JP5941741B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device for an electric railway vehicle that includes a current switching circuit for controlling an electric motor.

  An electric railway vehicle is equipped with a power converter such as a converter or an inverter in order to control an electric motor that drives the vehicle. These power conversion devices perform power conversion by switching at high frequency using semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) and GTOs (Gate Turn Off Thyristors). In order to reduce the noise generated during the switching operation, a three-level switching circuit that outputs currents of three levels of positive, negative, and neutral is often used.

  In a semiconductor element, heat is generated during energization and switching. If the semiconductor element becomes hot due to this heat, there is a concern that conversion efficiency may be reduced or element destruction may occur. Need to cool down. Since the power converter is mounted mainly under the vehicle floor where the mounting space is limited, a cooler is installed to efficiently cool a plurality of semiconductor elements with a small device configuration.

  When supplying cooling air to the cooler, the cooling air receives heat from the semiconductor elements installed on the windward side, and the temperature rises toward the leeward side. Accordingly, the temperature of the semiconductor element on the leeward side tends to increase.

  On the other hand, in the three-level switching circuit, the heat generation amounts of a plurality of semiconductor elements constituting the main circuit are different for each semiconductor element. Furthermore, there is a characteristic that the distribution of the heat generation amount for each semiconductor element changes during power running operation and regenerative operation, and the temperature of the semiconductor element having a high heat generation amount tends to increase.

  From these backgrounds, in order to efficiently cool the three-level switching circuit, in the plurality of semiconductor elements constituting the main circuit, the influence of the heat generation distribution of the semiconductor element changes depending on the operating conditions, and the influence of the temperature rise of the cooling air Need to be leveled.

  A heat pipe is often used as a component of the cooler. The heat pipe is a device that efficiently transports heat by a cycle in which a refrigerant is sealed inside, the refrigerant is boiled in the heat receiving part, condensed in the heat radiating part, and returned to the heat receiving part. As a power converter provided with a cooler using this heat pipe, the one shown in Patent Document 1 is known. The cooler described in FIGS. 1 to 6 of Patent Document 1 includes a heat receiving block, fins, a U-shaped heat pipe, and an L-shaped heat pipe. The heat receiving portions of the plurality of heat pipes are installed in the heat receiving block in a direction along the flow of the cooling air. The heat radiating portions of the plurality of heat pipes are erected in the vertical direction from the heat receiving block, and the plurality of fins are joined. The heat radiating part and the fin of the heat pipe are installed in the ventilation path and radiate heat by the cooling air supplied from the blower. In the heat receiving block, a plurality of semiconductor element groups constituting a circuit for one phase are installed in a direction orthogonal to the flow of the cooling air.

  On the other hand, as shown in Patent Document 2, a power conversion device including a cooler using a heat pipe is also known. The cooler includes a heat receiving block, fins, and a straight pipe heat pipe. The fins are installed along the vehicle traveling direction and radiate heat by the vehicle traveling wind. The straight pipe heat pipe is embedded in the heat receiving block along the vehicle traveling direction. In the heat receiving block, a semiconductor element group constituting one phase of the three-level switching circuit is linearly arranged in the vehicle traveling direction, that is, in the direction along the flow of the cooling air, and a plurality of linearly extending in the vehicle sleeper direction. A set is arranged.

JP 2011-233562 A JP 2007-104784 A

  In the configuration described in Patent Literature 1, heat transfer from the leeward side to the windward side is promoted by installing the heat receiving portions of the plurality of heat pipes in a direction along the flow of the cooling wind, and the leeward and windward temperatures are increased. While leveling, the longitudinal direction of the heat pipe heat receiving part is different from the direction in which the semiconductor element group constituting the circuit for one phase is installed, so the effect of temperature rise due to the distribution of heat generation for each semiconductor element There is a problem that leveling cannot be performed. In addition, when the cooling air temperature is below the freezing point of the refrigerant inside the heat pipe, the tip temperature of the heat pipe heat radiating part becomes below the freezing point of the refrigerant, and the refrigerant enclosed inside freezes at the tip of the heat radiating part and goes to the heat receiving part. There is a concern that dryout may occur, because the refrigerant in the heat receiving portion is not recirculated, the refrigerant in the heat receiving portion is depleted, and the heat transport capability is significantly reduced.

  Further, in the configuration described in Patent Document 2, heat transfer from the leeward side to the windward side and a large amount of heat generation are caused by inserting a straight pipe heat pipe in the vehicle traveling direction, that is, the cooling air flow direction. Heat transfer from the semiconductor element to the small semiconductor element is promoted, and the temperature is leveled. However, the heat transfer from the heat receiving block to the heat radiating part is only due to the heat conduction inside the heat radiating part, and there is a problem that the heat radiating efficiency is poor compared to the heat transport by the heat pipe.

  The present invention relates to a power conversion device capable of efficiently cooling by leveling the influence of the heat generation distribution of the semiconductor element depending on the operating conditions and the influence of the temperature rise of the cooling air on a plurality of semiconductor elements constituting the three-level main circuit. The purpose is to provide. Furthermore, it aims at suppressing freezing of a refrigerant | coolant even if cooling air temperature is below the freezing point of the refrigerant | coolant inside a heat pipe.

A power conversion device according to a first aspect of the present invention that solves the above-described problem is a plurality of semiconductor elements constituting a power conversion circuit, a housing in which the power conversion circuit is mounted, and heat from the semiconductor elements to the outside air A power converter comprising: a cooler; a blower that supplies cooling air to the cooler; and an air passage that includes the cooler and allows the cooling air to flow therethrough. The U-shaped heat pipe includes a plurality of fins, and the U-shaped heat pipe includes a first heat pipe and a second heat pipe, and the second heat pipe radiates heat more than the first heat pipe. The portion is short, the plurality of semiconductor elements are juxtaposed on one side surface of the heat receiving block, and the heat receiving portion of the plurality of U-shaped heat pipes is along the flow of the cooling air on the opposite surface of the heat receiving block In The heat dissipating parts of the plurality of U-shaped heat pipes are erected so as to rise in the vertical direction, and the plurality of fins are joined to the heat dissipating part of the U-shaped heat pipes and installed in the ventilation path. The plurality of semiconductor elements include a plurality of first IGBT modules that generate a large amount of heat during regenerative operation, a plurality of second IGBT modules that generate a large amount of heat during powering operation, and a small amount of heat compared to the IGBT module. It is composed of a plurality of clamp diode modules, and is arranged so that semiconductor elements having the same calorific value are arranged in a direction orthogonal to the flow of cooling air, and the clamp diode is connected to the first IGBT module with respect to the flow direction of cooling air. wherein said first 2IGBT disposed between the modules are arranged on the projection plane of each clamping diode module The second heat pipe is configured such that the area of the heat receiving portion of the two heat pipes is smaller than the area of the heat receiving portion of the second heat pipe disposed on the projection surface of each of the first IGBT module and each second IGBT module. The heat receiving part is arranged .

  In the power converter according to a second aspect of the invention, the heat receiving block includes a U-shaped heat pipe in which the heat receiving portion of the heat pipe is installed on the projection surfaces of both the first IGBT module and the clamp diode module, and the second IGBT module. A plurality of U-shaped heat pipes installed on the projection surfaces of both the clamp diode and the clamp diode, and a plurality of U-shaped heat pipes installed on the projection surface of a single semiconductor element, To do.

  The power conversion device according to a third aspect of the invention is characterized in that the plurality of U-shaped heat pipes are installed such that the respective heat radiating portions are staggered.

  In a power converter according to a fourth aspect of the present invention, in the cooler, an L-shaped heat pipe is installed at a position on the most windward side with respect to the cooling wind, or a position on the most leeward side, or on both the windward and leeward sides. It is characterized by that.

  In a power converter according to a fifth aspect of the invention, the plurality of fins are divided with respect to the flow direction of the cooling air, and the pitch of the fins on the windward side of the cooling air is made larger than that on the leeward side to reduce the number of fins. It is characterized by that.

  The power converter according to a sixth aspect of the present invention is characterized in that a plurality of air conditioning plates are installed on the windward side of the fin in the ventilation path.

  According to a seventh aspect of the present invention, there is provided the power conversion device according to the present invention, wherein the flow path is orthogonal to the flow of the cooling air between the fin joined to the most distal end side of the heat pipe heat dissipating part and the wall constituting the ventilation path. A flat plate is installed in the direction. Furthermore, it is more preferable that the distance between the flat plate and the fin joined to the tip side is shorter than the distance between the fin joined to the tip side and the tip of the heat pipe heat radiation part.

  The power converter according to an eighth aspect of the invention is characterized in that the plurality of flat plates are beams for maintaining the strength in the ventilation path.

  A power conversion device according to a ninth aspect includes a plurality of semiconductor elements constituting a power conversion circuit, and a cooler that dissipates heat from the semiconductor elements to the outside air, the cooler including a heat receiving block, a plurality of heat pipes, The plurality of semiconductor elements are arranged in parallel on one side surface of the heat receiving block, and a part of the plurality of heat pipes are embedded on the opposite surface of the heat receiving block. The heat pipe includes a heat receiving portion embedded in the heat receiving block and a heat radiating portion protruding from the heat receiving block, and a plurality of fins are joined to the heat radiating portion, and the plurality of heat pipes are: A first heat pipe in which a plurality of fins are joined from the root to the tip of the heat radiating portion, and a plurality of fins are joined at least to the base side of the heat radiating portion and are smaller than the first heat pipe. Wherein the fins are and a second heat pipe to be joined.

  The power conversion device according to a tenth aspect of the invention is characterized in that the second heat pipe has a shorter heat radiating portion than the first heat pipe.

  A drive system according to an eleventh aspect of the invention is a railway vehicle drive system equipped with the power conversion device according to any of the first to tenth aspects of the invention described above.

  According to the first invention, the heat receiving portion of the U-shaped heat pipe is installed in a direction along the flow of the cooling air, thereby promoting heat transfer from the leeward side to the windward side with respect to the cooling air. Therefore, the temperature rise of the leeward semiconductor element can be suppressed. In addition, the U-shaped heat pipe radiating part is erected so as to rise in the vertical direction, and a plurality of fins are joined to the radiating part and installed in the ventilation path, so that heat transfer from the heat receiving block to the fins is achieved. Since it can be promoted, fin efficiency is improved. Further, by installing the semiconductor elements having the same calorific value in a direction orthogonal to the flow of cooling air, the temperature in the direction orthogonal to the flow of cooling air can be made uniform. In addition, by installing a clamp diode module with a small amount of heat generation between IGBT modules with a large amount of heat generation, heat can be distributed within the heat receiving block, so that the temperature of each semiconductor element can be leveled. it can.

  According to the second invention, the heat receiving portion of the U-shaped heat pipe is installed on the projection surfaces of both the first IGBT module that generates a large amount of heat during regeneration and the clamp diode module that generates less heat than the IGBT module. Thus, heat transfer from the first IGBT module to the clamp diode can be promoted during regeneration, and both temperatures can be leveled. Also, heat transfer from the second IGBT module to the clamp diode side during power running is possible by installing heat-receiving parts of U-shaped heat pipes on the projection surfaces of both the second IGBT module and clamp diode module that generate a large amount of heat during power running. Can be promoted, and both temperatures can be leveled. Moreover, by installing the heat receiving part of the U-shaped heat pipe on the projection surface of a single semiconductor element, this heat pipe has a role of transporting only the heat of the semiconductor element to the fins. By mixing heat pipes, local temperature rise can be suppressed and the temperature of each semiconductor element can be leveled.

  According to the third invention, the heat sinks of the U-shaped heat pipe are installed in a staggered manner, so that the joints between the fins and the heat pipe are evenly arranged and heat is transported evenly to the fins. Efficiency is improved. In addition, the cross-sectional area of the flow path between the fins and between the heat pipes is larger than when the heat-radiating part of the heat pipe is arranged in a square shape, so the ventilation resistance between the fins is reduced and cooling is performed using a blower. In doing so, a large amount of cooling air can be supplied, so that the semiconductor element can be efficiently cooled.

  According to the fourth invention, by installing the L-shaped heat pipe so that the heat dissipating part is located at the most leeward position, the most leeward position, or both the leeward and leeward sides, The heat receiving portion of the heat pipe can be installed outside the projection surface. Thereby, even if a semiconductor element is installed outside the projection surface of the fin, heat can be efficiently transported to the fin by the L-shaped heat pipe, and thus the fin can be reduced in size.

  According to the fifth invention, the plurality of fins are divided in the flow direction of the cooling air, and the pitch of the fins on the windward side where the air temperature is low is made larger than that on the leeward side where the air temperature is high, thereby reducing the number of fins. As a result, the airflow resistance between the fins can be reduced, and a large amount of cooling air can be supplied when cooling using the blower, so that the semiconductor element can be efficiently cooled and the cooler can be reduced in weight. be able to.

  According to the sixth invention, in the ventilation path, by installing a plurality of air conditioning plates on the windward side of the fin, the air velocity of the cooling air supplied from the blower to the fin is uniform in the direction orthogonal to the flow of the cooling air. Therefore, even when the width of the fin is larger than the width of the blower outlet, the semiconductor element can be efficiently cooled.

  According to the seventh invention, in the ventilation path, a plurality of flat plates are arranged in a direction orthogonal to the flow of the cooling air between the fins joined to the most distal end side of the heat pipe heat dissipating part and the wall constituting the ventilation path. Since the cooling air can be prevented from leaking from between the fins, the semiconductor element can be efficiently cooled. Furthermore, the cooling that leaks from between the fins is achieved by making the distance between the flat plate and the fin joined to the tip side of the heat pipe radiating part shorter than the distance between the fin joined to the tip side and the tip of the heat pipe radiating part. The amount of wind can be further reduced.

  According to the eighth aspect of the invention, the flat plate that prevents the cooling air from leaking also serves as a beam for maintaining the strength in the ventilation path. Thereby, since the number of parts can be reduced, cost can be reduced and assemblability can be improved.

  According to the ninth invention, among the plurality of heat pipes, one in which a plurality of fins are joined from the base to the tip of the heat radiating part and one in which a plurality of fins are joined to the base side of the heat radiating part. Are installed together. The heat pipe heat dissipating part in which a plurality of fins are joined to the base side of the heat dissipating part has a smaller number of fins to be joined than the heat pipe heat dissipating part in which a plurality of fins are joined from the root to the tip. Since the resistance increases and the temperature difference with the cooling air also increases, the semiconductor element can be efficiently cooled without the refrigerant freezing even when the cooling air temperature is below the freezing point of the refrigerant inside the heat pipe. In addition, when the cooler is configured with only a heat pipe in which a plurality of fins are joined to the base side of the heat radiating part, the heat radiation area is smaller than that in which a plurality of fins are joined from the root to the tip. When the temperature is above the freezing point of the refrigerant, there is a concern that the cooling performance will deteriorate, but by mixing both, the cooling performance can be achieved both when the cooling air temperature is below the freezing point of the refrigerant and above the freezing point. can do.

  According to the tenth invention, the heat pipe that joins the plurality of fins only on the base side of the heat radiating part has the heat radiating part rather than the one that joins the plurality of fins at regular intervals from the base to the tip. It is shortened. When dryout occurs due to freezing of the refrigerant, the temperature of the semiconductor element rises remarkably and the temperature of the heat pipe heat sink increases accordingly, but by shortening the heat sink, the root of the heat sink is increased. Therefore, even if dryout occurs, the frozen refrigerant can be melted and the semiconductor element can be efficiently cooled.

  According to the eleventh aspect, it is possible to provide a drive system for a railway vehicle that can efficiently cool a semiconductor element, is small in size, light in weight, low in cost, and has good assemblability.

The perspective view showing the whole power converter device composition of a 1st embodiment of the present invention. The top view of FIG. AA sectional drawing of FIG. The circuit diagram for the converter main circuit two phases in the power converter device of 1st Embodiment of this invention. The bottom view of the cooler carried in the power converter of a 1st embodiment of the present invention. The top view of the cooler carried in the power converter of a 1st embodiment of the present invention. BB sectional drawing of FIG. CC sectional drawing of FIG. DD sectional drawing of FIG. EE sectional drawing of FIG. FF sectional drawing of FIG. G enlarged view of FIG. H enlarged view of FIG. I enlarged view of FIG. Sectional drawing seen from the vehicle running direction showing the state which mounted the power converter device of 1st Embodiment of this invention under the floor of the passenger room of a rail vehicle. The table | surface which shows the heat loss ratio of each semiconductor element at the time of power running operation and regenerative operation. The figure showing the temperature calculation result at the time of the power running operation of the cooler of patent document 1. FIG. The figure showing the temperature calculation result at the time of the regenerative operation of the cooler of patent document 1. FIG. The figure showing the temperature calculation result at the time of the power running operation of the cooler mounted in the power converter device of 1st Embodiment of this invention. The figure showing the temperature calculation result at the time of the regenerative operation of the cooler mounted in the power converter device of 1st Embodiment of this invention. H enlarged view of FIG. The top view showing arrangement | positioning of the heat pipe of the cooler mounted in the power converter device of 2nd Embodiment of this invention. Sectional drawing showing the structure of the fin of the cooler mounted in the power converter device of 3rd Embodiment of this invention. The top view showing the structure of the air conditioning board mounted in the power converter device of 4th Embodiment of this invention.

  Hereinafter, it will be described in detail with reference to the drawings.

  Hereinafter, the power converter of this invention is demonstrated in detail with reference to drawings. FIG. 1 is a perspective view showing the overall configuration of the power conversion apparatus according to the first embodiment of the present invention, FIG. 2 is a top view of FIG. 1, and FIG. 3 is a cross-sectional view taken along line AA of FIG.

  The power conversion apparatus 1000 includes a side plate 1110, a top plate 1120, and a bottom plate 1130. Further, sleeper direction beams 1161 and 1162 and traveling direction beams 1163 and 1164 are installed on the upper surface of the power conversion device 1000, and the strength of the power conversion device 1000 is maintained. A ventilation path bottom plate 1140 is installed between the top plate 1120 and the bottom plate 1130. A space surrounded by the side plate 1110, the top plate 1120, and the ventilation path bottom plate 1140 is the ventilation path 1150, and the cooling air 1210 flows through the ventilation path 1150. Further, a space surrounded by the side plate 1110, the bottom plate 1130, and the ventilation path bottom plate 1140 is a circuit component mounting space 1600, and includes a semiconductor element group 1500, a filter capacitor 1610, and a semiconductor constituting the main circuit of the power converter 1000. A gate driver 1620 for controlling switching of the element group 1500 is installed.

  The semiconductor element group 1500 in the circuit component mounting space 1600 is installed on the lower surface of the cooler 1700. The cooler 1700 is connected to the lower surface side of the ventilation path bottom plate 1140 with airtightness so that the cooling air 1210 does not flow into the circuit component mounting space 1600.

  On the other hand, the upper surface side of the cooler 1700 is installed in the ventilation path 1150. The cooler 1700, the side plate 1110, and the top plate 1120 are not in close contact with each other, and a gap is opened. In order to reduce the amount of the cooling air 1210 passing through the gap, a wind leak prevention is provided in the space around the cooler 1700. A plurality of plates 1191, 1192, 1193, 1194 are installed in the flow direction of the cooling air. The direction in which the respective wind leakage prevention plates 1191, 1192, 1193, and 1194 are installed is a direction orthogonal to the flow of the cooling air 1210. Further, the wind leak prevention plate 1194 is installed so as to protrude downward from the traveling direction beam 1163.

  The blower 1200 is installed such that the center of the outlet is approximately on the center line of the cooler 1700. The cooling air 1210 is sucked into the power conversion apparatus 1000 through the filter 1300 and is supplied from the outlet of the blower 1200 toward the cooler 1700. Here, since the width of the blower outlet of the blower 1200 is narrower than the width of the cooler 1700, the ventilation path 1150 is expanded to the same width as the cooler 1700 by the ventilation path expansion plates 1171 and 1172, and the ventilation path expansion plate. Reference numerals 1171 and 1172 are connected to a wind leakage prevention plate 1191 installed on the most windward side. In order to uniformly supply the cooling air 1210 to the cooler 1700, two air conditioning plates 1181 and 1182 are installed between the blower outlet of the blower 1200 and the cooler 1700. The two air conditioning plates 1181 and 1182 are installed so as to be symmetrical with respect to the center of the blower outlet of the blower 1200, and are installed so that the gap on the leeward side is wider than the windward side. The cooling air 1210 that has passed through the air conditioning plates 1181 and 1182 and the cooler 1700 is exhausted from the grill 1400 to the outside.

  Next, the main circuit configuration of the power converter and the cooler that cools the semiconductor element group will be described in detail. FIG. 4 is a circuit diagram showing a part of the main circuit in the power conversion device according to the first embodiment of the present invention. FIG. 4 shows the two phases of the converter main circuit. The first embodiment of the present invention is equipped with a circuit in which two main circuits are connected in parallel. One phase of the converter main circuit is configured by connecting two outer IGBT modules 1510, two inner IGBT modules 1520, and two clamp diode modules 1530 each. Specifically, the four IGBT modules are connected in series in the order of the outer IGBT module 1510, the inner IGBT module 1520, the inner IGBT module 1520, and the outer IGBT module 1510. The four IGBT modules connected in series are connected in series to each other. The two filter capacitors 1610 are connected in parallel. Further, the connection points of the outer IGBT module 1510 and the inner IGBT module 1520 are connected via two clamp diode modules 1530, and the connection points of the two clamp diode modules 1530 and the connection points of the two filter capacitors 1610 are connected. The

  FIG. 5 shows a bottom view of the cooler and the semiconductor element group. The heat receiving block 1710, which is one of the components of the cooler 1700, is constituted by two aluminum thick plates, and each is connected by a connecting bolt 1712. In addition, a plurality of screw holes 1711 for fixing the cooler are formed at the end of the heat receiving block 1710 and connected to the ventilation path bottom plate 1140 shown in FIG. A semiconductor element group 1500 is arranged in parallel on the lower surface of the heat receiving block 1710. In the semiconductor element group 1500, each module constituting one phase along the flow direction of the cooling air 1210 includes an outer IGBT module 1510, a clamp diode module 1530, an inner IGBT module 1520, a clamp diode module 1530, and an outer IGBT module 1510. A plurality of semiconductor element groups 1500 for a total of four phases are arranged in a direction orthogonal to the cooling air 1210.

  6 is a top view of the cooler, FIG. 7 is a sectional view taken along line BB in FIG. 6, FIG. 8 is a sectional view taken along line CC in FIG. 6, FIG. 9 is a sectional view taken along line DD in FIG. 10 is a cross-sectional view taken along line EE in FIG. 6, and FIG. 11 is a cross-sectional view taken along line FF in FIG. 6. The dotted line shown above the center line in FIG. 6 shows the heat receiving portion of the heat pipe, and the dotted line shown below the center line shows a projection view of the semiconductor element group 1500 installed on the lower surface. ing. A plurality of grooves are formed on the upper surface side of the heat receiving block 1710 along the flow direction of the cooling air 1210, and heat receiving portions 1721 of a plurality of U-shaped heat pipes 1720 and a plurality of L-shaped heat pipes are formed in the grooves. A heat receiving portion 1731 of 1730 is installed along the flow direction of the cooling air 1210, and a brazing material 1740 such as solder is poured into the groove and hardened, whereby the heat receiving block 1710, the U-shaped heat pipe 1720, and the L-shaped heat pipe 1730 is joined. Further, the heat radiating portion 1722 of the U-shaped heat pipe 1720 and the heat radiating portion 1732 of the L-shaped heat pipe 1730 are erected in the vertical direction, and each of the heat radiating portions 1722 and 1732 is provided with a through hole corresponding to the position of the heat radiating portion. A plurality of fins 1750 are press-fitted.

  On the other hand, a sealing material 1760 is installed over the entire circumference between the region where the heat pipe is installed on the upper surface of the heat receiving block 1710 and the screw hole 1711 for fixing the cooler. As a result, the ventilation path bottom plate 1140 and the cooler 1700 are connected in an airtight manner to prevent the cooling air from coming into direct contact with the semiconductor module.

  The arrangement of the heat pipe will be described. In the BB cross section shown in FIG. 7, the heat pipes are arranged in the order of the L-shaped heat pipe 1730, the five U-shaped heat pipes 1720, and the L-shaped heat pipe 1730 along the flow direction of the cooling air 1210. Installed. Here, the L-shaped heat pipes 1730 disposed at the upstream and downstream ends of the cooling air are installed in a direction in which the heat radiating portion is on the inside. In the CC cross section shown in FIG. 8, a short heat pipe 1780 having a heat radiating portion shorter than the U-shaped heat pipe 1720 shown in FIG. 7 is installed, and the short heat pipe is arranged along the flow direction of the cooling air 1210. 1780, U-shaped heat pipe 1720, short heat pipe 1780, short heat pipe 1780, U-shaped heat pipe 1720, short heat pipe 1780 are installed in this order. In the DD cross section shown in FIG. 9, an L-shaped heat pipe 1730, a short heat pipe 1780, a U-shaped heat pipe 1720, a short heat pipe 1780, a U-shaped heat pipe 1720, a short heat pipe 1780, and an L-shaped heat pipe. The pipes 1730 are installed in this order. Here, the L-shaped heat pipes 1730 disposed at the upstream and downstream ends of the cooling air are installed in a direction in which the heat radiating portion is on the inside. 10, a U-shaped heat pipe 1720, a short heat pipe 1780, a U-shaped heat pipe 1720, a U-shaped heat pipe 1720, a short heat pipe 1780, and a U-shaped heat pipe 1720 are installed in this order. Is done. In the FF cross section shown in FIG. 11, six U-shaped heat pipes 1720 are installed. As shown in FIG. 6, BB cross section, CC cross section, DD cross section, EE cross section, DD cross section, CC cross section, BB cross section, FF cross section, BB cross section By installing the heat pipe in the order of cross section, CC cross section, DD cross section, EE cross section, DD cross section, CC cross section, BB cross section, heat pipe heat receiving portions 1721, 1731 and The heat pipe heat radiation parts 1722 and 1732 are arranged in a staggered manner. That is, as shown in the B-B cross section and the D-D cross section, the rows of heat pipes arranged so that the heat dissipating part of the L-shaped heat pipe 1730 is located at the upstream and downstream ends of the cooling air, and C- Heat pipe heat receiving by alternately arranging rows of heat pipes in which U-shaped heat pipes 1720 are arranged at the upstream and downstream ends of the cooling air as in the C cross section, the EE cross section, and the FF cross section. The parts 1721 and 1731 and the heat pipe heat radiating parts 1722 and 1732 are arranged in a staggered manner, and the heat pipe heat receiving part is arranged on the entire surface of the heat receiving block 1710 while suppressing the ventilation resistance by the heat pipe heat radiating part. Can be improved. Moreover, the short heat pipe 1780 is also arranged without deviation. In 1st Embodiment of this invention, with respect to the total number of 196 heat pipes, there are 64 short heat pipes, or about 30% of the total.

  FIG. 12 shows an enlarged view of region G in FIG. In the heat receiving block 1710, the region directly below the U-shaped heat pipe heat radiating portion 1722 is a region 1770 where there is no heat pipe heat receiving portion, and the heat resistance is large and the temperature locally increases compared to the inside of the heat pipe heat receiving portion. There is concern. However, by arranging the heat pipe heat receiving portions 1721 and 1731 in a staggered manner as shown in FIG. 6, for example, in the vicinity of the region 1770 without the heat receiving portion in the BB cross section, the CC cross section or the FF cross section. Since the U-shaped heat pipe heat receiving part 1721 is arranged, heat transfer is promoted and local temperature rise is suppressed.

  Next, the positional relationship between the heat pipe and the semiconductor element group will be described. In the BB cross section shown in FIG. 7, the L-shaped heat pipe 1730 is provided with an L-shaped heat pipe heat radiating portion 1732 on the projection surface of the outer IGBT module 1510. The first and fifth U-shaped heat pipes 1720 from the windward side are provided with U-shaped heat pipe heat dissipating parts 1722 on the projection surfaces of both the outer IGBT module 1510 and the clamp diode module 1530. The second and fourth U-shaped heat pipes 1720 from the windward side are provided with a U-shaped heat pipe heat radiating portion 1722 on the projection surfaces of both the inner IGBT module 1520 and the clamp diode module 1530. The third U-shaped heat pipe 1720 from the windward side is provided with a U-shaped heat pipe heat radiating part 1722 on both the windward and leeward projection surfaces of the inner IGBT module 1520.

  In addition, in the FF cross section shown in FIG. 11, the first and sixth U-shaped heat pipes 1720 from the windward side are provided with a U-shaped heat pipe heat dissipation part 1722 on the projection surface of only the outer IGBT module 1510. The The second and fifth U-shaped heat pipes 1720 from the windward side are provided with a U-shaped heat pipe heat radiating portion 1722 on the projection surface of only the clamp diode module 1530. The third and fourth U-shaped heat pipes 1720 from the windward side are provided with a U-shaped heat pipe heat radiating portion 1722 on the projection surface of only the inner IGBT module 1520.

  Next, the fin configuration will be described. A plurality of leeward fins 1751 are press-fitted into the leeward heat pipe heat radiating portion with respect to the cooling air 1210, and a plurality of leeward fins 1752 are pressed into the leeward heat pipe radiating portion. The pitch of each of the plurality of leeward fins 1751 is larger than the pitch of each of the leeward fins 1752, and the number of fins is reduced. In the first embodiment of the present invention, there are 48 leeward fins, whereas there are 24 leeward fins, and the ratio of the number of both is 2: 1. In consideration of manufacturability, the fin 1750 is divided into four in a direction orthogonal to the flow of the cooling air 1210.

  The joining of the fin and the heat pipe will be described. FIG. 13 shows an enlarged view of region H in FIG. The fin 1750 is provided with a through hole corresponding to the position of the U-shaped heat pipe heat radiating portion 1722, and a burring 1790 is provided around the through hole so that the fin 1750 is press-fitted into the U-shaped heat pipe heat radiating portion 1722. In addition, the burring 1790 and the U-shaped heat pipe heat radiating portion 1722 are thermally connected by surface contact. Fins 1750 are connected to the heat radiating portion 1722 of the U-shaped heat pipe from the tip of the heat radiating portion to the base at equal intervals, whereas in the heat radiating portion 1782 of the short heat pipe, only the root side of the fin 1750 is In the first embodiment of the invention, only the base eight are connected, and the burring 1790 is not provided on the tip side so that the heat pipe heat dissipating part and the fin are not connected.

  Next, the positional relationship between the cooler and the wind leakage prevention plate will be described. FIG. 14 is an enlarged view of the region I in FIG. 3 and shows the positional relationship between the tip of the U-shaped heat pipe heat radiating portion 1722 and the wind leakage prevention plate 1194. The tip of the U-shaped heat pipe heat radiating part 1722 has a smaller diameter than the other end and the fins 1751 and 1752 cannot be press-fitted. It protrudes about 20-30mm from the fin. On the other hand, the wind leak prevention plate 1194 is installed at a position between the respective U-shaped heat pipe radiating portions 1722. The clearance between the wind leak prevention plate 1194 and the uppermost fin is about 5 mm, which is smaller than the clearance between the tip of the U-shaped heat pipe heat radiating portion 1722 and the uppermost fin.

  A state where the power conversion device is mounted under the floor of the railway vehicle cabin will be described. FIG. 15 is a sectional view as seen from the vehicle traveling direction. The depth direction in the drawing indicates the vehicle traveling direction, the left-right direction indicates the sleeper direction, and the up-down direction indicates the vertical direction. The power conversion apparatus 1000 is connected to the passenger compartment 2000 under the floor by a suspension member 3000. Cooling air 1210 ventilates the power converter 1000 in the direction of sleepers.

  Next, the effect of the first embodiment of the present invention will be described. As described above, in the first embodiment, among the plurality of heat pipes, the short heat pipes 1780 are arranged without being biased, and only four of the fins 1750 on the root side are connected to the heat radiating portion 1782 of the short heat pipes. ing. Since the heat dissipating part 1782 of the short heat pipe in which the fins 1750 are joined only on the root side, the number of fins 1750 to be joined is smaller than that in which a plurality of fins 1750 are joined at equal intervals from the root to the tip. Therefore, even if the temperature of the cooling air 1210 is equal to or lower than the freezing point of the refrigerant inside the heat pipe, the refrigerant does not freeze. The element group 1500 can be efficiently cooled.

  Further, when the cooler is configured only by the short heat pipe 1780 in which the plurality of fins 1750 are joined only on the base side of the heat radiating portion, the heat radiation area is larger than that in which the plurality of fins 1750 are connected from the root to the tip. However, when the temperature of the cooling air 1210 is equal to or higher than the freezing point of the refrigerant, there is a concern that the cooling performance is deteriorated, but by mixing both, the temperature of the cooling air 1210 is equal to or lower than the freezing point of the refrigerant. The cooling performance in the case of the freezing point or higher can be achieved.

  In addition, when dryout occurs in which all the refrigerant in the heat pipe freezes, the temperature of the heat pipe heat radiation portion rises as the temperature of the semiconductor element rises, but the U-shaped heat pipe 1720, L The short heat pipe 1780 having a shorter heat radiating portion than the letter-shaped heat pipe 1730 can reduce the temperature difference between the root and the tip of the heat radiating portion 1782, that is, can increase the temperature of the tip, so that it freezes even if dryout occurs. The melted refrigerant can be melted and the semiconductor element group 1500 can be efficiently cooled. That is, by configuring the cooler by combining two or more types of heat pipes with different numbers of fins connected to the heat radiating portion, while maintaining the cooling performance when the temperature of the cooling air 1210 is equal to or higher than the freezing point of the refrigerant, It is possible to prevent the refrigerant from freezing when the temperature of the cooling air 1210 is below the freezing point of the refrigerant.

  Further, since the heat receiving portion 1721 of the U-shaped heat pipe 1720 is installed in a direction along the flow of the cooling air 1210, heat transfer from the leeward side to the windward side can be promoted with respect to the cooling air 1210. It is possible to level the influence of the temperature rise of the cooling air and suppress the temperature rise of the leeward semiconductor element. Further, the heat radiating portion 1722 of the U-shaped heat pipe 1720 is erected so as to rise in the vertical direction, and a plurality of fins 1750 are joined to the U-shaped heat pipe radiating portion 1722 and installed in the ventilation path 1150. Since heat transfer from the heat receiving block 1710 to the fins 1750 can be promoted, fin efficiency is improved. Further, by installing the semiconductor elements having the same calorific value in a direction orthogonal to the flow of the cooling air 1210, the temperature in the direction orthogonal to the flow of the cooling air 1210 can be made uniform. Therefore, it is not necessary to install a heat pipe along the direction orthogonal to the flow of the cooling air in order to make the temperature uniform, and the heat receiving part of the heat pipe can be aligned with the flow direction of the cooling air. It becomes easy. Also, by installing a clamp diode module with a small amount of heat generation between IGBT modules with a large amount of heat generation, heat is transferred from the IGBT module with a large amount of heat generation to the clamp diode module with a small amount of heat generation, and the efficiency within the heat receiving block Thus, the temperature of the semiconductor element group 1500 can be leveled.

  Further, by installing the heat receiving portion 1721 of the U-shaped heat pipe 1720 on the projection surfaces of both the outer IGBT module 1510 that generates a large amount of heat during regeneration and the clamp diode module 1530 that generates a smaller amount of heat than the IGBT module, Heat transfer from the outer IGBT module 1510 to the clamp diode module 1530 can be promoted during regeneration, and both temperatures can be leveled. In addition, by installing the heat receiving portion 1721 of the U-shaped heat pipe 1720 on the projection surfaces of both the inner IGBT module 1520 and the clamp diode module 1530 that generate a large amount of heat during power running, the clamp diode from the inner IGBT module 1520 during power running. Heat transfer to the module 1530 side can be promoted, and both temperatures can be leveled. Further, by installing the heat receiving portion 1721 of the U-shaped heat pipe 1720 on the projection surface of a single semiconductor element, the heat pipe has a role of transporting heat of only the semiconductor element to the fins 1750. By mixing these heat pipes, local temperature rise can be suppressed and the temperature of the semiconductor element group 1500 can be leveled.

  In addition, by installing the heat dissipating parts 1722 of the U-shaped heat pipe 1720 in a staggered manner, the joints between the fins 1750 and the heat pipes are arranged evenly, and heat is transported to the fins 1750 evenly. improves. Further, since the cross-sectional area of the flow path between the fins and between the heat pipes is larger than when the heat radiating portion of the heat pipe is arranged in a square shape, the ventilation resistance between the fins is reduced, and the blower 1200 is used. Since a large amount of cooling air 1210 can be supplied during cooling, the semiconductor element group 1500 can be efficiently cooled.

  Further, by installing an L-shaped heat pipe 1730 at the most windward position, the most leeward position, or both the leeward and leeward sides so that the heat dissipating part is inside, the projection surface of the fin 1750 The heat receiving portion 1731 of the L-shaped heat pipe 1730 can be installed outside. Accordingly, even when the semiconductor element is installed outside the projection surface of the fin 1750, the heat of the semiconductor element can be efficiently transported to the inner fin 1750 by the L-shaped heat pipe 1730, and thus the fin 1750 can be downsized. can do.

  Further, the plurality of fins 1750 are divided in the flow direction of the cooling air, and the pitch of the fins 1751 on the leeward side where the air temperature is low is made larger than that of the fins 1752 on the leeward side where the air temperature is high, thereby reducing the number of fins. Accordingly, the airflow resistance between the fins can be reduced, and a large amount of cooling air 1210 can be supplied when cooling using the blower 1200. Therefore, the semiconductor element group 1500 can be efficiently cooled, and the cooler 1700 can be cooled. Can be reduced in weight.

  In addition, by installing a plurality of air conditioning plates 1181 and 1182 on the windward side of the fin 1750 in the ventilation path 1150, the wind speed of the cooling air 1210 supplied from the blower 1200 to the fin 1750 is orthogonal to the flow of the cooling air 1210. Since it can be made uniform in the direction, the semiconductor element group 1500 can be efficiently cooled even when the width of the fins 1750 is larger than the width of the outlet of the blower 1200.

  Further, in the ventilation path 1150, a direction perpendicular to the flow of the cooling air 1210 is provided between the fin joined to the most distal end side of the U-shaped heat pipe heat radiating portion 1722 and the top plate 1120 constituting the ventilation path 1150. By installing the plurality of wind leakage prevention plates 1191, 1192, 1193, and 1194, the cooling air 1210 can be prevented from leaking from between the fins, so that the semiconductor element group 1500 can be efficiently cooled. Further, the distance between the plurality of wind leakage prevention plates 1191, 1192, 1193, 1194 and the fins joined to the front end side of the U-shaped heat pipe radiating portion 1722 is set to the distance between the fin joined to the front end side and the U-shaped heat pipe. By making the distance shorter than the distance from the tip of the heat radiating portion 1722, the amount of cooling air 1210 leaking from between the fins can be further reduced.

  The wind leakage prevention plate 1194 also serves as a beam 1160 for maintaining the strength in the ventilation path 1150. Thereby, since the number of parts can be reduced, cost can be reduced and assemblability can be improved.

  With these configurations, the semiconductor element group 1500 can be efficiently cooled, and the power conversion apparatus 1000 that is compact, lightweight, low cost, and easy to assemble can be mounted on a railway vehicle.

  In order to verify the effect of the first embodiment of the present invention, the temperature of each semiconductor element was calculated using general-purpose thermal fluid analysis software and compared with Patent Document 1. As described above, in Patent Document 1, a plurality of semiconductor element groups constituting a circuit for one phase are installed in a direction orthogonal to the flow of cooling air, whereas in the first embodiment of the present invention, It is installed in the direction along the flow. The fin configuration and the cooling air amount were the same in each configuration, and the heat loss of each semiconductor element shown in FIG. 16 was given for each operating condition. In FIG. 16, the loss of each semiconductor element is expressed as a relative value based on the total loss in the power running operation.

  17 to 20 show the temperature rise of each semiconductor element calculated by the general-purpose thermal fluid analysis software. 17 shows a temperature rise during power running in the power conversion device described in Patent Document 1, FIG. 18 shows a temperature rise during regeneration, FIG. 19 shows a temperature rise during power running in the power conversion device according to the first embodiment of the present invention, FIG. 20 is a temperature rise at the time of regeneration. The underlined numerical value in the figure is a relative value (hereinafter referred to as a temperature increase ratio) based on the maximum temperature increase value in FIGS. According to these figures, the maximum temperature rise ratio in Patent Document 1 is 1.00 during power running and 0.78 during regeneration, whereas in the first embodiment of the present invention, it is 0.77 during regeneration. It was 0.76 at the time. Further, the difference between the maximum value and the minimum value of the temperature increase ratio, that is, the temperature variation is 0.59 in powering and 0.46 in regeneration in Patent Document 1, whereas in the first embodiment of the present invention. It was 0.34 at power running and 0.35 at regeneration. From this, it was shown that in the present invention, the temperature variation of each semiconductor element is reduced and the maximum temperature is also reduced as compared with Patent Document 1. In particular, it has been shown that the effect of reducing the temperature is great during power running, and the maximum temperature rise of the semiconductor element can be reduced by 23%.

  In the present invention, the three-level converter main circuit is taken as an example, but the present invention can also be applied to a three-level inverter main circuit. Further, in the second to eleventh inventions, the invention can be applied to a two-level converter or inverter. Further, in the first embodiment, the number of short heat pipes 1780 and the number of heat pipes connecting the fins 1750 only to the base side of the heat radiating portion is 64, which is about 30% of the total number of heat pipes. The invention is not limited to this, and is preferably about 20 to 50% of the total number. In the first embodiment, the number of fins 1750 connected only to the root side is eight with respect to the total number of upwind fins 1751 of 24. However, the present invention is not limited to this, and About 10 to 50% is desirable. Further, as shown in FIG. 21, fins that are joined to the heat radiating portion 1782 and fins that are not joined may be alternately arranged. Further, the fin 1750 is connected to only the eight heat sinks on the leeward heat pipe as shown in FIG. 13, and the heat sink on the leeward side is connected to the fins on the root side of the heat radiating part as shown in FIG. It is good also as a structure connected alternately. Furthermore, the temperature difference between the root and the tip of the heat radiating portion can be further reduced by covering the tip portion of the heat radiating portion where the fin 1750 is connected only to the base side with a heat insulating material or the like. it can.

  FIG. 22 shows the arrangement of heat pipes in the power conversion device according to the second embodiment of the present invention. In the second embodiment, the L-shaped heat pipe 1730 on the windward side is deleted, and the number of heat pipes is smaller than that in the first embodiment. Other configurations are the same as those of the first embodiment. When the temperature on the windward side is lower than the temperature on the leeward side, the resistance to ventilation between the fins can be further reduced by reducing the number of the heat pipes on the windward side in this way. It can cool, and also can reduce manufacturing cost.

  FIG. 23 shows the configuration of fins in the power conversion device according to the third embodiment of the present invention. In the third embodiment, the fins 1750 are not divided on the windward side and the leeward side as in the first embodiment, but all have the same pitch and the same number of sheets. Other configurations are the same as those of the first embodiment. When it is desired to reduce the temperature on the windward side, such a configuration improves the cooling performance on the windward side, so that the semiconductor element group 1500 on the windward side can be efficiently cooled.

  FIG. 24 shows an air conditioning plate in the power conversion device according to the fourth embodiment of the present invention. In the fourth embodiment, the number of air conditioning plates between the blower outlet of the blower 1200 and the cooler 1700 is increased to four. Other configurations are the same as those of the first embodiment. By increasing the number of air conditioning plates in this manner, the air velocity of the cooling air supplied to the cooler 1700 can be made more uniform, so that the semiconductor element group 1500 can be efficiently cooled.

1000 Power conversion device 1110 Side plate 1120 Top plate 1130 Bottom plate 1140 Ventilation channel bottom plate 1150 Ventilation channel 1161, 1162 Bridge direction beam 1163, 1164 Advancing direction beam 1171, 1172 Ventilation channel expansion plate 1181-1184 Air conditioning plate 1191-1195 Wind leakage prevention plate 1200 Blower 1210 Cooling air 1300 Filter 1400 Grill 1500 Semiconductor element group 1510 Outer IGBT module 1520 Inner IGBT module 1530 Clamp diode module 1600 Circuit component mounting space 1610 Filter capacitor 1620 Gate driver 1700 Cooler 1710 Heat receiving block 1711 Cooler fixing screw hole 1712 Connection Bolt 1720 U-shaped heat pipe 1721 U-shaped heat pipe heat receiving part 1722 U-shaped heat pipe heat radiating part 730 L-shaped heat pipe 1731 L-shaped heat pipe heat receiving part 1732 L-shaped heat pipe heat radiating part 1740 Brazing material 1750 Fin 1751 Upwind fins 1752 Downward fin 1760 Sealing material 1770 No heat receiving part 1780 Short heat pipe 1781 Short Heat pipe heat receiving part 1782 Short heat pipe heat radiating part 1790 Burling 2000 Room 3000 Suspension member

Claims (11)

A plurality of semiconductor elements constituting a power conversion circuit; a housing in which the power conversion circuit is mounted; a cooler that radiates heat from the semiconductor elements to the outside; and a blower that supplies cooling air to the cooler; A power conversion device comprising an air passage that includes the cooler and allows the cooling air to flow therethrough,
The cooler includes a heat receiving block, a plurality of U-shaped heat pipes, and a plurality of fins.
The U-shaped heat pipe includes a first heat pipe and a second heat pipe, and the second heat pipe has a shorter heat radiating portion than the first heat pipe,
The plurality of semiconductor elements are juxtaposed on one side of the heat receiving block,
The heat receiving portions of the plurality of U-shaped heat pipes are embedded in a direction along the flow of the cooling air on the opposite surface of the heat receiving block, and the heat radiating portions of the plurality of U-shaped heat pipes rise in the vertical direction. Erected,
The plurality of fins are joined to the heat radiating part of the U-shaped heat pipe and installed in the ventilation path,
The plurality of semiconductor elements include a plurality of first IGBT modules that generate a large amount of heat during regenerative operation, a plurality of second IGBT modules that generate a large amount of heat during power running, and a plurality of small amounts of heat generated as compared to the IGBT module. It consists of a clamp diode module,
The semiconductor elements having the same calorific value are arranged in a direction orthogonal to the flow of cooling air, and the clamp diode is installed between the first IGBT module and the second IGBT module with respect to the flow direction of the cooling air. ,
The area of the heat receiving portion of the second heat pipe disposed on the projection surface of each clamp diode module is the heat reception of the second heat pipe disposed on the projection surface of each first IGBT module and each second IGBT module. The power receiving device of the second heat pipe is disposed so as to be smaller than the area of the portion . The heat receiving block includes a U-shaped heat pipe in which a heat receiving portion of the heat pipe is installed on the projection surfaces of both the first IGBT module and the clamp diode module, and a second IG.
A plurality of U-shaped heat pipes installed on the projection surfaces of both the BT module and the clamp diode and a plurality of U-shaped heat pipes installed on the projection surface of a single semiconductor element are installed. The power conversion device according to claim 1, wherein the power conversion device is characterized. The power converter according to claim 2, wherein the plurality of U-shaped heat pipes are installed such that the respective heat radiating portions are staggered. In the cooler, the most windward position with respect to the cooling wind, or the most leeward position,
Alternatively, an L-shaped heat pipe is installed on both the windward side and the leeward side so that the heat dissipating part is inside the cooler. The plurality of fins are divided in the flow direction of cooling air, and the pitch of fins on the windward side of the cooling air is made larger than that on the leeward side to reduce the number of fins. Item 5. The power conversion device according to Item 4. The power converter according to any one of claims 1 to 5, wherein a plurality of air conditioning plates are installed on the windward side of the fin in the ventilation path. In the ventilation path, a flat plate is installed in a direction perpendicular to the flow of the cooling air between the fin that is joined to the most distal end side of the heat pipe heat dissipating part and the wall that constitutes the ventilation path. The distance between the fin joined to the tip side and the distance between the fin joined to the tip side and the tip of the heat pipe heat dissipating part is shorter than any one of claims 1 to 6. The power converter according to item. The power conversion device according to claim 7, wherein the flat plate is a beam for maintaining strength in the ventilation path by being joined to a wall constituting the ventilation path. A plurality of semiconductor elements constituting a power conversion circuit;
A cooler that dissipates heat from the semiconductor element to the outside air,
The cooler includes a heat receiving block, a plurality of heat pipes, and a plurality of fins.
On one side of the heat receiving block, the plurality of semiconductor elements are arranged in parallel,
A part of the plurality of heat pipes is embedded on the opposite surface of the heat receiving block,
The plurality of heat pipes include a heat receiving portion embedded in the heat receiving block, and a heat radiating portion protruding from the heat receiving block.
A plurality of fins are joined to the heat dissipation part,
The plurality of heat pipes are joined to a first heat pipe in which a plurality of fins are joined from the base to the tip of the heat radiating portion, and to a number of fins smaller than the first heat pipe on at least the base side of the heat radiating portion. It has a 2nd heat pipe, The power converter device of any one of Claim 1 thru | or 8 characterized by the above-mentioned.   The power converter according to claim 9, wherein the second heat pipe has a shorter heat radiating portion than the first heat pipe.   A drive system for a railway vehicle on which the power conversion device according to any one of claims 1 to 10 is mounted.