Power converter

Abstract

To solve the problem that it is necessary to reduce parasitic inductance of a capacitor connection wire connected between a power supply wire and a capacitor by suppressing heat reception of the capacitor caused by heat generated in the power supply wire to the capacitor connected to the power supply wire.SOLUTION: A power conversion device comprises: a power conversion circuit 10 including semiconductor switching elements 13u, 14u, 13v, 14v, 13w, and 14w; a power supply wire 60P electrically connected to the power conversion circuit 10; a capacitor element 20P; and a first capacitor connection wire 70P including a first opposite wiring part 71P which is electrically connected between the power supply wire 60P and one electrode of the capacitor element 20P and of which one end is electrically connected to the power supply wire 60P, and a second opposite wiring part 72P of which the other end is electrically connected to the one electrode of the capacitor element 20P and which is disposed so as to be opposed to the first opposite wiring part 71P.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a power converter that converts direct current to alternating current, converts alternating current to direct current, or steps up or steps down voltage. [Background Art]

[0002] Patent Document 1 discloses a method for preventing a capacitor constituting a filter circuit that reduces high-frequency noise caused by on / off switching of switching elements configuring an inverter from receiving heat generated in a connection conductor for power feeding, in a power converter including the inverter. The power converter disclosed in Patent Document 1 includes an inverter, a connection conductor that supplies power to the inverter, a filter circuit including a capacitor circuit and mounted on the connection conductor, a conductor portion electrically connected to the capacitor constituting the filter circuit and serving as a wiring part of the capacitor circuit, and a cooler on which the capacitor is mounted. The connection conductor, the conductor portion, and the cooler are arranged to overlap one another, and the conductor portion electrically connected to the connection conductor is in thermal contact with an extending portion of the cooler. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2018-121406 [Summary of Invention] [Problem to be Solved by the Invention]

[0004] In the power converter disclosed in Patent Document 1, the conductor portion serving as the wiring part of the capacitor circuit is configured such that a conductor pattern is provided on the surface of an insulating resin plate. Therefore, if the conductor portion is lengthened to obtain necessary cooling for the conductor portion, the parasitic inductance generated in the conductor portion increases, and the impedance characteristics of the capacitor at high frequencies deteriorate. In other words, if the parasitic inductance in the conductor increases, the impedance to high frequencies in the conductor increases, making it difficult for high-frequency noise currents generated by the on / off switching of the switching element to flow through the capacitor, thus impairing its function as a filter.

[0005] This disclosure has been made in view of the above-mentioned points, and relates to power supply wiring and capacitors connected to a power conversion circuit having semiconductor switching elements. element The capacitor is affected by the heat generated in the power supply wiring from the capacitor connection wiring connected between them. element The objective is to obtain a power conversion device that suppresses heat absorption while reducing parasitic inductance in the capacitor connection wiring. [Means for solving the problem]

[0006] The power conversion device relating to this disclosure includes a power conversion circuit having semiconductor switching elements, One end is electrically connected to the electrodes of a DC power supply, and the other end is Power supply wiring that is electrically connected to the power conversion circuit, For noise reduction Capacitor element and power supply wiring For noise reduction A first opposing wiring section is electrically connected between one electrode of the capacitor element, with one end electrically connected to the power supply wiring, and the other end is For noise reduction The device comprises a first capacitor connection wiring that is electrically connected to one electrode of a capacitor element and has a second opposing wiring portion that is positioned opposite the first opposing wiring portion. [Effects of the Invention]

[0007] According to this disclosure, capacitor element To suppress heat absorption, and to connect the power supply wiring and capacitors to the power conversion circuit. element This can reduce the parasitic inductance in the capacitor connection wiring connected between them. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing a power conversion device according to Embodiment 1. [Figure 2] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 1. [Figure 3] This is a cross-sectional view AA in Figure 2. [Figure 4] This is an equivalent circuit diagram of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 1. [Figure 5] This figure shows the parasitic inductance and thermal resistance of the first capacitor connection wiring on the positive electrode side in the power conversion device according to Embodiment 1. [Figure 6] This figure shows the impedance characteristics of the first capacitor connection wiring on the positive electrode side in the power conversion device according to Embodiment 1. [Figure 7] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 2. [Figure 8] This is a cross-sectional view AA in Figure 7. [Figure 9] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 3. [Figure 10] This is a cross-sectional view AA in Figure 9. [Figure 11] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 4. [Figure 12] This is a cross-sectional view AA in Figure 11. [Figure 13] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 5. [Figure 14] This is a cross-sectional view AA in Figure 13. [Figure 15] This is a top view showing the structure of the electrical path from the positive terminal power supply wiring to the housing in the power conversion device according to Embodiment 6. [Figure 16] This is a cross-sectional view AA of Figure 15. [Figure 17]FIG. 1 is an equivalent circuit diagram of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 6. [Figure 18] FIG. 3 is a top view illustrating a structure of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 7. [Figure 19] FIG. 6 is a sectional view taken along line A-A in FIG. 18. [Figure 20] FIG. 9 is an equivalent circuit diagram of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 7. [Figure 21] FIG. 12 is a top view illustrating a structure of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 8. [Figure 22] FIG. 15 is a sectional view taken along line A-A in FIG. 21. [Figure 23] FIG. 18 is a top view illustrating a structure of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 9. [Figure 24] FIG. 21 is a sectional view taken along line A-A in FIG. 23. [Figure 25] FIG. 24 is a top view illustrating a structure of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 10. [Figure 26] FIG. 27 is a sectional view taken along line A-A in FIG. 25. [Figure 27] FIG. 30 is a top view illustrating a structure of an electrical path from a positive-side power supply wiring to a housing in the power conversion apparatus according to Embodiment 11. [Figure 28] FIG. 33 is a sectional view taken along line A-A in FIG. 27. [Figure 29] FIG. 36 is a sectional view taken along line B-B in FIG. 27. [Figure 30] FIG. 39 is a sectional view taken along line C-C in FIG. 27. [Figure 31] FIG. 42 is a diagram illustrating on-off drive characteristics when a wide-gap semiconductor element is used as a switching element in the power conversion apparatus according to Embodiment 12. [Figure 32] FIG. 45 is a diagram illustrating frequency characteristics of the wide-gap semiconductor element in the power conversion apparatus according to Embodiment 12. [Modes for carrying out the invention]

[0009] Embodiment 1. The power conversion device according to Embodiment 1 will be described with reference to Figures 1 to 6. The power conversion device 300 according to Embodiment 1 includes a power conversion circuit 10, which is a three-phase inverter circuit that converts DC power from a power source 100 into three-phase AC power, and supplies the three-phase AC power to a load 200.

[0010] However, the power converter 300 according to Embodiment 1 is not limited to a power converter equipped with a three-phase inverter circuit that converts DC to three-phase AC, but may also be a power converter equipped with a single-phase inverter circuit that converts DC to single-phase AC, a power converter equipped with a converter circuit that converts AC to DC, or a power converter equipped with a DC-DC converter circuit that transforms voltage. Note that the term "power conversion circuit" includes all of the following: three-phase inverter circuits, single-phase inverter circuits, converter circuits, and DC-DC converter circuits.

[0011] The following describes a power conversion device 300 equipped with a power conversion circuit 10, which is a three-phase inverter circuit that converts direct current to three-phase alternating current. When the power converter 300 is applied to an electric vehicle or a hybrid vehicle, the power source 100 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. In the power supply 100, the positive electrode is electrically connected to the positive side input terminal 1P of the power converter 300, and the negative electrode is electrically connected to the negative side input terminal 1N of the power converter 300, and the power supply 100 supplies DC power to the power converter 300.

[0012] The load of 200 is a three-phase motor. In load 200, the U-phase input terminal is electrically connected to the u-phase output terminal 2U of the power converter 300, the V-phase input terminal is electrically connected to the v-phase output terminal 2V of the power converter 300, and the W-phase input terminal is electrically connected to the w-phase output terminal 2W of the power converter 300. Load 200 is supplied with three-phase AC power from the power converter 300. In the case of a power conversion device equipped with a converter circuit that converts three-phase AC to DC, the power source 100 is a three-phase motor which is a generator, and the load 200 is a secondary battery.

[0013] The power converter 300 according to Embodiment 1 is housed in a metal casing 400. The metal casing 400 is grounded. The metal casing 400 is integrated with a cooler (not shown). For illustrative purposes, the diagram shows the power converter 300 as being located outside the metal casing 400, even though it is housed within the metal casing 400. The metal casing 400 itself also functions as a grounding node for the power converter 300.

[0014] As shown in Figure 1, the power conversion device 300 according to Embodiment 1 includes a power conversion circuit 10, a capacitor element 20P for noise removal on the positive side, a capacitor element 20N for noise removal on the negative side, a capacitor element 20S for smoothing, a DC voltage sensor circuit 30, a u-phase current sensor circuit 40u, a v-phase current sensor circuit 40v, a w-phase current sensor circuit 40w, a control unit 50, a power supply wiring 60P on the positive side, a power supply wiring 60N on the negative side, and a first capacitor connection wiring 70P for connecting the capacitor element 20P on the positive side. It includes a second capacitor connection wire 80P for connecting the polar side capacitor element 20P, a first capacitor connection wire 70N for connecting the negative side capacitor element 20N, a second capacitor connection wire 80N for connecting the negative side capacitor element 20N, a first capacitor connection wire 70S for connecting the smoothing capacitor element 20S, a second capacitor connection wire 80S for connecting the smoothing capacitor element 20S, control lines 91uU, 91uD, 91vU, 91vD, 91wU, 91wD, and signal lines 92V, 92uI, 92vI, 92wI.

[0015] The power conversion circuit 10 is a switching circuit having semiconductor switching elements for controlling power. The power conversion circuit 10 is a three-phase inverter circuit using a three-phase bridge rectifier circuit (three-phase full-wave rectifier circuit) composed of semiconductor switching elements 13u, 14u, 13v, 14v, 13w, and 14w.

[0016] The semiconductor switching element group 13u is the semiconductor switching element group of the u-phase upper arm, and is electrically connected between the positive electrode input node 11P and the u-phase output node 15u. The positive-side input node 11P is electrically connected to the positive-side input terminal 1P of the power converter 300 via the positive-side power supply wiring 60P. The u-phase output node 15u is electrically connected to the u-phase output terminal 12u of the power conversion circuit 10 via the u-phase power supply wiring. The u-phase output terminal 12u is electrically connected to the u-phase output terminal 2U of the power converter 300 via the u-phase power supply wiring.

[0017] The semiconductor switching element group 13u includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element is an N-type metal oxide film field-effect transistor (MOSFET). Note that the semiconductor switching element may be an insulated-gate bipolar transistor (IGBT) instead of a MOSFET.

[0018] In the semiconductor switching element, the drain electrode is electrically connected to the input node 11P, the source electrode is electrically connected to the u-phase output node 15u, and the gate electrode is electrically connected to the control unit 50 via the control line 91uU. The semiconductor switching element receives a control signal from the control unit 50 via a control line 91uU to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0019] The semiconductor switching element group 14u is a group of semiconductor switching elements in the lower arm of the u-phase, and is electrically connected between the output node 15u of the u-phase and the negative electrode input node 11N. The negative-side input node 11N is electrically connected to the negative-side input terminal 1N of the power converter 300 via the negative-side power supply wiring 60N. The semiconductor switching element group 14u includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element may be a MOSFET or an IGBT.

[0020] In the semiconductor switching element, the drain electrode is electrically connected to the u-phase output node 15u, the source electrode is electrically connected to the input node 11N, and the gate electrode is electrically connected to the control unit 50 via the control line 91uD. The semiconductor switching element receives a control signal from the control unit 50 via a control line 91uD to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0021] The semiconductor switching element group 13v is the upper arm semiconductor switching element group of the v phase, and is electrically connected between the positive terminal input node 11P and the v phase output node 15v. The v-phase output node 15V is electrically connected to the v-phase output terminal 12V of the power conversion circuit 10 via the v-phase power supply wiring. The v-phase output terminal 12V is electrically connected to the v-phase output terminal 2V of the power converter 300 via the v-phase power supply wiring.

[0022] The semiconductor switching element group 13V includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element may be a MOSFET or an IGBT.

[0023] In the semiconductor switching element, the drain electrode is electrically connected to the input node 11P, the source electrode is electrically connected to the v-phase output node 15v, and the gate electrode is electrically connected to the control unit 50 via the control line 91vU. The semiconductor switching element receives a control signal from the control unit 50 via a control line 91vU to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0024] The semiconductor switching element group 14v is the lower arm semiconductor switching element group of the v phase, and is electrically connected between the v phase output node 15v and the negative electrode input node 11N. The semiconductor switching element group 14V includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element may be a MOSFET or an IGBT.

[0025] In the semiconductor switching element, the drain electrode is electrically connected to the v-phase output node 15V, the source electrode is electrically connected to the input node 11N, and the gate electrode is electrically connected to the control unit 50 via the control line 91VD. The semiconductor switching element receives a control signal from the control unit 50 via the control line 91vD to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0026] The semiconductor switching element group 13w is the upper arm semiconductor switching element group of the w phase, and is electrically connected between the positive electrode input node 11P and the w phase output node 15w. The w-phase output node 15w is electrically connected to the w-phase output terminal 12w of the power conversion circuit 10 via the w-phase power supply wiring. The w-phase output terminal 12w is electrically connected to the w-phase output terminal 2W of the power converter 300 via the w-phase power supply wiring.

[0027] The semiconductor switching element group 13w includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element may be a MOSFET or an IGBT.

[0028] In the semiconductor switching element, the drain electrode is electrically connected to the input node 11P, the source electrode is electrically connected to the w-phase output node 15w, and the gate electrode is electrically connected to the control unit 50 via the control line 91wU. The semiconductor switching element receives a control signal from the control unit 50 via a control line 91wU to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0029] The semiconductor switching element group 14w is the lower arm semiconductor switching element group of the w phase, and is electrically connected between the w phase output node 15w and the negative electrode side input node 11N. The semiconductor switching element group 14w includes one or more semiconductor switching elements connected in parallel, and a diode element connected in antiparallel to the semiconductor switching elements and operating as a recirculating diode. The semiconductor switching element may be a MOSFET or an IGBT.

[0030] In the semiconductor switching element, the drain electrode is electrically connected to the w-phase output node 15w, the source electrode is electrically connected to the input node 11N, and the gate electrode is electrically connected to the control unit 50 via the control line 91wD. The semiconductor switching element receives a control signal from the control unit 50 via the control line 91wD to its gate electrode, and is controlled on / off with a dead time in between, performing semiconductor switching operation. In a diode element, the cathode electrode is electrically connected to the drain electrode of the semiconductor switching element, and the anode electrode is electrically connected to the source electrode of the semiconductor switching element.

[0031] The semiconductor switching elements 13u, 14u, 13v, 14v, 13w, and 14w may be configured using individual power modules, or they may be configured as a single power module that incorporates all of them.

[0032] Capacitor element 20P is a Y-capacitor that suppresses common-mode noise current superimposed on the positive terminal power supply wiring 60P. The capacitor element 20P is connected between the power supply wiring 60P and the ground node which serves as the reference ground, in this example the metal enclosure 400. It is a positive-side noise-removing capacitor that prevents common-mode noise current from flowing towards the power supply wiring 60P.

[0033] In the capacitor element 20P, one electrode is electrically connected to the power supply wiring 60P via the first capacitor connection wiring 70P, and the other electrode is electrically connected to the ground node via the second capacitor connection wiring 80P. The capacitor element 20P is not limited to a single capacitor element, but includes multiple capacitor elements connected in parallel or multiple capacitor elements connected in series.

[0034] The capacitor element 20N is a Y-capacitor that suppresses common-mode noise current superimposed on the negative-side power supply wiring 60N. The capacitor element 20N is connected between the power supply wiring 60N and the ground node, and is a negative-side noise suppression capacitor that prevents common-mode noise current from flowing towards the power supply wiring 60N.

[0035] In the capacitor element 20N, one electrode is electrically connected to the power supply wiring 60N via the first capacitor connection wiring 70N, and the other electrode is electrically connected to the ground node via the second capacitor connection wiring 80N. The capacitor element 20N is not limited to a single capacitor element, but includes multiple capacitor elements connected in parallel or multiple capacitor elements connected in series.

[0036] Capacitor element 20S is, Positive side Power supply wiring 60P It is also a smoothing capacitor element that removes voltage ripple and noise appearing in the negative terminal power supply wiring 60N. In the capacitor element 20S, one electrode is electrically connected to the power supply wiring 60P via the first capacitor connection wiring 70S, and the other electrode is electrically connected to the power supply wiring 60N via the second capacitor connection wiring 80S.

[0037] The voltage sensor circuit 30 is connected in parallel to the capacitor element 20S, between the power supply wiring 60P and the power supply wiring 60N, and detects the DC voltage between the power supply wiring 60P and the power supply wiring 60N, that is, the input voltage of the power converter 300. The result detected by the voltage sensor circuit 30, that is, the input DC voltage value of the power converter 300, is output from the voltage sensor circuit 30 to the control unit 50 via the signal line 92V.

[0038] The u-phase current sensor circuit 40u detects the u-phase output current flowing through the u-phase power supply wiring connected to the u-phase output terminal 12u. The u-phase output current detected by the current sensor circuit 40u is output from the current sensor circuit 40u to the control unit 50 via the signal line 92uI. The v-phase current sensor circuit 40V detects the v-phase output current flowing through the v-phase power supply wiring connected to the v-phase output terminal 12V. The v-phase output current detected by the current sensor circuit 40V is output from the current sensor circuit 40V to the control unit 50 via the signal line 92VI. The W-phase current sensor circuit (40W) detects the W-phase output current flowing through the W-phase power supply wiring connected to the W-phase output terminal (12V). The w-phase output current detected by the current sensor circuit 40w is output from the current sensor circuit 40w to the control unit 50 via the signal line 92wI.

[0039] The control unit 50 acquires information on the input voltage of the power converter 300 from the voltage sensor circuit 30 via the signal line 92V, and acquires information on the output current of the u-phase, v-phase, and w-phase of the power converter 300 from the current sensor circuit 40u, current sensor circuit 40v, and current sensor circuit 40w, respectively, via the signal lines 92uI, 92vI, and 92wI.

[0040] The control unit 50 provides control signals via control lines 91uU, 91uD, 91vU, 91vD, 91wU, and 91wD to the gate electrodes of the semiconductor switching elements in semiconductor switching element groups 13u, 14u, 13v, 14v, 13w, and 14w, respectively, thereby controlling each semiconductor switching element to be on / off with a dead time in between. Each semiconductor switching element is turned on / off by the control unit 50, so that the DC current from the power supply 100, which has been smoothed by the smoothing capacitor element 20S, is converted into a three-phase current by the power conversion circuit 10 and supplied to the load 200.

[0041] Next, the structure of the electrical path from the positive terminal power supply wiring 60P to the metal housing 400 which serves as the ground node, via the positive terminal noise suppression capacitor element 20P, will be explained using Figures 2 and 3. The positive terminal power supply wiring 60P is a power supply wiring that is electrically connected to the power conversion circuit 10. The 60P power supply cable is a flat, plate-shaped conductor with a front and back side. In the power supply wiring 60P, one end is connected to the positive terminal 1P of the DC power supply 100, and the other end is connected to the positive terminal input node 11P of the power conversion circuit 10.

[0042] The first capacitor connection wire 70P is electrically connected between the power supply wire 60P and one electrode of the capacitor element 20P. The first capacitor connection wire 70P is a flat conductor with a front and back side. In the first capacitor connection wiring 70P, one end face is connected to the side of the power supply wiring 60P at the first connection point P1, and the other end is connected to one electrode terminal of the capacitor element 20P at the second connection point P2.

[0043] The first capacitor connection wiring 70P includes a first opposing wiring portion 71P, one end of which is electrically connected to the power supply wiring 60P at a first connection point P1; a second opposing wiring portion 72P, the other end of which is electrically connected to one electrode terminal of the capacitor element 20P at a second connection point P2 and which has an opposing portion positioned opposite to the opposing portion of the first opposing wiring portion 71P; and a bent wiring portion 73P that electrically connects the other end of the first opposing wiring portion 71P to one end of the second opposing wiring portion 72b. The first opposing wiring section 71P, the second opposing wiring section 72P, and the bent wiring section 73P are integrally formed flat conductors.

[0044] One end face of the first opposing wiring section 71P is electrically and mechanically connected to the side of the power supply wiring 60P at the first connection point P1 by soldering, welding, or screwing. The first opposing wiring portion 71P has an extending portion that extends from one end face connected to the side of the power supply wiring 60P at the first connection point P1 toward one electrode terminal of the capacitor element 20P, with both sides being on the same plane as the front and back of the power supply wiring 60P, and an opposing portion that is bent perpendicularly from this extending portion toward the side of the power supply wiring 60P toward the front and back.

[0045] The other end of the second opposing wiring section 72P is electrically and mechanically connected to one electrode terminal of the capacitor element 20P at the second connection point P2 by solder or the like. The second opposing wiring section 72P has an extending portion that extends in the direction of the power supply wiring 60P from the other end connected to one electrode terminal of the capacitor element 20P at the second connection point P2, with both sides being on the same plane as the front and back of the first opposing wiring section 71P, and an opposing portion that is bent at a right angle from this extending portion in a direction away from the capacitor element 20P with respect to the front and back, and whose surface faces the surface of the opposing portion of the first opposing wiring section 71P at equal intervals.

[0046] The bent wiring section 73P is formed continuously between the other end of the opposing portion of the first opposing wiring section 71P and the one end of the opposing portion of the second opposing wiring section 72P. The front and back sides of the bent wiring section 73P are parallel to the front and back sides of the extended portion of the first opposing wiring section 71P and the front and back sides of the extended portion of the second opposing wiring section 72P.

[0047] Although the bent wiring section 73P was made flat, the overall shape of the first capacitor connection wiring 70P was made curved when the bent wiring section 73P was made curved. Figure 3 In the illustration, it may be shown as a U-shape, and the bent wiring portion 73P may be shown as a straight line as the overall shape of the first capacitor connection wiring 70P Figure 3 The diagram may be shown as a V-shape. In other words, the first capacitor connection wiring 70P has a structure in which a portion of it is arranged opposite to the other, that is, the first opposing wiring portion 71P and the second opposing wiring portion 72P are formed continuously, that is, integrally, and the opposing portion of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P are arranged opposite to each other.

[0048] The second capacitor connection wire 80P is electrically connected between the other electrode terminal to which the other electrode of the capacitor element 20P is connected and the metal housing 400. The second capacitor connection wire, 80P, is a flat conductor with a front and back side. In the second capacitor connection wiring 80P, one end is electrically and mechanically connected to the other electrode terminal of the capacitor element 20P at the third connection point P3 by soldering or the like, and the other end is electrically and mechanically connected to the metal housing 400 at the fourth connection point P4 by soldering, welding, or screwing or the like.

[0049] The common-mode noise current CI flows through the first capacitor connection wiring 70P to the capacitor element 20P. The opposing electrode terminals of the capacitor element 20P are arranged in a direction perpendicular to the extended portion of the first opposing wiring portion 71P and the extended portion of the second opposing wiring portion 72P. In other words, the direction of the common-mode noise current CI flowing through the capacitor element 20P and the direction of the common-mode noise current CI flowing through the extended portion of the first opposing wiring section 71P and the extended portion of the second opposing wiring section 72P are on the same plane.

[0050] The wiring length DP1 of the first capacitor connection wiring 70P is longer than the straight-line distance DP0 from the first connection point P1, which is the connection point between one end face of the first capacitor connection wiring 70P and the side surface of the power supply wiring 60P, to the second connection point P2, which is the connection point between the other end of the first capacitor connection wiring 70P and one electrode terminal of the capacitor element 20P, due to the provision of opposing portions in the first opposing wiring portion 71P and the second opposing wiring portion 72P. Therefore, the thermal resistance of the first capacitor connection wiring 70P can be increased, making it less likely for the heat generated in the power supply wiring 60P to be transferred to the capacitor element 20P via the first capacitor connection wiring 70P. In short, this suppresses the heat absorbed by the 20P capacitor element by the heat generated in the 60P power supply wiring.

[0051] In other words, the thermal resistance Rth of the first capacitor connection wiring 70P can be expressed by the following equation (1). Rth = (1 / λ) × (D / A) (1) In equation (1), λ is the thermal conductivity, D is the length, and A is the cross-sectional area. As can be seen from equation (1), the thermal resistance Rth of the first capacitor connection wire 70P is proportional to the length D of the first capacitor connection wire 70P, and the thermal resistance Rth increases as the length D increases.

[0052] Next, the parasitic inductance in the first capacitor connection wiring 70P will be explained using Figures 4 and 5. Figure 4 is an equivalent circuit diagram of the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node (metal housing 400).

[0053] The first self-inductance Ls11P is the inductance from one end (first connection point P1) of the first opposing wiring portion 71P in the first capacitor connection wiring 70P to the midpoint P5 of the bent wiring portion 73P. The second self-inductance Ls12P is the inductance from the midpoint P5 of the bent wiring portion 73P in the first capacitor connection wiring 70P to the other end (second connection point P2) of the second opposing wiring portion 72P.

[0054] When a common-mode noise current CI flows through the first capacitor connection wiring 70P, the current flowing through the first opposing wiring section 71P and the current flowing through the second opposing wiring section 72P are in opposite directions. As a result, the magnetic fluxes generated by the first opposing wiring section 71P and the second opposing wiring section 72P cancel each other out. Therefore, the first parasitic inductance L11P from one end of the first opposing wiring portion 71P to the midpoint P5 of the bent wiring portion 73P in the first capacitor connection wiring 70P can be expressed by the following equation (2).

[0055] Furthermore, the second parasitic inductance L12P, which extends from the midpoint of the bent wiring portion 73P in the first capacitor connection wiring 70P to the other end P2 of the second opposing wiring portion 72P, can be expressed by the following equation (3). As a result, the parasitic inductance L1P from one end (first connection point P1) to the other end (second connection point P2) of the first capacitor connection wiring 70P can be expressed by the following equation (4).

[0056] L11P = Ls11P - M12P (2) L12P = Ls12P - M12P (3) L1P = L11P + L12P =Ls11P+Ls12P-2×M12P (4) In equations (2) to (4), M12P is the mutual inductance between the first opposing wiring section 71P and the second opposing wiring section 72P.

[0057] As can be seen from equation (4), when the length of the first capacitor connection wiring 70P is the same, the parasitic inductance L1P in this example, in which the first opposing wiring section 71P and the second opposing wiring section 72P are provided on the first capacitor connection wiring 70P, is (2 × M12P) smaller than the parasitic inductance of the first capacitor connection wiring in the comparative example in which the first opposing wiring section 71P and the second opposing wiring section 72P are not provided. In Figure 4, Ls2P represents the self-inductance of the second capacitor connection wiring 80P from one end (third connection point P3) to the other end (fourth connection point P4), and the parasitic inductance L2P of the second capacitor connection wiring 80P from one end to the other is the same as the self-inductance Ls2P.

[0058] As shown in Figure 5, the relationship between the parasitic inductance and thermal resistance of the first capacitor connection wiring 70P in this example and the comparative example is as follows: In this example, the wiring length DP1 of the first capacitor connection wiring 70P is increased to increase the thermal resistance, ensuring the thermal resistance necessary to prevent heat absorption of the capacitor element 20P, while simultaneously reducing the parasitic inductance of the first capacitor connection wiring 70P compared to the comparative example. Furthermore, because the parasitic inductance of the first capacitor connection wiring 70P was reduced, the high-frequency impedance is lower compared to the comparative example, as shown in Figure 6, thus improving the noise absorption effect.

[0059] As described above, in the power conversion device according to Embodiment 1, a first capacitor connection wiring 70P is continuously formed with respect to the capacitor element 20P for noise removal on the positive electrode side, electrically connected between the power supply wiring 60P on the positive electrode side and one electrode of the capacitor element 20P. The wiring has a first opposing wiring portion 71P, one end of which is electrically connected to the power supply wiring 60P on the positive electrode side, and a second opposing wiring portion 72P, the other end of which is electrically connected to one electrode of the capacitor element 20P. At least a portion of the first opposing wiring portion 71P and the second opposing wiring portion 72P are arranged opposite each other. Therefore, the power conversion device according to Embodiment 1 can suppress heat absorption of the capacitor element 20P due to heat generated in the power supply wiring 60P, reduce parasitic inductance in the first capacitor connection wiring 70P on the positive electrode side, and enhance the noise absorption effect of the capacitor element 20P.

[0060] In the power conversion device according to Embodiment 1, the positive terminal power supply wiring 60P and the first capacitor connection wiring are separate components, and the side surface of the power supply wiring 60P and one end surface of the first capacitor connection wiring 70P are electrically and mechanically connected by soldering, welding, or screwing. As a result, the thermal resistance is high at the first connection point P1 between the power supply wiring 60P and the first capacitor connection wiring 70P, further suppressing heat absorption by the capacitor element 20P due to heat generated in the power supply wiring 60P.

[0061] In the power conversion device according to Embodiment 1, the first capacitor connection wiring 70P is composed of a flat plate-shaped conductor integrally formed with the first opposing wiring portion 71P, the second opposing wiring portion 72P, and the bent wiring portion 73P. Due to the spring action provided by the bent wiring portion 73P, the positional accuracy between the other end of the second opposing wiring portion 72P and one electrode terminal of the capacitor element 20P is maintained at the second connection point P2, and the other end of the second opposing wiring portion 72P can be electrically and mechanically connected by solder or the like while pressure is applied and the other end is pressed against one electrode terminal of the capacitor element 20P.

[0062] In other words, the stress applied to one electrode terminal of the capacitor element 20P is absorbed by the spring action of the first capacitor connection wiring 70P, and the other end of the second opposing wiring section 72P can be electrically and mechanically connected to one electrode terminal of the capacitor element 20P without any gap between the other end of the second opposing wiring section 72P and one electrode terminal of the capacitor element 20P, while preventing a decrease in the performance of the capacitor element 20P due to pressure being applied to the capacitor element 20P.

[0063] By the way, in the power conversion device according to Embodiment 1, we have described how to suppress heat absorption by the capacitor element 20P for noise suppression on the positive electrode side and how to reduce parasitic inductance in the first capacitor connection wiring 70P which is electrically connected between the power supply wiring 60P on the positive electrode side and one electrode of the capacitor element 20P. However, by making the first capacitor connection wiring 70N which is electrically connected between the power supply wiring 60N on the negative electrode side and one electrode of the capacitor element 20N for noise suppression on the negative electrode side the same configuration as the first capacitor connection wiring 70P, it is possible to suppress heat absorption by the capacitor element 20N and reduce parasitic inductance in the first capacitor connection wiring 70N which is electrically connected between the power supply wiring 60N on the negative electrode side and one electrode of the capacitor element 20N.

[0064] In other words, the first capacitor connection wiring 70N is formed continuously, similar to the first capacitor connection wiring 70P, and has a first opposing wiring portion at one end that is electrically connected to the power supply wiring 60N on the negative electrode side, and a second opposing wiring portion at the other end that is electrically connected to one electrode of the capacitor element 20N, with at least a portion of each of the first opposing wiring portion and the second opposing wiring portion arranged opposite each other.

[0065] The following describes the first capacitor connection wiring 70N. The negative terminal power supply wiring 60N is a power supply wiring that is electrically connected to the power conversion circuit 10. The power supply wiring 60N is a flat, plate-shaped conductor with a front and back side. In the power supply wiring 60N, one end is connected to the negative terminal input terminal 1N to which the negative terminal of the DC power supply 100 is connected, and the other end is connected to the negative terminal input node 11N of the power conversion circuit 10.

[0066] The first capacitor connection wire 70N is electrically connected between the power supply wire 60N and one electrode of the capacitor element 20N. The first capacitor connection wire 70N is a flat conductor with a front and back side. In the first capacitor connection wiring 70N, one end face is connected to the side of the power supply wiring 60N at the first connection point, and the other end is connected to one electrode terminal of the capacitor element 20N at the second connection point.

[0067] The first capacitor connection wiring 70N includes a first opposing wiring portion, one end of which is electrically connected to the power supply wiring 60N; a second opposing wiring portion, the other end of which is electrically connected to one electrode terminal of the capacitor element 20N and which has an opposing portion positioned opposite the opposing portion of the first opposing wiring; and a bent wiring portion that electrically connects the other end of the first opposing wiring portion to one end of the second opposing wiring portion. In the first capacitor connection wiring 70N, the first opposing wiring section, the second opposing wiring section, and the bent wiring section are integrally formed flat conductors.

[0068] One end face of the first opposing wiring section is electrically and mechanically connected to the side of the power supply wiring 60N at the first connection point by soldering, welding, or screwing. The first opposing wiring section has an extended portion that extends from one end face toward one electrode terminal of the capacitor element 20N, with both sides being on the same plane as the front and back of the power supply wiring, and an opposing portion that is bent perpendicular to the front and back from this extended portion.

[0069] The other end of the second opposing wiring section is electrically and mechanically connected to one electrode terminal of the capacitor element 20N at the second connection point by solder or the like. The second opposing wiring section has an extended portion that extends from the other end face in the direction of the power supply wiring 60N, with its front and back surfaces being on the same plane as the front and back surfaces of the first opposing wiring section, and an opposing portion that is bent perpendicular to the front and back surfaces from this extended portion, with its surface facing the surface of the opposing portion of the first opposing wiring section at equal intervals.

[0070] The bent wiring section is formed continuously between the other end of the opposing portion in the first opposing wiring section and the one end of the opposing portion in the second opposing wiring section. The front and back of the bent wiring section are the front and back of the extended portion in the first opposing wiring section and the second opposing wiring section. department The extended portion is parallel to both the front and back surfaces. In other words, the first capacitor connection wiring 70N has a structure in which a portion of it is arranged opposite to the other, that is, the opposing portion in the first opposing wiring section and the opposing portion in the second opposing wiring section are arranged in that structure.

[0071] The second capacitor connection wiring 80N is electrically connected between the other electrode terminal to which the other electrode of the capacitor element 20N is connected and the metal housing 400. The second capacitor connection wire 80N is a flat conductor with a front and back side. In the second capacitor connection wiring 80N, one end is electrically and mechanically connected to the other electrode terminal of the capacitor element 20N at the third connection point by solder or the like, and the other end is electrically and mechanically connected to the metal housing 400 at the fourth connection point by soldering, welding, or screwing or the like.

[0072] The length of the first capacitor connection wiring 70N is longer than the straight-line distance from the first connection point, which is the connection point between one end face of the first capacitor connection wiring 70N and the side surface of the power supply wiring 60N, to the second connection point, which is the connection point between the other end of the first capacitor connection wiring 70N and one electrode terminal of the capacitor element 20N, due to the provision of opposing portions in the first opposing wiring portion and the second opposing wiring portion. Therefore, the thermal resistance of the first capacitor connection wiring 70N can be increased, making it difficult for the heat generated in the power supply wiring 60N to be transferred to the capacitor element 20N by the first capacitor connection wiring 70N. In short, this suppresses the heat absorbed by the capacitor element (20N) by the heat generated in the power supply wiring (60N).

[0073] Furthermore, by making the first capacitor connection wiring 70N a flat conductor integrally formed and having a first opposing wiring section, a second opposing wiring section, and a bent wiring section, when a common-mode noise current flows through the first capacitor connection wiring 70N, the current flowing through the first opposing wiring section and the current flowing through the second opposing wiring section are in opposite directions. As a result, the parasitic inductance of this example, in which the first capacitor connection wiring 70N is provided with a first opposing wiring section and a second opposing wiring section, is (2 × M12N) smaller than the parasitic inductance of the comparative example in which the first opposing wiring section and the second opposing wiring section are not provided. Therefore, the parasitic inductance in the first capacitor connection wiring 70N on the negative side can be reduced.

[0074] In short, by configuring the first capacitor connection wiring 70N to have a first opposing wiring section and a second opposing wiring section, similar to the first capacitor connection wiring 70P, it is possible to suppress heat absorption by the capacitor element 20N for noise suppression on the negative electrode side due to heat generated in the power supply wiring 60N on the negative electrode side, and to reduce the parasitic inductance in the first capacitor connection wiring 70N that is electrically connected between the power supply wiring 60N on the negative electrode side and one electrode of the capacitor element 20N, thereby enhancing the noise absorption effect of the capacitor element 20N.

[0075] Furthermore, by making the first capacitor connection wiring 70S, which is electrically connected between the positive-side power supply wiring 60P and one electrode of the smoothing capacitor element 20S, the same configuration as the first capacitor connection wiring 70P, it is possible to suppress heat absorption by the capacitor element 20S and reduce parasitic inductance in the first capacitor connection wiring 70S, which is electrically connected between the positive-side power supply wiring 60P and one electrode of the capacitor element 20S.

[0076] In other words, the first capacitor connection wiring 70S is formed continuously, similar to the first capacitor connection wiring 70P, and has a first opposing wiring portion at one end that is electrically connected to the power supply wiring 60P on the positive electrode side, and a second opposing wiring portion at the other end that is electrically connected to one electrode of the capacitor element 20S, with at least a portion of each of the first opposing wiring portion and the second opposing wiring portion arranged opposite each other.

[0077] The following describes the first capacitor connection wiring, 70S. The first capacitor connection wire 70S is electrically connected between the power supply wire 60P and one electrode of the capacitor element 20S. The first capacitor connection wire 70S is a flat conductor with a front and back side. In the first capacitor connection wiring 70S, one end face is connected to the side of the power supply wiring 60P at the first connection point, and the other end is connected to one electrode terminal of the capacitor element 20S at the second connection point.

[0078] The first capacitor connection wiring 70S includes a first opposing wiring portion, one end of which is electrically connected to the power supply wiring 60P; a second opposing wiring portion, the other end of which is electrically connected to one electrode terminal of the capacitor element 20S and which has an opposing portion positioned opposite the opposing portion of the first opposing wiring; and a bent wiring portion that electrically connects the other end of the first opposing wiring portion to one end of the second opposing wiring portion. In the first capacitor connection wiring 70S, the first opposing wiring section, the second opposing wiring section, and the bent wiring section are integrally formed flat conductors.

[0079] One end face of the first opposing wiring section is electrically and mechanically connected to the side of the power supply wiring 60P at the first connection point by soldering, welding, or screwing. The first opposing wiring section has an extending portion that extends from one end face toward one electrode terminal of the capacitor element 20S, with both the front and back surfaces being on the same plane as the front and back surfaces of the power supply wiring, and an opposing portion that is bent perpendicular to the front and back surfaces from this extending portion.

[0080] The other end of the second opposing wiring section is electrically and mechanically connected to one electrode terminal of the capacitor element 20S at the second connection point by solder or the like. The second opposing wiring section has an extended portion that extends from the other end face in the direction of the power supply wiring 60P, with its front and back surfaces being on the same plane as the front and back surfaces of the first opposing wiring section, and an opposing portion that is bent perpendicular to the front and back surfaces from this extended portion, with its surface facing the surface of the opposing portion of the first opposing wiring section at equal intervals.

[0081] The bent wiring section is formed continuously between the other end of the opposing portion in the first opposing wiring section and the one end of the opposing portion in the second opposing wiring section. The front and back of the bent wiring section are the front and back of the extended portion in the first opposing wiring section and the second opposing wiring section. department The extended portion is parallel to both the front and back surfaces. In other words, the first capacitor connection wiring 70S has a structure in which a portion of it is arranged opposite to the other, that is, the opposing portion in the first opposing wiring section and the opposing portion in the second opposing wiring section are arranged in that structure.

[0082] The second capacitor connection wiring 80S is electrically connected between the other electrode terminal to which the other electrode of the capacitor element 20S is connected and the negative electrode power supply wiring 60N. The second capacitor connection wire 80S is a flat conductor with a front and back side. In the second capacitor connection wiring 80S, one end is electrically and mechanically connected to the other electrode terminal of the capacitor element 20S at the third connection point by solder or the like, and the other end face is electrically and mechanically connected to the side of the negative electrode power supply wiring 60N at the fourth connection point by solder, welding, or screw fastening or the like.

[0083] The length of the first capacitor connection wiring 70S is longer than the straight-line distance from the first connection point, which is the connection point between one end face of the first capacitor connection wiring 70S and the side surface of the power supply wiring 60P, to the second connection point, which is the connection point between the other end of the first capacitor connection wiring 70S and one electrode terminal of the capacitor element 20S, due to the provision of opposing parts in the first opposing wiring section and opposing parts in the second opposing wiring section. Therefore, the thermal resistance of the first capacitor connection wiring 70S can be increased, making it difficult for the heat generated in the power supply wiring 60P to be transferred to the capacitor element 20S via the first capacitor connection wiring 70S. In short, this suppresses the heat absorbed by the capacitor element 20S due to the heat generated in the power supply wiring 60P.

[0084] Furthermore, by making the first capacitor connection wiring 70S a flat plate-shaped conductor integrally formed and having a first opposing wiring section, a second opposing wiring section, and a bent wiring section, when a normal mode noise current flows through the first capacitor connection wiring 70S, the current flowing through the first opposing wiring section and the current flowing through the second opposing wiring section are in opposite directions. As a result, the parasitic inductance in this example, in which the first capacitor connection wiring 70S is provided with a first opposing wiring section and a second opposing wiring section, is (2 × M12S) smaller than the parasitic inductance in the comparative example in which the first opposing wiring section and the second opposing wiring section are not provided. Therefore, the parasitic inductance in the first capacitor connection wiring 70S on the positive terminal side can be reduced.

[0085] In short, by configuring the first capacitor connection wiring 70S to have a first opposing wiring section and a second opposing wiring section, similar to the first capacitor connection wiring 70P, it is possible to suppress heat absorption by the smoothing capacitor element 20S due to heat generated in the positive-side power supply wiring 60P, and to reduce the parasitic inductance in the first capacitor connection wiring 70S which is electrically connected between the positive-side power supply wiring 60P and one electrode of the capacitor element 20S, thereby enhancing the noise absorption effect of the capacitor element 20S.

[0086] Furthermore, by configuring the second capacitor connection wiring 80S, which is electrically connected between the negative-side power supply wiring 60N and the other electrode of the smoothing capacitor element 20S, to include a first opposing wiring portion, one end of which is electrically connected to the negative-side power supply wiring 60N, a second opposing wiring portion, the other end of which is electrically connected to the other electrode terminal of the capacitor element 20S and which has an opposing portion positioned opposite to the opposing portion of the first opposing wiring, and a bent wiring portion that electrically connects the other end of the first opposing wiring portion to one end of the second opposing wiring portion, it is possible to suppress heat absorption by the smoothing capacitor element 20S due to heat generated in the negative-side power supply wiring 60N and to reduce parasitic inductance in the second capacitor connection wiring 80S, which is electrically connected between the negative-side power supply wiring 60N and the other electrode of the capacitor element 20S.

[0087] Although not shown in the figure, in a power converter equipped with a capacitor element (X capacitor) that removes normal mode noise, in which one electrode is connected to the positive-side power supply wiring 60P via a first capacitor connection wiring and the other electrode is connected to the ground node via a second capacitor connection wiring, the first capacitor connection wiring connected to the X capacitor comprises a first opposing wiring section, one end of which is electrically connected to the positive-side power supply wiring 60P, a second opposing wiring section, the other end of which is electrically connected to one electrode terminal of the X capacitor and has an opposing section positioned opposite the opposing section of the first opposing wiring, and a bent wiring section that electrically connects the other end of the first opposing wiring section and one end of the second opposing wiring section, thereby suppressing heat absorption by the X capacitor due to heat generated in the positive-side power supply wiring 60P and reducing parasitic inductance in the first capacitor connection wiring electrically connected between the positive-side power supply wiring 60P and one electrode of the X capacitor.

[0088] Furthermore, although not shown in the figure, in a power conversion device equipped with a capacitor element (X capacitor) that removes normal mode noise, in which one electrode is connected to the power supply wiring 60N on the negative side via a first capacitor connection wiring and the other electrode is connected to the ground node via a second capacitor connection wiring, the first capacitor connection wiring connected to the X capacitor comprises a first opposing wiring section, one end of which is electrically connected to the power supply wiring 60N on the negative side, a second opposing wiring section, the other end of which is electrically connected to one electrode terminal of the X capacitor and has an opposing section that is positioned opposite to the opposing section of the first opposing wiring, and a bent wiring section that electrically connects the other end of the first opposing wiring section and one end of the second opposing wiring section, it is possible to suppress heat absorption by the X capacitor due to heat generated in the power supply wiring 60N on the negative side and to reduce parasitic inductance in the first capacitor connection wiring that is electrically connected between the power supply wiring 60N on the negative side and one electrode of the X capacitor.

[0089] Embodiment 2. The power conversion device according to Embodiment 2 will be described with reference to Figures 7 and 8. The power converter according to Embodiment 1 has an electrical path structure from the positive-side power supply wiring 60P to the metal housing 400 which serves as a ground node via a capacitor element 20P for noise removal on the positive-side, in which the positive-side power supply wiring 60P and the first capacitor connection wiring 70P are separate components, and one end face of the first opposing wiring portion 71P of the first capacitor connection wiring 70P is electrically and mechanically connected to the side surface of the power supply wiring 60P at the first connection point P1 by soldering, welding, or screwing.

[0090] In contrast, the power converter according to Embodiment 2 has an electrical path structure from the positive-side power supply wiring 60P to the metal housing 400 which serves as a ground node via a capacitor element 20P for noise removal on the positive-side, in which the positive-side power supply wiring 60P and the first capacitor connection wiring 70P are integrally formed, and at the first connection point P1, the first capacitor connection wiring 70P is branched from the positive-side power supply wiring 60P on the same plane, and the first opposing wiring portion 71P, the second opposing wiring portion 72P and the bent wiring portion 73P of the first capacitor connection wiring 70P are integrally formed with the power supply wiring 60P.

[0091] In other respects, the power converter according to Embodiment 2 is the same as the power converter according to Embodiment 1. In the power conversion device according to Embodiment 2, the side surface of the power supply wiring 60P and one end surface of the first capacitor connection wiring 70P at the first connection point P1 are not physical interface surfaces, but virtual surfaces.

[0092] The power converter according to Embodiment 2, like the power converter according to Embodiment 1, can suppress heat absorption by the capacitor element 20P due to heat generated in the power supply wiring 60P, and can also reduce the parasitic inductance in the first capacitor connection wiring 70P on the positive electrode side, thereby enhancing the noise absorption effect of the capacitor element 20P. In Figures 7 and 8, the same reference numerals as those used in Figures 1 through 4 indicate the same or corresponding parts.

[0093] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, as shown in Embodiment 1, the negative-side power supply wiring 60N and the first capacitor connection wiring 70N may be integrally formed, as described above. In the structure of the electrical path shown in Embodiment 1, from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, the positive terminal power supply wiring 60P and the first capacitor connection wiring 70S may be integrally formed, as described above, and the negative terminal power supply wiring 60N and the second capacitor connection wiring 80S may be integrally formed.

[0094] Embodiment 3. The power conversion device according to Embodiment 3 will be described with reference to Figures 9 and 10. The power converter according to Embodiment 1 has an electrical path structure from the positive terminal power supply wiring 60P to the metal housing 400 which serves as a ground node via a capacitor element 20P for noise removal on the positive terminal side, in which the first opposing wiring section 71P, the second opposing wiring section 72P, and the bent wiring section 73P that constitute the first capacitor connection wiring 70P are integrally formed.

[0095] In contrast, the power conversion device according to Embodiment 3 has the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P configured with separate components. In other respects, the power converter according to Embodiment 3 is the same as the power converter according to Embodiment 1. In Figures 9 and 10, the same reference numerals as those used in Figures 1 through 4 indicate the same or corresponding parts.

[0096] In the power conversion device according to Embodiment 3, the first capacitor connection wiring 70P is made up of a connection wiring which is a flat plate-shaped conductor having two front and back sides, divided in the central part of the bent wiring section 73P, and the two connection wirings are electrically and mechanically connected at the end faces of each other in the central part of the bent wiring section 73P by soldering or the like.

[0097] In other words, the first capacitor connection wiring 70P comprises a connection wiring A having a first opposing wiring portion 71P at one end which is electrically connected to the power supply wiring 60P, and one wiring portion 73P1 of a bent wiring portion 73P formed continuously from the other end of the first opposing wiring portion 71P, and a connection wiring B having a second opposing wiring portion 72P at the other end which is electrically connected to one electrode terminal of the capacitor element 20P and which has an opposing portion positioned opposite to the opposing portion of the first opposing wiring portion 71P, and the other wiring portion 73P2 of a bent wiring portion 73P formed continuously from one end of the second opposing wiring portion 72P, wherein the other end face of one wiring portion 73P1 of the bent wiring portion 73P and the one end face of the other wiring portion 73P2 of the bent wiring portion 73P are electrically and mechanically connected by solder or the like.

[0098] As a result, the first capacitor connection wiring 70P forms an electrical path from the positive-side power supply wiring 60P to one electrode terminal of the capacitor element 20P via the route of the first opposing wiring section 71P - one wiring section 73P1 of the bent wiring section 73P - the other wiring section 73P2 of the bent wiring section 73P - the second opposing wiring section 72P. Note that the other end face of the first opposing wiring section 71P and one end face of one wiring section 73P1 of the bent wiring section 73P, as well as the other end face of the second opposing wiring section 72P and the other end face of the other wiring section 73P2 of the bent wiring section 73P, are not physical boundary surfaces but virtual surfaces.

[0099] Thus, since the first capacitor connection wiring 70P is composed of connection wiring A having a first opposing wiring portion 71P and connection wiring B having a second opposing wiring portion 72P, there are no constraints on the bending process when forming the bent wiring portion 73P. Therefore, the distance D1 between the opposing portion of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P can be shortened, and the opposing portions of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P can be placed in close proximity.

[0100] As a result, the cancellation effect between the magnetic flux generated by the common-mode noise current CI at the opposing part of the first opposing wiring section 71P and the magnetic flux generated by the common-mode noise current CI at the opposing part of the second opposing wiring section 72P is strengthened. In other words, the mutual inductance M12P between the first opposing wiring section 71P and the second opposing wiring section 72P increases, the parasitic inductance in the first capacitor connection wiring 70P can be further reduced, and the noise absorption effect of the capacitor element 20P can be enhanced.

[0101] Furthermore, since the other end face of one wiring section 73P1 of the bent wiring section 73P and the other end face of the other wiring section 73P2 of the bent wiring section 73P are connected by solder or the like, the thermal resistance at the connection point can be increased, further suppressing the heat absorbed by the capacitor element 20P by the heat generated in the power supply wiring 60P.

[0102] As described above, the power converter according to Embodiment 3 has the same effects as the power converter according to Embodiment 1. Furthermore, since the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P are made of separate parts and connected to each other, the heat absorption of the capacitor element 20P due to the heat generated in the power supply wiring 60P is further suppressed, and the parasitic inductance in the positive electrode side first capacitor connection wiring 70P is further reduced, thereby further enhancing the noise absorption effect of the capacitor element 20P.

[0103] In addition, in the power conversion device according to Embodiment 3, the positive terminal power supply wiring 60P and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2.

[0104] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, as shown in Embodiment 1, the first capacitor connection wiring 70N may be divided in the middle of the bent wiring section into two separate components, connection wirings A and B, which are flat conductors with a front and back side. Connection wiring A has a first opposing wiring section, one end of which is electrically connected to the power supply wiring 60N, and one wiring section of a bent wiring section formed continuously from the other end of the first opposing wiring section. Connection wiring B has a second opposing wiring section, the other end of which is electrically connected to one electrode terminal of the capacitor element 20N, and which has an opposing section positioned opposite to the opposing section of the first opposing wiring section, and the other wiring section of a bent wiring section formed continuously from one end of the second opposing wiring section. The other end face of one wiring section of the bent wiring section and the one end face of the other wiring section of the bent wiring section may be electrically and mechanically connected by solder or the like.

[0105] Furthermore, in the structure of the electrical path from the positive-side power supply wiring 60P to the negative-side power supply wiring 60N via the smoothing capacitor element 20S as shown in Embodiment 1, the first capacitor connection wiring 70S may be divided in the central part of the bent wiring section into two separate components, connection wirings A and B, which are flat conductors with a front and back side. Connection wiring A has a first opposing wiring section, one end of which is electrically connected to the power supply wiring 60N, and one wiring section of a bent wiring section formed continuously from the other end of the first opposing wiring section. Connection wiring B has a second opposing wiring section, the other end of which is electrically connected to one electrode terminal of the capacitor element 20S and which has an opposing section positioned opposite to the opposing section of the first opposing wiring section, and the other wiring section of a bent wiring section formed continuously from one end of the second opposing wiring section. The other end face of one wiring section of the bent wiring section and the one end face of the other wiring section of the bent wiring section may be electrically and mechanically connected by solder or the like.

[0106] Embodiment 4. The power conversion device according to Embodiment 4 will be described with reference to Figures 11 and 12. The power conversion device according to Embodiment 4 is characterized in that, in the power conversion device according to Embodiment 1, the length of the second capacitor connection wiring 80P is shorter than the length of the first capacitor connection wiring 70P. In Figures 11 and 12, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0107] In the power conversion device according to Embodiment 4, as shown in Figure 12, the length DP2 of the second capacitor connection wiring 80P, that is, the length DP2 of the second capacitor connection wiring 80P from the third connection point P3 connected to the other electrode terminal of the capacitor element 20P to the fourth connection point P4 connected to the metal housing 400, is made shorter than the length DP1 of the first capacitor connection wiring 70P, that is, the length DP1 of the first capacitor connection wiring 70P from the first connection point P1 where the first opposing wiring section 71P is connected to the power supply wiring 60P to the second connection point P2 where the second opposing wiring section 72P is connected to one electrode terminal of the capacitor element 20P.

[0108] In this way, by shortening the length DP2 of the second capacitor connection wiring 80P, the thermal resistance of the second capacitor connection wiring 80P can be reduced, and the heat generated by the capacitor element 20P can be transferred to the metal housing 400 more quickly.

[0109] As described above, the power conversion device according to Embodiment 4, similar to that described in Embodiment 1, can suppress heat absorption by the capacitor element 20P due to heat generated in the power supply wiring 60P, and can also reduce the parasitic inductance in the first capacitor connection wiring 70P on the positive electrode side, thereby enhancing the noise absorption effect of the capacitor element 20P. Furthermore, the power conversion device according to Embodiment 4 has the characteristic that the length of the second capacitor connection wiring 80P is shorter than the length of the first capacitor connection wiring 70P, so that the heat generated by the self-heating of the capacitor element 20P can be effectively dissipated to the metal housing 400.

[0110] In addition, in the power conversion device according to Embodiment 4, the positive terminal power supply wiring 60P and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2. Furthermore, in the power conversion device according to Embodiment 4, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P may be configured with separate components and connected to each other.

[0111] In the structure of the electrical path shown in Embodiment 1, from the power supply wiring 60N on the negative terminal side to the ground node via the noise-removing capacitor element 20N on the negative terminal side, the length of the second capacitor connection wiring 80N may be shorter than the length of the first capacitor connection wiring 70N, as described above.

[0112] Embodiment 5. A power conversion device according to Embodiment 5 will be described with reference to Figures 13 and 14. The power conversion device according to Embodiment 5 is characterized in that, in the power conversion device according to Embodiment 1, the first capacitor connection wiring 70P and one electrode of the positive-side noise-removing capacitor element 20P are integrally formed from the same material, or the first capacitor connection wiring 70P and one electrode of the capacitor element 20P are integrally formed from the same material as the electrode terminal to which they are connected, that is, the first capacitor connection wiring 70P and the capacitor element 20P are integrally formed. In Figures 13 and 14, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0113] The power conversion device according to Embodiment 5 has an electrode terminal integrally formed to which one electrode of a capacitor element 20P is connected, extending from the other end of the extended portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P. The front and back of the electrode terminal to which one electrode of the capacitor element 20P is connected are located on the same plane as the front and back of the extended portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P. The other electrode of the capacitor element 20P is positioned opposite the other electrode and connected to the electrode terminal.

[0114] The second capacitor connection wiring 80P may have an electrode terminal integrally formed from one end to the other electrode of the capacitor element 20P, which is connected to it. In the power conversion device according to Embodiment 5, the other end face of the extended portion of the second opposing wiring portion 72P and the end face of one electrode terminal of the capacitor element 20P at the second connection point P2 are not physical interface surfaces, but rather virtual surfaces.

[0115] In addition, in the power conversion device according to Embodiment 5, the power supply wiring 60P on the positive terminal side and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2. Furthermore, in the power conversion device according to Embodiment 5, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P may be configured with separate components and connected to each other. Furthermore, in the power conversion device according to Embodiment 5, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the length of the first capacitor connection wiring 70P.

[0116] In the structure of the electrical path from the negative terminal power supply wiring 60N to the ground node via the negative terminal noise suppression capacitor element 20N as shown in Embodiment 1, the first capacitor connection wiring 70N and the capacitor element 20N may be integrally formed, as described above. In the structure of the electrical path shown in Embodiment 1, from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, the first capacitor connection wiring 70S and the capacitor element 20S may be integrally formed, as described above.

[0117] Embodiment 6. A power conversion device according to Embodiment 6 will be described with reference to Figures 15 to 17. In the power conversion device according to Embodiment 1, the direction in which the common-mode noise current CI flows through the capacitor element 20P for noise removal on the positive electrode side is the same as the direction in which the first capacitor connection wiring 70P extends from the side of the power supply wiring 60P.

[0118] In contrast, the power conversion device according to Embodiment 6 has a structure in which the capacitor element 20P is positioned such that at least a portion of the current direction of the common-mode noise current CI flowing between one electrode and the other electrode faces at least a portion of the opposing portion of at least one of the opposing portions of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P. In other respects, the power converter according to Embodiment 6 is the same as the power converter according to Embodiment 1. In Figures 15 to 17, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0119] In the power conversion device according to Embodiment 6, the capacitor element 20P is positioned relative to the first capacitor connection wiring 70P such that the direction in which the common-mode noise current CI flows through the capacitor element 20P is perpendicular to the direction in which the first capacitor connection wiring 70P extends from the side surface of the power supply wiring 60P, that is, parallel to the direction of the common-mode noise current CI flowing through the opposing portion of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P, and such that the magnetic flux generated by the common-mode noise current CI flowing through the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P cancels each other out.

[0120] The front and back surfaces of one electrode of the capacitor element 20P are parallel to the front and back surfaces of the extended portion of the second opposing wiring portion 72P, and the other electrode of the capacitor element 20P is positioned opposite to one electrode of the capacitor element 20P on the side where the bent wiring portion 73P of the first capacitor connection wiring 70P is located. The common-mode noise current CI flowing through the opposing part of the second opposing wiring section 72P and the common-mode noise current CI flowing through the capacitor element 20P flow in opposite directions. By shortening the distance between the opposing part of the second opposing wiring section 72P and the side surface of the capacitor element 20P that is parallel to the direction of the common-mode noise current CI flowing through the capacitor element 20P, the magnetic flux generated by the common-mode noise current CI flowing through the opposing part of the second opposing wiring section 72P and the magnetic flux generated by the common-mode noise current CI flowing through the capacitor element 20P cancel each other out.

[0121] The parasitic inductance of the first capacitor connection wiring 70P in the electrical path from the positive-side power supply wiring 60P configured in this way, through the positive-side noise-removing capacitor element 20P, to the metal housing 400 which serves as the ground node, will be explained with reference to Figure 17. Figure 17 is an equivalent circuit diagram of the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node (metal housing 400).

[0122] The first parasitic inductance L11P from one end (first connection point P1) of the first opposing wiring portion 71P in the first capacitor connection wiring 70P to the midpoint P5 of the bent wiring portion 73P is expressed by equation (2) above. On the other hand, the second parasitic inductance L12P, which is measured from the midpoint P5 of the bent wiring portion 73P in the first capacitor connection wiring 70P to the other end (second connection point P2) of the second opposing wiring portion 72P, can be expressed by the following equation (5). As a result, the parasitic inductance L1P from one end (first connection point P1) to the other end (second connection point P2) of the first capacitor connection wiring 70P can be expressed by the following equation (6).

[0123] L12P = Ls12P - M12P - M1cP (5) L1P = L11P + L12P =Ls11P+Ls12P-2×M12P-M1cP (6) In equations (5) and (6), M1cP is the mutual inductance between the second opposing wiring section 72P and the capacitor element 20P.

[0124] As can be understood from equation (6), when the length of the first capacitor connection wiring 70P is the same, the parasitic inductance L1P in this example, in which the first opposing wiring section 71P and the second opposing wiring section 72P are provided on the first capacitor connection wiring 70P and the direction of the common-mode noise current CI flowing through the capacitor element 20P is positioned to face at least a part of the opposing section of the second opposing wiring section 72P, is (2 × M12P + M1cP) smaller than the parasitic inductance of the first capacitor connection wiring in the comparative example in which the first opposing wiring section 71P and the second opposing wiring section 72P are not provided.

[0125] Furthermore, the parasitic inductance LcP of the capacitor element 20P can be expressed by the following equation (7). LcP = LscP - M1cP (7) In equation (7), LscP is the self-inductance of the capacitor element 20P. As can be seen from equation (7), the parasitic inductance LcP of the capacitor element 20P is M1cP smaller than the parasitic inductance (LscP) of the capacitor element 20P in the example where the current direction of the common-mode noise current CI flowing through the capacitor element 20P is not positioned opposite the second opposing wiring section 72P.

[0126] As a result, the parasitic inductance in the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node can be reduced, the impedance in that electrical path to the high-frequency common-mode noise current CI can be reduced, and the noise absorption effect can be further enhanced.

[0127] As described above, the power converter according to Embodiment 6 has the same effects as the power converter according to Embodiment 1. Furthermore, since the capacitor element 20P is positioned facing the opposing part of the second opposing wiring section 72P such that the direction of the common-mode noise current CI flowing through the capacitor element 20P faces the opposing part of the second opposing wiring section 72P, the parasitic inductance in the first capacitor connection wiring 70P on the positive electrode side is further reduced, and the parasitic inductance of the capacitor element 20P is also reduced, thereby further enhancing the noise absorption effect of the capacitor element 20P.

[0128] In addition, in the power conversion device according to Embodiment 6, as shown in Embodiment 2, the power supply wiring 60P on the positive terminal side and the first capacitor connection wiring 70P may be integrally formed. Furthermore, in the power conversion device according to Embodiment 6, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P may be configured with separate components and connected to each other.

[0129] Furthermore, in the power conversion device according to Embodiment 6, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the length of the first capacitor connection wiring 70P. Furthermore, in the power conversion device according to Embodiment 6, as shown in Embodiment 5, the first capacitor connection wiring 70P and the capacitor element 20P may be integrally formed.

[0130] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, as shown in Embodiment 1, the capacitor element 20N may be arranged facing the opposing part of the second opposing wiring section, similar to the above, such that the direction of the common-mode noise current flowing through the capacitor element 20N faces the opposing part of the second opposing wiring section.

[0131] In the structure of the electrical path from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, as shown in Embodiment 1, the capacitor element 20S may be arranged facing the opposing part of the second opposing wiring section, similar to the above, such that the direction of the normal mode noise current flowing through the capacitor element 20S faces the opposing part of the second opposing wiring section.

[0132] Embodiment 7. The power conversion device according to Embodiment 7 will be described with reference to Figures 18 to 20. The power conversion device according to Embodiment 1 is configured such that the second capacitor connection wiring 80P simply electrically connects the other electrode terminal to which the other electrode of the positive-side noise-removing capacitor element 20P is connected, and the metal housing 400.

[0133] In contrast, the power conversion device according to Embodiment 7 is configured such that at least a portion of the capacitor element 20P is positioned opposite at least a portion of the second capacitor connection wiring 80P. In other words, the direction of the common-mode noise current flowing between one electrode and the other electrode of the capacitor element 20P and the direction of the common-mode noise current flowing through the opposing portion 81P of the second capacitor connection wiring 80P opposite the capacitor element 20P are opposite, so that the magnetic fluxes generated by each common-mode noise current cancel each other out.

[0134] In other respects, the embodiment 7 The power converter is the same as the power converter according to Embodiment 1. In Figures 18 to 20, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0135] In the power conversion device according to Embodiment 7, the second capacitor connection wiring 80P has a facing portion 81P that is positioned opposite the capacitor element 20P. The direction of the common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P is opposite to at least a portion of the direction of the common-mode noise current CI flowing between one electrode and the other electrode of the capacitor element 20P, and the directions of the common-mode noise currents CI are opposite to each other.

[0136] The opposing portion 81P of the second capacitor connection wiring 80P and the capacitor element 20P are positioned such that the magnetic flux generated by the common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P cancels out the magnetic flux generated by the common-mode noise current CI flowing through the capacitor element 20P.

[0137] The second capacitor connection wiring 80P has a first extension portion, one end of which is electrically and mechanically connected by solder or the like to the other electrode terminal of the capacitor element 20P to which the other electrode of the capacitor element 20P is connected at the third connection point P3; a counter portion 81P, which is bent at a right angle toward the capacitor element 20P, continuously from the other end of the first extension portion and positioned opposite the side of the capacitor element 20P, parallel to the direction of the common-mode noise current CI flowing through the capacitor element 20P; and a second extension portion, which is bent at a right angle toward away from the capacitor element 20P, continuously from the other end of the counter portion 81P, the other end of which is electrically and mechanically connected by solder or the like to the metal housing 400 at the fourth connection point P4.

[0138] The common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P and the common-mode noise current CI flowing through the capacitor element 20P flow in opposite directions. By shortening the distance between the opposing portion 81P of the second capacitor connection wiring 80P and the side surface of the capacitor element 20P, the magnetic flux generated by the common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P and the magnetic flux generated by the common-mode noise current CI flowing through the capacitor element 20P cancel each other out.

[0139] The parasitic inductance of the second capacitor connection wiring 80P in the electrical path from the positive-side power supply wiring 60P configured in this way, through the positive-side noise-removing capacitor element 20P, to the metal housing 400 which serves as the ground node, will be explained using Figure 20. Figure 20 is an equivalent circuit diagram of the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node (metal housing 400).

[0140] The parasitic inductance L2P from one end (third connection point P3) to the other end (fourth connection point P4) in the second capacitor connection wiring 80P can be expressed by the following equation (8). Furthermore, the parasitic inductance LcP of the capacitor element 20P can be expressed by the following equation (9). L2P = Ls2P - M2cP (8) LcP = LscP - M2cP (9) In equations (8) and (9), M2cP is the mutual inductance between the opposing portion 81P of the second capacitor connection wiring 80P and the capacitor element 20P.

[0141] As can be understood from equation (8), the second capacitor connection wiring 80P has a counter portion 81P that is positioned opposite to the direction of the common-mode noise current flowing through the capacitor element 20P and generates a magnetic flux that cancels out the magnetic flux generated by the common-mode noise current CI flowing through the capacitor element 20P. As a result, the parasitic inductance L2P of the second capacitor connection wiring 80P in this example is M2cP smaller than the parasitic inductance Ls2P of the second capacitor connection wiring in the comparative example which does not have a counter portion. Furthermore, as can be seen from equation (8), the parasitic inductance LcP of the capacitor element 20P in this example is M2cP smaller than the parasitic inductance LscP of the capacitor element in the comparative example.

[0142] As a result, the parasitic inductance in the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node can be reduced, the impedance in that electrical path to the high-frequency common-mode noise current CI can be reduced, and the noise absorption effect can be further enhanced.

[0143] As described above, the power converter according to Embodiment 7 has the same effects as the power converter according to Embodiment 1. Furthermore, since a counter portion 81P facing the direction of the common-mode noise current CI flowing through the capacitor element 20P is provided on the second capacitor connection wiring 80P, the parasitic inductance in the second capacitor connection wiring 80P is reduced, and the parasitic inductance of the capacitor element 20P is also reduced, thereby further enhancing the noise absorption effect of the capacitor element 20P.

[0144] In addition, in the power conversion device according to Embodiment 7, the positive terminal power supply wiring 60P and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2. Furthermore, in the power conversion device according to Embodiment 7, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P may be configured with separate components and connected to each other.

[0145] Furthermore, in the power conversion device according to Embodiment 7, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the length of the first capacitor connection wiring 70P. Furthermore, in the power conversion device according to Embodiment 7, as shown in Embodiment 5, the first capacitor connection wiring 70P and the capacitor element 20P may be integrally formed.

[0146] Furthermore, in the power conversion device according to Embodiment 7, as shown in Embodiment 6, the capacitor element 20P may be arranged facing the opposing portion of the second opposing wiring portion 72P in the first capacitor connection wiring 70P, such that the direction of the common-mode noise current CI flowing through the capacitor element 20P faces the opposing portion of the second opposing wiring portion 72P.

[0147] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N as shown in Embodiment 1, a configuration may be provided in the second capacitor connection wiring 80N that is opposite to the current direction of the common-mode noise current flowing through the capacitor element 20N, as described above.

[0148] In the structure of the electrical path from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, as shown in Embodiment 1, a configuration may be provided in the second capacitor connection wiring 80S that is opposite to the direction of the normal mode noise current flowing through the capacitor element 20S, similar to the above.

[0149] Embodiment 8. The power conversion device according to Embodiment 8 will be described with reference to Figures 21 and 22. The power conversion device according to Embodiment 1 has a configuration in which the second opposing wiring portion 72P of the first capacitor connection wiring 70P has an opposing portion that faces the opposing portion of the first opposing wiring portion 71P, and an extending portion that extends continuously from one end of the opposing portion and whose other end is connected to one electrode terminal of the capacitor element 20P at the second connection point P2.

[0150] In contrast, the power conversion device according to Embodiment 8 uses a capacitor element 20P which has one electrode terminal 21P and the other electrode terminal 22P, each of which is a flat plate-shaped conductor protruding from the main body in one direction. The surface of one electrode terminal 21P of the capacitor element is positioned opposite the surface of the opposing portion in the first opposing wiring section 71P, and the tip surface of one electrode terminal 21P of the capacitor element 20P is electrically and mechanically connected to the other end surface of the opposing portion in the second opposing wiring section 72P by soldering or welding. The second connection point P2 is the connection point between the tip surface of one electrode terminal 21P of the capacitor element 20P and the other end surface of the opposing portion of the second opposing wiring portion 72P.

[0151] Furthermore, the tip surface of the other electrode terminal 22P of the capacitor element 20P is electrically and mechanically connected to one end surface of the second capacitor connection wiring 80P by soldering or welding. The third connection point P3 is the point where the tip surface of the other electrode terminal 22P of the capacitor element 20P connects to the other end surface of one end surface of the second capacitor connection wiring 80P. In other respects, the power converter according to Embodiment 8 is the same as the power converter according to Embodiment 1. In Figures 21 and 22, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0152] In the power conversion device according to Embodiment 8, the capacitor element 20P for noise suppression on the positive electrode side comprises a body having one electrode and the other electrode arranged facing each other, a pair of sides parallel to each of the one electrode and the other electrode, one electrode terminal 21P which is a flat plate-shaped conductor that is electrically connected to one electrode, is located on one of the pair of sides of the body and protrudes from the body in one direction, and the other electrode terminal 22P which is a flat plate-shaped conductor that is located on the other of the pair of sides of the body and protrudes from the body in one direction.

[0153] One electrode terminal 21P and the other electrode terminal 22P protrude in one direction from the main body in parallel, with their back surfaces facing each other. The direction in which one electrode terminal 21P and the other electrode terminal 22P protrude is perpendicular to the direction of the common-mode noise current CI flowing between the one electrode and the other electrode in the capacitor element 20P.

[0154] The first capacitor connection wiring 70P is a flat conductor and comprises a first opposing wiring section 71P, a second opposing wiring section 72P, and a bent wiring section 73P, which are formed integrally and continuously. The second opposing wiring portion 72P is bent at a right angle toward the capacitor element 20P, with one end continuing from the other end of the bent wiring portion 73P, and has an opposing portion whose surface faces the surface of a portion of the opposing portion located on the bent wiring portion 73P side of the first opposing wiring portion 71P.

[0155] The surface of one electrode terminal 21P of the capacitor element 20P is positioned opposite the surface of the opposing portion in the first opposing wiring portion 71P. The tip surface of one electrode terminal 21P of the capacitor element 20P is electrically and mechanically connected to the other end surface of the opposing portion of the second opposing wiring portion 72P by soldering, welding, or the like. The surface of the opposing portion of the second opposing wiring section 72P and the surface of one electrode terminal 21P of the capacitor element 20P face the surface of the opposing portion of the first opposing wiring section 71P at equal intervals.

[0156] The common-mode noise current CI flowing through the opposing part of the first opposing wiring section 71P and the common-mode noise current CI flowing through the opposing part of the second opposing wiring section 72P and one electrode terminal 21P of the capacitor element 20P flow in opposite directions. By shortening the distance between the surface of the opposing part of the first opposing wiring section 71P and the surface of the opposing part of the second opposing wiring section 72P and one electrode terminal 21P of the capacitor element 20P, the magnetic flux generated by the common-mode noise current CI flowing through the opposing part of the first opposing wiring section 71P and the magnetic flux generated by the common-mode noise current CI flowing through the opposing part of the second opposing wiring section 72P and one electrode terminal 21P of the capacitor element 20P cancel each other out.

[0157] With this configuration, one end of the first capacitor connection wiring 70P and the power supply wiring 60P to The actual wiring length from the first connection point P1 to one electrode of the capacitor element 20P is the sum of the length of the first opposing wiring portion 71P, the length of the bent wiring portion 73P, the length of the opposing portion of the second opposing wiring portion 72P, and the length of one electrode terminal 21P of the capacitor element 20P. This length is approximately the same as the length of the first capacitor connection wiring 70P in the power conversion device according to Embodiment 1, and the thermal resistance from the first connection point P1 to one electrode of the capacitor element 20P increases.

[0158] On the other hand, the parasitic inductance from the first connection point P1 to one electrode of the capacitor element 20P is the sum of the first self-inductance from one end of the first opposing wiring section 71P (first connection point P1) to the midpoint P5 of the bent wiring section 73P, and the second self-inductance which is the sum of the self-inductance from the midpoint P5 of the bent wiring section 73P to the other end of the second opposing wiring section 72P (second connection point P2) and the self-inductance of one electrode terminal 21P of the capacitor element 20P, minus twice the mutual inductance due to the opposing part of the first opposing wiring section 71P, the opposing part of the second opposing wiring section 72P, and the other end of the second opposing wiring section 72P (second connection point P2), and one electrode terminal 21P of the capacitor element 20P.

[0159] As described above, the power conversion device according to Embodiment 8 uses a capacitor element 20P that has one electrode terminal 21P and the other electrode terminal 22P, which are flat conductors. The surface of one electrode terminal 21P of the capacitor element 20P is positioned opposite the surface of the opposing portion in the first opposing wiring portion 71P, and the tip surface of one electrode terminal 21P of the capacitor element 20P is electrically and mechanically connected to the other end surface of the opposing portion in the second opposing wiring portion 72P. This configuration suppresses heat absorption of the capacitor element 20P by heat generated in the power supply wiring 60P, reduces parasitic inductance from the connection point P1 between the positive electrode side first capacitor connection wiring 70P and the power supply wiring 60P to one electrode of the capacitor element 20P, and enhances the noise absorption effect of the capacitor element 20P.

[0160] In this example, the capacitor element 20P is provided as a capacitor element having one electrode terminal 21P and the other electrode terminal 22P, each being a flat conductor. However, it may also be provided as a capacitor element having one electrode terminal 21P and the other electrode terminal 22P, each being a cylindrical conductor or a prismatic conductor. A capacitor element having one electrode terminal 21P and the other electrode terminal 22P, each being a cylindrical or prismatic conductor, is similar to a capacitor element having one electrode terminal 21P and the other electrode terminal 22P, each being a flat conductor, in which one electrode terminal is positioned opposite the opposing portion of the first opposing wiring section 71P, the tip of the one electrode terminal is electrically and mechanically connected to the other end of the opposing portion of the second opposing wiring section 72P by soldering or welding, and the opposing portion of the one electrode terminal and the opposing portion of the second opposing wiring section 72P are positioned at equal intervals opposite the opposing portion of the first opposing wiring section 71P.

[0161] In addition, in the power conversion device according to Embodiment 8, the positive terminal power supply wiring 60P and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2. Furthermore, in the power conversion device according to Embodiment 8, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the sum of the length of the first capacitor connection wiring 70P and the length of one electrode terminal 21P of the capacitor element 20P.

[0162] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N shown in Embodiment 1, as described above, a capacitor element 20N may be used in which each of the capacitor elements 20N has one electrode terminal and the other electrode terminal, which are flat plate-shaped conductors protruding from the main body in one direction, and the surface of one electrode terminal of the capacitor element 20N is positioned opposite to the surface of the opposing portion in the first opposing wiring portion of the first capacitor connection wiring 70N, and the tip surface of one electrode terminal of the capacitor element 20N is electrically and mechanically connected to the other end surface of the opposing portion in the second opposing wiring portion 72N of the first capacitor connection wiring 70N.

[0163] Furthermore, in the structure of the electrical path from the positive-side power supply wiring 60P to the negative-side power supply wiring 60N via the smoothing capacitor element 20S as shown in Embodiment 1, a capacitor element 20S may be used in which each capacitor element 20S has one electrode terminal and the other electrode terminal, which are flat conductors protruding from the main body in one direction, as described above, and the surface of one electrode terminal of the capacitor element 20S is positioned opposite to the surface of the opposing portion in the first opposing wiring portion of the first capacitor connection wiring 70S, and the tip surface of one electrode terminal of the capacitor element 20S is electrically and mechanically connected to the other end surface of the opposing portion in the second opposing wiring portion 72S of the first capacitor connection wiring 70S.

[0164] Embodiment 9. The power conversion device according to Embodiment 9 will be described with reference to Figures 23 and 24. The power conversion device according to Embodiment 9 is configured to further include a resistor 85P electrically connected in series with the capacitor element 20P, compared to the power conversion device according to Embodiment 1. In other respects, the embodiment 9 The power converter is the same as the power converter according to Embodiment 1. In Figures 23 and 24, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0165] The power conversion device according to Embodiment 9 includes a resistive element 85P that is electrically connected between the other electrode terminal to which the other electrode of the capacitor element 20P for noise removal on the positive electrode side is connected, and one end (third connection point P3) of the second capacitor connection wiring 80P. The resistor element 85P is a snubber resistor that forms an RC snubber circuit in cooperation with the capacitor element 20P to suppress ringing generated by the switching operation of the semiconductor switching element group 13u, 14u, 13v, 14v, 13w, and 14w in the power conversion circuit 10.

[0166] The resistor element 85P reduces common-mode noise by converting the common-mode noise current flowing through the capacitor element 20P into heat. Thus, although heat is applied to the capacitor element 20P due to the self-heating of the resistor element 85P, the length of the first capacitor connection wiring 70P is made longer and the thermal resistance of the first capacitor connection wiring 70P is made larger. Therefore, even in a power conversion device equipped with a resistor element 85P connected in series with the capacitor element 20P, the heat absorbed by the capacitor element 20P due to the heat generated in the power supply wiring 60P is suppressed, and the function of the capacitor element 20P as a noise suppression capacitor is not reduced.

[0167] As described above, the power conversion device according to Embodiment 9 is provided with a resistor 85P connected in series with the capacitor element 20P, and is a power conversion device that suppresses ringing generated by the switching operation of the semiconductor switching element group 13u, 14u, 13v, 14v, 13w, 14w in the power conversion circuit 10. This suppresses heat absorption of the capacitor element 20P due to heat generated in the power supply wiring 60P, reduces parasitic inductance in the first capacitor connection wiring 70P on the positive electrode side, and enhances the noise absorption effect of the capacitor element 20P.

[0168] In addition, in the power conversion device according to Embodiment 9, the power supply wiring 60P on the positive terminal side and the first capacitor connection wiring 70P may be integrally formed, as shown in Embodiment 2. Furthermore, in the power conversion device according to Embodiment 9, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P in the first capacitor connection wiring 70P may be configured with separate components and connected to each other.

[0169] Furthermore, in the power conversion device according to Embodiment 9, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the length of the first capacitor connection wiring 70P. Furthermore, in the power conversion device according to Embodiment 9, as shown in Embodiment 5, the first capacitor connection wiring 70P and the capacitor element 20P may be integrally formed.

[0170] In the power conversion device according to Embodiment 9, as shown in Embodiment 6, the capacitor element 20P may be arranged facing the opposing portion of the second opposing wiring portion 72P in the first capacitor connection wiring 70P, such that the direction of the common-mode noise current CI flowing through the capacitor element 20P faces the opposing portion of the second opposing wiring portion 72P. In the power conversion device according to Embodiment 9, as shown in Embodiment 7, a configuration may be adopted in which a counter portion facing the current direction of the common-mode noise current CI flowing through the capacitor element 20P is provided on the second capacitor connection wiring 80P.

[0171] In the power conversion device according to Embodiment 9, as shown in Embodiment 8, a capacitor element 20P is used which has one electrode terminal 21P and the other electrode terminal 22P, which are flat conductors. The surface of one electrode terminal 21P of the capacitor element 20P is positioned opposite the surface of the opposing portion of the first opposing wiring portion 71P of the first capacitor connection wiring 70P, and the tip surface of one electrode terminal 21P of the capacitor element 20P is electrically and mechanically connected to the other end surface of the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P.

[0172] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, as shown in Embodiment 1, a configuration may be provided in which a resistive element is electrically connected in series with the capacitor element 20N, similar to the above. Furthermore, in the structure of the electrical path shown in Embodiment 1, from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, a configuration may be provided that includes a resistive element electrically connected in series with the capacitor element 20S, similar to the above.

[0173] Embodiment 10. A power conversion device according to Embodiment 10 will be described with reference to Figures 25 and 26. The power conversion device according to Embodiment 9 has a configuration in which the second capacitor connection wiring 80P is simply electrically connected between the metal housing 400 and the resistive element 85P, which is connected to the other electrode terminal to which the other electrode of the positive-side noise-removing capacitor element 20P is connected.

[0174] In contrast, the power conversion device according to Embodiment 10 is configured such that at least a portion of the resistive element 85P is positioned opposite to at least one component of the first capacitor connection wiring 70P on the positive side, the first opposing wiring portion 71P and the second opposing wiring portion 72P of the first capacitor connection wiring 70P on the positive side, the capacitor element 20P for noise removal on the positive side, and the second capacitor connection wiring 80P on the positive side, where the common-mode noise currents CI are in opposite directions.

[0175] In other respects, the power converter according to Embodiment 10 is the same as the power converter according to Embodiment 9. In Figures 25 and 26, the same reference numerals as those used in Figures 1 to 4 and Figures 23 and 24 indicate the same or corresponding parts.

[0176] The following describes a power conversion device according to Embodiment 10, in which the resistive element 85P is positioned opposite the second capacitor connection wiring 80P. The power conversion device according to Embodiment 10 is configured such that the common-mode noise current flowing through the resistor 85P has a direction opposite to that of the second capacitor connection wiring 80P, that is, the direction of the common-mode noise current flowing through the resistor 85P and the direction of the common-mode noise current flowing through the opposing portion 82P of the second capacitor connection wiring 80P facing the resistor 85P are in opposite directions, so that the magnetic fluxes generated by each common-mode noise current cancel each other out.

[0177] In the power conversion device according to Embodiment 10, the second capacitor connection wiring 80P has a facing portion 81P that is positioned opposite the resistive element 85P. The direction of the common-mode noise current CI flowing through the opposite portion 81P of the second capacitor connection wiring 80P is opposite to at least a portion of the direction of the common-mode noise current CI flowing through the resistor element 85P, and the directions of the common-mode noise currents CI are opposite to each other.

[0178] The opposing portion 81P of the second capacitor connection wiring 80P and the capacitor element 20P are positioned such that the magnetic flux generated by the common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P cancels out the magnetic flux generated by the common-mode noise current CI flowing through the resistor element 85P.

[0179] The second capacitor connection wiring 80P has a first extension portion, one end of which is electrically and mechanically connected by solder or the like to the other end of a resistor 85P, one end of which is connected to the other electrode terminal of the capacitor element 20P at the third connection point P3; a counter portion 82P, which is bent at a right angle toward the resistor 85P, continuously from the other end of the first extension portion and positioned opposite the side of the resistor 85P, parallel to the direction of the common-mode noise current CI flowing through the resistor 85P; and a second extension portion, which is bent at a right angle toward away from the resistor 85P, continuously from the other end of the counter portion 82P, the other end of which is electrically and mechanically connected by solder or the like to the metal housing 400 at the fourth connection point P4.

[0180] The common-mode noise current CI flowing through the opposing portion 82P of the second capacitor connection wiring 80P and the common-mode noise current CI flowing through the resistor element 85P flow in opposite directions. By shortening the distance between the opposing portion 82P of the second capacitor connection wiring 80P and the side surface of the resistor element 85P, the magnetic flux generated by the common-mode noise current CI flowing through the opposing portion 81P of the second capacitor connection wiring 80P and the magnetic flux generated by the common-mode noise current CI flowing through the resistor element 85P cancel each other out.

[0181] In the electrical path from the positive-side power supply wiring 60P configured in this way, through the positive-side noise-removing capacitor element 20P to the metal housing 400 which serves as the ground node, the parasitic inductance of the second capacitor connection wiring 80P is reduced by the mutual inductance between the opposing portion 82P of the second capacitor connection wiring 80P and the resistive element 85P. Furthermore, the parasitic inductance of the resistor element 85P is also reduced by the mutual inductance between the opposing portion 82P of the second capacitor connection wiring 80P and the resistor element 85P.

[0182] As a result, the parasitic inductance in the electrical path from the power supply wiring 60P through the capacitor element 20P to the ground node can be reduced, the impedance in that electrical path to the high-frequency common-mode noise current CI can be reduced, and the noise absorption effect can be further enhanced.

[0183] As described above, the power converter according to Embodiment 10 has the same effects as the power converter according to Embodiment 9. In addition, since the opposing portion 82P facing the direction of the common-mode noise current CI flowing through the resistive element 85P is provided on the second capacitor connection wiring 80P, the parasitic inductance in the second capacitor connection wiring 80P is reduced, and the parasitic inductance of the resistive element 85P is also reduced, thereby further enhancing the noise absorption effect of the capacitor element 20P.

[0184] In the power conversion device according to Embodiment 10, the resistive element 85P is not limited to being positioned opposite the opposing portion 82P of the second capacitor connection wiring 80P. It may also be positioned opposite the opposing portion of the first opposing wiring portion 71P and the second opposing wiring portion 72P of the first capacitor connection wiring 70P, and at least one component of the capacitor element 20P, where a common-mode noise current CI flows in the opposite direction to the resistive element 85P.

[0185] In the structure of the electrical path from the negative-side power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, as shown in Embodiment 9, at least a portion of the resistive element 85P may be arranged to face at least a portion of the second capacitor connection wiring 80P, as described above.

[0186] Furthermore, in the structure of the electrical path from the positive terminal power supply wiring 60P to the negative terminal power supply wiring 60N via the smoothing capacitor element 20S, as shown in Embodiment 9, at least a portion of the resistive element 85P may be arranged to face at least a portion of the second capacitor connection wiring 80P, similar to the above.

[0187] Embodiment 11. The power conversion device according to Embodiment 11 will be described with reference to Figures 27 to 30. The power converter according to Embodiment 11 has a configuration in which, with respect to the first capacitor connection wiring 70P on the positive side, the capacitor element 20P for noise removal on the positive side, and the second capacitor connection wiring 80P on the positive side, and the first capacitor connection wiring 70N on the negative side, the capacitor element 20N for noise removal on the negative side, and the second capacitor connection wiring 80N on the negative side shown in Embodiment 1, the positive side component and the negative side component are arranged opposite each other in at least one positive side component and at least one negative side component, such that the common mode noise current CIP on the positive side and the common mode noise current CIN on the negative side are in opposite directions.

[0188] In other respects, the power converter according to Embodiment 11 is the same as the power converter according to Embodiment 1. In Figures 27 to 30, the same reference numerals as those used in Figures 1 to 4 indicate the same or corresponding parts.

[0189] This document will describe the structure of the electrical path from the positive-side power supply wiring 60P to the metal housing 400 which serves as the ground node via the positive-side noise-removing capacitor element 20P, and the structure of the electrical path from the negative-side power supply wiring 60N to the metal housing 400 via the negative-side noise-removing capacitor element 20N, with particular emphasis on the arrangement of the two.

[0190] The power supply wiring 60P on the positive terminal side and the power supply wiring 60N on the negative terminal side are arranged in parallel with a gap between them in the vertical and horizontal directions. For convenience, the vertical direction is the direction connecting the front and back of power supply wiring 60P and the front and back of power supply wiring 60N, as shown in Figures 28 and 29, and the horizontal direction is the direction perpendicular to the vertical direction and the extending direction of power supply wiring 60P and the negative terminal power supply wiring 60N, as shown in Figures 28 to 30.

[0191] Furthermore, for convenience, the front-to-back direction will be defined as the direction in which the power supply wiring 60P and the negative terminal power supply wiring 60N extend, and the up-and-down direction will be defined as shown in Figure 29. In the following explanation, to avoid complexity, we will use the up-and-down, left-and-right, and front-and-back directions defined above.

[0192] As shown in Figures 27 and 28, the first capacitor connection wiring 70P on the positive electrode side includes a first opposing wiring portion 71P, one end of which is electrically connected to the power supply wiring 60P on the positive electrode side at a first connection point P1P; a second opposing wiring portion 72P, the other end of which is electrically connected to one electrode terminal of the capacitor element 20P on the positive electrode side at a second connection point P2P, and which has an opposing portion that is positioned opposite the opposing portion of the first opposing wiring portion 71P in the left-right direction; and a bent wiring portion 73P that electrically connects the other end of the first opposing wiring portion 71P to one end of the second opposing wiring portion 72b. The first opposing wiring section 71P, the second opposing wiring section 72P, and the bent wiring section 73P are integrally formed flat conductors.

[0193] One end face of the first opposing wiring section 71P is electrically and mechanically connected to the side of the power supply wiring 60P at the first connection point P1P by soldering, welding, or screwing. The first opposing wiring portion 71P has an extending portion that extends to the right, from one end face connected to the side of the power supply wiring 60P at the first connection point P1P, toward one electrode terminal of the capacitor element 20P, with both sides being on the same plane as the front and back of the power supply wiring 60P, and an opposing portion that is bent at a right angle from this extending portion toward the side of the power supply wiring 60P with respect to the front and back, that is, toward downward.

[0194] The other end of the second opposing wiring section 72P is electrically and mechanically connected to one electrode terminal of the capacitor element 20P at the second connection point P2P by solder or the like. The second opposing wiring section 72P has a front and back surface that is the same as the front and back surfaces of the first opposing wiring section 71P, and an extending section that extends to the left from the other end connected to one electrode terminal of the capacitor element 20P at the second connection point P2P toward the power supply wiring 60P, and an opposing section that is bent at a right angle from this extending section toward the downward direction toward the capacitor element 20P with respect to the front and back surfaces, and whose surface faces the surface of the opposing section of the first opposing wiring section 71P at equal intervals.

[0195] The bent wiring section 73P is formed continuously between the other end of the opposing portion of the first opposing wiring section 71P and the one end of the opposing portion of the second opposing wiring section 72P. The front and back surfaces of the bent wiring section 73P are parallel to the front and back surfaces of the extended portion of the first opposing wiring section 71P and the front and back surfaces of the extended portion of the second opposing wiring section 72P, and lie on the same horizontal plane as the front and back surfaces of the power supply wiring 60N.

[0196] Although the bent wiring portion 73P is shown as a flat surface, the bent wiring portion 73P may be made curved, and the overall shape of the first capacitor connection wiring 70P may be U-shaped as shown in Figure 28. In other words, the first capacitor connection wiring 70P is structured such that the first opposing wiring portion 71P and the second opposing wiring portion 72P are formed continuously, that is, integrally, and the opposing portion of the first opposing wiring portion 71P and the opposing portion of the second opposing wiring portion 72P are arranged in parallel to each other.

[0197] The second capacitor connection wire 80P on the positive side is electrically and mechanically connected at one end to the other electrode terminal of the capacitor element 20P at the third connection point P3P by soldering or the like, and the other end is electrically and mechanically connected at the fourth connection point P4P to the metal housing 400 by soldering, welding, or screwing.

[0198] The first capacitor connection wiring 70N on the negative electrode side includes a first opposing wiring portion 71N one end of which is electrically connected to the power supply wiring 60N on the negative electrode side at a first connection point P1N, as shown in FIG. 27 and FIG. 29, and the other end is at a second connection point P2N which is electrically connected to one electrode terminal of the negative electrode side capacitor element 20N, and includes: a second opposing wiring portion 72N having an opposing portion disposed to oppose the opposing portion of the first opposing wiring portion 71N in the left-right direction; and a bent wiring portion 73N electrically connecting the other end of the first opposing wiring portion 71N and one end of the second opposing wiring portion 72b. The first opposing wiring portion 71N, the second opposing wiring portion 72N, and the bent wiring portion 73N are integrally formed flat plate-shaped conductors.

[0199] One end face of the first opposing wiring portion 71N is electrically and mechanically connected to the side face of the power supply wiring 60N at the first connection point P1N by means of soldering, welding, screwing or the like. The front and back sides of the first opposing wiring portion 71N are flush with the front and back sides of the power supply wiring 60N. The first opposing wiring portion 71N has: an extending portion extending from one end face connected to the side face of the power supply wiring 60N at the first connection point P1N toward one electrode terminal of the capacitor element 20N, that is, in the rightward direction; and an opposing portion bent perpendicularly from the extending portion in a direction away from the side face of the power supply wiring 60N with respect to the front and back sides, that is, in the upward direction.

[0200] The opposing portion of the first opposing wiring portion 71N is disposed to oppose the opposing portion of the first opposing wiring portion 71P in the positive electrode side first capacitor connection wiring 70P in the front-rear direction. The length of the opposing portion of the first opposing wiring portion 71N is the same as the length of the opposing portion of the first opposing wiring portion 71P. As shown in FIG. 30, the common mode noise current CIP flowing through the opposing portion of the first opposing wiring portion 71P in the positive electrode side first capacitor connection wiring 70P and the common mode noise current CIN flowing through the opposing portion of the first opposing wiring portion 71N in the negative electrode side first capacitor connection wiring 70N flow in opposite directions.

[0201] Therefore, the first opposing wiring portion 71N of the first capacitor connection wiring 70N is positioned relative to the second opposing wiring portion 72P of the first capacitor connection wiring 70P such that the magnetic flux generated by the common-mode noise current CIN flowing through the opposing portion of the first opposing wiring portion 71N of the first capacitor connection wiring 70N and the magnetic flux generated by the common-mode noise current CIP flowing through the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P cancel each other out.

[0202] The other end of the second opposing wiring section 72N is electrically and mechanically connected to one electrode terminal of the capacitor element 20N at the second connection point P2N by solder or the like. The second opposing wiring section 72N has an extending portion that extends to the left, from the other end connected to one electrode terminal of the capacitor element 20N at the second connection point P2N toward the power supply wiring 60N, with both sides being on the same plane as the front and back of the first opposing wiring section 71N, and an opposing portion that is bent at a right angle from this extending portion toward the upward direction, with respect to the front and back, away from the capacitor element 20N, with respect to the front and back, and whose surface faces the surface of the opposing portion of the first opposing wiring section 71N at equal intervals.

[0203] The opposing portion of the second opposing wiring portion 72N is positioned in the front-to-back direction opposite the opposing portion of the second opposing wiring portion 72P in the first capacitor connection wiring 70P on the positive electrode side. The length of the opposing portion of the second opposing wiring section 72N is the same as the length of the opposing portion of the second opposing wiring section 72P. The common-mode noise current CIP flowing through the opposing portion of the second opposing wiring section 72P in the first capacitor connection wiring 70P on the positive side and the common-mode noise current CIN flowing through the opposing portion of the second opposing wiring section 72N in the first capacitor connection wiring 70N on the negative side are in opposite directions.

[0204] Therefore, the opposing portion of the second opposing portion 72N of the first capacitor connection wiring 70N is positioned relative to the opposing portion of the second opposing portion 72P of the first capacitor connection wiring 70P such that the magnetic flux generated by the common-mode noise current CIN flowing through the opposing portion of the second opposing portion 72N of the first capacitor connection wiring 70N and the magnetic flux generated by the common-mode noise current CIP flowing through the opposing portion of the second opposing portion 72P of the first capacitor connection wiring 70P cancel each other out.

[0205] The bent wiring portion 73N is formed continuously between the other end of the opposing portion of the first opposing wiring portion 71N and the one end of the opposing portion of the second opposing wiring portion 72N. The front and back surfaces of the bent wiring section 73N are parallel to the front and back surfaces of the extended portion of the first opposing wiring section 71N and the front and back surfaces of the extended portion of the second opposing wiring section 72N, and lie on the same horizontal plane as the front and back surfaces of the power supply wiring 60P.

[0206] Although the bent wiring portion 73N is shown as a flat surface, the bent wiring portion 73N may be made a curved surface, and the overall shape of the first capacitor connection wiring 70N may be U-shaped as shown in Figure 29. In other words, the first capacitor connection wiring 70N is formed such that the first opposing wiring portion 71N and the second opposing wiring portion 72N are formed continuously, that is, integrally, and the opposing portion of the first opposing wiring portion 71N and the opposing portion of the second opposing wiring portion 72N are arranged in parallel to each other, and the opposing portion of the first opposing wiring portion 71N is arranged in parallel to the opposing portion of the first opposing wiring portion 71P, and the opposing portion of the second opposing wiring portion 72N is arranged opposite to the opposing portion of the second opposing wiring portion 72P.

[0207] The second capacitor connection wiring 80N on the negative side is electrically and mechanically connected at one end to the other electrode terminal of the capacitor element 20N at the third connection point P3N by soldering or the like, and at the other end is electrically and mechanically connected to the metal housing 400 at the fourth connection point P4 by soldering, welding, or screwing.

[0208] In the electrical path from the positive-side power supply wiring 60P to the metal housing 400 which serves as a ground node via the positive-side noise suppression capacitor element 20P, the parasitic inductance of the first capacitor connection wiring 70P on the positive side is further reduced by the mutual inductance between the opposing parts of the first opposing wiring section 71P and the opposing parts of the first opposing wiring section 71N, and the mutual inductance between the opposing parts of the second opposing wiring section 72P and the opposing parts of the second opposing wiring section 72N.

[0209] Similarly, the parasitic inductance of the first capacitor connection wiring 70N on the negative side in the electrical path from the power supply wiring 60N on the negative side to the metal housing 400 which serves as a ground node via the capacitor element 20N for noise suppression on the negative side is further reduced by the mutual inductance between the opposing portion of the first opposing wiring section 71N and the opposing portion of the first opposing wiring section 71P, and the mutual inductance between the opposing portion of the second opposing wiring section 72N and the opposing portion of the second opposing wiring section 72P.

[0210] As described above, in the power converter according to Embodiment 11, the first capacitor connection wiring 70P, which is electrically connected between the power supply wiring 60P on the positive side and one electrode of the noise-removing capacitor element 20P on the positive side, has a first opposing wiring section 71P and a second opposing wiring section 72P, with opposing portions facing each other. This suppresses heat absorption by the capacitor element 20P due to heat generated in the power supply wiring 60P and reduces parasitic inductance in the first capacitor connection wiring 70P on the positive side. The first capacitor connection wiring 70N, which is electrically connected between the power supply wiring 60N on the negative side and one electrode of the noise-removing capacitor element 20N on the negative side, has a first opposing wiring section 71N and a second opposing wiring section Since it has 72N, it suppresses heat absorption of the capacitor element 20N due to heat generated in the power supply wiring 60N, and reduces parasitic inductance in the first capacitor connection wiring 70N on the negative side. Moreover, since the opposing portion of the first opposing wiring section 71P and the opposing portion of the first opposing wiring section 71N face each other, and the opposing portion of the second opposing wiring section 72P and the opposing portion of the second opposing wiring section 72N face each other, it is possible to further reduce the parasitic inductance in the first capacitor connection wiring 70P on the positive side, thereby enhancing the noise absorption effect of the capacitor element 20P.

[0211] In the power conversion device according to Embodiment 11, the first capacitor connection wiring 70P may be positioned opposite the capacitor element 20N or the second capacitor connection wiring 80N such that the common-mode noise current CIP flowing through the first capacitor connection wiring 70P on the positive side flows in the opposite direction to the common-mode noise current CIN flowing through the capacitor element 20N on the negative side or the second capacitor connection wiring 80N on the negative side.

[0212] Furthermore, in the power conversion device according to Embodiment 11, the capacitor element 20P may be positioned opposite the first capacitor connection wiring 70N, the capacitor element 20N, or the second capacitor connection wiring 80N so that the common-mode noise current CIP flowing through the positive-side capacitor element 20P flows in the opposite direction to the common-mode noise current CIN flowing through the negative-side first capacitor connection wiring 70N, the negative-side capacitor element 20N, or the negative-side second capacitor connection wiring 80N.

[0213] Furthermore, in the power conversion device according to Embodiment 11, the second capacitor connection wiring 80P may be positioned opposite the first capacitor connection wiring 70N, the capacitor element 20N, or the second capacitor connection wiring 80N so that the common-mode noise current CIP flowing through the second capacitor connection wiring 80P on the positive side flows in the opposite direction to the common-mode noise current CIN flowing through the first capacitor connection wiring 70N on the negative side, the capacitor element 20N on the negative side, or the second capacitor connection wiring 80N on the negative side.

[0214] In addition, in the power conversion device according to Embodiment 11, as shown in Embodiment 2, the power supply wiring 60P on the positive terminal side and the first capacitor connection wiring 70P may be integrally formed, and the power supply wiring 60N on the positive terminal side and the first capacitor connection wiring 70N may be integrally formed. Furthermore, in the power conversion device according to Embodiment 11, as shown in Embodiment 3, the first opposing wiring section 71P and the second opposing wiring section 72P of the first capacitor connection wiring 70P may be made of separate parts and connected together, or the first opposing wiring section 71N and the second opposing wiring section 72N of the first capacitor connection wiring 70N may be made of separate parts and connected together.

[0215] Furthermore, in the power conversion device according to Embodiment 11, as shown in Embodiment 4, the length of the second capacitor connection wiring 80P may be shorter than the length of the first capacitor connection wiring 70P, and the length of the second capacitor connection wiring 80N may be shorter than the length of the first capacitor connection wiring 70N. Furthermore, the power converter according to the eleventh embodiment may also have a structure in which the first capacitor connection wiring 70P and the capacitor element 20P are integrally formed, and a structure in which the first capacitor connection wiring 70N and the capacitor element 20N are integrally formed, as shown in the fifth embodiment.

[0216] In the power converter according to the eleventh embodiment, as shown in the sixth embodiment, the capacitor element 20P may be disposed opposite to the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P such that the current direction of the common mode noise current CIP flowing through the capacitor element 20P is opposite to the opposing portion of the second opposing wiring portion 72P; and the capacitor element 20N may be disposed opposite to the opposing portion of the second opposing wiring portion 72N of the first capacitor connection wiring 70N such that the current direction of the common mode noise current CIN flowing through the capacitor element 20N is opposite to the opposing portion of the second opposing wiring portion 72N.

[0217] In the power converter according to the eleventh embodiment, as shown in the seventh embodiment, the second capacitor connection wiring 80P may be provided with an opposing portion that faces the current direction of the common mode noise current CIP flowing through the capacitor element 20P, and the second capacitor connection wiring 80N may be provided with an opposing portion that faces the current direction of the common mode noise current CIN flowing through the capacitor element 20N.

[0218] In the power conversion device according to Embodiment 11, as shown in Embodiment 8, a capacitor element 20P is used which has one electrode terminal 21P and the other electrode terminal 22P, which are flat conductors, and the surface of one electrode terminal 21P of the capacitor element 20P is positioned opposite the surface of the opposing portion of the first opposing wiring portion 71P of the first capacitor connection wiring 70P, and the tip surface of one electrode terminal 21P of the capacitor element 20P is positioned opposite the other end surface of the opposing portion of the second opposing wiring portion 72P of the first capacitor connection wiring 70P. The capacitor element 20N may be configured to be electrically and mechanically connected, and may be configured to be a capacitor element having one electrode terminal 21N and the other electrode terminal 22N which are flat conductors, with the surface of one electrode terminal 21N of the capacitor element 20N facing the surface of the opposing portion of the first opposing wiring portion 71N of the first capacitor connection wiring 70N, and the tip surface of one electrode terminal 21N of the capacitor element 20N being electrically and mechanically connected to the other end surface of the opposing portion of the second opposing wiring portion 72N of the first capacitor connection wiring 70N.

[0219] In the power conversion device according to Embodiment 11, as shown in Embodiment 9, a resistor 85P may be provided in series with the capacitor element 20P, or a resistor may be provided in series with the capacitor element 20N.

[0220] In the power conversion device according to Embodiment 11, as shown in Embodiment 10, at least a portion of the resistor 85P connected in series with the capacitor element 20P is configured to be positioned opposite to at least one component of the first opposing wiring section 71P and the second opposing wiring section 72P of the first capacitor connection wiring 70P, the capacitor element 20P, and the second capacitor connection wiring 80P, where the common-mode noise current CIP is in opposite directions to each other. Alternatively, at least a portion of the resistor 85P connected in series with the capacitor element 20P may be positioned opposite to at least one component of the first opposing wiring section 71N and the second opposing wiring section 72N of the first capacitor connection wiring 70N, the capacitor element 20N, and the second capacitor connection wiring 80N, where the common-mode noise current CIN is in opposite directions to each other.

[0221] Embodiment 12. A power conversion device according to Embodiment 12 will be described with reference to Figures 31 and 32. The power conversion device according to Embodiment 12 is characterized in that, in the power conversion device according to Embodiment 1, wide-bandgap semiconductor elements are used as semiconductor switching elements in the semiconductor switching element group 13u, 14u, 13v, 14v, 13w, 14w that constitute the power conversion circuit 10.

[0222] Other configurations are as follows: 12 Since the power conversion device is the same as the power conversion device according to Embodiment 1, the explanation will focus on the wide-bandgap semiconductor element (hereinafter abbreviated as wide-bandgap semiconductor element). Wide-bandgap semiconductor devices are semiconductor devices with a wider bandgap compared to semiconductor devices using commonly used silicon (Si) or gallium arsenide (GaAs) semiconductor materials, and are semiconductor devices using silicon carbide (SiC) or gallium nitride (GaN) semiconductor materials.

[0223] The semiconductor material of the wide-bandgap semiconductor device has physical properties such as high thermal conductivity, electron velocity, and dielectric breakdown field strength. When the wide-bandgap semiconductor device is used as the semiconductor switching element of the semiconductor switching element group 13u, 14u, 13v, 14v, 13w, 14w that constitutes the power conversion circuit 10, the power conversion circuit 10 can be significantly miniaturized and made more efficient.

[0224] In other words, the power conversion device according to Embodiment 12 is a power conversion device that achieves miniaturization and high efficiency by using wide-bandgap semiconductor elements as semiconductor switching elements in the semiconductor switching element group 13u, 14u, 13v, 14v, 13w, 14w that constitute the power conversion circuit 10. It suppresses heat absorption of the capacitor element 20P due to heat generated in the power supply wiring 60P in the electrical path from the power supply wiring 60P to the ground node via the capacitor element 20P, and reduces the parasitic inductance of the first capacitor connection wiring 70P in the electrical path from the power supply wiring 60P to the ground node via the capacitor element 20P. This makes it possible to enhance the noise absorption effect of the capacitor element 20P without impairing its function as a filter for high-frequency common-mode noise current CI.

[0225] Figure 31 shows the on / off drive characteristics when a wide-bandgap semiconductor element is used as a switching element. For comparison, Figure 31 also shows the on / off drive characteristics when a conventional semiconductor element using silicon is used as a switching element. In Figure 31, the horizontal axis represents time, the vertical axis represents the signal level, the dashed line represents the on / off drive characteristics of a wide-bandgap semiconductor device, and the solid line represents the on / off drive characteristics of a normal semiconductor device.

[0226] As is clear from Figure 31, the rise time tr11 from off to on and the fall time tr12 from on to off in a wide-bandgap semiconductor device are shorter than the rise time tr21 and fall time tr22 in a normal semiconductor device, and the pulse application time Ton1 in a wide-bandgap semiconductor device can also be shorter than the pulse application time Ton2 in a normal semiconductor device. As a result, when wide-bandgap semiconductor elements are used as switching elements, it is possible to increase the speed and frequency of switching operations. In other words, by using wide-bandgap semiconductor elements as semiconductor switching elements constituting the power conversion circuit 10, a power conversion device that achieves higher speed and higher frequency can be obtained.

[0227] On the other hand, Figure 32 shows the frequency characteristics with respect to noise when a wide-bandgap semiconductor element is used as a switching element. For comparison, Figure 32 also shows the frequency characteristics with respect to noise when a conventional semiconductor element using silicon is used as a switching element. In Figure 32, the horizontal axis represents frequency, the vertical axis represents noise level, the dashed line represents the frequency characteristics of a wide-bandgap semiconductor device, and the solid line represents the frequency characteristics of a typical semiconductor device.

[0228] In Figure 32, fa1 represents the frequency at which the noise level in a wide-bandgap semiconductor device begins to attenuate at 20 dB / decade, fa2 represents the frequency at which the noise level in a normal semiconductor device begins to attenuate at 20 dB / decade, fc1 represents the frequency at which the noise level in a wide-bandgap semiconductor device begins to attenuate at 40 dB / decade, and fc2 represents the frequency at which the noise level in a normal semiconductor device begins to attenuate at 40 dB / decade.

[0229] As is clear from Figure 32, the frequency fa1 at which the noise level in a wide-bandgap semiconductor device begins to attenuate at 20 dB / decade is shifted to a significantly higher frequency than the frequency fa2 at which the noise level in a normal semiconductor device begins to attenuate at 20 dB / decade, and the frequency fc1 at which the noise level in a wide-bandgap semiconductor device begins to attenuate at 40 dB / decade is shifted to a significantly higher frequency than the frequency fc2 at which the noise level in a normal semiconductor device begins to attenuate at 40 dB / decade.

[0230] This can also be understood from the following: In other words, the frequency fa at which the noise level begins to attenuate at 20 dB / decade is given by equation (10), and the frequency fc at which the noise level begins to attenuate at 40 dB / decade is given by equation (11). fa = 1 / (π × Ton) (10) fc = 1 / (π × tr) (11) In equation (10), Ton represents the pulse application time, and tr represents the rise time and fall time.

[0231] Therefore, as is clear from equation (10) above, shortening the pulse application time Ton increases the frequency fa, and as is clear from equation (11) above, shortening the rise time and fall time tr increases the frequency fc.

[0232] When using wide-bandgap semiconductor elements as semiconductor switching elements constituting the power conversion circuit 10 to increase speed and frequency, the frequencies fa and fc increase. However, as explained in Embodiment 1, the first capacitor connection wiring 70P has a first opposing wiring section 71P and a second opposing wiring section 72P, and at least a portion of each of the first opposing wiring section 71P and the second opposing wiring section 72P is arranged opposite each other. Therefore, the parasitic inductance of the first capacitor connection wiring 70P is reduced, and the noise absorption effect of the capacitor element 20P can be enhanced without impairing its function as a filter for high-frequency common-mode noise current CI in the capacitor element 20P.

[0233] As described above, the power conversion device according to Embodiment 12 achieves miniaturization and high efficiency by using wide-bandgap semiconductor elements as semiconductor switching elements constituting the power conversion circuit 10. Similar to the description in Embodiment 1, the heat absorbed by the capacitor element 20P due to the heat generated in the positive-side power supply wiring 60P is suppressed by the first capacitor connection wiring 70P, and the parasitic inductance in the first capacitor connection wiring 70P is reduced, thereby enhancing the noise absorption effect of the capacitor element 20P.

[0234] Furthermore, in the power conversion device according to Embodiment 12, as shown in Embodiment 1, Negative electrode side In the structure of the electrical path from the power supply wiring 60N to the ground node via the negative-side noise-removing capacitor element 20N, the first capacitor connection wiring 70N on the negative side has a first opposing wiring section and a second opposing wiring section, and by arranging at least a portion of each of the first opposing wiring section and the second opposing wiring section P opposite each other, the heat absorbed by the capacitor element 20N due to the heat generated in the power supply wiring 60N on the negative side can be suppressed by the first capacitor connection wiring 70N, and the parasitic inductance in the first capacitor connection wiring 70N can be reduced to enhance the noise absorption effect of the capacitor element 20P.

[0235] Furthermore, in the power conversion device according to Embodiment 12, in the structure of the electrical path from the positive-side power supply wiring 60P to the negative-side power supply wiring 60N via the smoothing capacitor element 20S as shown in Embodiment 1, the first capacitor connection wiring 70S on the positive-side has a first opposing wiring section and a second opposing wiring section, and at least a portion of each of the first opposing wiring section and the second opposing wiring section P is arranged opposite each other. This structure allows the first capacitor connection wiring 70S to suppress heat absorption by the capacitor element 20S due to heat generated in the positive-side power supply wiring 60P, and also reduces the parasitic inductance in the first capacitor connection wiring 70S, thereby enhancing the noise absorption effect of the capacitor element 20P.

[0236] Embodiment 2 Therefore, in Embodiment 11 as well, wide-bandgap semiconductor elements may be used as semiconductor switching elements in the group of semiconductor switching elements 13u, 14u, 13v, 14v, 13w, and 14w that constitute the power conversion circuit 10.

[0237] Furthermore, it is possible to freely combine the embodiments, modify any component of each embodiment, or omit any component of each embodiment. Furthermore, the various features, aspects, and functions described in one or more embodiments are not limited to the application of the described embodiments, but can be applied individually or in combination to other embodiments. [Industrial applicability]

[0238] The power conversion device according to this disclosure is applicable to power conversion devices such as inverters and converters in the power electronics field, and is particularly suitable for power conversion devices for electric powertrains such as hybrid vehicles and electric vehicles. [Explanation of Symbols]

[0239] 100 Power supply, 200 Load, 300 Power converter, 10 Power conversion circuit, 13u, 14u, 13v, 14v, 13w, 14w Semiconductor switching element group, 20P Capacitor element, 20N Capacitor element, 20S Smoothing capacitor, 30 Voltage sensor circuit, 40u Current sensor circuit, 40v Current sensor circuit, 40w Current sensor circuit, 50 Control unit, 60P Power supply wiring for positive terminal, 60N Power supply wiring for negative terminal, 70P First capacitor connection wiring, 71P First opposing wiring section, 72P Second opposing wiring section, 73P Bent wiring section, 80P Second capacitor connection wiring, 85P Snubber resistor, 70N First capacitor connection wiring, 71N First opposing wiring section, 72N Second opposing wiring section, 73N Bent wiring section, 80N Second capacitor connection wiring, 70S First capacitor connection wiring, 80S Second capacitor connection wiring, 91uU, 91uD, 91vU, 91vD, 91wU, 91wD Control lines, 92V, 92uI, 92vI, 92wI Signal lines.

Claims

1. A power conversion circuit having semiconductor switching elements, A power supply wiring having one end electrically connected to the electrodes of a DC power supply and the other end electrically connected to the power conversion circuit, A capacitor element for noise reduction, A first capacitor connection wiring has a first opposing wiring portion, one end of which is electrically connected to the power supply wiring and one electrode of the noise-reducing capacitor element, and the other end of which is electrically connected to one electrode of the noise-reducing capacitor element, and a second opposing wiring portion, which is positioned opposite the first opposing wiring portion. A power conversion device equipped with the following features.

2. The aforementioned power conversion circuit is an inverter circuit that converts direct current to alternating current. The aforementioned power supply wiring is the positive-side power supply wiring, one end of the positive-side power supply wiring is connected to the positive-side input terminal to which the positive terminal of the DC power supply is connected, and the other end of the positive-side power supply wiring is connected to the positive-side input terminal of the inverter circuit. The aforementioned noise-reducing capacitor element is a noise-reducing capacitor element on the positive electrode side. The system includes a second capacitor connection wiring that is electrically connected between the other electrode of the noise-removing capacitor element on the positive side and the ground node. The power conversion device according to claim 1.

3. The aforementioned power conversion circuit is an inverter circuit that converts direct current to alternating current. The power supply wiring is the negative-side power supply wiring, one end of the negative-side power supply wiring is connected to the negative-side input terminal to which the negative terminal of the DC power supply is connected, and the other end of the negative-side power supply wiring is connected to the negative-side input terminal of the inverter circuit. The aforementioned noise-removing capacitor element is a noise-removing capacitor element on the negative electrode side. The system includes a second capacitor connection wiring that is electrically connected between the other electrode of the noise-removing capacitor element on the negative side and the ground node. The power conversion device according to claim 1.

4. The first capacitor connection wiring has a bent wiring portion that electrically connects the other end of the first opposing wiring portion and one end of the second opposing wiring portion. The first opposing wiring section, the second opposing wiring section, and the bent wiring section are integrally formed as a flat plate-shaped conductor. A power conversion device according to any one of claims 1 to 3.

5. The power conversion device according to any one of claims 1 to 3, wherein the power supply wiring and the first capacitor connection wiring are integrally formed from the same material.

6. The power conversion device according to any one of claims 1 to 3, wherein the first opposing wiring portion and the second opposing wiring portion in the first capacitor connection wiring are separate components.

7. The power conversion device according to claim 2 or claim 3, wherein the length of the second capacitor connection wiring is shorter than the length of the first capacitor connection wiring.

8. The power conversion device according to any one of claims 1 to 3, wherein the first capacitor connection wiring and one electrode of the noise-removing capacitor element are integrally formed.

9. The power conversion device according to any one of claims 1 to 3, wherein the noise-removing capacitor element is arranged such that at least a portion of the current direction between one electrode and the other electrode faces at least a portion of at least one of the opposing wiring portions of the first opposing wiring portion and the second opposing wiring portion of the first capacitor connection wiring.

10. The power conversion device according to claim 2 or 3, wherein the noise-removing capacitor element is arranged such that at least a portion of the current direction between one electrode and the other electrode faces at least a portion of the second capacitor connection wiring.

11. The noise-reducing capacitor element comprises a body having one electrode and the other electrode inside, and having a pair of sides parallel to each of the one electrode and the other electrode, one electrode terminal electrically connected to the one electrode, located on one of the pair of sides of the body and protruding from the body in one direction, and the other electrode terminal located on the other of the pair of sides of the body and protruding from the body in one direction, The surface of one electrode terminal of the noise-reducing capacitor element is positioned opposite the surface of the first opposing wiring section, and the tip of one electrode terminal of the noise-reducing capacitor element is electrically and mechanically connected to the other end of the second opposing wiring section. A power conversion device according to any one of claims 1 to 3.

12. The power conversion device according to any one of claims 1 to 3, further comprising a resistive element electrically connected in series with the noise-removing capacitor element.

13. The noise reduction capacitor element is electrically connected in series with a resistive element, The resistive element is positioned opposite to the first opposing wiring portion and the second opposing wiring portion of the first capacitor connection wiring, the noise suppression capacitor element, and at least one component of the second capacitor connection wiring, such that the noise currents flowing through them are in opposite directions. The power conversion device according to claim 2 or claim 3.

14. A power conversion circuit having semiconductor switching elements, A power supply wiring for the positive terminal, one end of which is connected to the positive terminal input terminal to which the positive terminal of a DC power supply is connected, and the other end of which is connected to the positive terminal input terminal of the power conversion circuit, A power supply wiring for the negative terminal, one end of which is connected to the negative terminal input terminal to which the negative terminal of the DC power supply is connected, and the other end of which is connected to the negative terminal input terminal of the power conversion circuit, A capacitor element for noise reduction on the positive terminal side, A capacitor element for noise reduction on the negative terminal side, A first capacitor connection wiring on the positive side is electrically connected between the power supply wiring on the positive side and one electrode of the noise-removing capacitor element on the positive side, A first capacitor connection wiring on the negative side is electrically connected between the power supply wiring on the negative side and one electrode of the noise-removing capacitor element on the negative side, A second capacitor connection wiring on the positive side is electrically connected between the other electrode of the noise-removing capacitor element on the positive side and the ground node, The system comprises a second capacitor connection wiring on the negative side, which is electrically connected between the other electrode of the noise-removing capacitor element on the negative side and the ground node, A power converter comprising at least one positive-side component from the positive-side first capacitor connection wiring, the positive-side noise-removing capacitor element, and the positive-side second capacitor connection wiring, and at least one negative-side component from the negative-side first capacitor connection wiring, the negative-side noise-removing capacitor element, and the negative-side second capacitor connection wiring, wherein the positive-side component and the negative-side component are arranged opposite each other, with the noise currents flowing in opposite directions.

15. The first capacitor connection wiring on the positive electrode side has a first opposing wiring portion on the positive electrode side, one end of which is electrically connected to the power supply wiring on the positive electrode side, and a second opposing wiring portion on the positive electrode side, the other end of which is electrically connected to one electrode of the noise-removing capacitor element on the positive electrode side and is positioned opposite the first opposing wiring portion on the positive electrode side. The first capacitor connection wiring on the negative side has a first opposing wiring portion on the negative side, one end of which is electrically connected to the power supply wiring on the negative side, and a second opposing wiring portion on the negative side, the other end of which is electrically connected to one electrode of the noise-removing capacitor element on the negative side and is positioned opposite the first opposing wiring portion on the negative side. The power conversion device according to claim 14.

16. The power conversion device according to any one of claims 1 to 3, 14, or 15, wherein the semiconductor switching element is a wide-bandgap semiconductor element.

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