105a is stored in the second storage space B, and the inductor element 105b is stored in the third storage space C. The main transformer 104, the inductor element 105a, and the inductor The element 105b is fixed in contact with the bottom surfaces of the respective storage spaces A, B, and C. That is, it contacts the bottom wall surface that forms the storage spaces A, B, and C of the case 101. The storage spaces A, B, and C are also arranged along the flow of the cooling medium in the arrow direction.

Therefore, heat generated from the main transformer 104 and / or the inductor element 105 is transmitted from the bottom surface of the main transformer 104 and / or the inductor element 105 to the bottom wall surface of the case 101 and directly radiated.

Also, each storage space A, B, and C is formed by the wall-like ribs 101a to 101e having a predetermined height as described above, and thus also functions as a reservoir. Therefore, the reservoir portion where the ribs 101a to 101e are present is filled with a resin having both heat dissipation and insulation properties.

That is, as shown in FIG. 8, a gap is provided between the main transformer 104, the inductor element 105, and the ribs 101a to 101e of the case. In this gap, a urethane resin having heat dissipation and insulation, Also, a heat radiating resin 300 made of silicon resin or the like having heat radiating and insulating properties is filled. The heat-dissipating resin 300 is represented by diagonal grid lines shown in the storage spaces A, B, and C in the drawing.

This heat-dissipating resin 300 is obtained by mixing insulating resin having fluidity as a base material and powder having insulating properties and heat-dissipating properties such as alumina powder, and after filling each storage space A, B, C. It is solidified by natural drying or heat drying.

Accordingly, the four side surfaces of the main transformer 104 and the inductor element 105 are also in contact with the case 101 so as to be able to dissipate heat via the heat radiating resin 300, and the heat from the four side surfaces is absorbed by the heat radiating resin 300 and Heat is radiated to the case through the ribs 101a to 101e.

In particular, the coil part 105c of the inductor element 105a and the coil part 105d part of the inductor element 105b can transmit heat directly to the wall surface of the case 101 through the heat-dissipating resin 300, so that heat can be radiated efficiently.

Qualitatively, the greater the thickness of the ribs 101a to 101e, the greater the effect of transferring heat to the bottom surface.

Here, the filling time of the heat-dissipating resin 300 is a method of filling the heat-dissipating resin 300 after the main transformer 104 and the inductor element 105 are assembled in the storage spaces A, B, and C, and the heat-dissipating property in the storage spaces A, B, and C. There is a method of assembling the main transformer 104 and the inductor element 105 after filling the resin 300.

In this embodiment, the main transformer 104 and the inductor element 105 are assembled after the storage spaces A, B, and C are filled with the heat radiating resin 300. This is because voids and the like can be reduced between the ribs 101a to 101e and the main transformer 104 and the inductor element 105.

As described above, the heat generated from the main transformer 104 and the inductor element 105 is radiated from the bottom surfaces of the main transformer 104 and the inductor element 105, and is also radiated from the four side surfaces of the main transformer 104 and the inductor element 105. Heat can be dissipated very efficiently.

Further, since

ribs

105c and 105d exist between the main transformer 104 and the inductor element 105, the rib 101c causes interference between the heat generated from the main transformer 104 and the heat generated by the inductor element 105a, and the rib 101d corresponds to the main transformer 104. This serves to prevent interference between the heat generation from the inductor element 105b and the inductor element 105b. That is, thermal interference between the main transformer 104 and the inductor element 105 is prevented, and the temperature rise of the magnetic component is reduced.

In this embodiment, the thickness of the rib is set to 2 mm or more because the thickness is preferably 2 mm or more from the viewpoint of molding and strength by using aluminum die cast as the material of the case 101. Yes.

Further, the

ribs

101c and 101d are formed with a continuous groove 115a and groove 115b having a predetermined depth along the rib in the vicinity of the center thereof, thereby preventing the heat from the main transformer 104 and the interference of the inductor element 105b. It also plays a role to prevent.

In addition, the gap between the main transformer 104, the inductor element 105, and each of the ribs 101a to 101e is preferably as narrow as possible from the viewpoint of heat dissipation. Therefore, a space of 1 mm or more is provided.

Of course, since it varies depending on the material of the case to be used and the assembling method, it is possible to appropriately select how to measure the dimensions according to the situation.

According to the power conversion device 1 of the present embodiment described above, the main transformer 104 and the inductor element 105, which are heat generating components of the DC-DC converter device 100, can be efficiently cooled, and as a result, the device in a high temperature environment It is possible to prevent the deterioration of the function and the deterioration of the component parts.

Although the above explanation has been given taking an example of a power conversion device mounted on a vehicle such as PHEV or EV, the present invention is not limited to these and may be applied to a power conversion device used for a vehicle such as a construction machine. it can.

Further, in this embodiment, the power conversion device in which the inverter and the converter are integrated has been described as an example. However, a configuration in which a refrigerant water channel is provided on the converter side to form a single unit is also applicable.

DESCRIPTION OF SYMBOLS 100 ... Converter apparatus, 101 ... Case, 13 ... Inlet piping, 14 ... Outlet piping, 200 ... Inverter apparatus, 201 ... Inverter case, 102 ... Case cover, 104 ... Main transformer, 104a, b ... Terminal of main transformer, 105 ... Inductor element, 103 ... Refrigerant water channel, 107 ... Boost circuit board (LV circuit board), 108 ... Control circuit board, 109 ... Base plate, 101a-e ... Rib on case, 101f-k ... Fixing of base plate on case 110, metal plate, 111 ... AC bus bar, 111a, b ... bus bar, 111c ... resin holder, 112a to 112f ... set screw, 113a, b ... terminal of HV module, 114 resonance coil, 114a, b ... resonance coil Terminals, H1 to H4... Switching elements.

Claims

A transformer that converts voltage values;
An inductor element;
A metal case for housing the transformer and the inductor element;
A refrigerant flow path disposed along the bottom surface outside the case,
The case forms a rib standing from the bottom surface inside the case,
The transformer is disposed in a first housing space formed by the rib and the case, and the inductor element is disposed in a second housing space formed by the rib and the case,
The first housing space is filled with a resin composition so as to fill between the transformer and the rib,
The second housing space is filled with a resin composition so as to fill between the inductor element and the rib,
The first storage space and the second storage space are power conversion devices arranged along the flow direction of the refrigerant flow path.
The power conversion device according to claim 1,
The said rib is a power converter device which forms the groove | channel extended from the front-end | tip of the said rib to the approximate center of the said rib.