POWER CONVERSION DEVICE

Abstract

A power conversion device (1) comprises power units (11 and 21), fans (46 and 47) for generating air flows that flow through the power units (11 and 21), and a housing (40) that houses the power units (11 and 21) and the fans (46 and 47). The power conversion device (1) further comprises heat-conducting bases (51 and 61) and coolers (50 and 60) that are thermally coupled to the respective bases (51 and 61) and arranged outside the housing (40) at positions on both sides of the housing (40) in the horizontal direction. The power units (11 and 21) each contain capacitors (FC11 and FC12 or FC21 and FC22) that are arranged with a cavity therebetween in a direction away from a main surface of the corresponding base (51 or 61).

Description

Technical field

[0001] The present disclosure relates to a power conversion device. background

[0002] Each railway vehicle is equipped with a power conversion device. The power conversion device converts electrical energy supplied from a power source into electrical energy that is transmitted to load devices such as motors, lighting systems, and air conditioners, and feeds the converted electrical energy to the load devices. This type of power conversion device is disclosed, for example, in Patent Literature 1. Citation listPatent literature

[0003] Patent Literature 1: Unexamined Japanese Patent Application, Publication No. 2009-96460 Summary of the inventionTechnical problem

[0004] The components of the power conversion device to be installed in a railway vehicle are housed in a casing that defines a closed space. The components generate heat when power is applied, but the amounts of heat generated per unit time vary among the components. Such differences in heat generation cause locally high temperatures at a specific location within the casing of the power conversion device, resulting in a high temperature of the component located at that location. This phenomenon can be problematic not only for a power conversion device to be installed in a vehicle, but also for a power conversion device that contains a component that generates a large amount of heat.

[0005] An object of the present disclosure, achieved in view of the above-mentioned situations, is to provide a power conversion device that is protected from locally high temperatures in the housing. Solution to the problem

[0006] To achieve the above-mentioned object, a power conversion device according to the present disclosure includes power units, fans, a housing, bases with thermal conductivity, and coolers. The power units each include series-connected capacitors and a power conversion circuit having primary terminals between which the capacitors are connected. The power conversion circuit converts direct current input through the capacitors into electrical energy, which is output to a load device. The fans are provided for the respective power units to generate airflows that flow through the corresponding power units. The housing accommodates the power units and the fans. The power units are arranged on the respective bases.The coolers are thermally coupled to the respective bases and are arranged horizontally outside the chassis at positions on both sides of the chassis. The capacitors contained in each of the power units are arranged with a cavity between them in a direction away from a main surface of the base where the power unit is mounted. Advantageous effects of the invention

[0007] The power conversion device according to the present disclosure includes the power units and the fans provided for the respective power units to generate airflows that flow through the corresponding power units. The capacitors included in each of the power units are arranged with a cavity therebetween in a direction away from the main surface of the base on which the power unit is arranged. The fans generate airflows that flow through the power units and generate large amounts of heat, thus preventing locally high temperatures inside the housing. Short description of the drawings Fig. 1 is a block diagram illustrating a power conversion device according to Embodiment 1; Fig. 2 illustrates an exemplary manner of installing the power conversion device according to Embodiment 1 in a railway vehicle; Fig. 3 is a sectional view of a housing according to Embodiment 1; Fig. 4 illustrates an exemplary arrangement of components of the power conversion device according to Embodiment 1; Fig. 5 is a sectional view of the power conversion device according to Embodiment 1, taken along the line VV of Fig. 4 was recorded; Fig. 6 is a sectional view of the power conversion device according to Embodiment 1, taken along line VI-VI of Fig. 4 was recorded; Fig. 7 illustrates exemplary air flows in the power conversion device according to Embodiment 1; Fig. 8 illustrates an exemplary arrangement of components of a power conversion device according to Embodiment 2; Fig. 9 is a sectional view of the power conversion device according to Embodiment 2, taken along the line IX-IX of Fig. 8 was taken; Fig. 10 illustrates exemplary air flows in the power conversion device according to Embodiment 2; Fig. 11 illustrates an exemplary arrangement of components of a power conversion device according to Embodiment 3; Fig. 12 is a sectional view of the power conversion device according to Embodiment 3, taken along the line XII-XII of Fig. 11 was taken; and Fig. 13 illustrates exemplary air flows in the power conversion device according to Embodiment 3. Description of the embodiments

[0008] A power conversion device according to some embodiments will be described in detail below with reference to the accompanying drawings. In the drawings, identical or corresponding components are denoted by the same reference numerals. Embodiment 1

[0009] The following describes a power conversion device 1 according to Embodiment 1, focusing on an exemplary power conversion device installed in a railway vehicle and supplying electrical power to load devices such as motors, lighting devices, and air conditioners. Fig. The power conversion device 1 shown in FIG. 1 converts electrical power supplied from a power source (not shown) into electrical power supplied to the motors IM1, IM2, IM3, and IM4, which are examples of the load devices. The power conversion device 1 then feeds the converted electrical power to the motors IM1, IM2, IM3, and IM4.

[0010] The power conversion device 1 includes a terminal 1a connected to the power source, which in a specific example is a pantograph, a grounded terminal 1b, a transformer 10 that reduces the voltage of the alternating current supplied by the power source, a power unit 11 that converts the alternating current reduced by the transformer 10 into alternating current supplied to the motors IM1 and IM2, and a power unit 21 that converts the alternating current reduced by the transformer 10 into alternating current supplied to the motors IM3 and IM4. The pantograph receives electrical power from a substation via a power supply line. Examples of the pantograph include a pantograph and a contact strip, and examples of the power supply line include an overhead line and a third rail.

[0011] The power conversion device 1 further includes a contactor MC1 that electrically connects the power unit 11 to the power source or electrically disconnects the power unit 11 from the power source, and a contactor MC2 that electrically connects the power unit 21 to the power source and electrically disconnects the power unit 21 from the power source. The power conversion device 1 also includes a contactor control circuit 31 that closes or opens the contactors MC1 and MC2, and a power unit control circuit 32 that controls switching elements included in the power units 11 and 21.

[0012] The power unit 11 includes a converter 12 that converts the alternating current, which is subject to voltage reduction by the transformer 10, into direct current and outputs the converted direct current, as well as filter capacitors FC11 and FC12 that are charged with the direct current output by the converter 12. The power unit 11 further includes an inverter 13 that serves as a power conversion circuit and has primary terminals between which the filter capacitors FC11 and FC12 are connected. The inverter 13 converts the direct current supplied via the filter capacitors FC11 and FC12 into alternating current, which is supplied to the motors IM1 and IM2, and outputs the converted alternating current.

[0013] The filter capacitors FC11 and FC12 are connected in series. Specifically, one end of the filter capacitor FC11 is electrically connected to the positive electrode terminal on the secondary side of the converter 12 and one of the primary terminals of the inverter 13. One end of the filter capacitor FC12 is electrically connected to the other end of the filter capacitor FC11 and the neutral terminal on the secondary side of the converter 12. The other end of the filter capacitor FC12 is electrically connected to the negative electrode terminal on the secondary side of the converter 12 and the other of the primary terminals of the inverter 13.

[0014] The power unit 21 includes a converter 22 that converts the alternating current, which is subject to voltage reduction by the transformer 10, into direct current and outputs the converted direct current, as well as filter capacitors FC21 and FC22 that are charged with the direct current output by the converter 22. The power unit 21 further includes an inverter 23 that serves as a power conversion circuit with primary terminals between which the filter capacitors FC21 and FC22 are connected. The inverter 23 converts the direct current supplied via the filter capacitors FC21 and FC22 into alternating current, which is supplied to the motors IM3 and IM4, and outputs the converted alternating current.

[0015] The filter capacitors FC21 and FC22 are connected in series. Specifically, one end of the filter capacitor FC21 is electrically connected to the positive electrode terminal on the secondary side of the converter 22 and one of the primary terminals of the inverter 23. One end of the filter capacitor FC22 is electrically connected to the other end of the filter capacitor FC21 and the neutral terminal on the secondary side of the converter 22. The other end of the filter capacitor FC22 is electrically connected to the negative electrode terminal on the secondary side of the converter 22 and the other end of the primary terminals of the inverter 23.

[0016] The transformer 10 comprises a primary winding 10a, the ends of which are connected to the respective terminals 1a and 1b, a secondary winding 10b electrically connected to the power unit 11, a secondary winding 10c electrically connected to the power unit 21, and an iron core 10d provided with the primary winding 10a and the secondary windings 10b and 10c wound around it.

[0017] One end of contactor MC1 is electrically connected to one end of secondary winding 10b, and the other end is electrically connected to one of the primary terminals of converter 12. Contactor MC1 consists of an electromagnetic AC contactor that is closed or opened by contactor control circuit 31. When contactor MC1 is closed, it electrically connects secondary winding 10b to converter 12. This process electrically connects power unit 11 to the power source. When contactor MC1 is opened, it electrically disconnects secondary winding 10b from converter 12. This process electrically disconnects power unit 11 from the power source.

[0018] The contactor MC2 is connected at one end to one end of the secondary winding 10c and at the other end to one of the primary terminals of the converter 22. The contactor MC2 consists of an electromagnetic AC contactor that is closed or opened by the contactor control circuit 31. When the contactor MC2 is closed, it electrically connects the secondary winding 10c to the converter 22. This process electrically connects the power unit 21 to the power source. When the contactor MC2 is opened, it electrically disconnects the secondary winding 10c from the converter 22. This process electrically disconnects the power unit 21 from the power source.

[0019] One of the primary terminals of the converter 12 is electrically connected to the other end of the contactor MC1, and the other of the primary terminals of the converter 12 is electrically connected to the other end of the secondary winding 10b. The converter 12 includes several switching elements that are turned on or off by the control circuit 32 of the power supply. The converter 12 converts the alternating current supplied via the secondary winding 10b into direct current and outputs the direct current. The positive terminal on the secondary side of the converter 12 is electrically connected to one end of the filter capacitor FC11. The neutral terminal on the secondary side of the converter 12 is electrically connected to the junction point between the filter capacitors FC11 and FC12. The negative terminal on the secondary side of the converter 12 is electrically connected to the other end of the filter capacitor FC12. The filter capacitors FC11 and FC12 are charged with direct current from the converter 12.

[0020] The filter capacitors FC11 and FC12 are connected between the primary terminals of inverter 13. Inverter 13 contains several switching elements that are switched on or off by the power supply control circuit 32. Inverter 13 converts the direct current supplied via the filter capacitors FC11 and FC12 into alternating current and outputs the alternating current. Inverter 13 has secondary terminals that are electrically connected to the motors IM1 and IM2.

[0021] One of the primary terminals of the converter 22 is electrically connected to the other end of the contactor MC2, and the other of the primary terminals of the converter 22 is electrically connected to the other end of the secondary winding 10c. The converter 22 includes several switching elements that are turned on or off by the control circuit 32 of the power supply. The converter 22 converts the alternating current supplied via the secondary winding 10c into direct current and outputs the direct current. The positive terminal on the secondary side of the converter 22 is electrically connected to one end of the filter capacitor FC21. The neutral terminal on the secondary side of the converter 22 is electrically connected to the junction point between the filter capacitors FC21 and FC22. The negative terminal on the secondary side of the converter 22 is electrically connected to the other end of the filter capacitor FC22. The filter capacitors FC21 and FC22 are charged with direct current from the converter 22.

[0022] The filter capacitors FC21 and FC22 are connected between the primary terminals of the inverter 23. The inverter 23 contains several switching elements that are switched on or off by the power supply control circuit 32. The inverter 23 converts the direct current supplied via the filter capacitors FC21 and FC22 into alternating current and outputs the alternating current. The inverter 23 has secondary terminals that are electrically connected to the motors IM3 and IM4.

[0023] For example, motors IM1, IM2, IM3, and IM4 are three-phase asynchronous motors. Motors IM1, IM2, IM3, and IM4 are supplied with electrical energy by power conversion device 1, causing them to rotate. This rotation generates propulsion for the rail vehicle. For example, a car body is equipped with two bogies. While one of the bogies is equipped with motors IM1 and IM2, the other bogie is equipped with motors IM3 and IM4.

[0024] Contactor control circuit 31 closes contactors MC1 and MC2 upon commencement of operation of the rail vehicle. For example, contactor control circuit 31 closes contactors MC1 and MC2 in response to a switch actuation to raise a pantograph, which is an example of a current collector, and bring it into contact with the overhead line.

[0025] The power unit control circuit 32 receives a running command for the railway vehicle from a driver's cab (not shown) and controls the switching operations of the switching elements included in each of the power converters 12 and 22 and the inverters 13 and 23 according to the running command. The running command includes a running command for accelerating the railway vehicle, a braking command for decelerating the railway vehicle, or a coasting command for coasting the railway vehicle. The idle command indicates a state in which neither the running command nor the braking command is received. Specifically, the power unit control circuit 32 generates control commands for controlling the respective switching elements in the converters 12 and 22 and the inverters 13 and 23 in accordance with the running command and transmits the control commands to the corresponding switching elements in the converters 12 and 22 and the inverters 13 and 23.

[0026] The components of the power conversion device 1 described above are arranged in a Fig. 2. The housing 40 is installed under the floor of a car body 100 of the rail vehicle with fastening elements 101. The power conversion device 1 further comprises coolers 50 and 60. The cooler 50 is thermally coupled to the engine 11 housed in the housing 40 and dissipates the heat transferred from the engine 11 to the ambient air, thus cooling the engine 11. The cooler 60 is thermally coupled to the power unit 21 housed in the housing 40 and dissipates the heat transferred from the power unit 21 to the ambient air, thus cooling the power unit 21. In Fig. 2, the X-axis represents the direction of travel of the rail vehicle, and the Y-axis represents the width direction of the vehicle body 100. The Z-axis is orthogonal to the X and Y axes. The Z-axis represents the vertical direction, while the rail vehicle is oriented horizontally. The same applies to the subsequent drawings.

[0027] The housing 40 is made of a material rigid enough to resist deformation due to vibrations during operation of the rail vehicle. Examples of the material include metals such as aluminum, iron, and stainless steel. The housing 40 is firmly connected to the car body 100 such that any shift in the relative positional relationship between the car body 100 and the housing 40 due to vibrations during operation of the rail vehicle is prevented.

[0028] The radiators 50 and 60 are arranged outside the housing 40 at positions on both sides of the housing 40 in the horizontal direction, specifically in the Y-axis direction. The sum of the Y-axis widths of the radiators 50 and 60 and the Y-axis width of the housing 40 is preferably substantially equal to the Y-axis width of the vehicle body 100. With this configuration, the space under the floor of the vehicle body 100 can be efficiently utilized.

[0029] The interior of the housing 40, in which the components of the power conversion device 1 are housed, is divided into several compartments. Specifically, the power conversion device 1 comprises, as shown in Fig. 3, two first partition elements 42 and 43 are shown, which divide the interior of the housing 40. The first partition elements 42 and 43 are spaced apart from each other in the direction in which two walls 40a and 40b of the housing 40 face each other, i.e., in the direction of the Y-axis. The first partition wall elements 42 and 43 are oriented such that the individual main surfaces run parallel to the walls 40a and 40b. The first partition elements 42 and 43 have, for example, the shape of a flat plate and are attached to the inner surfaces of the housing 40, wherein they are oriented such that the main surfaces are orthogonal to the Y-axis.

[0030] The power conversion device 1 preferably further includes a second partition member 44 that partitions the space between the wall 40a and the first partition member 42 disposed adjacent to the wall 40a, and a second partition member 45 that partitions the space between the wall 40b and the first partition members 43 disposed adjacent to the wall 40b. The second partition members 44 and 45 extend in the direction in which the two walls 40a and 40b face each other, that is, in the Y-axis direction and the Z-axis direction. The second partition member 44 is fixed to the wall 40a, the first partition member 42, and the inner surfaces of the housing 40, and partitions the space between the wall 40a and the first partition member 42. The second partition member 45 is fixed to the wall 40b, the first partition member 43 and the inner surfaces of the housing 40 and separates the space between the wall 40b and the first partition member 43.

[0031] The first partition members 42 and 43 and the second partition members 44 and 45 divide the interior of the housing 40 into a first compartment 71, a second compartment 72, a third compartment 73, a fourth compartment 74, and a fifth compartment 75. Specifically, the first compartment 71 is defined between the wall 40a and the first partition member 42 and is located closer to the negative side along the X-axis than the second partition member 44. The second compartment 72 is defined between the wall 40b and the first partition member 43 and is located more on the negative side along the X-axis than the second partition member 45. The third compartment 73 is defined between the wall 40a and the first partition member 42 and is located more on the positive side along the X-axis than the second partition member 44. The fourth compartment 74 is defined between the wall 40b and the first partition member 43 and is located more on the positive side along the X-axis as the second separating element 45.The fifth compartment 75 is located between the first separating elements 42 and 43.

[0032] The first partition member 42 has first air holes 42a and 42b. The first partition member 43 has first air holes 43a and 43b. The second partition member 44 has a second air hole 44a. The second partition member 45 has a second air hole 45a. Through these air holes, the air inside the housing 40 can circulate through the first compartment 71, the second compartment 72, the third compartment 73, the fourth compartment 74, and the fifth compartment 75.

[0033] The components of the power conversion device 1 are arranged in the housing 40, as described below with reference to Fig. 4. The components of the power conversion device 1, particularly the electronic components included in the power conversion device 1, all generate heat when energized, but the amounts of heat generation are different from each other. For example, the amounts of heat generation of the power units 11 and 21 per unit time are greater than the amounts of heat generation of the contactor control circuit 31, the power unit control circuit 32, and the contactors MC1 and MC2 per unit time.

[0034] The power unit 11, which generates a large amount of heat, is arranged at a position adjacent to the wall 40a corresponding to the end of the Y-axis, between the wall 40a and the first partition member 42 adjacent to the wall 40a. For example, the power unit 11 is housed in the first compartment 71 and thermally coupled to the cooler 50. The part of the wall 40a facing the first compartment 71 in which the power unit 11 is housed has an opening 41a. The opening 41a enables maintenance of the power unit 11 housed in the first compartment 71.

[0035] The opening 41a is closed by a heat-conducting base 51. The base 51 is made of a material with high thermal conductivity. Examples of the material are metals such as aluminum and iron. The base 51 has, for example, the shape of a flat plate and is attached to the housing 40, in particular to the outer surface of the wall 40a, and is oriented such that one of the main surfaces closes the opening 41a. The power unit 11 is attached to the surface of the base 51 facing the opening 41a.

[0036] The cooler 50 is thermally coupled to the base 51 and dissipates the heat transferred from the power unit 11 via the base 51. Specifically, the cooler 50 includes a plurality of fins 52 mounted on the base 51 and a cover 53 attached to the housing 40 to cover the base 51 and the fins 52.

[0037] The ribs 52 are made of flat plate elements. The ribs 52 are attached to the other main surface of the base 51 such that the main surfaces of the ribs 52 are orthogonal to the Z-axis and the ribs 52 are spaced apart from each other in the Z-axis direction. The cover 53 has air holes 53a through which ambient air can penetrate the cover 53 and flow between the ribs 52.

[0038] The cooler 50 transfers the heat to the cooling air flowing along the outer surface of the wall 40a. For example, the movement of the rail vehicle generates a wind flowing in the opposite direction to the direction of travel of the rail vehicle. This wind enters the cover 53, flows between the ribs 52, and is guided along the wall 40a.

[0039] In Fig. 4, for simplicity of illustration, the filter capacitors FC11 and FC12 are shown alone as components of the power unit 11. The filter capacitors FC11 and FC12 are arranged with a cavity therebetween in a direction away from the main surface of the base 51 to which the power unit 11 is attached, specifically toward the negative side along the Y axis. The filter capacitors FC11 and FC12 are fixed to the base 51 with fixing members not shown. The switching elements of the converter 12 and the switching elements of the inverter 13 are fixed to the base 51, although these structures are not shown.

[0040] The power unit 21, which generates a large amount of heat, is arranged at a position adjacent to the wall 40b corresponding to the end of the Y-axis, between the wall 40b and the first partition 43 arranged adjacent to the wall 40b. The power unit 21 is housed, for example, in the second compartment 72 and is thermally coupled to the cooler 60. The part of the wall 40b facing the second compartment 72 in which the power unit 21 is housed has an opening 41b. The opening 41b enables maintenance of the power unit 21 housed in the second compartment 72.

[0041] The opening 41b is closed by a heat-conducting base 61. The base 61 is made of a material with high thermal conductivity. Examples of the material are metals such as aluminum and iron. The base 61 has, for example, the shape of a flat plate and is attached to the housing 40, in particular to the outer surface of the wall 40b, and is oriented such that one of the main surfaces closes the opening 41b. The power unit 21 is attached to the surface of the base 61 facing the opening 41b.

[0042] The cooler 60 is thermally coupled to the base 61 and dissipates the heat transferred from the power unit 21 via the base 61. Specifically, the cooler 60 includes a plurality of fins 62 mounted on the base 61 and a cover 63 attached to the housing 40 to cover the base 61 and the fins 62.

[0043] The ribs 62 are made of flat plate elements. The ribs 62 are attached to the other main surface of the base 61 such that the main surfaces of the ribs 62 are orthogonal to the Z-axis and the ribs 62 are spaced apart from each other in the Z-axis direction. The cover 63 has air holes 63a through which ambient air can penetrate the cover 63 and flow between the ribs 62.

[0044] The cooler 60 transfers the heat to the cooling air flowing along the outer surface of the wall 40b. For example, the movement of the rail vehicle generates a wind that flows opposite to the direction of travel of the rail vehicle. This wind enters the cover 63, flows between the fins 62, and is guided along the wall 40b. The wind absorbs heat from the fins 62 and thus cools the power unit 21.

[0045] Fig. 4 shows only the filter capacitors FC21 and FC22 as components of the power unit 21 for simplicity of illustration. The filter capacitors FC21 and FC22 are arranged with a cavity therebetween in a direction away from the main surface of the base 61 to which the power unit 21 is attached, specifically toward the positive side along the Y axis. The filter capacitors FC21 and FC22 are attached to the base 61 with attachment members not shown. The switching elements included in the converter 22 and the switching elements included in the inverter 23 are attached to the base 61, although these structures are not shown.

[0046] The contactors MC1 and MC2 and the contactor control circuit 31 are arranged at positions adjacent to the power unit 11 via the second separator 44. For example, the contactors MC1 and MC2 and the contactor control circuit 31 are housed in the third compartment 73.

[0047] The power unit control circuit 32 is arranged at a position adjacent to the power unit 21 via the second separator 45. For example, the engine control circuit 32 is housed in the fourth compartment 74.

[0048] The fifth compartment 75 accommodates elements such as electrical lines and busbars that electrically connect the individual components of the power conversion device 1 to one another, although these structures are not shown.

[0049] The air temperatures in the first compartment 71 and the second compartment 72, which house the power units 11 and 21, which generate large amounts of heat, are higher than in the other compartments, particularly the third compartment 73, the fourth compartment 74, and the fifth compartment 75. To avoid a locally high temperature inside the housing 40, the power conversion device 1 further includes fans 46 and 47 provided for the respective power units 11 and 21. The fans 46 and 47 generate air currents that flow through the corresponding power units 11 and 21. The fans 46 and 47 are housed in the housing 40.

[0050] Specifically, the power conversion device 1 includes the fan 46 disposed near the first air hole 42a and the fan 47 disposed near the first air hole 43a. The proximity of the first air holes 42a and 43a means positions within the first air holes 42a and 43a and positions around the first air holes 42a and 43a, respectively. For example, the fans 46 and 47 are provided on the inner walls of the first air holes 42a and 43a, the main surfaces of the first partition wall members 42 and 43, or the portions of the inner surfaces of the casing 40 adjacent to the first partition wall members 42 and 43, respectively.

[0051] During operation of the power units 11 and 21, the fans 46 and 47 are driven by electrical energy supplied from a power source (not shown). For example, the fans 46 and 47 are powered by the power source that also supplies power to other devices in the vehicle, such as air conditioning systems and lighting devices. The fans 46 and 47 receive control commands from the control circuit 32 of the unit and are driven during the switching operations of the switching elements included in at least one of the power units 11 and 21.

[0052] The fan 46 generates an airflow that flows through the power unit 11. The fan 46 is, for example, an axial fan. The fan 46 is oriented so that the rotation axis is parallel to the Y-axis and conveys air toward the power unit 11. In other words, the fan 46 conveys air from the fifth compartment 75, which houses electronic components that generate small amounts of heat, to the first compartment 71, which houses electronic components that generate large amounts of heat. Considering the characteristics of cool air present vertically below and warm air present vertically above, the fan 46 is preferably arranged vertically below near the first air opening 42a, as shown in Fig. 5, which is a sectional view along the line VV of Fig. 4 is.

[0053] Since the filter capacitors FC11 and FC12 are arranged with a cavity between them as described above, the air supplied by the fan 46 flows through the cavity between the filter capacitors FC11 and FC12. This flowing air cools the filter capacitors FC11 and FC12.

[0054] The Fig. The fan 47 shown in Figure 4 generates an airflow that flows through the power unit 21. The fan 47 is, for example, an axial fan. The fan 47 is oriented so that the axis of rotation is parallel to the Y-axis and conveys air toward the power unit 21. In other words, the fan 47 conveys air from the fifth compartment 75, which houses electronic components that generate small amounts of heat, to the second compartment 72, which houses electronic components that generate large amounts of heat. Considering the characteristics of cool air present vertically below and warm air present vertically above, the fan 47 is preferably arranged vertically below near the first air opening 43a, as shown in Fig. 6, which is a sectional view along the line VI-VI of Fig. 4 is.

[0055] Since the filter capacitors FC21 and FC22 are arranged with a cavity between them as described above, the air supplied by the fan 47 flows through the cavity between the filter capacitors FC21 and FC22. This flowing air cools the filter capacitors FC21 and FC22.

[0056] The operation of the fans 46 and 47 causes air circulation inside the housing 40, as indicated by the arrows in Fig. 7. Specifically, the operation of the fan 46 generates airflow from the fifth compartment 75 through the first air opening 42a toward the first compartment 71. The air introduced from the fifth compartment 75 into the first compartment 71 flows through the second air opening 44a into the third compartment 73. The air entering the third compartment 73 flows through the first air opening 42b into the fifth compartment 75. The air entering the fifth compartment 75 is guided along the X-axis toward the negative side and flows through the first air opening 42a into the first compartment 71.

[0057] The operation of the fan 47 generates an airflow from the fifth compartment 75 through the first air opening 43a toward the second compartment 72. The air introduced from the fifth compartment 75 into the second compartment 72 flows into the fourth compartment 74 through the second air opening 45a. The air that entered the fourth compartment 74 flows into the fifth compartment 75 through the first air opening 43b. The air that entered the fifth compartment 75 is guided along the X-axis toward the negative side and flows into the second compartment 72 through the first air opening 43a.

[0058] As described above, in the power conversion device 1 according to Embodiment 1, the fans 46 and 47 generate airflows that pass through the power units 11 and 21 and generate large amounts of heat, and can thus avoid a locally high temperature inside the casing 40.

[0059] The filter capacitors FC11 and FC12, arranged with a cavity therebetween, can allow the air supplied by the fan 46 to flow through the cavity between the filter capacitors FC11 and FC12. The filter capacitors FC21 and FC22, arranged with a cavity therebetween, can allow the air supplied by the fan 47 to flow through the cavity between the filter capacitors FC21 and FC22. These structures can achieve efficient cooling of the filter capacitors FC11, FC12, FC21, and FC22, which generate large amounts of heat. Embodiment 2

[0060] The fans 46 and 47 may be arranged at different positions than in the example described above. Next, a power conversion device 2 according to Embodiment 2 will be described, which has fans 46 and 47 arranged at different positions than in the power conversion device 1, focusing on the differences from Embodiment 1.

[0061] The Fig. The power conversion device 2 shown in FIG. 8 has the same configuration as the power conversion device 1, except for the positions of the fans 46 and 47. The fans 46 and 47 in the power conversion device 2 are respectively disposed near the second air holes 44a and 45a. The proximity of the second air holes 44a and 45a refers to the positions within the second air holes 44a and 45a and the positions around the second air holes 44a and 45a, respectively. For example, the fans 46 and 47 are respectively provided on the inner walls of the second air holes 44a and 45a, the main surfaces of the second partition wall members 44 and 45, or the portions of the inner surfaces of the casing 40 adjacent to the second partition wall members 44 and 45.

[0062] The fan 46 generates an airflow that flows through the power unit 11. The fan 46 is, for example, an axial fan. The fan 46 is oriented so that the rotation axis is parallel to the X-axis and conveys air toward the power unit 11, particularly into the cavity between the filter capacitors FC11 and FC12. In other words, the fan 46 conveys air from the third compartment 73, which houses electronic components that generate small amounts of heat, into the first compartment 71, which houses electronic components that generate large amounts of heat. Considering the characteristics of cool air present vertically below and warm air present vertically above, the fan 46 is preferably arranged vertically below near the second air opening 44a, as shown in Fig. 9, which is a sectional view along the line IX-IX of Fig. 8. This structure makes it easier for the cool air present vertically below in the third compartment 73 to flow smoothly into the first compartment 71.

[0063] The filter capacitors FC11 and FC12, arranged with a cavity therebetween in the Y-axis direction as in Embodiment 1, can allow the air supplied from the fan 46 to flow in the X-axis direction through the cavity between the filter capacitors FC11 and FC12. Such airflow can efficiently cool the filter capacitors FC11 and FC12.

[0064] The Fig. The fan 47 shown in Figure 8 generates an airflow that flows through the power unit 21. The fan 47 is, for example, an axial fan. The fan 47 is oriented so that the axis of rotation is parallel to the X-axis and conveys air toward the power unit 21, in particular into the cavity between the filter capacitors FC21 and FC22. In other words, the fan 47 conveys air from the fourth compartment 74, which houses electronic components that generate small amounts of heat, into the second compartment 72, which houses electronic components that generate large amounts of heat. Considering the characteristics of cool air present vertically below and warm air present vertically above, the fan 47 is preferably arranged vertically below near the second air opening 45a, as shown in Fig. 9. This structure facilitates the cool air present vertically below in the fourth compartment 74 to flow smoothly into the second compartment 72.

[0065] The filter capacitors FC21 and FC22, arranged with a cavity therebetween in the Y-axis direction as in Embodiment 1, can allow the air supplied from the fan 47 to flow in the X-axis direction through the cavity between the filter capacitors FC21 and FC22. Such airflow can efficiently cool the filter capacitors FC21 and FC22.

[0066] The operation of the fans 46 and 47 causes air circulation inside the housing 40, as indicated by the arrows in Fig. 10. Specifically, the operation of the fan 46 generates an airflow from the third compartment 73 through the second air opening 44a toward the first compartment 71. At least a portion of the air introduced from the third compartment 73 into the first compartment 71 flows through the cavity between the filter capacitors FC11 and FC12 toward the negative side along the X-axis. The air that entered the first compartment 71 flows through the first air hole 42a into the fifth compartment 75. The air that entered the fifth compartment 75 is guided toward the positive side along the X-axis and flows through the first air opening 42b into the third compartment 73.

[0067] The operation of the fan 47 generates an airflow from the fourth compartment 74 through the second air opening 45a toward the second compartment 72. At least a portion of the air introduced from the fourth compartment 74 into the second compartment 72 flows through the cavity between the filter capacitors FC21 and FC22 toward the negative side along the X-axis. The air that entered the second compartment 72 flows through the first air hole 43a into the fifth compartment 75. The air that entered the fifth compartment 75 is directed toward the positive side along the X-axis and flows through the first air hole 43b into the fourth compartment 74.

[0068] As described above, in the power conversion device 2 according to Embodiment 2, the fans 46 and 47 generate airflows that pass through the power units 11 and 21 and generate large amounts of heat, thus preventing a locally high temperature inside the casing 40. The fan 46 drives air toward the negative side along the X-axis against the filter capacitors FC11 and FC12 arranged with a cavity therebetween in the Y-axis direction, thus causing the air to flow in the X-axis direction along the outer surfaces of the casings of the filter capacitors FC11 and FC12. By such airflow, efficient cooling of the filter capacitors FC11 and FC12 can be achieved.

[0069] The fan 47 drives air in the X-axis direction against the filter capacitors FC21 and FC22, which are arranged in the Y-axis direction with a cavity between them, and thus causes the air to flow in the X-axis direction along the outer surfaces of the housings of the filter capacitors FC21 and FC22. Such airflow can achieve efficient cooling of the filter capacitors FC21 and FC22. Embodiment 3

[0070] The housing 40 may have a different structure than that in the examples described above. Next, a power conversion device 3 according to Embodiment 3, which has a housing 40 with a different structure than those in Embodiments 1 and 2, will be described, focusing on the differences from Embodiments 1 and 2.

[0071] The Fig. The power conversion device 3 shown in Figure 11 includes, in addition to the components of the power conversion device 2, a third partition member 48 that divides the space between the first partition members 42 and 43. The compartment defined between the first partition members 42 and 43, which is closer to the negative side along the X-axis than the third partition member 48, is referred to as the sixth compartment 76. The compartment defined between the first partition wall members 42 and 43, which is closer to the positive side along the X-axis than the third partition wall member 48, is referred to as the seventh compartment 77.

[0072] The fans 46 and 47 are respectively disposed near the second air holes 44a and 45a as in Embodiment 2, but the fan 47 moves air in a different direction than in Embodiment 2. Specifically, the fan 47 moves air in a direction away from the drive unit 21. For example, the fan 47 pulls the air located in the cavity between the filter capacitors FC21 and FC22 toward the positive side along the X-axis. In other words, the fan 47 moves air from the second compartment 72, which houses electronic components that generate large amounts of heat, to the fourth compartment 74, which houses electronic components that generate small amounts of heat.

[0073] Considering the characteristics of cool air present vertically below and warm air present vertically above, the fan 47 is preferably arranged vertically above near the second air opening 45a, as shown in Fig. 12, which is a sectional view along the line XII-XII of Fig. 11. This structure facilitates the warm air present vertically at the top of the second compartment 72 to flow smoothly into the fourth compartment 74.

[0074] The operation of the fans 46 and 47 causes air circulation inside the housing 40, as indicated by the arrows in Fig. 13. Specifically, the operation of the fan 46 generates airflow from the third compartment 73 through the second air opening 44a toward the first compartment 71. At least a portion of the air introduced from the third compartment 73 into the first compartment 71 flows through the cavity between the filter capacitors FC11 and FC12 toward the negative side along the X-axis. The air that entered the first compartment 71 flows through the first air hole 42a into the sixth compartment 76. The air that entered the sixth compartment 76 is then directed toward the negative side along the Y-axis and flows through the first air opening 43a into the second compartment 72.

[0075] The operation of the fan 47 generates an airflow from the second compartment 72 through the second air opening 45a toward the fourth compartment 74. The fan 47 draws the air in the second compartment 72 toward the fourth compartment 74. For example, the air between the filter capacitors FC21 and FC22 in the second compartment 72 flows toward the positive side along the X-axis. The air introduced from the second compartment 72 into the fourth compartment 74 flows through the first air opening 43b into the seventh compartment 77. The air that entered the seventh compartment 77 is then directed toward the positive side along the Y-axis and flows through the first air opening 42b into the third compartment 73.

[0076] As described above, in the power conversion device 3 according to Embodiment 3, the fans 46 and 47 generate airflows that flow through the power elements 11 and 21, generating a large amount of heat, and can thus prevent a locally high temperature inside the case 40. The fan 46 drives air toward the negative side along the X-axis against the filter capacitors FC11 and FC12, which are arranged with a cavity therebetween in the Y-axis direction, and thus causes the air to flow in the X-axis direction along the outer surfaces of the cases of the filter capacitors FC11 and FC12. By such airflow, efficient cooling of the filter capacitors FC11 and FC12 can be achieved.

[0077] The fan 47 draws the air toward the positive side along the X-axis against the filter capacitors FC21 and FC22, which are arranged with a cavity in between in the Y-axis direction, thus causing the air to flow in the X-axis direction along the outer surfaces of the housings of the filter capacitors FC21 and FC22. Such airflow can achieve efficient cooling of the filter capacitors FC21 and FC22.

[0078] The embodiments described above are not to be understood as limiting the scope of the present disclosure. The embodiments described above can be combined with one another as desired. For example, the embodiments described in Fig. 4 may further comprise an auxiliary fan 46 disposed near the second air opening 44a and an auxiliary fan 47 disposed near the second air opening 45a, as in Embodiment 2. In this case, the auxiliary fan 46 supplies air in a direction away from the power unit 11, specifically toward the positive side along the X-axis, and the auxiliary fan 47 supplies air in a direction away from the power unit 21, specifically toward the positive side along the X-axis.

[0079] The power conversion device 1 may have any circuit configuration other than those in the examples described above, provided that the power conversion device 1 includes power units, each including a plurality of capacitors. For example, the power conversion device 1 may be a multilevel inverter or a direct current-to-direct current (DC-DC) converter.

[0080] In another example, the power conversion device 1 may include surge suppression resistors for suppressing surges in the power units 11 and 21. For example, one of the surge suppression resistors for suppressing surges in the power unit 11 may be housed together with the power unit 11 in the first compartment 71. Another of the surge suppression resistors for suppressing the surge in the power section 21 may be housed in the second compartment 72 together with the power section 21.

[0081] In another example, the power conversion device 1 may include charging resistors for suppressing inrush current in the filter capacitors FC11 and FC12 included in the power unit 11 and in the filter capacitors FC21 and FC22 included in the power unit 21. For example, one of the charging resistors for suppressing inrush current in the filter capacitors FC11 and FC12 may be housed in the first compartment 71 together with the power unit 11. Another of the charging resistors for suppressing inrush current in the filter capacitors FC21 and FC22 may be housed in the second compartment 72 together with the power unit 21.

[0082] The power conversion device 1 can supply electrical energy to any electronic device as a load device, except for the motors IM1, IM2, IM3 and IM4.

[0083] The fifth compartment 75 can accommodate sensors not shown, such as current sensors that measure the values of the phase current supplied by the power units 11 and 21.

[0084] The fans 46 and 47 may be replaced by any number of fans and arranged in a different location than in the examples described above, provided that the fans can cool the power units 11 and 21, which generate large amounts of heat. For example, the power conversion device 1 may be equipped with Fig. 4 include a fan arranged near the first air opening 42b and a fan arranged near the first air opening 43b.

[0085] Each of the power conversion devices 1 to 3 can also be installed in a railway vehicle of a DC feed system, as well as in a railway vehicle of an AC feed system. Each of the power conversion devices 1 to 3 can be installed in any moving body, such as an automobile, aircraft, or ship, other than the railway vehicle.

[0086] The first partition members 42 and 43 and the second partition members 44 and 45 may have different shapes and be arranged at different positions depending on the sizes of the power units 11 and 21, which are different from those in the examples described above. For example, the first partition wall members 42 and 43 and the second partition wall members 44 and 45 may have a curved surface.

[0087] The first separating element 42 and the second separating element 44 can be formed as a single piece. The first separating element 43 and the second separating element 45 can be formed as a single piece. The first separating elements 42 and 43, the second separating elements 44 and 45, and the third separating element 48 can be formed as a single piece.

[0088] The housing 40 may be mounted at a location other than under the floor of the vehicle body 100. For example, the housing 40 may be mounted on the roof of the vehicle body 100.

[0089] The foregoing describes some exemplary embodiments for explanatory purposes. Although specific embodiments have been presented in the foregoing discussion, those skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention will be defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. List of reference symbols 1, 2, 3 Power conversion device 1a, 1b connection 10 Transformer 10a Primary winding 10b, 10c Secondary winding 10d iron core 11, 21 power unit 12, 22 converters 13, 23 inverters 31 Contactor control circuit 32 Power unit control circuit 40 housings 40a, 40b Wall 41a, 41b opening 42, 43 First separating element 42a, 42b, 43a, 43b First air hole 44, 45 Second separating element 44a, 45a Second air hole 46, 47 Blower 48 Separator 50, 60 coolers 51, 61 base 52, 62 rib 53, 63 Cover 53a, 63a air hole 71 First compartment 72 Second compartment 73 Third compartment 74 Fourth compartment 75 Fifth compartment 76 Sixth compartment 77 Seventh compartment 100 vehicle body 101 fitting FC11, FC12, FC21, FC22 filter capacitor IM1, IM2, IM3, IM4 engine MC1, MC2 contactor QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2009-96460

[0003]

Claims

[1] Power conversion device comprising: Performance units, each comprising capacitors connected in series and a power conversion circuit having primary terminals between which the capacitors are connected, the power conversion circuit being configured to convert direct current supplied via the capacitors into electrical power to be supplied to a load device; Fans provided for the respective power units to generate air flows that flow through the corresponding power units; a housing designed to accommodate the power units and the fans; Bases with thermal conductivity on which the respective power units are provided; and Coolers that are thermally coupled to the respective bases and are arranged outside the case at positions on both sides of the case in a horizontal direction, wherein the capacitors contained in each of the power units are arranged with a cavity therebetween in a direction away from a main surface of the base to which the power unit is attached. [2] The power conversion device according to claim 1, wherein each of the fans generates an airflow that flows through the cavity between the capacitors included in the corresponding power unit. [3] Power conversion device according to claim 1 or 2, wherein at least one of the bases is attached to one of two housing walls, the two walls being arranged between the coolers and facing each other in the horizontal direction, and at least one other of the bases is attached to the other of the two walls. [4] Power conversion device according to claim 3, wherein the power units comprise two power units arranged at positions adjacent to the respective two walls, and each of the coolers dissipates heat transferred from the power unit through the base, which is thermally coupled, to cooling air flowing along an outer surface of the wall to which the base is attached. [5] The power conversion device according to claim 3 or 4, further comprising: two first partition elements which are spaced apart from each other in a direction in which the two walls are opposite each other, are aligned such that main surfaces of the two first partition elements are parallel to the two walls, and are designed to divide an interior space of the housing, wherein each of the power units is arranged between one of the two walls and one of the two first partition elements next to one wall. [6] The power conversion device according to claim 5, wherein each of the two first separating members includes a first air hole. [7] The power conversion device according to claim 6, wherein each of the fans is arranged near the corresponding first air hole. [8] Power conversion device according to one of claims 5 to 7, further comprising: at least one second partition element having a main surface extending in the direction in which the two walls face each other and in a vertical direction, each separating a space between one of the two walls and one of the two first partition elements adjacent to the one wall. [9] The power conversion device according to claim 8, further comprising: a power unit control circuit for controlling switching elements included in each of the power units, wherein the power unit control circuit is arranged at a position adjacent to one of the power units via the at least one second separating element. [10] The power conversion device according to claim 8 or 9, further comprising: a contactor for electrically connecting each of the power units to a power source or for electrically disconnecting each of the power units from the power source, wherein the contactor is arranged at a position adjacent to one of the power units via the at least one second isolating element. [11] The power conversion device according to claim 10, further comprising: a contactor control circuit for closing or opening the contactor, whereby the contactor control circuit is arranged at a position adjacent to one of the power units via the at least one second isolating element. [12] The power conversion device according to any one of claims 8 to 11, wherein each of said at least one second separating member comprises a second air hole. [13] The power conversion device according to claim 12, wherein each of the fans is arranged near the second air hole. [14] A power conversion device according to claim 7 or 13, wherein the fans supply air to the respective power units. [15] Power conversion device according to claim 13, wherein the at least one second separating element comprises two second separating elements, one of the two second dividing elements separates a space between one of the two walls and one of the two first dividing elements next to one of the walls, the other of the two second dividing elements separates a space between the other of the two walls and the other of the two first dividing elements next to the other wall, one of the fans, which is arranged vertically above in the vicinity of the second air hole of the one second separating element, supplies air in a direction away from the corresponding power unit, and another of the fans, arranged vertically below near the second air hole of the other second partition member, supplies air toward the corresponding power unit.

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