JP2017175748A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink structure that can effectively cool a pyrogenic semiconductor device and suppress increase in temperature of a control circuit.SOLUTION: A power conversion device 1, which converts DC power to single-phase or three-phase AC power to output the power, comprises: a housing storing an electric circuit for converting the power and having a bottom part 3E; an opening 17 provided at the bottom part 3E of the housing; and a heat sink 8 in which a pyrogenic semiconductor device IPM constituting the electric circuit is provided in an external plate 8A to be thermally conductive and a plurality of radiating fins 8B are arranged parallely at the opposite side of the external plate 8A to face the opening 17 so that air flows through between the radiation fins. In the heat sink 8, coating members 12 are provided on an upper part of the external plate 8A excluding a position where the semiconductor device IPM is arranged and on a lateral surface which does not constitute flow of air between the radiating fins 8B.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power converter, and more particularly to a heat sink attached to a power converter that converts DC power into single-phase or three-phase AC power and can be superimposed on the system. .

As a power converter (power conditioner) for indoor installation solar power generation system,
In order to obtain a product with good heat dissipation characteristics and the case surface does not reach a high temperature, the case is made of a metal case, and an orthogonal conversion circuit for converting the DC power generated by the solar cell into AC power is provided in the case. There is something to prepare. There is known a power conversion device including a heat module having a power module forming the orthogonal conversion circuit, for example, a semiconductor switching element which is a heat-generating electrical component (see Patent Document 1).

This Patent Document 1 describes an effect that cooling inside the casing of the power conversion device can be satisfactorily performed and that a burn or electric shock can be prevented when a person touches the casing of the power conversion device. That is, in this power conversion device, the heat module is used to perform heat dissipation by an air cooling method using a heat sink integrally attached to the power module, and the power module is brought into contact with the large surface area of a large number of fins attached to the heat sink. Can be cooled.

In the above power converter, heat can be radiated by using a heat sink. In the above-described power conversion device, slit-like ventilation holes are formed so that air flows through the inside and outside of the housing, and particularly between the fins of the heat sink. However, for example, when the air flow inside the housing is insufficient, there is a possibility that Joule heat generated from an element that generates a large amount of heat, such as a semiconductor switching element, may enter the housing. As a result, when the heat resistance limit of these circuit elements is exceeded, there is a possibility that the protection device for the element is activated or the element is destroyed.

FIG. 9 is an explanatory diagram showing a configuration of a heat sink attached to a conventional power conversion device for a solar power generation system.
In the conventional heat sink 8-1, a circuit element (electric part) having a large heat generation amount, for example, an IPM (intelligent power module) constituting the inverter unit (INV) can be thermally conducted on the outer surface plate 8A of the heat sink 8-1. It was attached. A plurality of heat radiating fins 8B were installed in parallel on the opposite surface side of the outer surface plate 8A of the heat sink 8-1. The heat sink 8-1 was installed on the bottom 3E (not shown) forming one side surface of the metal casing. Air (arrow) flowing in from an opening (not shown) provided in the lower wall 3B (back side of FIG. 9) of the metal casing flows between the heat radiating fins 8B to cool the IPM, Upper wall 3A
The metal casing is configured to flow out (arrow) from an opening (not shown) provided on the front surface side of FIG. Reference numeral 20 denotes a mounting screw.

To increase the output capacity of the inverter unit (IPM), use a large heat sink with high cooling capacity instead of the heat sink 1A, or use the heat sink 1A, but install a blower to force air between the radiating fins 4 There is a method such as distributing. However, each method has a problem that it cannot be installed in the metal casing because the apparatus is large, and a new problem such as a significant increase in cost occurs.

JP 2009-164351 A

An object of the present invention is to provide a heat sink or a heat sink capable of effectively cooling a heat-generating semiconductor element or electrical component and suppressing an increase in temperature in a housing without increasing the size and cost of the apparatus. It is providing the provided power converter.

The power conversion device of the present invention is a power conversion device that converts DC power into single-phase or three-phase AC power and outputs the power, and stores a housing that houses an electrical circuit that performs conversion, and a housing. An opening provided at the bottom of the body and an exothermic semiconductor element constituting an electric circuit are provided on the outer plate so as to be capable of conducting heat, and the outer plate faces the opening on the opposite side where the semiconductor element is not provided. A plurality of radiating fins provided in parallel with each other so that air flows between the radiating fins, and the heat sink has a portion of the outer surface plate excluding the portion where the semiconductor element is provided and air between the radiating fins. It is characterized in that a coating member is provided on the outer surface not in contact with the flow.

In the power converter of the present invention, the heat energy can be prevented from being dissipated from the surface of the outer surface plate and the outer surface of the heat sink into the housing by the covering member of the heat sink.

Further, the temperature of the heat radiating fins is increased, and the temperature difference between the temperature of the heat radiating fins and the temperature of the air flowing between the heat radiating fins is increased, and the heat radiating efficiency is improved.

FIG. 1 is an explanatory diagram showing a schematic electrical configuration of a power converter for a photovoltaic power generation system. FIG. 2 is a perspective explanatory view showing the internal configuration of the power conversion device according to one embodiment of the present invention. FIG. 3 is a perspective explanatory view showing a configuration in which a substrate, electrical components, a lid and the like are removed from the power conversion device of the present invention shown in FIG. FIG. 4 is an explanatory view showing an upper wall of the power conversion device of the present invention shown in FIGS. It is explanatory drawing which shows the lower wall of the power converter device of this invention shown to FIG. 5, FIG. It is explanatory drawing which shows the bottom part of the power converter device of this invention shown to FIG. 6, FIG. FIG. 7A is a cross-sectional explanatory view showing the configuration of the heat sink attached to the power conversion device according to one embodiment of the present invention, and FIG. 7B shows the heat sink attached to the power conversion device obliquely from above. FIG. FIG. 8 is an explanatory view showing an example of a method for attaching a covering member to a heat sink. FIG. 9 is an explanatory diagram showing a configuration of a heat sink attached to a conventional power conversion device for a solar power generation system.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing a schematic electrical configuration of a power conversion device for a photovoltaic power generation system.
DC power from a solar cell (PV) that is renewable energy is boosted by a booster (DC / DC converter) by a chopper operation. The DC power boosted by this booster (DC / DC converter) is a low-frequency (50 Hz or 60 Hz) single-phase or three-phase AC that can be substantially synchronized with the frequency of the commercial power system (GRID) by the inverter (INV). It is converted into electric power (DC / AC conversion). This AC power is superimposed on the commercial power system (GRID) as a sinusoidal AC power through a filter unit (LPF) that constitutes a low-pass filter circuit. These operations are appropriately controlled by the control circuit.

As shown in FIG. 2, the power converter device 1 which concerns on one embodiment of this invention converts the direct-current power obtained from a solar cell into the alternating current which can be superimposed on a commercial power system. The power converter 1 includes a booster (BS
), Inverter unit (INV), filter unit (LPF), etc. (in FIG.
An electrical component 6 constituting an electrical circuit (shown as NV) is accommodated in the metal housing 2.
The metal housing 2 is composed of a main body (housing) 3 and a lid 4, and the main body 3 has an upper wall 3A and a lower wall 3B.
, A bottomed casing composed of a right wall 3C, a left wall 3D, and a bottom 3E. The main body 3 constitutes a rectangular box having a front opening 3F. The lid 4 is detachably attached to the main body 3 with mounting screws so as to close the front opening 3F of the main body 3. The lid 4 can be freely opened and closed by a hinge on the right wall 3C or the left wall 3D of the main body 3. The lid 4 is not limited to the same metal as the metal housing 2 and may be configured to have a design that can achieve a design effect using a synthetic resin or the like.

In the metal housing 2 of the power conversion device 1 of the present invention, a substrate 7 on which an electrical component 6 is mounted is attached with a cylindrical spacer 18 so as to be arranged in parallel with the bottom 3E in the main body 3. In the booster (BS), inverter (INV), etc., the switching element generates heat and becomes high temperature. Therefore, in order to dissipate the generated heat, it is modularized in a form that is housed in one or a separate package. . This is called an IPM (intelligent power module) and corresponds to the electrical component 6 or the semiconductor element of the present invention.

In the IPM, a metal heat radiating surface such as aluminum on the back side of the IPM is attached to the outer surface plate 8A of the heat sink 8 having good heat conductivity such as aluminum with a fixing tool such as a screw in a heat conductive state. As shown in FIG. 2, the heat sink 8 has a plurality of heat radiating fins 8B extending in the vertical direction on the opposite surface side of the outer surface plate 8A where the IPM is not provided. The heat radiating fins 8B are attached to the bottom 3E with a fixing tool such as a screw 20 so as to face the opening 17 provided in the bottom 3E of the metal housing 2. It is also possible to use a metal housing that does not have the opening 17 in the bottom 3E.
The heat generated by the IPM is transmitted from the outer plate 8A to the heat radiating fins 8B, and air taken into the metal housing 2 from the ventilation holes 10 provided in the lower wall 3B of the metal housing 2 as shown in FIGS. When rising between the fins 8B, heat is radiated to the air and cooled. The air whose temperature has risen due to heat dissipation is discharged to the outside of the metal housing 2 through the ventilation holes 11 provided in the upper wall 3A (see FIG. 4) of the metal housing 2.
The wall surface (lower wall 3B and upper wall 3) of the metal housing 2 on the extension of the radiation fins 8B installed in parallel.
A) is provided with ventilation holes 10, 11 through which air passes. For example, the ventilation holes 10 and 11 are configured by a plurality of slits facing the air passage between the radiation fins 8B.

When the diode also generates a large amount of heat, it is modularized in a state of being housed in a package, and is attached to the front surface of the outer surface plate 8A of the heat sink 8 by a fixing tool such as a screw. If the diode is included in the IPM and packaged, it is easy to remove the heat sink 8 from the outer surface plate 8A.

In the metal housing 2, a reactor arrangement portion 9 is provided next to the heat sink 8 in the vertical direction. The direct current reactor L <b> 1 and the alternating current reactor L <b> 2 are attached to the reactor placement portion 9 via a support plate 24 by a fixing tool such as a screw.

Wirings such as a DC input wiring from the solar cell (PV), an AC output wiring connected to the commercial power system (GRID), and a ground wire are introduced from the wiring introduction opening 23 shown in FIGS. A wiring (not shown) is connected to a predetermined connection portion of the electric circuit, and the electric circuit of the power conversion device 1 of the present invention is constructed by this wiring.

FIG. 7A is a cross-sectional explanatory view showing a configuration of a heat sink attached to the power conversion device for the photovoltaic power generation system according to one embodiment of the present invention, and FIG. 7B is attached to the power conversion device. It is explanatory drawing which looked at the heat sink from diagonally upward.
The heat sink 8 attached to the power conversion device of the present invention has an IPM (intelligent power module) in which a switching element of an inverter unit (INV) is housed as a circuit element having a large calorific value. It is attached as possible.
A plurality of heat dissipating fins 8B are provided in parallel to the opposite surface side of the outer surface plate 8A.
The outer surface 13 that does not constitute the flow of air between the portion of the outer surface plate 8A excluding the portion 16 (corresponding to the projected area portion of the electrical component) where the IPM is mounted on the outer surface plate 8A so as to be able to conduct heat, 14, the covering member 12 is provided so as to be substantially free of gaps.
The heat radiating fins 8B of the heat sink 8 are provided so as to face the opening 17 provided in the bottom portion 3E that forms one side surface of the metal casing 2.
Reference numeral 20 denotes an attachment screw for attaching the heat sink 8 to the bottom 3E. The covering member provided on the outer surface plate 8A of the heat sink 8 constitutes the first heat insulating member, and the covering members provided on the outer surface sides 13 and 14 constitute the second heat insulating member. In the present embodiment, since the first covering member and the second covering member are integrally formed by punching from a single iron plate and then bending, they are simply referred to as the covering member 12 as described above.
In addition, the first covering member and the second covering member may be configured separately and integrally formed, or may be integrally formed by screwing to the heat sink 8, respectively. The configuration is not limited.

A covering member 12 is put on and attached to the outer surface plate 8A excluding a portion where the IPM is attached, with substantially no gap. The covering member 12 is made of a material (such as an iron plate or a resin material) having a heat insulating effect. Therefore, the heat transmitted from the exothermic IPM (electrical component) to the outer surface plate 8A can be prevented from being dissipated from the surface of the outer surface plate 8A of the heat sink 8 into the metal housing 2 by heat radiation, heat conduction, or the like. Control circuit board 7 housed inside
Temperature rise such as can be suppressed. Then, the heat from the surface of the outer plate 8A of the heat sink 8 is reflected by the covering member 12 toward the radiation fin 8B. Due to this reflection, the temperature of the radiating fin 8B rises, and the temperature difference between the temperature of the radiating fin 8B and the temperature of the air flowing between the radiating fins 8B increases. As the temperature difference increases, the amount of heat transferred from the radiating fins 8B to the air increases, so that the radiating effect of the radiating fins 8B is improved and the cooling efficiency of the IPM is improved.

Since the covering member 12 is similarly mounted on the outer surfaces 13 and 14 of the heat sink 8, heat energy is dissipated from the outer surfaces 13 and 14 into the metal housing 2 by heat radiation, heat conduction, or the like. Can be further suppressed. At the same time, it can contribute to the temperature rise of the heat radiating fins 8B, and the cooling efficiency can be further improved.
Further, the covering member 12 has at least a heat insulating effect, and has an outer surface plate 8A and an outer surface 13.
, 14 is provided in a state where there is substantially no gap, so that air heated in the gap when there is a gap circulates in the metal casing 2 and raises the temperature in the metal casing 2. Is suppressed. Since the surface temperature of the outer side surfaces 13 and 14 is away from the electrical components that are the heating elements, the temperature does not become as high as that of the outer surface plate 8A of the heat sink 8. Therefore, there may be a slight gap between the outer side surfaces 13 and 14 and the covering member 12. It is. At this time, the air heated in the gap is drawn by the air flowing between the radiating fins 8B, and the amount of air circulating in the metal housing 2 is reduced.

The material of the covering member 12 is not particularly limited as long as it has a heat shielding effect, and can suppress the dissipation of heat energy by heat radiation or heat conduction in the metal housing 2, and has high mechanical strength,
Any material that is durable and highly reliable can be used. Specific examples include ceramics, heat-resistant engineering plastics, metals or foams thereof, and compositions and laminates combining these.

FIG. 8 is an explanatory view showing an example of a method for attaching a covering member to a heat sink. Note that the IPM shown in FIG. 7 and the IPM shown in FIG. 8 are different in shape, but show an embodiment in which the shape of the IPM is not limited.
As shown in FIG. 8, a plurality of radiating fins 8B are installed in parallel on the opposite surface side of the outer surface plate 8A. The IPM is mounted on the outer surface plate 8A of the heat sink 8 so as to be able to conduct heat. A portion of the outer plate 8A excluding the portion 16 where the IPM is mounted and attached to the outer plate 8A so as to be capable of conducting heat and the outer surfaces 13 and 14 that do not constitute the air flow between the radiating fins 8B are substantially free of gaps. The covering member 12 is fixed in the absence. The covering member 12 is installed at a predetermined location of the heat sink 8 and fixed and mounted on the bottom portion 3E using screws 20.

INDUSTRIAL APPLICABILITY The present invention can be used for a power conversion device that suppresses a temperature rise in a housing that includes a heat sink and an electric circuit in the housing.

The description of the above embodiment is for explaining the present invention, and does not limit the invention described in the claims or reduce the scope thereof. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Metal housing 3 Main body 3A Upper wall 3B Lower wall 3C Right wall 3D Left wall 3E Bottom part 4 Cover body 6 Electrical component 7 Board | substrate 8, 8-1 Heat sink 8A Outer plate 8B Radiation fin 10, 11 Ventilation hole 12 Covering Members 13 and 14 Outer surface 16 Location where IPM is provided 17 Opening

Claims (4)

In a power converter that converts DC power into single-phase or three-phase AC power and outputs it,
A housing that houses the electrical circuit that performs the conversion and has a bottom portion, an opening provided in the bottom portion of the housing, and a heat-generating semiconductor element that constitutes the electrical circuit are provided on the outer plate so as to conduct heat. And a heat sink in a state where a plurality of radiating fins are provided in parallel so that air flows between the radiating fins facing the opening on the opposite surface side of the outer plate where the semiconductor element is not provided. Prepared,
The heat sink has a structure in which a covering member is provided on a portion of the outer plate excluding a portion where the semiconductor element is provided and an outer surface not in contact with the air flow between the radiating fins. apparatus. The power conversion device according to claim 1, wherein a ventilation hole through which the air passes is provided on a wall surface of the casing on an extension of the heat dissipating fins installed in parallel. The power conversion apparatus according to claim 1, wherein the covering member has at least a heat insulating effect and is provided in the outer plate with substantially no gap. A heat sink having a heat-generating electrical component on one side so that heat conduction is possible, and a plurality of heat radiation fins in parallel on the other side, and a heat sink that cools the electrical components with air flowing between the heat radiation fins In the power conversion device provided in the housing, and provided with a ventilation hole through which the air flowing between the radiating fins passes in the housing, one side of the heat sink is substantially excluded except at least a projected area portion of the electrical component. A first covering member that covers one side of the heat sink without a gap; a surface of the radiation fin that does not contact the air flowing between the radiation fins; A power conversion device comprising: a second covering member configured integrally with the covering member.

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