JP6368634B2 - Power converter and railway vehicle equipped with the same - Google Patents

Description

The present invention relates to a power converter.

  The power conversion device has a function of converting power supplied from a DC power source into AC power for supplying an AC electric load such as a rotating machine, or a function of converting AC power generated by the rotating machine into DC power. ing. This power conversion device has a plurality of semiconductor elements, and the semiconductor elements convert power efficiently by repeating conduction operation and interruption operation. For this reason, it is applied to a hybrid vehicle, a railway vehicle system, and the like, and in particular, many railway vehicle systems operate a driving motor only with electric power obtained from an overhead line, so that it is important to improve the efficiency of the power converter. Moreover, in the railway vehicle system, not only a motor for driving the vehicle but also a power supply for lighting and air conditioning equipment in the vehicle, and many power conversion devices are mounted.

  In order to increase the efficiency of the power conversion device, since it is composed of semiconductor elements as described above, it is important to reduce the loss of the semiconductor. When a semiconductor element is applied to a power converter, conduction loss (forward conduction loss, reverse conduction loss) that occurs during conduction operation, and switching loss (turn-on loss, turn-off loss, recovery loss) that occurs during interruption operation In order to reduce the loss, each reduction is necessary. In particular, a power conversion device used for a drive motor of a railway vehicle system has an operation mode in which the switching loss accounts for 70% or more of the total loss, and switching loss reduction is important.

  Increasing the switching speed is effective for reducing the switching loss. The circuit portion of the power conversion circuit includes a capacitor unit in which a plurality of capacitor cells are incorporated, a semiconductor module in which a plurality of semiconductor elements are mounted, and a DC wiring that electrically connects the capacitor unit and the semiconductor module. When the speed is increased, the current change rate (di / dt) and the jumping voltage Vp due to the parasitic inductance Ls of the capacitor unit, the semiconductor module, and the DC wiring described above increase, and exceed the breakdown voltage of the semiconductor element. In some cases, the semiconductor element may be destroyed.

  Therefore, as a technique for reducing the parasitic inductance, there is JP-A-2011-258848 (Patent Document 1). Patent Document 1 describes a method for reducing wiring inductance by staggering the electrode directions of capacitors in a case of a capacitor cell. However, in the wiring structure shown in FIG. 1 in Patent Document 1, the lengths of wiring between the capacitor cell and the positive electrode terminal and the negative electrode terminal of the case are different. As a result, the impedance between each capacitor cell and the terminal of the case varies, and current imbalance occurs, which may cause heat generation and deterioration in the capacitor cell where current is concentrated.

As a technique for reducing the impedance variation, there is JP-A-2004-165309 (Patent Document 2). As a technique for reducing the impedance variation, FIG. 10 and FIG. 11 in Patent Document 2 are introduced. In FIG. 10, the wiring lengths of each capacitor cell and the positive external terminal and the negative external terminal are close to each other, but when the number of capacitor cells is larger, the wiring of each capacitor cell and the positive external terminal and the negative external terminal Variations in length increase. Further, the configuration of FIG. 11 tends to have a larger variation than that of FIG.

JP 2011-258848 A JP 2004-165309 A

As described above, there has not yet been invented a technique that achieves both a reduction in parasitic inductance, which becomes a problem when the switching speed is increased, and a reduction in current imbalance of each capacitor cell. Therefore, the present invention proposes a capacitor wiring structure that solves the above two problems.

In order to solve the above problems, a wiring structure that realizes a reduction in inductance and a reduction in current imbalance is proposed.
Specifically, in a power conversion device having a capacitor unit that stores a plurality of capacitor cells, a semiconductor module that includes a switching element, and a wiring that connects the capacitor unit and the semiconductor module, the capacitor unit is the first of the capacitor units. A plurality of capacitor cells comprising a first positive electrode terminal and a first negative electrode terminal disposed on a surface, a second positive electrode terminal and a second negative electrode terminal disposed on a second surface different from the first surface; Part of the capacitor cell has a positive electrode on one end face and a negative electrode on the other end face, and the other capacitor cell has a negative electrode on one end face and a positive electrode on the other end face. The positive electrode on the side end and the first positive electrode terminal are connected by a first positive electrode wiring, and the negative electrode on the one end surface of the capacitor cell and the first negative electrode terminal are connected by a first negative electrode wiring. The positive electrode on the other end surface of the capacitor cell and the second positive electrode terminal are connected by a second positive electrode wiring, and the negative electrode on the other end surface of the capacitor cell and the second negative electrode terminal are connected by a second negative electrode wiring. The first positive electrode wiring and the first negative electrode wiring are configured by flat plates parallel to each other, and the second positive electrode wiring and the second negative electrode wiring are configured by flat plates parallel to each other. .

  Both reduction of the inductance of the capacitor and reduction of current imbalance between the capacitor cells are achieved.

It is a railway vehicle schematic diagram used as the example of application of the present invention. It is an example of the circuit diagram of the drive device of a rail vehicle. It is an example of the operation | movement waveform of the circuit diagram described in FIG. 2 is a configuration diagram of a capacitor unit in Embodiment 1. FIG. 6 is a configuration diagram of a capacitor unit in Embodiment 2. FIG. It is an exploded inclination figure of the power converter device in Example 3. FIG. It is an inclination figure of the power converter device in Example 3. FIG. It is an exploded inclination figure of the power converter device in Example 4. FIG. It is an inclination figure of the power converter device in Example 4. FIG. 10 is an example of a circuit diagram of a drive device in Embodiment 5. It is an exploded inclination figure of the power converter device in Example 5. FIG. It is an inclination figure of the power converter device in Example 5. FIG.

  Hereinafter, the system and circuit operation of the present invention will be described with reference to FIGS. In each drawing and each example, a MOSFET is described as an example of a semiconductor module, but the present invention can also be applied to an IGBT. Further, as a base material of any of the switching element and the diode, silicon or a semiconductor material having a band gap larger than silicon can be used.

  FIG. 1 is a schematic diagram of a motor drive device which is one of power conversion devices for a railway vehicle as an example to which the present invention is applied. Electric power is supplied from the overhead wire 2 to the motor drive device of the railway vehicle, and the power conversion device 1 drives the motor 111 by outputting an AC voltage having a variable voltage and variable frequency. The motor 111 is mechanically coupled to the axle of the railway vehicle and drives the axle of the railway vehicle. The electrical ground is connected via the rail 3. Here, although the voltage of the overhead line 2 may be either DC or AC, the following description will be made assuming that the voltage of the overhead line 2 is a DC voltage of 1500V.

  FIG. 2 is a circuit diagram of the single-phase power converter 4. Here, a single-phase power converter is shown as an example of the power converter 1, but a three-phase power converter may be used. Further, the inductance symbol used in the single-phase power converter indicates the parasitic inductance of the wiring.

  The single-phase power converter 4 includes capacitor cells 102a and 102b that smooth the DC voltage applied to the power converter by the DC power supply 101, a capacitor unit 103 that unitizes the capacitor cells 102a and 102b, and four switching elements Q1 to Q1. Q4. The switching elements Q1 and Q2 are connected in series, and the connection point of the switching elements Q1 and Q2 is an AC output point to the motor 111. Similarly, the switching elements Q3 and Q4 are connected in series, and the connection point of the switching elements Q3 and Q4 is an AC output point to the motor 111.

  Here, when the switching elements Q1 to Q4 are IGBTs, it is necessary to connect the diodes D1 to D4 to the switching elements Q1 to Q4 in antiparallel, and when the switching elements Q1 to Q4 are MOSFETs, the diodes MOSFET parasitic diodes can be used as D1 to D4. Here, the capacitor unit 103 is configured by a circuit in which two capacitor cells are connected in parallel, but the number of parallel units may be two or more.

  When the 2-in-1 package in which the switching elements Q1, Q2 and Q3, Q4 are the same package is applied, the single-phase power conversion device 4 includes a semiconductor module 108 including the switching elements Q1, Q2 (and diodes D1, D2), and The semiconductor module 109 includes switching elements Q3 and Q4 (and diodes D3 and D4). The capacitor cells 102a and 102b may be either electrolytic capacitors or film capacitors. 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 parasitic inductance in the single-phase power conversion device 4 includes wiring parasitic inductances 104a and 104b of each capacitor cell inside the capacitor unit 103, wiring parasitic inductance 105 between the capacitor unit 103 and the semiconductor modules 108 and 109, and semiconductors. There are parasitic inductances 106a and 106b of the internal wiring of the modules 108 and 109.

  Here, when the voltage of the overhead wire 2 is alternating current, a converter device that converts alternating current into direct current is connected between the power conversion device 1 and the overhead wire 2, and the converter device becomes the direct current power source 101.

  FIG. 3 shows operation waveforms according to the first embodiment of the present invention. As an operation of the single-phase power conversion device 4, the switching elements Q <b> 1 to Q <b> 4 perform a switching operation, thereby converting DC power supplied from the DC power supply 101 into AC power and driving the motor 111. Hereinafter, a specific operation will be described by taking the switching element Q1 as an example.

  At t = t0, the gate-source voltage VGS of the switching element Q1 is 0V. At this time, since the switching element Q1 is in the OFF state, 1500 V of the DC power supply 101 is applied to the drain-source voltage VDS, and the drain current ID does not flow.

  At t = t1, when the gate-source voltage VGS is higher than the turn-on threshold voltage of the switching element Q1, for example, 15V, the switching element Q1 is turned on and the drain current ID starts to flow. The on-time of the switching element Q1 is controlled by a current flowing through the motor 111, for example, PWM (Pulse Width Modulation) control.

  At t = t2, the gate-source voltage VGS of the switching element Q1 becomes 0V, and shifts to the off state. At this time, since the drain current ID decreases to 0 A with the current change rate di / dt, an induced electromotive force is generated in the parasitic inductances 104, 105, and 106 of the wiring. That is, the instantaneous surge voltage 11 is generated in the drain-source voltage VDS of the switching element Q1, and the single-phase power conversion device 4 breaks down when the maximum rated voltage of the switching element Q1 is exceeded.

  Also during the period from t = t3 to t8, the gate voltage VGS of the switching element Q1 becomes 0V from the turn-on threshold voltage, and the transition from the on state to the off state (t = t4, t6, t8) is the same as t = t2. A surge voltage 11 is generated.

  This surge voltage is calculated by multiplying the current change rate di / dt and the parasitic inductance 110, which is the added value of each parasitic inductance (104, 105, 106). Therefore, when the switching speed is increased in order to reduce the switching loss, that is, the current change rate di / dt is increased, the induced electromotive force generated in the parasitic inductance 110 is increased, so that the surge voltage is increased, and the single-phase power conversion device Since 4 causes failure, it is necessary to reduce the parasitic inductance.

  Further, since the current waveform at the time of switching is accompanied by a steep current change as shown in FIG. 3, it includes a high frequency component. Generally, the current change time dt of a railway inverter is several hundred μs, and the current includes a frequency of several MHz, and this high-frequency current flows through the capacitor cell 102. If the parasitic inductance of the wiring to each capacitor cell is different, the current flowing in each capacitor cell is also biased, causing the capacitor cell to generate heat and shorten its life.

  The present invention was devised in order to solve the above-mentioned problems, and the present invention will be described below using examples.

  FIG. 4 shows the internal structure of the capacitor unit 103 in FIG. The capacitor unit 103 includes a plurality of capacitor cells 102a and 102b. Capacitor cell 102a is provided with a capacitor cell positive terminal 112a on one end face and a capacitor cell negative terminal 113a on the other end face. The capacitor cell 102b has a capacitor cell positive terminal 112b on the other end face, and a capacitor cell negative terminal 113b on the one end face. That is, the capacitor cell 102a and the capacitor cell 102b are arranged so that the polar directions are opposite to each other.

Further, the first surface 201 of the capacitor unit 103 is provided with a positive electrode terminal 114 and a negative electrode terminal 118, and a second surface 202 opposite to the first surface is provided with a positive electrode terminal 115 and a negative electrode terminal 119. The terminals 114, 115, 118, and 119 are arranged so that the poles are paired. That is, by arranging the positive electrode terminals 114 and 115 and the negative electrode terminals 118 and 119 of the capacitor unit on diagonal lines, the total wiring length between the capacitor cells can be made more uniform.

  The capacitor cell positive terminal 112a and the positive electrode terminal 114 are connected by a positive electrode wiring 120, the capacitor cell positive terminal 112b and the positive electrode terminal 115 are connected by a positive electrode wiring 121, and the capacitor cell negative terminal 113a and the negative electrode terminal 119 are connected by a negative electrode wiring 122. The capacitor cell negative terminal 113 b and the negative terminal 118 are connected by a negative wiring 123.

  When one positive terminal is connected to the capacitor cell positive terminal on one end face as shown in FIG. 4, the other positive terminal is connected to the capacitor cell positive terminal on the other end face. When connected to the capacitor cell negative terminal on the end face, the other negative terminal is connected to the capacitor cell negative terminal on the other end face. With this structure, the total wiring in the capacitor unit is obtained by adding the wiring length from the positive terminal of the capacitor unit 103 to the positive terminal of the capacitor cell and the wiring length from the negative terminal of the capacitor unit 103 to the negative terminal of the capacitor cell. It is possible to make the length the same between the capacitor cells (suppress variation in the total wiring length), and the parasitic inductance of the wiring in each capacitor cell is almost the same, so that the current imbalance between the capacitor cells can be reduced.

  Further, as indicated by arrows in FIG. 4, the direction of current flows in the opposite direction between the positive electrode wiring 120 and the negative electrode wiring 123 and between the positive electrode wiring 121 and the negative electrode wiring 122. Therefore, by configuring the positive electrode wiring 120 and the negative electrode wiring 123 and the positive electrode wiring 121 and the negative electrode wiring 122 as flat plates that are parallel to each other, it is possible to reduce the inductance of the internal wiring of the capacitor unit.

4 shows an example in which the terminal direction of each capacitor cell and the terminal direction of the capacitor unit are substantially orthogonal to each other. However, the present invention is not limited to this, and the terminal direction of each capacitor cell and the capacitor unit are not limited thereto. The terminal directions may be substantially the same direction, and the above-described effects of the present invention can be obtained regardless of the relationship.

  FIG. 5 shows an example of the wiring structure when the number of capacitor cells in FIG. 4 is increased to a large number. FIG. 5 shows an example in which eight capacitor cells are provided. As in FIG. 4, the four capacitor cells 102a are provided with the capacitor cell positive terminal 112a on the upper side, the capacitor cell negative terminal 113a on the lower side, and the other four capacitor cells 102b have the capacitor cell positive terminal 112b on the lower side. However, the capacitor cell negative terminal 113b is provided on the upper side. In addition, a pair of terminals (a positive terminal 114 and a negative terminal 118) are provided on the left side of the capacitor unit 103, and a pair of terminals (a positive terminal 115 and a negative terminal 119) are also provided on the right side.

  Further, the positive electrode wiring 120 connects the upper four capacitor cell positive terminals 112a and the positive electrode terminal 114 on the left side surface of the capacitor unit. The negative wiring 123 connects the upper four capacitor cell negative terminals 113b and the negative terminal 118 on the left side of the capacitor unit. Furthermore, the positive electrode wiring 121 connects the lower four capacitor cell positive terminals 112b and the positive electrode terminal 115 on the right side surface of the capacitor unit. The negative wiring 122 connects the lower four capacitor cell negative terminals 113a and the negative terminal 119 on the right side of the capacitor unit.

  With this structure, the total wiring in the capacitor unit is obtained by adding the wiring length from the positive terminal of the capacitor unit 103 to the positive terminal of the capacitor cell and the wiring length from the negative terminal of the capacitor unit 103 to the negative terminal of the capacitor cell. It is possible to make the length the same between the capacitor cells (suppress variation in the total wiring length), and the parasitic inductance of the wiring in each capacitor cell is almost the same, so that the current imbalance between the capacitor cells can be reduced.

  Further, by arranging the positive terminals 114 and 115 and the negative terminals 118 and 119 of the capacitor unit on the diagonal lines, the total wiring length between the capacitor cells can be made more uniform.

Similarly to the current flow indicated by the arrows in FIG. 4, the direction of current flows in the opposite direction in each of the positive electrode wiring 120 and the negative electrode wiring 123, and the positive electrode wiring 121 and the negative electrode wiring 122. Therefore, by configuring the positive electrode wiring 120 and the negative electrode wiring 123 and the positive electrode wiring 121 and the negative electrode wiring 122 as flat plates that are parallel to each other, it is possible to reduce the inductance of the internal wiring of the capacitor unit. Here, by arranging the capacitor cells 102a and 102b whose poles are opposite to each other at the left and right end portions, the overlapping area of the positive electrode wiring and the negative electrode wiring is increased, so that the effect of reducing the inductance is increased.

  FIG. 6 is an exploded tilt view of the single-phase power conversion device 4 in the third embodiment, and FIG. 7 is a tilt view of the single-phase power conversion device 4.

  6 and 7, an example in which the single-phase power conversion device 4 is configured by connecting the capacitor unit 103 shown in FIGS. 4 and 5 and the semiconductor modules 108 and 109 by the P-side wiring 124 and the N-side wiring 125. It is.

  The positive terminals 114 and 115 at both ends of the capacitor unit 103 and the P-side terminals 126 and 127 of the semiconductor modules 108 and 109 are connected by the P-side wiring 124, and the negative terminals 118 and 119 at both ends of the capacitor unit 103 and the semiconductor modules 108 and 109 are connected. N-side terminals 128 and 129 are connected by an N-side wiring 125. Thus, since the positive electrode terminals and negative electrode terminals of both ends of the capacitor unit are connected by wiring and the semiconductor module is connected to the wiring, the semiconductor module is connected to the semiconductor module via the capacitor cell from the P-side terminal of the semiconductor module. Since the wiring length of the current path returning to the N-side terminal is uniform among the capacitor cells, the parasitic inductance of the wiring in each capacitor cell is substantially the same, and the current imbalance between the capacitor cells can be reduced.

  In the present embodiment, the positive electrode terminals 114 and 115 and the negative electrode terminals 118 and 119 are provided in the left and right direction of the capacitor unit, and the semiconductor module is arranged below the capacitor unit. Therefore, the semiconductor module may be arranged at a position other than the lower side of the capacitor unit.

Here, the current flowing from the P-side terminal 127 to the positive terminal 115 via the P-side wiring 124 flows in the capacitor unit 103 and returns from the negative terminal 118 to the N-side terminal 129 via the N-side wiring 125. The current flowing from the P-side terminal 127 to the positive terminal 114 via the P-side wiring 124 flows in the capacitor unit 103 and returns from the negative terminal 119 to the N-side terminal 129 via the N-side wiring 125. As described above, the currents flowing through the P-side wiring 124 and the N-side wiring 125 are reversed. Therefore, the parasitic inductance 105 can be reduced by forming the P-side wiring 124 and the N-side wiring 125 in a parallel plate structure.

  FIG. 8 is an exploded tilt view of the single-phase power conversion device 4 in the fourth embodiment, and FIG. 9 is a tilt view of the single-phase power conversion device 4.

  FIG. 8 shows an embodiment in which a plurality of capacitor units 103 shown in FIGS. 4 and 5 are connected in parallel.

Also in the present embodiment, as in the third embodiment, the wiring length of the current path that returns from the P-side terminal of the semiconductor module to the N-side terminal of the semiconductor module via the capacitor cell is uniform among the capacitor cells. The parasitic inductance of the wiring in each capacitor cell is almost the same, and current imbalance between the capacitor cells can be reduced. Further, the parasitic inductance 105 can be reduced by configuring the P-side wiring 124 and the N-side wiring 125 with flat plates parallel to each other. When a plurality of capacitor units are used, the capacitor unit 103a and the capacitor unit 103b are arranged so that the positive and negative terminals of the capacitor unit 103a and the capacitor unit 103b are staggered. Since the current flows, the effect of reducing the parasitic inductance 105 is improved.

    10 to 12 show a fifth embodiment. FIG. 10 shows a circuit diagram in the case where a three-phase power converter and a three-phase motor 130 are applied as a driving device for a railway vehicle. The structure of the part which is not demonstrated is the same structure as FIG. The three-phase power conversion device includes a capacitor unit 103 and six switching elements Q1 to Q6. Switching elements Q1 and Q2 are connected in series, and the connection point of switching elements Q1 and Q2 is an AC output point to three-phase motor 130. Similarly, switching elements Q3 and Q4 and switching elements Q5 and Q6 are connected in series, and the connection point of the switching elements is an AC output point to the three-phase motor 130.

  Here, when the switching elements Q1 to Q6 are IGBTs, it is necessary to connect the diodes D1 to D6 to the switching elements Q1 to Q6 in antiparallel, and when the switching elements Q1 to Q6 are MOSFETs, the diodes MOSFET parasitic diodes can be used as D1 to D6.

  When the 2-in-1 package in which the switching elements Q1, Q2 and Q3, Q4 and Q5, Q6 are the same package is applied, the three-phase power conversion device includes a switching element Q1, Q2 (and diodes D1, D2). , And a semiconductor module 109 including switching elements Q3 and Q4 (and diodes D3 and D4) and a semiconductor module 110 including switching elements Q5 and Q6 (and diodes D5 and D6).

In addition, the parasitic inductance in the three-phase power converter includes the parasitic inductances 104a and 104b of the capacitor cells in the capacitor unit 103, the parasitic inductance 105 of the wiring between the capacitor unit 103 and the semiconductor modules 108 and 109, and the semiconductor module. There are parasitic inductances 106a, 106b, 106c of the internal wirings 108, 109, 110.

  FIG. 11 is an exploded slope view of the three-phase power converter in the fifth embodiment, and FIG. 12 is a slope view of the three-phase power converter. The structure of the part which is not mentioned is the same structure as FIG.6 and FIG.7.

  11 and 12 show an example in which the capacitor unit 103 shown in FIGS. 4 and 5 and the semiconductor modules 108, 109, 110 are connected by the P-side wiring 124 and the N-side wiring 125 to constitute a three-phase power converter. Show.

    Even when three semiconductor modules constituting the three-phase power converter are connected to the P-side wiring 124 and the N-side wiring 125 as in this embodiment, the P-side terminals 126, 127, 131 of the semiconductor module are used. Since the wiring length of the current path that returns to the N-side terminals 128, 129, and 132 of the semiconductor module through the capacitor unit is substantially uniform among the capacitor cells, the parasitic inductance of the wiring in each capacitor cell is substantially the same. Thus, current imbalance between the capacitor cells can be reduced.

As in the third embodiment shown in FIGS. 6 and 7, the currents flowing in the P-side wiring 124 and the N-side wiring 125 are opposite to each other. Therefore, the P-side wiring 124 and the N-side wiring 125 are made of flat plates parallel to each other. By configuring, the parasitic inductance 105 can be reduced.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Overhead wire 3 Rail 11 Surge voltage Q1-Q6 Switching element D1-D6 Diode 101 DC power supply 102 Capacitor cell 102a Capacitor cell 102b Capacitor cell 103 Capacitor unit 103a Capacitor unit 103b Capacitor unit 104a Parasitic inductance 104b Parasitic inductance 105 Parasitic inductance 106a Parasitic inductance 106b Parasitic inductance 108-110 Semiconductor module 111 Single phase motor 112a Capacitor cell positive terminal 112b Capacitor cell positive terminal 113a Capacitor cell negative terminal 113b Capacitor cell negative terminal 114-115 Positive terminal 118-119 Negative terminal 120-123 Wiring 124 P side wiring 125 N side wiring 126, 127, 131 P side terminals 128, 129 132 N-side terminal 130 a three-phase motor

Claims (10)

In a power conversion device having a capacitor unit storing a plurality of capacitor cells, a semiconductor module provided with a switching element, and wiring connecting the capacitor unit and the semiconductor module,
The capacitor unit includes a first positive electrode terminal and a first negative electrode terminal arranged on the first surface of the capacitor unit, and a second positive electrode terminal arranged on a second surface different from the first surface. And a second negative terminal,
Some of the plurality of capacitor cells have a positive electrode on one end face, a negative electrode on the other end face, and the other capacitor cells have a negative electrode on one end face and a positive electrode on the other end face. ,
The positive electrode on the one end face of the capacitor cell and the first positive electrode terminal are connected by a first positive electrode wiring,
The negative electrode on the one end face of the capacitor cell and the first negative electrode terminal are connected by a first negative electrode wiring,
The positive electrode on the other end face of the capacitor cell and the second positive electrode terminal are connected by a second positive electrode wiring,
The negative electrode on the other end face of the capacitor cell and the second negative electrode terminal are connected by a second negative electrode wiring,
The first positive electrode wiring and the first negative electrode wiring are configured by flat plates parallel to each other, and the second positive electrode wiring and the second negative electrode wiring are configured by flat plates parallel to each other. Power converter. The power conversion device according to claim 1,
The semiconductor module has a module positive terminal and a module negative terminal,
The first positive terminal, the second positive terminal, and the module positive terminal of the capacitor unit are connected by a third positive wiring, and the first negative terminal, the second negative terminal, and the module negative terminal of the capacitor unit. Are connected by a third negative electrode wiring. The power conversion device according to claim 2,
The power converter according to claim 3, wherein the third positive electrode wiring and the third negative electrode wiring are configured by flat plates parallel to each other. In the power converter device according to any one of claims 1 to 3,
The first surface provided with the first positive electrode terminal and the first negative electrode terminal is opposite to the second surface provided with the second positive electrode terminal and the second negative electrode terminal. A power conversion device characterized by being a surface. In the power converter according to any one of claims 1 to 4,
The first positive electrode terminal and the second positive electrode terminal are disposed on a diagonal line, and the first negative electrode terminal and the second negative electrode terminal are disposed on a diagonal line. Conversion device. In the power converter according to any one of claims 1 to 5,
The power conversion device is a three-phase power conversion device including three semiconductor modules. The power converter according to any one of claims 1 to 6,
A plurality of the capacitor units;
The first positive terminals and the first negative terminals of the plurality of capacitor units are arranged in a staggered manner on the first surface, and the second positive terminals and the second of the plurality of capacitor units The negative electrode terminals are arranged in a staggered manner on the second surface. In the power converter according to any one of claims 1 to 7,
The power conversion device, wherein the switching element is an IGBT or a MOSFET. In the power converter according to any one of claims 1 to 8,
Wherein the switching element is a power conversion apparatus characterized by a base material of a semiconductor material having a band gap larger than silicon or silicon.   A railway vehicle comprising: the power conversion device according to any one of claims 1 to 9; and a motor driven by the power conversion device.