JP2016019401A - Power conversion device integrated motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device integrated motor which improves the degree of freedom in layout of a power conversion device.SOLUTION: A DC smoothing electrolytic capacitor 17 is connected to a packaging board 12 of a power semiconductor apparatus 16 while being fixed to a power conversion device side housing 3. In that case, the electrolytic capacitor 17 is disposed in such a manner that its length direction becomes parallel with an inner peripheral wall of the power conversion device side housing 3. Therefore, the electrolytic capacitor 17 is firmly fixed, vibration resistance can be improved and heat generated by the electrolytic capacitor 17 is efficiently transferred to the power conversion device side housing 3. The electrolytic capacitor 17 and the packaging board 12 are connected by a twist wire 32, a coaxial wire 33 or a flexible substrate 24, thereby suppressing generation of noise. Further, the electrolytic capacitor 17 is accommodated within a recess 18 formed on the inner peripheral wall of the power conversion device side housing 3, and an insulative sheet member 19 having a heat radiation property is interposed between the electrolytic capacitor 17 and the power conversion device side housing 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power converter integrated motor in which a power converter is integrally attached to a motor, and is particularly suitable when a power semiconductor and a DC smoothing electrolytic capacitor are used in the power converter.

  In-vehicle motors such as assist motors for electric power steering and compressors for in-vehicle air conditioners have become mainstream. It is becoming. In industrial applications, electric motors with integrated power conversion devices have been developed for the purpose of space saving and panel-less (non-control panel) structure. In a power conversion device, a power semiconductor is generally used to adjust power to an electric motor. Power semiconductors handle a large amount of power and generate a large amount of heat due to loss. For this reason, a power semiconductor cooling structure is important for miniaturization of the electric power converter integrated motor. Next, the electrolytic capacitor for DC voltage smoothing greatly affects the layout of the power converter. Although the loss caused by the electrolytic capacitor is small compared to the loss of the power semiconductor, the electrolytic capacitor is a loss due to the ripple current and the equivalent series resistance, and generates self-heating. In view of this, in Patent Document 1 described below, a contrivance is made to release heat generated by the electrolytic capacitor mounted on the mounting substrate together with the power semiconductor to the cooling body.

JP 2005-527775 A

By the way, in patent document 1, it is not different from a general board | substrate by the point that the electrolytic capacitor is mounted on the mounting board with the power semiconductor, and the layout of the power converter device by an electrolytic capacitor will still be restrict | limited greatly.
The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a power converter integrated motor having a high degree of freedom with respect to the layout of the power converter.

  In order to solve the above problems, according to one aspect of the present invention, there is provided a power converter integrated motor in which an electric motor and a power converter that converts power to the motor by a power semiconductor are integrally arranged. A motor-side housing that houses the motor, a power converter-side housing that is connected to the motor-side housing and houses the power converter, and a power semiconductor mounting substrate fixed to the power converter-side housing There is provided a power converter integrated motor including a DC smoothing electrolytic capacitor connected to the DC.

  According to the electric power converter integrated motor of the present invention, the electrolytic capacitor for direct current smoothing is connected to the power semiconductor mounting substrate in a state of being fixed to the power converter side housing, thereby efficiently cooling the electrolytic capacitor. In addition, the degree of freedom with respect to the layout of the power converter can be increased.

1 is a longitudinal sectional view showing an embodiment of an electric motor integrated with a power converter according to the present invention. It is a circuit diagram of the power semiconductor and electrolytic capacitor which are used for the power converter device of FIG. It is a perspective view which shows the fixation structure of the electrolytic capacitor in the power converter device of FIG. It is sectional drawing of the flexible substrate which connects an electrolytic capacitor and a mounting substrate in the power converter device of FIG. It is explanatory drawing of the other example of the structure which connects a flexible substrate to a mounting substrate. It is explanatory drawing of the fixing structure in the case of connecting an electrolytic capacitor to a flexible substrate. It is explanatory drawing of the twist line which connects an electrolytic capacitor and a mounting substrate. It is sectional drawing of the coaxial line which connects an electrolytic capacitor and a mounting substrate. It is explanatory drawing of the connection structure of a twist line or a coaxial line, and a mounting board.

  Hereinafter, an embodiment of an electric motor integrated with a power converter according to the present invention will be described with reference to the drawings. In FIG. 1 which shows the longitudinal cross-section of the electric power converter integrated motor of this embodiment, the electric power converter 1 is arrange | positioned at the left side of the figure, and the electric motor 2 is arrange | positioned at the right side of the figure, and they are connected in series. Among these, the power conversion device 1 is housed in the power conversion device side housing 3, the motor 2 is housed in the motor side housing 4, and the power conversion device side housing 3 and the motor side housing 4 are housing connection members. It is connected via the cum lid member 5. The casings 3 and 4 and the lid member 5 are approximately cylindrical and are formed of a metal material having excellent thermal conductivity, for example, aluminum die casting.

  In this electric power converter integrated motor, the rotating shaft 6 of the electric motor 2 is arranged in the left-right direction in the figure. The motor-side housing 4 is a bottomed cylindrical body in which a disk-like bottom plate portion 4a is disposed on the right side of FIG. Further, the casing connecting member / lid member 5 is a cylindrical body having the same outer diameter as that of the motor-side casing 4, and a lid portion 5 a is formed in the center portion in the axial direction. The opening at the left end of FIG. 1 is covered with the lid 5a of the casing connecting member / lid member 5 so that the motor-side casing 4 is sealed. The rotating shaft 6 is rotatably supported by a bearing 7 press-fitted into the central portion of the bottom plate portion 4 a of the motor-side housing 4 and the central portion of the lid portion 5 a of the housing connecting member / lid member 5. The rotary shaft 6 has a right end in FIG. 1, that is, one end in the axial direction, protrudes outside through the bottom plate portion 4a of the motor-side casing 4, and outputs are taken out therefrom.

  In the motor-side internal space surrounded by the motor-side casing 4 and the casing connecting member / lid member 5, the rotor core 8 is integrally formed on the outer periphery of the rotating shaft 6. A stator core 9 fixed to the side housing 4 is formed. Thereby, the electric motor 2 is comprised in the electric motor side housing | casing 4, and the rotating shaft 6 is rotated by supplying electric power to the stator core 9, for example. Further, for example, by adjusting the power supplied to the stator core 9, the rotation state of the rotating shaft 6 can be adjusted.

  On the other hand, the power conversion device side housing 3 is a bottomed cylindrical body in which a disc-shaped bottom plate portion 3a is disposed on the left side of FIG. 1, and an opening at the right end in the drawing is a housing connecting member / lid. The cover 5 is covered with a member 5. Further, an O-ring 10 is interposed between the peripheral wall portion 3b of the power conversion device side housing 3 and the peripheral wall portion 5b of the housing connecting member / lid member 5, whereby the power conversion device side housing 3 is sealed. Yes. An inverter module 11 that forms the core of the power conversion device 1 is housed in the internal space on the power conversion device side surrounded by the power conversion device side housing 3 and the housing connecting member / lid member 5. The inverter module 11 includes, for example, a power conversion unit that converts AC voltage into DC voltage, and a control unit that controls the rotation state of the rotating shaft of the electric motor. The control unit controls the rotation state of the rotating shaft 6 of the electric motor 2 by adjusting the power supplied to the stator core 9 by, for example, pulse width modulation of the DC voltage converted by the power conversion unit. Note that a heat radiating portion 3c protruding inside the housing is provided on the inner peripheral wall of the bottom plate portion 3a of the power conversion device side housing 3. The heat radiating portion 3c is made of an individual member made of, for example, metal having good thermal conductivity, and contacts the power semiconductor device to be described later to transfer the heat to the power conversion device side housing 3 to release it. is there.

  The inverter module 11 is formed on the mounting substrate 12. The mounting substrate 12 is obtained by forming a wiring pattern on the surface of a substrate made of a resin such as glass epoxy. The mounting substrate 12 is fixed to a substrate fixing portion 13 formed inside the power conversion device side housing 3 via a fixing tool 14 such as a screw. Various electronic components are mounted on the mounting substrate 12. Among these electronic components, a diode rectifier (not shown) necessary for the power conversion unit, a power semiconductor device 16 necessary for the control unit, and the like are included. Is also included. For example, heat generated due to loss of electronic components is transferred from the internal space of the power converter side housing 3 to the power converter side housing 3 itself. Since the power conversion device side housing 3 is in contact with outside air, the power conversion device side housing 3 serves as a cooling body for electronic components. The mounting substrate 12 may be formed with wiring patterns on both the front and back surfaces. Also, two or more mounting boards 12 can be used in combination.

  The diode rectifier is, for example, a three-phase full-wave rectifier that rectifies a three-phase AC voltage, and can convert the AC voltage into a DC voltage as is well known. However, a pulsating component still remains in the output voltage of the diode rectifier, and this pulsating component is smoothed by the DC smoothing electrolytic capacitor 17 and supplied to the power semiconductor device 16. In the circuit diagram of the electrolytic capacitor 17 and the power semiconductor device 16 shown in FIG. 2, the DC smoothing electrolytic capacitor 17 is connected between the positive pole and the negative pole obtained as the output of the diode rectifier, and the transistors connected in parallel are connected. (Insulated Gate Bipolar Transistor: IGBT) A pair of Tr and a diode D is connected in series as a pair of power semiconductors 15 and three pairs of these power semiconductors 15 are connected in parallel with an electrolytic capacitor 17, and each pair The electric power of the electric motor 2 composed of a three-phase motor is output from the connection portion between the power semiconductors 15 in FIG. Each power semiconductor 15 can control the rotation state of the electric motor 2 by adjusting the electric power to the electric motor 2 by pulse width modulation, for example. As is well known, the power semiconductor 15 handles a large amount of power and generates a large amount of heat. Since the power semiconductor device 16 in which the power semiconductor 15 is housed is in contact with the heat radiating portion 3c described above, the heat of the power semiconductor device 16 is transmitted through the heat radiating portion 3c to the bottom plate portion 3a of the power conversion device side body 3. The power semiconductor device 16 and thus the power semiconductor 15 are cooled. Further, since the above diode rectifier also generates a large amount of heat, it is desirable that the heat of the diode rectifier is transmitted to the power converter side housing 3 via a heat radiating unit (not shown) to be cooled.

  As shown in FIG. 1, the electrolytic capacitor 17 of this embodiment is fixed to the bottom plate portion 3 a of the power conversion device side housing 3. As is well known, the electrolytic capacitor 17 has a cylindrical shape, and is arranged so that its longitudinal direction (axial direction) is parallel to the inner peripheral wall of the bottom plate portion 3a of the power conversion device side body 3, and in this state, the bottom plate portion It is fixed to 3a. Thus, by fixing the electrolytic capacitor 17 sideways, the electrolytic capacitor 17 can be firmly fixed, and the vibration resistance can be improved. In FIG. 3 showing the fixing structure of the electrolytic capacitor 17, a rectangular recess 18 having a size longer than the length of the electrolytic capacitor 17 is formed on the inner peripheral wall of the bottom plate portion 3 a of the power conversion device side body 3. The electrolytic capacitor 17 is fixed so as to be housed inside. An insulating sheet member 19 having heat dissipation is interposed between the power converter side housing 3 serving as a cooling body and the electrolytic capacitor 17, and a band-shaped fixing member 20 is applied to the electrolytic capacitor 17. 20 is fixed to the inner peripheral wall of the bottom plate portion 3a of the power conversion device side housing 3 by a fixing tool 21 such as a screw, and thereby the electrolytic capacitor 17 is fixed to the power conversion device side housing 3. Note that a large number of heat radiation fins 22 are formed on the outer peripheral wall of the bottom plate portion 3 a of the power conversion device side housing 3.

  The electrolytic capacitor 17 is a component whose life is determined by the ambient temperature, and tends to be a bottleneck related to product reliability. The lifetime of the electrolytic capacitor 17 is assumed to follow Arrhenius' law, and the lifetime is halved when the temperature increases by 10 ° C. Therefore, it is a component with a large mounting constraint such as being unable to be placed in the immediate vicinity of the power semiconductor device 16 having a high temperature, which causes a significant limitation on the component layout on the mounting substrate 12.

  Further, in general electrical equipment, a withstand voltage test exceeding 1000 V is often imposed as a type test between a casing (FG: Frame Grand) and a high voltage section (three-phase input or three-phase output). If there is no insulating sheet member between the power converter side housing 3 and the DC smoothing electrolytic capacitor 17, a voltage is applied between the power converter side housing 3 and the terminal of the electrolytic capacitor 17 during the withstand voltage test. Will be applied. In the electrolytic capacitor 17 that is normally sold, since the withstand voltage value between the housing and the terminal is not specified in the catalog, it is necessary to protect the terminal with an insulating sheet member 19. Further, as described above, the DC smoothing electrolytic capacitor 17 self-heats, so it is necessary to release the heat generation to the power converter side housing 3, and therefore, it is made of a material having good heat dissipation, that is, high thermal conductivity. The sheet member 19 needs to be configured. In this case, too, the electrolytic capacitor 17 can be laid and brought into contact with the sheet member 19 to efficiently transfer the heat of the electrolytic capacitor 17 from the sheet member 19 to the power conversion device side housing 3.

  As a material of the sheet member 19 having a high thermal conductivity and excellent insulating properties, for example, silicone can be used. When the silicone sheet member 19 is used, the silicone sheet itself has adhesiveness. Therefore, when the requirement for vibration against the electrolytic capacitor 17 is small, only the silicone sheet member 19 is used for the DC smoothing electrolytic capacitor. 17 may be fixed. An adhesive may be used for fixing the electrolytic capacitor 17 for direct current smoothing. Examples of the adhesive material include an epoxy resin and a silicone resin. In addition, as the fixing member 20 for fixing the electrolytic capacitor 17 to the power conversion device side housing 3, it is desirable to use an insulating resin in consideration of the above-described withstand voltage test. When the fixing member 20 is made of a conductive material, a method of interposing an insulating sheet between the electrolytic capacitor 17 and the fixing member 20, or an insulating spacer for insulating the fixing member 20 from the power conversion device side housing 3. Is interposed between the fixing member 20 and the power conversion device side housing 3.

  Further, in this embodiment, a pressure valve space 23 is formed between the pressure valve 17 a provided at one end in the longitudinal direction of the cylindrical electrolytic capacitor 17 for DC smoothing and the recess 18. Yes. The electrolytic capacitor 17 is provided with a pressure valve 17a that operates in the event of an abnormality, for example, at one end in the longitudinal direction. If the pressure valve 17a is blocked, there is a possibility that the pressure valve 17a does not operate during an abnormality. Therefore, in this embodiment, a pressure valve space 23 is formed between the pressure valve 17a of the electrolytic capacitor 17 and the recess 18 in which the electrolytic capacitor 17 is accommodated, so that the pressure valve 17a operates normally when an abnormality occurs.

  Next, a connection structure between the electrolytic capacitor 17 and the mounting substrate 12 will be described. In the power conversion device 1 using the power semiconductor device 16 that switches a high voltage and a large current in submicroseconds, the purpose is to suppress a surge voltage generated at the time of switching, the purpose to suppress noise radiated from the conducting wire, or the voltage Therefore, it is necessary to reduce the inductance between the power semiconductor device 16 and the DC smoothing electrolytic capacitor 17 as much as possible. Therefore, it is desirable to minimize the inductance with a wiring structure in which the positive pole and the negative pole are arranged along each other.

  4 is a cross-sectional view of the flexible substrate 24 used in the electrolytic capacitor-mounted substrate connection structure in the electric power converter integrated motor shown in FIG. The flexible substrate 24 is arranged so that the positive pole 24b and the negative pole 24c are along each other via the insulating layer 24a, thereby minimizing radiated noise. In the electrolytic capacitor-mounting substrate connection structure using the flexible substrate 24, as shown in FIG. 1, the electrolytic capacitor 17 is connected to the flexible substrate 24 by soldering or the like, and the end of the flexible substrate 24 is connected to the relay substrate 25. The connector 26 attached to the relay board 25 and the connector 26 attached to the mounting board 12 are connected. Further, as shown in FIG. 5, a positive electrode pattern 27 and a negative electrode pattern 28 are formed on the relay substrate 25, and a similar positive electrode pattern 27 and a negative electrode pattern 28 are formed on the mounting substrate 12. There is also a method in which the negative electrode patterns 28 are fixed to each other with the negative electrode connection screw 30 while the 27 are fixed to each other with the positive electrode connection screw 29. When the electrolytic capacitor 17 is required to have vibration resistance, as shown in FIG. 6, the vibration resistance can be improved by potting between the flexible substrate 24 and the electrolytic capacitor 17 with an insulating resin 31. it can.

  Further, examples of the conductive wire structure that minimizes radiated noise include the twisted wire 32 shown in FIG. 7 and the coaxial wire 33 shown in FIG. As is well known, the twisted wire 32 shown in FIG. 7 is formed by twisting a positive electrode wire 32a with a positive electrode insulated and a negative electrode wire 32b with a negative electrode covered with an insulation. Since the direction of magnetic flux is reversed, it is difficult to emit noise to the outside. Further, as is well known, the coaxial wire 33 shown in FIG. 8 has an insulating layer 33b formed on the outer periphery of the core wire 33a constituting the positive pole, and a negative pole constituted by the braided wire 33c arranged on the outer periphery thereof. Therefore, the negative pole formed by the braided wire 33c serves as a shield, making it difficult to emit noise to the outside. Then, as an electrolytic capacitor-mounting board connection structure in the case of using these twisted wires 32 and coaxial wires 33, for example, as shown in FIG. 9, a connector 26 is connected to the ends of the twisted wires 32 and coaxial wires 33. There is a method of connecting the connector 26 and the connector 26 attached to the mounting board 12.

As described above, in the electric power converter integrated motor of this embodiment, the DC smoothing electrolytic capacitor 17 is connected to the mounting substrate 12 of the power semiconductor device 16 in a state of being fixed to the electric power converter side housing 3. Thus, the electrolytic capacitor 17 can be efficiently cooled, and the degree of freedom with respect to the layout of the power converter 1 can be increased.
Further, by arranging the longitudinal direction of the electrolytic capacitor 17 in a direction parallel to the inner peripheral wall of the power converter side housing 3, the electrolytic capacitor 17 can be firmly fixed to improve the vibration resistance, and the electrolytic capacitor 17 can be improved. The heat generated by the capacitor 17 can be efficiently transmitted to the power converter side housing 3 to cool the electrolytic capacitor 17 efficiently.

Further, the electrolytic capacitor 17 and the mounting substrate 12 are connected by any one of the flexible substrate 24 in which the positive electrode 24b and the negative electrode 24c are arranged in parallel via the twisted wire 32, the coaxial wire 33 or the insulating layer 24a. Thus, it is possible to reduce the inductance of the connection structure between them and to suppress the generation of noise.
Further, by storing and fixing the electrolytic capacitor 17 in the recess 18 formed on the inner peripheral wall of the power conversion device-side housing 3, the degree of freedom in layout can be further increased.

In addition, since the pressure valve space 23 for opening the pressure valve 17a of the electrolytic capacitor 17 is formed in the concave portion 18, the pressure valve 17a of the electrolytic capacitor 17 operates normally at the time of abnormality.
In addition, since the insulating sheet member 19 having heat dissipation is interposed between the electrolytic capacitor 17 and the power converter side housing 3, the electrolytic capacitor 17 can be efficiently radiated and at the time of a withstand voltage test. The electrolytic capacitor 17 can be insulated.

In addition, a heat radiating portion 3c for contacting the power semiconductor device 16 in which the power semiconductor 15 is accommodated and transferring the heat of the power semiconductor device 16 to the power conversion device casing 3 to release the heat is provided on the electric power conversion device side casing 3. By providing it on the inner peripheral wall, the power semiconductor device 16 and thus the power semiconductor 15 can be efficiently cooled.
In the previous embodiment, the individual heat dissipating part 3c is attached to the inner peripheral wall of the bottom plate part 3a of the power conversion device side housing 3, and the heat of the power semiconductor device 16 is transmitted to the power conversion device side housing 3 to escape. However, for example, the bottom plate portion 3a of the power conversion device side housing 3 may be recessed inside the housing to constitute the heat radiation portion 3c.

DESCRIPTION OF SYMBOLS 1 Power conversion device 2 Electric motor 3 Power conversion device side housing | casing 3c Heat radiation part 4 Motor side housing | casing 5 Housing | casing connection member and cover member 6 Rotating shaft 7 Bearing 8 Rotor core 9 Stator core 10 O-ring 11 Inverter module 12 Mounting board 13 Board fixing Part 14 Fixing Tool 15 Power Semiconductor 16 Power Semiconductor Device 17 Electrolytic Capacitor 18 Recess 19 Sheet Member 20 Fixing Member 21 Fixing Tool 22 Fin 23 Pressure Valve Space 24 Flexible Board 25 Relay Board 26 Connector 27 Positive Electrode Pattern 28 Negative Electrode Pattern 29 Plus Pole connection screw 30 Negative pole connection screw 31 Resin 32 Twist wire 33 Coaxial wire Tr Transistor D Diode

Claims (7)

A power converter integrated motor in which a motor and a power converter that converts power to the motor by a power semiconductor are integrally disposed,
An electric motor side housing for storing the electric motor;
A power converter side casing that is connected to the motor side casing and houses the power converter;
A power converter integrated motor, comprising: a DC smoothing electrolytic capacitor connected to the power semiconductor mounting substrate in a state of being fixed to the power converter side casing.   2. The electric power converter integrated motor according to claim 1, wherein a longitudinal direction of the electrolytic capacitor is arranged in a direction parallel to an inner peripheral wall of the power converter side housing.   The electrolytic capacitor and the mounting substrate are connected by any one of a flexible substrate in which a positive electrode and a negative electrode are arranged in parallel via a twisted wire, a coaxial wire, or an insulating layer. The electric power converter integrated motor according to 2.   The electric power converter integrated motor according to any one of claims 1 to 3, wherein a recess for accommodating and fixing the electrolytic capacitor is formed on an inner peripheral wall of the power converter side housing.   5. The electric power converter integrated motor according to claim 4, wherein a pressure valve space for opening the pressure valve of the electrolytic capacitor is provided in the recess.   6. The power converter according to claim 1, wherein an insulating sheet member having heat dissipation is interposed between the electrolytic capacitor and the power converter side housing. Body motor. A heat dissipating part is provided on the inner peripheral wall of the electric power conversion device side housing to contact the power semiconductor device in which the power semiconductor is housed and to transfer the heat of the power semiconductor device to the power conversion device housing The electric motor integrated with an electric power converter according to any one of claims 1 to 6,

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