Power converters and rail vehicles

Abstract

Power converter that includes: a plurality of semiconductor modules (108-110) provided therein with a plurality of switching devices (Q1-Q6); a heat absorption block (7) provided on a first side with the plurality of semiconductor modules (108-110) and a gate driver (G / D); a cooling fin (4) provided on a second side of the heat absorbing block (7); a filter capacitor (102, 103) electrically connected to the semiconductor modules (108-110) by means of busbars (201, 202); and the gate driver (G / D) for transmitting a control signal to the switching devices (Q1-Q6), wherein the semiconductor modules (108-110) are arranged in such a way that the longitudinal direction (30) of the semiconductor module (108-110) is oriented in a direction parallel to the cooling air (40) and the gate driver (G / D) is arranged perpendicular to the longitudinal direction (30) on the underside of the semiconductor module (108-110) in the direction of gravity; and the busbars (201, 202) comprise a positive busbar (201) and a negative busbar (202) and are formed by two U-shaped copper plates, one large and one small; and the filter capacitor (102, 103) is arranged in an interior space between the busbars (201, 202) designed as U-shaped copper plates.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a power converter, and more particularly relates to a power converter configured using a 2-in-1 semiconductor switching device and a railway vehicle. BACKGROUND OF THE INVENTION

[0002] In a power converter, which in recent years is typically an inverter or converter, a semiconductor module is mounted on which several IGBTs (insulated gate bipolar transistors) or MOSFETs (metal oxide semiconductor field effect transistors) are mounted to reduce loss.

[0003] Although Si (silicon) has been primarily developed as the material configuring the semiconductor module, the use of wide band-gap semiconductors such as SiC (silicon carbide) and GaN (gallium nitride) is being considered to further reduce loss. SiC can accelerate the switching speed compared to Si and can reduce switching loss.

[0004] On the other hand, it is desirable for semiconductor switching devices to be small in size to configure a stack by compactly accommodating a power converter configured by multiple semiconductor switching devices in one package. As a technique for downsizing, a two-device module (2-in-1 semiconductor switching device module) is known in which an arm configured by connecting two semiconductor switching devices in series is manufactured as a single unit.

[0005] JP 2006-42406 A relates to a stacked structure of the power converter configured using the two-device module. More specifically, the structure is "a stacked structure of a power converter characterized in that, in the stacked structure of a power converter configured by a plurality of power semiconductor devices connected in parallel to a power conversion circuit for performing multi-phase AC output or multi-phase AC input for each phase, a radiator for cooling the power conversion devices, and a radiator cooling fan, the power semiconductor devices, when arranged on the radiator, are arranged for each phase in parallel to the air flow direction of the radiator cooling fan.

[0006] EP 2 842 791 A2 relates to a power converter for rail vehicles comprising a filter capacitor that smooths a direct voltage, an overvoltage protection device that releases charge accumulated in the filter capacitor, a plurality of power switching elements that convert a direct voltage into an alternating voltage, a cooling unit that cools the power switching elements, and a conductor rail that electrically connects the filter capacitor, the overvoltage protection device and the power switching elements.

[0007] EP 2 675 053 A1 relates to a filter capacitor that stores direct current and a semiconductor device module that performs a switching operation that converts the direct current stored in the filter capacitor into alternating current. The filter capacitor and the semiconductor device module are electrically connected to each other via a laminated bus bar. The laminated bus bar includes a first bus bar and a second bus bar in which a plurality of connecting conductors are laminated through an insulator. The second bus bar is provided with heat-radiating portions formed by exposing a portion of the conductor in each flat plate surface. SUMMARY OF THE INVENTION

[0008] In a power converter with a stack configuration configured using a two-device module, downsizing, capacity increase, and countermeasures against heat generation are implemented simultaneously. Even in JP 2006-42406-A, the countermeasure has been implemented from these perspectives; however, it is insufficient from the perspective of a fully unified arrangement.

[0009] From the perspective of reducing thermal influence on a gate driver, which is particularly a single electronic component housed in a stack, a heat generation factor inside and outside the stack, in addition to a 2-in-1 semiconductor switching module including a CT and a core, is required. Furthermore, it is necessary to simplify the interior of the stack, which includes a gate wiring arrangement.

[0010] From the above, the present invention is intended to provide a railway vehicle and a power converter having a stack structure comprehensively considered from the viewpoints of downsizing and heat generation.

[0011] The above object is achieved by the subject matter of the independent claims. Preferred developments are described in the subclaims.

[0012] A rail vehicle and a power converter having a stacked structure are provided, which are comprehensively considered from the perspectives of downsizing and heat generation. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing a positional relationship between each module of the semiconductor modules, a heat receiving block that supports and mounts the modules, and cooling fins; Fig. 2 is a schematic diagram showing a circuit configuration of a general three-phase power converter; Fig. 3 is a perspective view illustrating a connection relationship between capacitors, the semiconductor modules, and bus bars; Fig. 4 is a schematic diagram showing an arrangement, a connection relationship between Fig. 1 and Fig. 3; and Fig. 5 is a schematic diagram illustrating an arrangement of 2-in-1 modules arranged on the heat receiving block and a positional relationship between electrodes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An example of the present invention will now be described with reference to the drawings. Example

[0014] First, Fig. 2 describes a circuit configuration of a general three-phase power inverter. Incidentally, the present invention is applicable to both the single-phase configuration and the multi-phase configuration including three or more phases; however, a case of three phases is described here.

[0015] In Fig. 2, a three-phase power converter 5 is configured by capacitors 102, 103 for smoothing the DC power 101 and by switching devices Q1-Q6. When the switching devices Q1, Q2 and Q3, Q4 and Q5, Q6 each use the 2-in-1 module of the same module, the three-phase power converter 5 is configured by a semiconductor module 108 including the switching devices Q1, Q2, a semiconductor module 109 including the switching devices Q3, Q4, and a semiconductor module 110 including the switching devices Q1, Q2.

[0016] The capacitors 102, 103 can be electrolytic capacitors and thin-film capacitors. To increase their capacitance, the capacitors 102, 103 can be configured by connecting multiple small-capacitance capacitor cells in parallel. Here, when the switching devices Q1-Q6 are IGBTs, the diodes D1-D6 must be connected in parallel in the opposite direction to the respective IGBTs. When the switching devices Q1-Q6 are MOSFETs, parasitic diodes of the MOSFETs can be used as the diodes D1-D6. Furthermore, a drain diode of the switching device Q1 is described in D, a gate diode is described in G, and a source diode is described in S.

[0017] The semiconductor module 108 is configured by the switching devices Q1 and Q2 connected in series, and the connection point of the switching devices Q1 and Q2 becomes the U-phase AC output for a motor 311. Similarly, the semiconductor module 109 is configured by the switching devices Q3 and Q4 connected in series, and the connection point of the switching devices Q3 and Q4 becomes the V-phase AC output point for the motor 311. The semiconductor module 110 is configured by the switching devices Q5 and Q6 connected in series, and the connection point of the switching devices Q5 and Q6 becomes the W-phase AC output point for the motor 311.

[0018] Wiring is used to electrically connect the capacitors 102, 103 and the semiconductor modules 108, 109, 110. The wiring contains parasitic inductances 104, 105, 106, whose values depend on the material, length, and shape of the wiring.

[0019] If the stack structure is designed primarily to reduce and uniform the parasitic inductances 104, 105 and 106, the wiring part of the electrical circuit is made of Fig. 2 configured by busbars. In the electrical circuit of Fig. 2, for a specific busbar configuration part, the wiring between the positive-side electrodes of the capacitors 102, 103 and the positive-side electrodes of the semiconductor modules 108-110 is established by a busbar 201, and the wiring between the negative-side electrodes of the capacitors 102, 103 and the negative-side electrodes of the semiconductor modules 108-110 is established by a busbar 202. Furthermore, it is preferable to configure the wiring between the connection point of the series connection devices of the semiconductor modules 108-110 and a motor 311, which is a load, for each phase by a busbar 203.

[0020] Fig. 3 is a perspective view illustrating a connection relationship between the capacitors 102, 103, the semiconductor modules 108-110, and the bus bars 201, 202, 203. Among them, for example, for the bus bars 201, 202, a positive and a negative bus bar 201, 202 are formed by two U-shaped copper plates, a large one and a small one, with the positive bus bar 201 being arranged inside the negative bus bar 202. The capacitors 102, 103 are arranged in an interior space of the two U-shaped copper plates 201, 202, a large one and a small one. Between the positive and the negative bus bars 201, 202 formed by the two U-shaped copper plates, a large one and a small one, and the capacitors 102, 103, for example,a positive and a negative electrode 301, 302, which are installed so as to be fixed in advance to the sides of the capacitors 102, 103, are crimped to the busbars 201, 202, the electrodes 301, 302 being screwed from the sides of the busbars 201, 202 so as to be electrically connected.

[0021] The two side plate portions of the U-shaped busbars 201, 202 are used for connections between the capacitors 102, 103 and the positive and negative busbars 201, 202, and the bottom plate portions of the U-shaped copper plates 201, 202 are used for connections between the semiconductor modules 108-110 and the positive and negative busbars 201, 202. Incidentally, although not clearly shown in the diagram, insulation between both busbars is ensured when the positive busbar 201 is disposed within the negative busbar 202. Furthermore, insulation is also ensured in this case, although the negative electrode 302 must pass through a hole portion opened in the positive busbar 201 to be connected to the negative busbar 202.

[0022] Below is Fig. 3 describes a connection relationship between the semiconductor modules 108-110 and the positive and negative bus bars 201, 202. Incidentally, in the example of the illustration, a case is shown in which each of the semiconductor modules 108-110 has three modules connected in parallel to make the current large. As shown in the figure, between the positive and negative bus bars 201, 202, which are formed by two U-shaped plates, one large and one small, and each module of the semiconductor modules 108-110 for each phase, with three modules connected in parallel, for example, a plurality of parallel conductors are provided. For example, the positive and negative electrodes 401, 402, which are installed so as to be fixed in advance to each of the sides of the modules 108-110, are crimped to the busbars 201, 202, and the electrodes 401, 402 are screwed from the sides of the busbars 201, 202 so as to be electrically connected.Although the positive electrode 401 has to pass through a hole part opened in the negative bus bar 202 to be connected to the positive bus bar 201, the insulation is also ensured in this case.

[0023] In addition, Fig. 3 shows the busbar 203 for externally outputting the AC output from the semiconductor modules 108-110. If Fig. 3, the plurality of parallel semiconductor modules 108 are connected to a U phase of a three-phase AC, the plurality of parallel semiconductor modules 109 are connected to a V phase, and the plurality of parallel semiconductor modules 110 are connected to a W phase. The parallel semiconductor modules of each phase are commonly connected to an external output using the bus bars 203U, 203V, 203W of each phase. The diagram shows external connection parts of the bus bar 203. The bus bars 203U, 203V, 203W are L-shaped plate materials and commonly connect the electrodes 403 of the parallel semiconductor modules of each phase through the bent rear part.

[0024] Fig. 1 is a schematic diagram illustrating a positional relationship between each module of the semiconductor modules 108-110, a heat receiving block 7 for supporting and mounting the modules, and cooling fins 4. On the heat receiving block 7, each module (108a, 108b, 108c, 109a, 109b, 109c, 110a, 110b, 110c) of the semiconductor modules 108-110 and a gate driver G / D are arranged on one side, and the plurality of cooling fins 4 are arranged on the other side. Incidentally, in Fig. 1 the specification of the electrode for connecting each module with the other part is omitted; however, the connection relationship is shown by Fig. 4 described separately.

[0025] Fig. 1 illustrates the case where three modules are connected in parallel to make the current high, where there is a relationship in which the 2-in-1 modules 108a, 108b, 108c are connected to the AC U phase, and the 2-in-1 modules 109a, 109b, 109c are connected to the AC V phase, and the 2-in-1 modules 110a, 110b, 110c are connected to the AC W phase.

[0026] As in Fig. 1, the 2-in-1 module (108a, 108b, 108c, 109a, 109b, 109c, 110a, 110b, 110c) in the case of the present invention has a rectangular shape and is arranged such that the longitudinal direction runs in the left-right direction 30 of the illustration. On the other hand, the direction of the cooling air passing through the cooling fins 4 is also a left-right direction 40 of the illustration. The power converter 5 is here in the Fig. 4 under the floor of a rail vehicle. That is, at the position shown in Fig. The top side shown in Figure 4 is a floor material of the rail vehicle, and the bottom side is a track. Furthermore, the power converter 5 is mounted so that the direction of the cooling air 40 is adapted to the traveling direction of the rail vehicle. Furthermore, the semiconductor modules and the capacitors on the left side of the heat absorbing block 7 are housed in a casing, and the cooling fins 4 on the right side are exposed from the heat absorbing block 7 to the underbody space of the rail vehicle, with the cooling air 40 generated during the traveling of the rail vehicle passing between the cooling fins 4.

[0027] Fig. 4 is a schematic diagram showing an arrangement of a connection relationship between Fig. 1 and Fig. 3, where the left side of Fig. 4 the capacitor side Fig. 3 and the right side of Fig. 4 is the side of the cooling fins 4. In the figure, for the positive and negative busbars 201, 202 formed by the two U-shaped copper plates, the large and the small, the U-shaped side plate part of the negative busbar 202 of the outer side appears at the front in the illustration. The capacitors 102, 103 are stacked in two positions in the depth direction, with only the capacitor 103 indicated in the illustration, and in the side plate part, a screw part 500 of the negative electrode 301 can be seen, which connects the capacitor 103 and the negative busbar 202.

[0028] As in Fig. 1, the 2-in-1 modules are arranged so that the longitudinal direction runs in the left-right direction and stacked in three positions in the height direction. In the case of Fig. 4 the 2-in-1 modules 108a, 108b, 108c can be seen arranged transversely.

[0029] Each of the 2-in-1 modules 108, 109, 110 has electrodes arranged in the direction of three types of busbars. Two of the electrodes are the electrodes 401, 402 for connection to the positive and negative busbars 201, 202. The specification of the 2-in-1 module from Fig. Figure 4 illustrates that the top terminals are the electrodes 401, 402 and that they are connected to the positive and negative bus bars 201, 202.

[0030] The third electrode is directed to the bus bar 203 to receive the AC output from Fig. 2. The three busbars 203U, 203V, and 203W for the AC-U, AC-V, and AC-W phases are plate-like elements formed in L shapes, and are connected to the 2-in-1 modules 108, 109, and 110 via electrodes 403 at the unillustrated bent portions (shown by dotted lines) for each phase. The motor 311 is connected to the busbars 203U, 203V, and 203W.

[0031] As from Fig. 4, viewed from the left side, in this arrangement, the filter capacitors 102, 103 are arranged for smoothing on a protrusion plane of the heat receiving block 7 of a radiator, and the terminals 301, 302 of the filter capacitors 102, 103 are arranged on both sides (left-right) in the same direction as the flow direction of the cooling air. Although the terminals 301, 302 of the filter capacitors 102, 103 are configured here to be arranged on both sides of the filter capacitors, the terminals may be configured to be arranged on one side.

[0032] Fig. Figure 5 is a schematic diagram showing an arrangement of the 2-in-1 modules arranged on the heat receiving block and a positional relationship between the electrodes. It is a schematic diagram showing a cross section AA of Fig. 4. In the figure, there is a configuration in which the AC-U phase, the AC-V phase, and the AC-W phase are formed in the left-right direction on the heat dissipation block 7, and multiple parallel modules of each phase are arranged in the height direction, and three modules are arranged in parallel to make the current high. Thus, the number of parallel modules in the height direction can be increased as the current is increased. Incidentally, in each module, the left two circles are the positive electrodes 401, the next two circles are the negative electrodes 402, and the right two circles are the electrodes 403 leading to AC terminals.

[0033] In addition, the arrangement of Fig. 5, at the bottom position, the gate drivers G / D for providing a positive and a negative control signal to each semiconductor device of the 2-in-1 module are arranged at a position adjacent to the bottom of each semiconductor device of the 2-in-1 module that configures a phase. With this configuration, it is possible to transmit the control signals collectively from the bottom to the modules connected in parallel in the height direction to configure a phase, and it is possible to expand freely without considering mixed contact and the like even when the number of modules is increased. This is because the gate wiring structure (layered bus bar structure) is simple.

[0034] If the power converter of the stack configuration consists of Fig. 5 is mounted on the rail vehicle, it is preferably arranged, for example, at the bottom of the rail vehicle, with the top side of the illustration at the top; in this case, the thermal influence on the gate driver G / D, which is the only electronic component in the stack, can be reduced. Since the heat in the stack is mainly generated in the semiconductor module and the heated air rises, the gate driver G / D arranged below the semiconductor module is not heated by the heated air.

[0035] Furthermore, since the modules are arranged transversely, this arrangement allows for a reduced height in the direction of gravity. As a result, an upper space in a box configuration can be effectively utilized, and the core and CT, which are the heat-generating components, are located in the upper space. This helps further reduce the thermal impact on the gate driver G / D, which is the only electronic component in the stack.

[0036] There Fig. 5 a schematic representation of the side of the heat absorption block 7 in the cross section AA of Fig. 4, the busbars 203U, 203V, 203W are not specified; however, they are in Fig. 5 is indicated by the dotted line for ease of understanding. Each of the busbars 203U, 203V, 203W is arranged together at the electrodes 403 of the modules of each phase in the height direction. In the arrangement of Fig.5, here, the busbars 203U, 203V, 203W through which large AC currents flow, and the signal lines 33U, 33V, 33W through which weak control signals flow are arranged in the same direction; however, the other busbars 201, 202 are arranged between the signal lines 33U, 33V, 33W and the busbars 203U, 203V, 203W, and the signal lines 33U, 33V, 33W and the busbars 203U, 203V, 203W are arranged at positions spaced from each other; so that the signal lines are hardly affected by the large currents flowing through the busbars 203U, 203V, 203W.

[0037] Although the above description is based on the example of supplying power to a three-phase load, the load may be a single-phase load. Furthermore, the circuit configuration can be not only two-level, but also three-level, and it can be from the inverter or converter. Furthermore, the cooling system is not limited to fin cooling. The cooling air can be not only airflow but also fan-assisted.

[0038] According to the above-described example of the present invention, the power converter includes "a plurality of semiconductor modules provided therein with a plurality of switching devices; a heat receiving block provided on one side with the plurality of semiconductor modules; a cooling fin provided on the other side of the heat receiving block; a filter capacitor electrically connected to the semiconductor modules; and / or a gate driver for transmitting a control signal to the switching devices; the semiconductor modules are arranged such that the longitudinal direction of the semiconductor module is oriented in a direction parallel to the cooling air, and the gate driver is arranged on a lower side in the direction of gravity," so that the signal lines from the gate driver G / D to the modules can be simplified (the wiring length is shortened, the wiring is not overlapped to be easily wired).In addition, an effect can be obtained that the gate driver G / D is hardly affected by heat since it is positioned on the bottom.

[0039] In addition, the "plural semiconductor modules are arranged on one side of the heat receiving block in a flow direction of the cooling air and in a direction perpendicular to the flow direction at a plurality of positions, and the plural semiconductor modules arranged in the direction perpendicular to the flow direction of the cooling air are connected to a common gate driver to configure one phase of a conversion circuit," so that the gate driver G / D can be further arranged in the height restriction.

[0040] Furthermore, "a filter capacitor for smoothing is arranged on a protrusion plane of the heat-absorbing block of a radiator, and terminals of the filter capacitor are arranged on one side or both sides in the same direction as the flow direction of the cooling air." Therefore, since the circuit current flows in the left-right direction and the gate control signal of the gate driver G / D flows in the up-down direction, the circuit current and the gate control signal do not interfere with each other, and noise hardly enters the gate control signal. In the example, the terminals of the filter capacitor are configured to be arranged on one side or both sides in the same direction as the flow direction of the cooling air, and they may be configured to be arranged on one side or both sides in the direction perpendicular to the flow direction of the cooling air.Although in this configuration, the effect that the noise hardly enters the gate control signal cannot be obtained because the main circuit current and the gate control signal of the gate driver G / D flow in the up-down direction, the noise problem can be solved by appropriately designing the distance between the power rails and the signal lines of the gate control signal.

Claims

[1] Power converter, which includes: a plurality of semiconductor modules (108-110) provided therein with a plurality of switching devices (Q1-Q6); a heat absorption block (7) provided on a first side with the plurality of semiconductor modules (108-110) and a gate driver (G / D); a cooling fin (4) provided on a second side of the heat absorbing block (7); a filter capacitor (102, 103) electrically connected to the semiconductor modules (108-110) by means of busbars (201, 202); and the gate driver (G / D) for transmitting a control signal to the switching devices (Q1-Q6), wherein the semiconductor modules (108-110) are arranged in such a way that the longitudinal direction (30) of the semiconductor module (108-110) is oriented in a direction parallel to the cooling air (40) and the gate driver (G / D) is arranged perpendicular to the longitudinal direction (30) on the underside of the semiconductor module (108-110) in the direction of gravity; and the busbars (201, 202) comprise a positive busbar (201) and a negative busbar (202) and are formed by two U-shaped copper plates, one large and one small; and the filter capacitor (102, 103) is arranged in an interior space between the busbars (201, 202) designed as U-shaped copper plates. [2] Power converter according to claim 1, wherein the plurality of semiconductor modules (108-110) are arranged on the first side of the heat absorption block (7) at a plurality of positions in a flow direction of the cooling air (40) and in a direction perpendicular to the flow direction, and the plurality of semiconductor modules (108-110) arranged in the direction perpendicular to the flow direction of the cooling air (40) are connected to a common gate driver to configure one phase of a conversion circuit. [3] Power converter according to claim 1, wherein a filter capacitor (102, 103) for smoothing is arranged on the first side in a plane parallel to the arrangement plane of the semiconductor modules on the heat absorption block (7) of a cooler; and the connections (301, 302) of the filter capacitor (102, 103) are screwed from one side of the mutually perpendicular sections of the busbars (201, 202) and are arranged on each of the two section sides in the same direction as the flow direction of the cooling air (40). [4] Power converter according to claim 1, wherein a filter capacitor (102, 103) for smoothing is arranged on the first side in a plane parallel to the semiconductor module projection plane side of the heat receiving block (7) of a cooler; and the terminals (301, 302) of the filter capacitor (102, 103) are screwed at a location on the mutually perpendicular sections of the busbars (201, 202) and are arranged on a side of the filter capacitor (102, 103) opposite one of the mutually perpendicular sections of the busbars (201, 202) in the same direction as the flow direction of the cooling air (40). [5] Power converter according to claim 1, wherein a filter capacitor (102, 103) for smoothing is arranged on the first side in a plane parallel to the left side of the semiconductor module projection plane side of the heat absorption block (7) of a cooler; and the terminals (301, 302) of the filter capacitor (102, 103) are arranged on both sides of the filter capacitor (102, 103) in the direction perpendicular to the flow direction of the cooling air (40). [6] Power converter according to claim 1, wherein a filter capacitor (102, 103) for smoothing is arranged on the first side in a plane parallel to a semiconductor module arrangement plane of the heat absorption block (7) of a cooler; and the terminals (301, 302) of the filter capacitor (102, 103) are arranged on one side of the filter capacitor (102, 103) opposite one of the mutually perpendicular sections of the busbars (201, 202) in the direction perpendicular to the flow direction of the cooling air (40). [7] A power converter configured such that cooling air (40) flows in a transverse direction (30) on one side of a heat absorbing block (7), and a plurality of 2-in-1 switching device modules are arranged on another side of the heat absorbing block (7), which configure a power conversion circuit for switching between DC power and AC power, wherein on the other side of the heat absorption block (7), the modules are arranged in such a way that the longitudinal direction of the module is a transverse direction (30) and the module of each AC phase is arranged in the transverse direction (30), and a plurality of parallel modules configuring each phase are arranged one below the other in the height direction of the module of the phase, and a control signal for the plurality of modules of each phase is provided by the gate driver (G / D) arranged on the lower side in the height direction, wherein the power converter comprises a plurality of semiconductor modules (108-110) provided therein with a plurality of switching devices (Q1-Q6) and a filter capacitor (102, 103) electrically connected to the semiconductor modules (108-110) by means of busbars (201, 202), and wherein the busbars (201, 202) comprise a positive busbar (201) and a negative busbar (202) and are formed by two U-shaped copper plates, one large and one small, and the filter capacitor (102, 103) is arranged in an interior space between the busbars (201, 202) designed as U-shaped copper plates. [8] A rail vehicle equipped with the power converter according to any one of claims 1 to 7.

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