JP6429720B2 - Power converter and railway vehicle - Google Patents

Description

  The present invention relates to a power conversion device, and more particularly, to a power conversion device and a railway vehicle configured using a 2 in 1 semiconductor switching element.

  In recent years, power converters typified by inverters and converters are equipped with a plurality of semiconductor modules including IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

  The material constituting the semiconductor module has been developed centering on Si (Silicon), but application of wide gap semiconductors such as SiC (Silicon Carbide) and GaN (Gallium Nitride) has been studied for further reduction of loss. SiC can speed up the switching operation compared with Si, and can reduce switching loss.

  On the other hand, in order to form a stack by compactly storing a power conversion device including a plurality of semiconductor switching elements in a housing, it is desired that the semiconductor switching elements be small. As a technique for miniaturization, it is known to provide a module with two elements (a 2-in-1 semiconductor switching element module) in which a leg formed by connecting two semiconductor switching elements in series is used as one unit.

  Patent Document 1 relates to a stack structure of a power conversion device configured using a module with two elements. Specifically, "one or more power conversion circuits that perform multiphase AC output or input, a plurality of power semiconductor elements connected in parallel, a radiator for cooling these power semiconductor elements, and a radiator In a stack structure of a power conversion device configured with a cooling fan, when the power semiconductor element is disposed on the radiator, the phase is parallel to the ventilation direction of the radiator cooling fan for each phase. The stack structure of the power conversion device characterized by being arranged in the "."

JP 2006-42406 A

  According to the stack structure of the power conversion device according to Patent Document 1 configured using a module including two elements, it is possible to reduce the size, but this is not sufficient from the viewpoint of cooling the semiconductor switching element. Although the detailed reason will be clarified in the embodiment of the present invention, the longitudinal direction of the module configured in a rectangular shape and the ventilation direction of the cooling fin attached to the stack are optimized by using the module with two elements. There is no reason for it.

  In view of the above, it is an object of the present invention to provide a stack-type power conversion device and a railway vehicle that are compact and take into consideration the improvement in cooling performance.

From the above, in the present invention, the cooling air flows in one direction along the one surface of the heat receiving block in the present invention , and the power conversion that switches the direct current and the alternating current to the other surface of the heat receiving block. A power conversion device in which a plurality of modules of 2-in-1 switching elements constituting a circuit are arranged, and a smoothing capacitor is connected to the module via a bus bar,
About the other side of the heat receiving block, the module is arranged in a second direction whose longitudinal direction is orthogonal to the first direction, and a plurality of the modules of each AC phase are arranged in series along the second direction. And arranged in the first direction of the module of the phase, and arranged at the end of the second side of the other surface of the heat receiving block. Giving an ignition signal from the gate drive device to the plurality of modules in each phase;
Two upper and lower U-shaped positive and negative bus bars are arranged on the upper surface side of the other surface where the plurality of modules of the heat receiving block are arranged, and the other bus bar is arranged in one bus bar and the other bus bar. Placing the capacitor for smoothing in the internal space
The power conversion device is characterized in that the electrodes formed on the plurality of modules and the smoothing capacitor are electrically connected to each other by pressure bonding to the bus bar .

  It is possible to provide a power conversion device and a railway vehicle having a stack structure that is compact and takes cooling performance into consideration.

The figure which shows the positional relationship of each module of a semiconductor module, the heat receiving block which supports and mounts the said module, and a cooling fin. The figure which shows the circuit structure of a general three-phase power converter device. The perspective view which showed the connection relationship between a capacitor | condenser, a semiconductor module, and a positive / negative bus bar. The figure which shows the arrangement | positioning and connection relationship of FIG. 1, FIG. The figure which showed the positional relationship of the arrangement | positioning of a 2 in 1 module arrange | positioned on a heat receiving block, and an electrode.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a circuit configuration of a general power conversion device will be described with reference to FIG.

  In FIG. 2, the power converter 5 includes capacitors 102 and 103 that smooth the DC power supply 101 and switching elements Q1 to Q6. Although this figure illustrates a three-phase circuit, it may be a single-phase circuit or a multi-phase circuit having three or more phases. When the switching elements Q1, Q2 and Q3, Q4, and the 2-in-1 module in which Q5 and Q6 are the same modules are used, the power conversion device 5 includes the semiconductor module 108 having the switching elements Q1 and Q2, and the switching elements Q3 and Q4. And a semiconductor module 1110 having switching elements Q1 and Q2.

  The capacitors 102 and 103 may be either electrolytic capacitors or film capacitors. In order to increase the capacity of the capacitors 102 and 103, a large number of capacitor cells having a small capacity may be connected in parallel. Here, when the switching elements Q1 to Q6 are IGBTs, it is necessary to connect the diodes D1 to D6 in parallel in the opposite direction to the IGBT, and when the switching elements Q1 to Q6 are MOSFETs, the diodes D1 to D6 are required. A MOSFET parasitic diode can be used as D6. In addition, the drain electrode of the switching element Q1 is indicated by D, the gate electrode is indicated by G, and the source electrode is indicated by S.

  The semiconductor module 108 is configured by connecting switching elements Q 1 and Q 2 in series, and a connection point between the switching elements Q 1 and Q 2 is a U-phase AC output point to the motor 111. Similarly, the semiconductor module 109 is configured by connecting switching elements Q3 and Q4 in series, and a connection point between the switching elements Q3 and Q4 is a V-phase AC output point to the motor 111. The semiconductor module 110 is configured by connecting switching elements Q5 and Q6 in series, and a connection point between the switching elements Q5 and Q6 is a W-phase AC output point to the motor 111.

  Wiring is used to electrically connect the capacitors 102 and 103 and the semiconductor modules 108, 109 and 110. This wiring has parasitic inductances 104, 105, and 106, and their values depend on the wiring material, length, and shape.

  For the main purpose of reducing and making the parasitic inductances 104, 105 and 106 uniform, when the stack structure is used, the wiring portion of the electric circuit of FIG. In the electric circuit of FIG. 2, the specific bus bar constituent part is that the wiring between the positive side electrodes of the capacitors 102 and 103 and the positive side electrodes of the semiconductor modules 108 to 110 is the bus bar 201, and the negative side electrodes of the capacitors 102 and 103 are The wiring between the negative electrodes of the semiconductor modules 108 to 110 is referred to as a bus bar 202. Moreover, it is good to comprise between the connection point of the serial switching element of the semiconductor modules 108-110 and the motor 311 which is a load by the bus bar 203 for every phase.

  FIG. 3 is a perspective view showing a connection relationship among the capacitors 102 and 103, the semiconductor modules 108 to 110, and the positive and negative bus bars 201 and 202. The positive and negative bus bars 201 and 202 are formed by two large and small U-shaped copper plates, and the positive bus bar 201 is disposed in the negative bus bar 202, for example. Capacitors 102 and 103 are arranged in the internal space of two large and small U-shaped copper plates 201 and 202. Between the positive and negative bus bars 201, 202 formed of two large and small U-shaped copper plates and the capacitors 102, 103, for example, positive and negative electrodes 301, 302 fixed in advance on the capacitors 102, 103 side are connected to the bus bars 201, 202. The electrodes 301 and 302 are screwed from the bus bar 201 and 202 side to be electrically connected.

  Connection between the capacitors 102 and 103 and the positive and negative bus bars 201 and 202 is performed using both side plate portions of the U-shaped bus bars 201 and 202, and the semiconductor modules 108 to 110 and the positive and negative bus bars 201 and 202 are connected. The connection between the two is performed using the bottom plate portions of the U-shaped copper plates 201 and 202. Although not clearly shown in the figure, when the positive bus bar 201 is arranged in the negative bus bar 202, it is assumed that insulation between both bus bars is secured. Further, in order for the negative electrode 302 to be connected to the negative bus bar 202, it is necessary to pass through a hole formed in the positive bus bar 201. In this case, insulation is also ensured.

  Next, referring to FIG. 3, the connection relationship between the semiconductor modules 108 to 110 and the positive and negative bus bars 201 and 202 will be described. In the illustrated example, each of the semiconductor modules 108 to 110 shows a case where three modules are connected in parallel in order to obtain a large current. As shown in the figure, between each module of the positive and negative bus bars 201 and 202 formed of two large and small U-shaped copper plates and semiconductor modules 108 to 110 connected in parallel in three modules for each phase, for example, each module 108 The positive and negative electrodes 401 and 402 fixedly installed on the ˜110 side are pressed against the bus bars 201 and 202, and the electrodes 401 and 402 are screwed from the bus bar 201 and 202 side to be electrically connected.

  FIG. 1 is a diagram showing a positional relationship between each of the semiconductor modules 108 to 110 and the heat receiving block 7 and the cooling fin 4 that support and mount the module. The heat receiving block 7 has each module (108a, 108b, 108c, 109a, 109b, 109c, 110a, 110b, 110c) and the gate drive device G / D arranged on one side and cooled on the other side. A plurality of fins 4 are arranged. In FIG. 1, the display of electrodes for connecting each module to other parts is omitted, but the connection relationship will be described separately with reference to FIG.

  This FIG. 1 shows a case where three modules are connected in parallel in order to obtain a large current. The 2 in 1 modules 108a, 108b and 108c are connected to the U phase of AC, and the 2 in 1 modules 109a, 109b and 109c are AC. The 2 in 1 modules 110a, 110b, and 110c are connected to the AC W phase.

As shown in FIG. 1, in the case of the present invention, the 2-in-1 module (108a, 108b, 108c, 109a, 109b, 109c, 110a, 110b, 110c) has a rectangular shape, and the longitudinal direction is the vertical direction 30 shown in the figure. It is arranged. On the other hand, the direction of the cooling air passing through the cooling fins 4 is the horizontal direction 40 shown in the figure, and the directions 30 and 40 are orthogonal to each other. In this figure, since 108 is the U phase, 109 is the V phase, and 110 is the W phase, the direction of the phase-specific module is also arranged in the longitudinal direction 30.

According to FIG. 1, it is clear that the length of the cooler in the direction in which the cooling air flows is shorter than the length in the direction orthogonal to the cooling air.

The present invention is characterized in that the longitudinal direction of the rectangular 2 in 1 module is arranged in a direction orthogonal to the direction of the cooling air passing through the cooling fins 4. This is because the installation size of the 2 in 1 module in the cooling air flow direction can be reduced by setting the 2 in 1 module vertically, and as a result, the ventilation resistance between the cooling fins 4 can be reduced, and the cooling air between the cooling fins 4 can be reduced. This is explained by the fact that the cooling efficiency is improved and the cooling efficiency is improved, so that the cooling fins 4 can be miniaturized.

  4 is a diagram showing the arrangement and connection relationship of FIGS. 1 and 3, where the left side of FIG. 4 is the capacitor side of FIG. 3 and the right side of FIG. 4 is the cooling fin 4 side. Here, the power converter 5 is mounted under the floor of the railway vehicle in the direction shown in FIG. That is, there is a railroad car floor on the upper side and a track on the lower side shown in FIG. The cooling air 40 is mounted in a direction in which the direction of the cooling air 40 coincides with the traveling direction of the railway vehicle. Further, the left semiconductor module and the condenser are housed in the housing from the heat receiving block 7, and the right cooling fin 4 is exposed from the heat receiving block 7 to the underfloor space of the railway vehicle, so that the cooling air 40 generated when the railway vehicle travels is generated. Passes between the cooling fins 4.

  In this figure, the positive and negative bus bars 201 and 202 formed of two large and small U-shaped copper plates have a U-shaped shape, and the U-shaped of the positive bus bar 201 is placed inside the negative bus bar 202. The shape is visible. Capacitors 102 and 103 are stacked in two stages in the height direction, and electrodes 102 are connected between capacitors 102 and 103 and negative bus bar 202. Similarly, the capacitors 102 and 103 and the positive bus bar 201 are connected by an electrode 301.

  From each of the 2-in-1 modules 108, 109, and 110 stacked in three stages in the height direction, electrodes are arranged toward three types of bus bars. Two of them are electrodes 401 and 402 for connection to the positive and negative bus bars 201 and 202. The third electrode is directed to the bus bar 203 for obtaining the AC output of FIG. Three bus bars 203U, 203V, and 203W for AC U, V, and W phases are plate-shaped members formed in an L shape, and are not shown in the figure but are bent (shown by dotted lines). Thus, the 2-in-1 modules 108, 109, and 110 for each phase are connected in common. The bus bars 203U, 203V, and 203W are connected to the motor 311.

As is apparent from the left side of FIG. 4, in this arrangement, the smoothing filter capacitors 102 and 103 are arranged on the projection surface of the heat receiving block 7 of the cooler, and the terminals 301 and 302 of the filter capacitors 102 and 103 are cooled. It arrange | positions at the both sides of the direction (vertical up-down direction) orthogonal to the direction 40 where a wind flows.

  FIG. 5 is a diagram showing the arrangement of the 2-in-1 modules arranged on the heat receiving block 7 and the positional relationship of the electrodes. It is a figure which shows the AA cross section of FIG. According to this figure, the U phase, V phase, and W phase of alternating current are formed from the lower stage to the upper stage on the heat receiving block 7, and each phase (each stage) is arranged in three modules in parallel to increase the current. It is. Therefore, in order to increase the current, it is only necessary to increase the number of parallel modules in the lateral direction (that is, the traveling direction of the railway vehicle), and it is not necessary to increase the vertical dimension under the floor where there are severe restrictions. It can also be applied to products that require a large current.

  In each module, the upper two circles are the positive electrodes 401, the next two circles are the negative electrodes 402, and the bottom two circles are the electrodes 403 that reach the AC terminal. FIG. 5 shows the AA cross section of FIG. 4, so the AC output bus bars 203U, 203V, and 203W are not shown on this figure. However, for convenience, as indicated by the dotted lines. It is.

  Further, according to the arrangement of FIG. 5, the gate drive device G / D that gives positive and negative firing signals to the respective semiconductor elements of the 2-in-1 module on the left side position is adjacent to the respective semiconductor elements of the 2-in-1 module constituting one phase. Is placed in. In this configuration, it is possible to transmit ignition signals to a plurality of modules connected in parallel and constituting one phase from the lateral direction through the signal lines 33U, 33V, and 33W, even if the number of modules increases. Free expansion is possible without considering the contact with other parts.

According to FIG. 1 and FIG. 5 in which the features of the present invention are clearly shown, the module is vertically placed so that the longitudinal direction of the module is orthogonal to the ventilation direction. Moreover, the several phase comprised by a 2 in 1 switching element is arrange | positioned in the direction orthogonal to cooling air. As a result, in the present invention, the cross-sectional structure is common even if the number of modules in parallel increases, and design expansion is extremely easy.

  Assuming that the stack is mounted on a vehicle, the rail direction of the power unit can be configured with an optimal dimension according to the control capacity of the motor 311. Incidentally, in a vehicle-mounted scene, the upper part of FIG. 5 is fixedly attached to the lower part of the vehicle. When the control capacity is large, the box longitudinal direction is large, and when the control capacity is small, the box longitudinal direction is small.

  Moreover, cooling can be performed efficiently for the reason described above in comparison with the patent literature. In addition, although the said description illustrated about the case where it electrically feeds to a three-phase load, this may be a single phase load. Further, not only a two-level circuit but also a three-level circuit configuration may be used, regardless of an inverter or a converter. The cooler is not limited to fin cooling. The cooling air may be not only traveling air but also a fan.

According to the embodiments of the present invention described above, “a power conversion circuit that switches between direct current and alternating current, a 2 in 1 switching element that constitutes the power conversion circuit, a cooler for cooling the 2 in 1 switching element, and a smoothing filter” A gate drive device that sends signals to the capacitor and the switching element is provided, and the longitudinal direction of the 2 in 1 switching element is arranged in a direction orthogonal to the cooling air, and a plurality of phases that are configured by the 2 in 1 switching element are orthogonal to the cooling air By adopting the “power conversion device characterized by being arranged in the direction”, the effect that the longitudinal direction of the module is perpendicular to the cooling air and the cooling performance is improved is obtained.

  In addition, the gate drive device G / D is arranged at a position adjacent to the 2 in 1 element, thereby simplifying the signal line from the gate drive device G / D to the module (the wiring length is short and the wiring is not overlapped). Easy). The gate drive device G / D can be arranged within the height restriction, which can contribute to downsizing.

  The 2 in 1 switching elements are installed in different numbers depending on the control capacity, and the 2 in 1 switching elements connected in parallel are arranged so that each of them is arranged in the direction in which the cooling air flows. The signal line from D to the module can be simplified.

The smoothing filter capacitor is arranged on the projection surface of the heat receiving block of the cooler, and the terminals of the filter capacitor are arranged on both sides of the direction perpendicular to the direction of the cooling air flow, so that the main circuit current flows in the vertical direction. Since the gate signals of the gate drive device G / D flow in the left-right direction, there is an effect that the gate signals do not interfere with each other and noise is not easily applied to the gate signals. In this embodiment, the filter capacitor terminals are arranged on both sides in the direction orthogonal to the direction in which the cooling air flows, but may be arranged on one side in the direction orthogonal to the direction in which the cooling air flows. Even in this configuration, since the main circuit current flows in the vertical direction, there is an effect that noise is hardly applied to the gate signal.

The same effect can be obtained by arranging the smoothing filter capacitor on the projection surface of the heat receiving block of the cooler and arranging the terminals of the filter capacitor at one place on one side in the direction orthogonal to the direction in which the cooling air flows.

4: Cooling fin 5: Three-phase power converter 7: Heat receiving block 101: DC power supply 102, 103: Capacitors 104, 105, 106: Parasitic inductances 108, 109, 110: Semiconductor modules 201, 202, 203: Bus bar 301, 302, 401, 402, 403: Electrode 311: Motors Q1-Q6: Switching elements D1-D6: Diode D: Drain electrode G: Gate electrode S: Source electrode G / D: Gate drive

Claims (6)

A module of a 2-in-1 switching element that constitutes a power conversion circuit that switches a direct current and an alternating current on one surface of the heat receiving block so that cooling air flows in a first direction along the one surface and switches the direct current and the alternating current on the other surface of the heat receiving block. Is a power converter for connecting a smoothing capacitor to the module via a bus bar,
About the other side of the heat receiving block, the module is arranged in a second direction whose longitudinal direction is orthogonal to the first direction, and a plurality of the modules of each AC phase are arranged in series along the second direction. And a plurality of parallel modules constituting each AC phase arranged in the first direction of the module of the phase, and arranged at the end of the other side of the heat receiving block in the second direction. Giving firing signals to the plurality of modules of each phase from the drive device;
Two upper and lower U-shaped positive and negative bus bars are arranged on the upper surface side of the other surface where the plurality of modules of the heat receiving block are arranged, and the other bus bar is arranged in one bus bar and the other bus bar. Placing the capacitor for smoothing in the internal space
An electric power converter characterized in that electrodes formed on the plurality of modules and the smoothing capacitor are electrically connected to each other by pressure bonding to the bus bar. The power conversion device according to claim 1,
For the U-shaped bus bar composed of a bottom portion and side portions on both sides of the bottom portion, the bottom portion of the bus bar is positioned on the upper surface side of the other surface of the heat receiving block, and the side portion of the bus bar is The power converter is extended from the bottom side in a direction opposite to the direction of the heat receiving block with respect to the bottom side . The power conversion device according to claim 2,
The said side part of the said bus-bar is arrange | positioned along said 2nd direction, The power converter device characterized by the above-mentioned. The power conversion device according to claim 2 or 3, wherein
An electrode formed on the smoothing capacitor is electrically connected by being crimped to one or both of the side portions of the bus bar.   A railway vehicle on which the power conversion device according to any one of claims 1 to 4 is loaded. The railway vehicle according to claim 5,
The railroad vehicle, wherein the power conversion device is arranged such that the gate drive device arranged at an end portion in the second direction on the other surface of the heat receiving block is positioned on the lower side in the gravity direction.

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