JP2007089357A - Power module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inverter circuit that can reduce the size of device and can simplify wiring. <P>SOLUTION: Ring-shaped bus bars 10, 11 (11u, 11v and 11w) and 12 are arranged along the external periphery of a motor. A plurality of IGBTs 2a, 2b and 2c are mounted on the bus bars 11u, 11v abd 11w, respectively. The IGBTs 2a, 2b and 2c are connected to the bus bar 10 via a bonding wire 28. The bus bars 11u, 11v and 11w are connected to an electromagnetic coil 15 via connecting electrodes 29u, 29v and 29w. An IGBT 1a, an IGBT 1b and an IGBT 1c are formed on the bus bar 12 so as to correspond to the IGBT 2a, the IGBT 2b and the IGBT 2c, respectively. The IGBTs 1a, 1b and 1c are connected to the bus bars 11u, 11v and 11w by a bonding wire 26, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power module, and more particularly, to a power module including an electric motor and an inverter circuit for driving the electric motor.

  In recent years, attention has been paid to a hybrid vehicle (HEV) using both a gasoline engine and an electric motor as power sources due to an increase in environmental awareness. In HEV, an electric motor is AC driven by switching a DC power supply by an inverter circuit including a plurality of power switching elements.

  FIG. 1 is a circuit diagram showing a configuration of a PWM control inverter circuit for driving a three-phase (U-phase, V-phase, W-phase) electric motor 4. FIG. 1 shows an example in which IGBTs 1a to 1c and 2a to 2c are used as power switching elements.

  In addition, the technique regarding the brushless motor for vehicles provided with a ring-shaped bus bar is disclosed by the following patent document 1, for example.

JP 2003-134759 A

  According to the conventional inverter circuit shown in FIG. 1, since the inverter circuit and the electric motor 4 are individually configured as separate units, there is a problem that the apparatus becomes large as a whole.

  Further, since the nodes 6u, 6v, 6w of the inverter circuit and the electrodes 5u, 5v, 5w of each phase of the electric motor 4 are connected to each other by a large current wiring cable, the wiring is complicated and large. There is also a problem that wiring space is required.

  Furthermore, it is necessary to dispose a heat dissipation structure for dissipating the heat generated from the IGBTs 1a to 1c and 2a to 2c individually for each IGBT, and the heat dissipation structure for the IGBTs 1a to 1c and 2a to 2c and the electric motor There is also a problem that the apparatus is increased in size because it is necessary to dispose the heat dissipation structure for 4 separately.

  The present invention has been made to solve such a problem, and an object of the present invention is to obtain an inverter circuit capable of realizing downsizing of the apparatus and simplification of wiring.

  A power module according to a first invention includes a motor having a plurality of electromagnetic coils, and a series connection body in which a first power element and a second power element are connected in series in this order between a power supply voltage and a reference voltage. A plurality of sets, an inverter circuit in which an electromagnetic coil is connected to a connection point between the first power element and the second power element, and a first annular conductor and a second annular conductor arranged concentrically along the outer periphery of the motor The plurality of first power elements are mounted on the first annular conductor, and the plurality of second power elements are mounted on the second annular conductor.

  The power module according to the second invention is the power module according to the first invention, and further includes a third annular conductor disposed concentrically with the first annular conductor and the second annular conductor, and the first annular conductor. Is supplied with a power supply voltage, a reference voltage is applied to the third annular conductor, a current inflow electrode of the first power element is connected to the first annular conductor, and a current outflow electrode of the first power element is the second A current inflow electrode of the second power element is connected to the second annular conductor, and a current outflow electrode of the second power element is connected to the third annular conductor. .

  A power module according to a third invention is characterized in that, in the power module according to the first or second invention, the first power element and the second power element are transistors using a wide band gap semiconductor. .

  A power module according to a fourth aspect of the invention is characterized in that, in the power module according to any one of the first to third aspects, the electromagnetic coil is a distributed-winding stator electromagnetic coil.

  The power module according to a fifth aspect of the invention is characterized in that, in the power module according to any one of the first to third aspects, the electromagnetic coil is a concentrated winding stator electromagnetic coil.

  According to the power module according to the first to fifth aspects of the present invention, the power module includes the first annular conductor and the second annular conductor disposed concentrically along the outer periphery of the motor, and the plurality of first power elements are the first annular elements. The second power element is mounted on the conductor, and the plurality of second power elements are mounted on the second annular conductor. Accordingly, the motor and the inverter circuit are structurally integrated, and the plurality of first power elements and the plurality of second power elements are integrated through the first annular conductor and the second annular conductor, respectively. Since the heat dissipation structure can be simplified, the overall size of the apparatus can be reduced.

  Further, since the plurality of first power elements are mounted on the first annular conductor and the plurality of second power elements are mounted on the second annular conductor, power consumption can be distributed.

  Furthermore, since a wiring cable having a large amount of current for connecting the inverter circuit and the motor is not necessary, wiring can be simplified.

  Particularly in the power module according to the third aspect of the invention, the first power element and the second power element are constituted by transistors using a wide band gap semiconductor that can operate at a high temperature. Therefore, an inverter circuit that can operate in a high temperature environment like a motor can be realized.

  In particular, according to the power module of the fourth aspect of the present invention, the plurality of first power elements and the plurality of second power elements can be operated in parallel by applying to the distributed winding stator electromagnetic coil. Therefore, even when the current capacity of each power element is small, a large current can be handled by the parallel operation.

  In particular, according to the power module of the fifth invention, the first power element and the second power element are individually arranged so as to correspond to the electromagnetic coil of each phase by applying to the concentrated winding stator electromagnetic coil. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the element which attached | subjected the same or corresponding code | symbol in different drawing shall show the same or corresponding element.

  The circuit configuration of the inverter circuit according to the present embodiment is the same as the configuration shown in FIG. However, in the inverter circuit according to the present embodiment, as will be described later, the inverter circuit and the electric motor 4 are individually integrated as separate units in that the inverter circuit and the electric motor 4 are structurally integrated. This is different from the conventional inverter circuit configured as described above.

  Referring to FIG. 1, IGBTs 1a and 2a are connected in series via a node 6u between a positive DC power supply voltage VH and a reference voltage VL (for example, 0 V). Specifically, the collector electrode (current inflow electrode) of the IGBT 1a is connected to the power supply voltage VH, and the emitter electrode (current outflow electrode) is connected to the node 6u. The collector electrode of the IGBT 2a is connected to the node 6u, and the emitter electrode is connected to the reference voltage VL. Similarly, the IGBTs 1b and 2b are connected in series via the node 6v between the power supply voltage VH and the reference voltage VL, and the IGBTs 1c and 2c connect the node 6w between the power supply voltage VH and the reference voltage VL. Are connected in series.

  A free wheel diode 3 is connected in antiparallel to each of the IGBTs 1a to 1c and 2a to 2c. For example, regarding the IGBT 1a, the anode electrode of the freewheel diode 3 is connected to the emitter electrode of the IGBT 1a, and the cathode electrode is connected to the collector electrode of the IGBT 1a.

  The gate electrodes (control electrodes) of the IGBTs 1 a to 1 c and 2 a to 2 c are connected to the control circuit 7. The control circuit 7 drives the IGBTs 1a to 1c and 2a to 2c by applying voltage pulses to the gate electrodes of the IGBTs 1a to 1c and 2a to 2c, respectively.

  The nodes 6u, 6v, 6w are connected to the electrodes 5u, 5v, 5w of each phase of the electric motor 4, respectively. Depending on which of the IGBTs 1a to 1c and the IGBTs 2a to 2c is driven by the control circuit 7, the direction of the current flowing in the electromagnetic coil included in the electric motor 4 can be controlled. Moreover, the magnitude | size of the electric current which flows into an electromagnetic coil can be controlled with the pulse width of the voltage pulse applied to each gate electrode of IGBT1a-1c, 2a-2c from the control circuit 7. FIG.

  Although FIG. 1 shows an example in which IGBTs 1a to 1c and 2a to 2c are used as power switching elements, other power switching elements such as power MOSFETs may be used instead of IGBTs. Alternatively, a transistor capable of operating at a high temperature using a wide band gap semiconductor such as SiC, GaN, or C may be used. When a wide band gap device is used, an inverter circuit that can operate in a high-temperature environment can be realized like the electric motor 4.

  FIG. 2 is a plan view schematically showing the structure of the inverter circuit according to the present embodiment, together with a plurality of electromagnetic coils 15 provided in the electric motor 4. FIG. 5 is a perspective view schematically showing the overall structure of the inverter circuit according to the present embodiment. FIG. 2 shows an example in which the present invention is applied to a distributed winding stator electromagnetic coil. The electromagnetic coil 15 is disposed on the outer ring of the rotation mechanism provided in the electric motor 4.

  A ring-shaped bus bar 10 is disposed along the outer periphery of the motor. A reference voltage VL is applied to the bus bar 10 via a high-current wiring cable.

  On the outside of the bus bar 10, a ring-shaped bus bar 11 (reference numerals 11u, 11v, 11w in FIG. 2) is disposed concentrically with the bus bar 10. The bus bar 11 is divided into a bus bar 11u corresponding to the U phase of the electric motor 4, a bus bar 11v corresponding to the V phase, and a bus bar 11w corresponding to the W phase. A plurality of IGBTs 2a are mounted on the bus bar 11u. The IGBT 2a is connected to the bus bar 10 via a bonding wire 28. Similarly, a plurality of IGBTs 2b and 2c are mounted on the bus bars 11v and 11w, respectively, and the IGBTs 2b and 2c are connected to the bus bar 10 via bonding wires 28. The bus bar 11u is connected to the electromagnetic coil 15 through the connection electrode 29u. Similarly, the bus bars 11v and 11w are connected to the electromagnetic coil 15 via connection electrodes 29v and 29w, respectively.

  A ring-shaped bus bar 12 is disposed outside the bus bar 11 so as to be concentric with the bus bars 10 and 11. A power supply voltage VH is applied to the bus bar 12 via a large-current wiring cable. On the bus bar 12, an IGBT 1a is mounted corresponding to the IGBT 2a, an IGBT 1b corresponding to the IGBT 2b, and an IGBT 1c corresponding to the IGBT 2c. The IGBTs 1a, 1b, and 1c are connected to the bus bars 11u, 11v, and 11w through bonding wires 26, respectively.

  The material of the bus bars 10 to 12 is, for example, copper, and the bus bars 10 to 12 are all conductive.

  According to the example shown in FIG. 2, four sets of IGBTs 1 a and 2 a are arranged corresponding to the U phase of the electric motor 4, and the four sets of IGBTs 1 a and 2 a operate in parallel, The current flowing through the electromagnetic coil 15 is controlled. Similarly, the current flowing through the V-phase electromagnetic coil 15 is controlled by operating the four sets of IGBTs 1b and 2b in parallel, and the W-phase electromagnetic coil 15 is operated by operating the four sets of IGBTs 1c and 2c in parallel. Is controlled. Therefore, even when the current capacities of the IGBTs 1a to 1c and 2a to 2c are small, a large current can be handled by the parallel operation.

  Referring to FIG. 5, connector 50 is a connector for inputting a control signal applied to each gate electrode of IGBTs 1a to 1c and 2a to 2c from control circuit 7 shown in FIG. The terminal 51 is a terminal to which the power supply voltage VH is input, and the terminal 52 is a terminal to which the reference voltage VL is input. The bus bars 10 to 12 are sealed with a sealing protector 47 made of insulating resin.

  FIG. 3 is a plan view schematically showing another structure of the inverter circuit according to the present embodiment, corresponding to FIG. FIG. 3 shows an example in which the present invention is applied to a concentrated winding stator electromagnetic coil.

  Similarly to FIG. 2, the electromagnetic coil 15 is disposed on the outer ring of the rotation mechanism provided in the electric motor 4. A ring-shaped bus bar 10 is disposed along the outer periphery of the motor, and a reference voltage VL is applied to the bus bar 10.

  On the outside of the bus bar 10, a ring-shaped bus bar 11 (reference numerals 11 u, 11 v, 11 w in FIG. 3) is disposed concentrically with the bus bar 10. The bus bar 11 is divided into a plurality of bus bars 11u corresponding to the U phase of the electric motor 4, a plurality of bus bars 11v corresponding to the V phase, and a plurality of bus bars 11w corresponding to the W phase.

  One IGBT 2 a is mounted on each bus bar 11 u, and the IGBT 2 a is connected to the bus bar 10 via a bonding wire 28. Similarly, one IGBT 2b, 2c is mounted on each bus bar 11v, 11w, and the IGBT 2b, 2c is connected to the bus bar 10 via a bonding wire 28. The bus bars 11u, 11v, and 11w are connected to the electromagnetic coil 15 through connection electrodes 29u, 29v, and 29w, respectively.

  As in FIG. 2, a ring-shaped bus bar 12 is disposed outside the bus bar 11, and a power supply voltage VH is applied to the bus bar 12. On the bus bar 12, an IGBT 1a is mounted corresponding to the IGBT 2a, an IGBT 1b corresponding to the IGBT 2b, and an IGBT 1c corresponding to the IGBT 2c. The IGBTs 1a, 1b, and 1c are connected to the bus bars 11u, 11v, and 11w through bonding wires 26, respectively.

  According to the example shown in FIG. 3, by applying the present invention to a concentrated winding stator electromagnetic coil, IGBTs 1 a to 1 c and IGBTs 2 a to 2 c correspond to each of the electromagnetic coils 15 of each phase of U, V, and W. Can be arranged individually.

  FIG. 4 is a cross-sectional view showing the structure of the bus bars 10 to 12 according to the present embodiment. Bus bars 10 to 12 are formed on the upper surface of the substrate 20. An IGBT 2 (corresponding to the IGBTs 2a to 2c shown in FIGS. 1 to 3) is mounted on the upper surface of the bus bar 11, and an IGBT 1 (corresponding to the IGBTs 1a to 1c shown in FIGS. 1 to 3) is mounted on the upper surface of the bus bar 12. Has been implemented.

  Specifically, a gate electrode 2G and an emitter electrode 2E are formed on the top surface of the IGBT 2, and a collector electrode 2C is formed on the bottom surface. The collector electrode 2 </ b> C is bonded on the upper surface of the bus bar 11. Similarly, a gate electrode 1G and an emitter electrode 1E are formed on the top surface of the IGBT 1, and a collector electrode 1C is formed on the bottom surface. The collector electrode 1 </ b> C is bonded on the upper surface of the bus bar 12.

  The emitter electrode 2E is connected to the upper surface of the bus bar 10 via a bonding wire 28, and the emitter electrode 1E is connected to the upper surface of the bus bar 11 via a bonding wire 26.

  A substrate 21 is formed on the upper surface of the substrate 20 so as to cover the bus bars 10 to 12 and the IGBTs 1 and 2. Electrodes 23 and 24 are formed on the upper surface of the substrate 21. The electrodes 23 and 24 are connected to the control circuit 7 shown in FIG. A bonding wire 27 is connected to the electrode 24, and the bonding wire 27 is connected to the gate electrode 2 </ b> G via a through hole formed in the substrate 21. Similarly, a bonding wire 25 is connected to the electrode 23, and the bonding wire 25 is connected to the gate electrode 1 </ b> G through a through hole formed in the substrate 21.

  A connection electrode 29 (corresponding to the connection electrodes 29 u to 29 w shown in FIGS. 2 and 3) is formed on the upper surface of the substrate 21, and one end of the connection electrode 29 is a through hole formed in the substrate 21. Is connected to the upper surface of the bus bar 11. The other end of the connection electrode 29 is connected to the electromagnetic coil 15 of the electric motor 4 by welding or the like.

  A part of the drive circuit for driving the electric motor 4 can be mounted on the upper surface of the substrate 21.

  A substrate 22 is formed on the upper surface of the substrate 21 so as to cover the electrodes 23 and 24 and the connection electrode 29.

  The substrates 20 to 22 are formed using an insulating material having a high thermal conductivity, such as ceramic. The internal space defined by the substrates 20 to 22 is sealed with an insulating material 30 such as resin.

  According to the power module according to the present embodiment, as shown in FIGS. 2 and 3, the ring-shaped bus bars 11 and 12 are arranged concentrically along the outer periphery of the electric motor 4, and a plurality of IGBTs 1a are arranged. ˜1c is mounted on the bus bar 12, and the plurality of IGBTs 2a to 2c are mounted on the bus bar 11, respectively. Therefore, the electric motor 4 and the inverter circuit are structurally integrated, and the plurality of IGBTs 1a to 1c and the plurality of IGBTs 2a to 2c are integrated through the bus bars 12 and 11, respectively, thereby simplifying the heat dissipation structure. Therefore, the overall size of the apparatus can be reduced. In addition, since the plurality of IGBTs 1 a to 1 c are mounted on the bus bar 12 and the plurality of IGBTs 2 a to 2 c are mounted on the bus bar 11, heat generated from the respective IGBTs 1 a to 1 c and 2 a to 2 c can be dispersed. The heat dissipation effect can also be enhanced.

  Moreover, since several IGBT1a-1c is mounted on the bus-bar 12, and several IGBT2a-2c is mounted on the bus-bar 11, power consumption can be disperse | distributed.

  Further, as shown in FIG. 4, the bus bar 11 and the electromagnetic coil 15 are connected to each other by the connection electrode 29, so that a large current amount of wiring cable for connecting the inverter circuit and the electric motor 4 is not required. . Therefore, the wiring can be simplified.

It is a circuit diagram which shows the structure of the PWM control inverter circuit for driving a three-phase electric motor. It is a top view which shows typically the structure of the inverter circuit which concerns on embodiment of this invention with the several electromagnetic coil with which an electric motor is provided. FIG. 5 is a plan view schematically showing another structure of the inverter circuit according to the embodiment of the present invention corresponding to FIG. 2. It is sectional drawing which shows the structure of the bus-bar which concerns on embodiment of this invention. It is a perspective view which shows typically the whole structure of the inverter circuit which concerns on embodiment of this invention.

Explanation of symbols

1a-1c, 2a-2c IGBT
4 Electric motor 6u-6w Node 10, 11u-11w, 12 Bus bar 15 Electromagnetic coil

Claims (5)

A motor having a plurality of electromagnetic coils;
A plurality of series connection bodies in which a first power element and a second power element are connected in series in this order between a power supply voltage and a reference voltage, and a connection point between the first power element and the second power element An inverter circuit connected to the electromagnetic coil;
A first annular conductor and a second annular conductor disposed concentrically along the outer periphery of the motor;
A plurality of the first power elements are mounted on the first annular conductor;
The power module, wherein the plurality of second power elements are mounted on the second annular conductor. A third annular conductor disposed concentrically with the first annular conductor and the second annular conductor;
The power supply voltage is applied to the first annular conductor,
The reference voltage is applied to the third annular conductor,
A current inflow electrode of the first power element is connected to the first annular conductor;
A current outflow electrode of the first power element is connected to the second annular conductor;
A current inflow electrode of the second power element is connected to the second annular conductor;
The power module according to claim 1, wherein a current outflow electrode of the second power element is connected to the third annular conductor.   The power module according to claim 1 or 2, wherein the first power element and the second power element are transistors using a wide band gap semiconductor.   The power module according to claim 1, wherein the electromagnetic coil is a distributed winding stator electromagnetic coil.   The power module according to claim 1, wherein the electromagnetic coil is a concentrated winding stator electromagnetic coil.

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