JP2017069356A - Electric power conversion device and railway vehicle equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a motor of an axial fan installed at a downstream side of a cooler.SOLUTION: An electric power conversion device includes: power semiconductor elements; a heat receiving member in which the power semiconductor elements are provided on one surface; and heat radiation members provided on the other surface of the heat receiving member. The electric power conversion device includes fans for flowing cooling air to areas between the heat radiation members. The fans are disposed at the cooling air downstream side of the heat radiation members. The electric power conversion device includes a duct which guides the cooling air from the heat radiation members to the fans. An opening part which communicates with outer air is provided at a part of the duct.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power conversion device and a railway vehicle equipped with the same.

  The power conversion device is for controlling an electric motor that drives a vehicle such as an electric railway vehicle, and is installed under the floor of the vehicle. Since the space under the floor of the vehicle is limited, it is desired to reduce the size of the power conversion device. In a conventional power conversion device, as in Patent Document 1, a semiconductor element is attached to a heat receiving member, a fin is attached to a heat pipe raised from the heat receiving member, and air is blown between the fins by a blower provided on the upstream side of the fin. A structure for cooling the power semiconductor element by doing so is known. Further, Patent Document 2 shows a structure in which a plurality of axial fans are provided on the upstream side of a fin to cool an electronic component attached to the fin.

JP 2014-17488 A Japanese Patent Laid-Open No. 2002-280779

  In the case of a system in which air is blown between fins by a blower provided on the upstream side of a heat radiating portion consisting of a heat pipe and a fin attached thereto, in order to obtain sufficient cooling performance, it is necessary to provide a large blower. There was a problem that a large space was required for the duct from the heat pipe to the heat-radiating part. Therefore, in order to reduce the blower and duct space, a structure in which small axial fans are dispersed and arranged on the upstream side as in Patent Document 2 is conceivable. When this structure is applied to a heat pipe heat dissipation unit consisting of fins and heat pipes, cooling air will not flow evenly if the distance between the fan and heat sink is reduced in order to reduce the size of the device. There was a problem that could not be obtained. Therefore, it is conceivable to provide a fan on the downstream side of the heat pipe heat dissipation unit. However, when the fan is installed downstream of the heat pipe heat radiating section, air heated by the heat generated by the semiconductor element hits the fan motor, and there is a problem that the reliability and life of the fan motor are reduced.

  An object of the present invention is to reduce the size of a cooling device, to maintain a good wind speed distribution to ensure cooling performance, and to improve the reliability of a fan motor.

  In order to achieve the above object, in the power conversion device of the present invention, a plurality of power semiconductor elements, a heat receiving member provided on one surface with the plurality of power semiconductor elements, and provided on the other surface of the heat receiving member are provided. A power conversion device comprising a plurality of heat dissipating members, comprising a plurality of fans for flowing cooling air between the heat dissipating members, disposing the plurality of fans downstream of the heat dissipating members and dissipating heat. A duct that guides cooling air from the member to the fan is provided, and an opening that communicates with the outside air is provided in a part of the duct.

  To improve the reliability of the fan motor by obtaining a good wind speed distribution and ensuring cooling performance, and by reducing the temperature of the air that has risen due to the heat generated by the power semiconductor elements, thereby suppressing the heating of the fan motor by the air. Can do.

It is a vertical sectional view of the direction perpendicular to the advancing direction of vehicles of the power converter in one embodiment of the present invention. It is sectional drawing of the horizontal direction of the power converter device in one Embodiment of this invention. It is a vertical sectional view of a direction perpendicular to a sleeper direction of a vehicle of a power converter in one embodiment of the present invention. It is a figure which shows the structure which mounted the power converter device of this invention in the rail vehicle. It is a vertical sectional view in a direction perpendicular to the traveling direction of the power converter according to another embodiment (second embodiment) of the present invention. It is sectional drawing of the horizontal direction of the power converter device in other embodiment (2nd Embodiment) of this invention. It is AA sectional drawing in FIG. 5 of the power converter device in other embodiment (2nd Embodiment) of this invention. It is a vertical sectional view of a direction perpendicular to the advancing direction of a power converter in still another embodiment (third embodiment) of the present invention. It is BB sectional drawing in FIG. 8 of the power converter device in further another embodiment (3rd Embodiment) of this invention. It is a table | surface which shows the calculation result of the air temperature of the fan motor vicinity in this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a configuration diagram when the power conversion device according to one embodiment (first embodiment) of the present invention is mounted on a railway vehicle. The power conversion device of the present invention is provided under the floor of a railway vehicle, etc., and controls the rotational speed of the electric motor mounted on the undercarriage and driving the wheels by changing the frequency of AC power supplied to the electric motor driving the vehicle. I do. In FIG. 4, the power conversion device 1000 is fixed in a state where it is suspended from the floor material of the vehicle body 1001, and is mounted in a space under the floor. In addition, a fan is provided, and the heat generated from the power semiconductor modules 7 and 8 of the power converter is released to the atmosphere by flowing wind in the left-right direction approximately perpendicular to the traveling direction of the vehicle.

  FIG. 1 shows a vertical sectional view in a direction perpendicular to the traveling direction of the vehicle of the power conversion device in the present embodiment, FIG. 2 shows a horizontal sectional view, and FIG. 3 shows a vertical sectional view in a direction perpendicular to the sleeper direction. . The arrows 40 in FIGS. 1 to 3 indicate the general direction of air flow by the fan. 1 to 3, power semiconductor modules 7 and 8 including a plurality of power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) are installed on one side of a heat receiving member 6 made of a metal such as an aluminum alloy. Yes. For example, when the power converter is a three-level circuit converter that converts AC power into DC power, 7 is an IGBT module, and 8 is a clamp diode module. Further, the plurality of power semiconductor modules 7 and 8 constitute a power conversion device. Hereinafter, these power semiconductor modules are also referred to as power semiconductor elements. The power semiconductor elements 7 and 8 are fixed by a heat receiving member 6 and screws (not shown) through a member (not shown) such as grease. Cases 21 and 22 for sealing the power semiconductor elements 7 and 8 on the inner side are provided on the power semiconductor elements 7 and 8 side of the heat receiving member 6, and electrical components 25 such as filter capacitors and IGBT drive circuits are provided in the case. It is installed together with the power semiconductor elements 7 and 8. On the opposite side of the power semiconductor element installation surface of the heat receiving member 6, heat receiving portions of the U-shaped heat pipes 3 and 4 are embedded, and the heat receiving portions are thermally connected to the heat receiving member 6 by soldering or the like. A plurality of fins 5 made of a metal such as aluminum or copper are connected to the heat radiating portions of the U-shaped heat pipes 3 and 4 by press fitting or the like.

  When a current flows through the power semiconductor element installed in the heat receiving member 6, the power semiconductor element generates heat, and the heat is transmitted to the evaporation portion 301 of the heat pipe 3 embedded in the heat receiving member 6. A working fluid such as pure water is sealed in the heat pipe, and the working fluid evaporates in the evaporating unit 301 and takes heat of the power semiconductor element. The evaporated working fluid moves to the heat radiating section 302 of the heat pipe, condenses in the heat radiating section 302 and radiates heat while returning to the liquid. The radiated heat is transmitted to the air directly from the heat pipe heat radiating portion 302 or via the fins 5. The operation of the liquid condensed in the heat pipe heat radiating unit 302 returning to the evaporating unit 301 and evaporating is continuously performed. Install heat pipes with long and short heat sinks. The heat radiation part of the heat pipe 3 in FIG. 1 is longer than the heat radiation part of the heat pipe 4, and the heat radiation part of the heat pipe 4 is shorter than the heat radiation part of the heat pipe 3. The heat pipe 4 having a short heat radiating portion has a cooling performance of the power semiconductor element by operating the heat pipe by melting quickly after starting when the working fluid in the heat pipe is frozen when the outside air is at a low temperature. Plays the role of maintaining.

  The fins 5 and the heat pipes 3 and 4 are accommodated in the duct 9. The ceiling surface of the duct 9 is supported by the support column 32. When the axial fan 1 is driven, outside air enters the inlet duct 10 from the suction grille 23, passes through the filter 24, and reaches the radiating fins 5. The suction grille 23 and the filter 24 prevent foreign matters from entering the fin portion and clogging the fins and destroying the fins and the heat pipe. The air guided between the heat radiating fins 5 takes heat from the power semiconductor elements 7 and 8 through the heat pipes 3 and 4 and the fins 5 and the temperature rises. A fan motor 2 for driving the fan is attached to the fan 1, and if high-temperature air hits the fan 1, the reliability of the fan motor is lowered and the life may be shortened. Therefore, openings 12 and 16 are provided above and below the outlet duct 11 between the outlet of the fin 5 and the fan 1. From these openings, outside air is introduced from the outside of the duct, and the introduced outside air is mixed with the heated air flowing out between the fins 5, and the temperature of the heated air is lowered. Therefore, since the heated high-temperature air does not directly hit the fan motor 2, the reliability of the fan motor 2 can be improved. Covers 13 and 14 for preventing raindrops and the like from directly entering are provided above the opening 12. Similarly, covers 17 and 18 are provided below the opening 16. The openings 12 and 16 are provided with a wire mesh or the like 20 to prevent intrusion of foreign matter. Therefore, the air taken in from the opening 15 flows into the outlet duct 11 via the opening 12 provided with the wire mesh 20. Similarly, the air taken in from the opening 19 flows into the outlet duct 11 through the opening 16 provided with the wire mesh 20.

  The calculation results of the air temperature in the vicinity of the fan motor with and without the openings 12 and 16 of the outlet duct 11 are shown in the table of FIG. According to the table, when the fan is provided at the outlet and the opening is not provided at the outlet duct (left column), the temperature rise from the outside air temperature of the inlet of the fan is 28.1K. On the other hand, when the fan is provided at the outlet and the opening is provided in the outlet duct (center row), the temperature rise from the outside air temperature at the inlet of the fan is 18.5K, so the openings 12 and 16 are provided. Thus, it can be seen that the air temperature at the fan inlet around the fan motor 2 can be lowered by about 10 ° C.

  Further, when the openings 12 and 16 are provided (center row), the air volume 40.8 of the heat radiating section is slightly smaller than the left row 41.8 and the right row 41.5 where no opening is provided in the outlet duct. As a result, the temperature of the semiconductor element mounting surface of the heat receiving member 6 is higher than that in the case where the fan is provided at the outlet and the opening is not provided in the outlet duct (left column). It is relatively small with respect to the reduction rate of the air temperature of the part. As shown in the right column of the table, when a fan is installed at the inlet of the duct upstream of the heat radiating section, the cooling air is biased, so the temperature rise on the module mounting surface is larger than the air volume of the heat radiating section. It can be seen that the cooling performance of the power semiconductor element is degraded.

  As described above, according to the present embodiment, the air temperature around the fan motor can be lowered while ensuring the cooling performance for the power semiconductor element, so that the reliability and life of the fan motor can be improved.

  FIG. 5 is a vertical sectional view of a power converter perpendicular to the traveling direction of a railway vehicle in another embodiment (second embodiment) of the present invention, FIG. 6 is a horizontal sectional view, and FIG. -A shows a cross-sectional view. In the present embodiment, in addition to the openings 12 and 16 provided on the upper and lower surfaces of the outlet duct 11 as in the first embodiment, the openings 26 are also provided on the side surfaces of the outlet duct 11. Covers 28, 29, 30, and 31 are provided to prevent the traveling wind from directly hitting the opening 26. In addition, in order to prevent foreign matter from entering from the opening 26, the opening 26 is provided with a wire net 27 or the like. By providing the opening 26 on the side surface in addition to the upper and lower sides of the outlet duct, the cooling effect of the fan motor 2 can be enhanced. In this embodiment, the flow path width of the cooling air is narrower than in the first embodiment, and the number of fans installed is small. As described above, when the number of fans is small, the openings may be provided only on the side surfaces without providing the openings above and below the outlet duct 11. Further, in the present embodiment, an example in which a heat pipe is installed so that the flow direction of the cooling air and the longitudinal direction of the U-shaped heat pipe coincide with each other in a two-level inverter in which the heat generation of each power semiconductor element is substantially equal. ing. The structures not mentioned in the present embodiment are the same as those in the first embodiment.

  As described above, according to the present embodiment, the cooling effect of the fan motor 2 can be enhanced by providing the opening 26 on the side surface in addition to the upper and lower sides of the outlet duct.

  FIG. 8 shows a vertical cross-sectional view of a power conversion device perpendicular to the traveling direction of a railway vehicle in still another embodiment (third embodiment) of the present invention, and FIG. 9 shows a cross-sectional view along BB in FIG. 8 and 9, the power semiconductor elements 7 and 8 are attached to the fin base 50 of the heat sink, and a plurality of fins 51 are connected to the fin base 50. As the material of the fin base 50 and the fin 51, aluminum or copper is used. The structures not mentioned in the present embodiment are the same as those in the first embodiment.

  As in the first embodiment, even in a structure that is cooled by a heat sink using fins, the air temperature around the fan motor can be lowered while ensuring the cooling performance of the power semiconductor element, as in the first embodiment. The reliability and life of the fan motor can be improved.

  Moreover, in the structure cooled by the heat sink using a fin like this embodiment, it is also possible to provide an opening part on the upper and lower sides and right and left of an exit duct like 2nd Embodiment.

DESCRIPTION OF SYMBOLS 1 ... Axial fan 2 ... Fan motor 3, 4 ... Heat pipe 5 ... Fin 6 ... Heat receiving member 7, 8 ... Power semiconductor element 9, 10, 11 ... Duct 12, 16 ... Duct opening 13, 14, 15, 17 , 18, 19 ... opening cover 20 ... wire mesh

Claims (6)

A plurality of power semiconductor elements;
A heat receiving member provided on one surface with the plurality of power semiconductor elements;
A plurality of heat dissipating members provided on the other surface of the heat receiving member;
A plurality of fans for flowing cooling air between the plurality of heat radiating members; and disposing the plurality of fans on the cooling air downstream side of the heat radiating members;
A duct for guiding the cooling air from the heat dissipation member to the fan;
An electric power converter comprising an opening communicating with outside air in a part of the duct. The power conversion device according to claim 1,
An opening communicating with outside air is provided in the duct between the heat dissipation member and the fan.
The power converter characterized by the above-mentioned. In the power converter device according to claim 1 or 2,
The power converter according to claim 1, wherein the opening is provided on at least one of an upper surface, a lower surface, and a side surface of the duct.   The power converter according to any one of claims 1 to 3, wherein a cover is provided in the opening.   The power converter according to any one of claims 1 to 4, wherein the opening is covered with a net-like member.   A railway vehicle in which the power conversion device according to any one of claims 1 to 5 is mounted under a floor.

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