JP2004319562A - Inverter module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter module that can be incorporated and disposed easily in a motor and can be reduced in size and capacitance by improving the cooling performance of the module. <P>SOLUTION: The inverter module 11 is constituted by constituting each phase output unit 10 by disposing two sets of semiconductor modules 19 and 19, which are provided with bare chip-like IGBT power elements 22 and diode elements 23 and between which a terminal board 14 provided with an output terminal 15 and a gate signal input terminal 16 is interposed, between a trisected annular positive electrode plate 12 provided with an anode-side input terminal 18 and a trisected annular negative electrode plate 13 provided with a cathode-side input terminal 17. Then three sets of phase output units 10, 10, and 10 thus constituted are annularly connected to each other. In addition, a capacitor module 26 is disposed between the positive and negative electrode plates 12 and 13 and, at the same time, the space between the electrode plates 12 and 13 is sealed with a resin 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inverter module to be used by being incorporated in an electric motor provided in a hybrid system vehicle, an electric vehicle, or the like.
[0002]
[Prior art]
In hybrid system vehicles and electric vehicles, efficient drive systems are required to improve the cruising distance.Synchronous motors using permanent magnets are often used instead of induction motors to reduce size and increase efficiency. In addition, further miniaturization is being promoted by incorporating an inverter into the synchronous motor.
[0003]
However, the semiconductor module and the capacitor module provided in the inverter generate heat during operation, but their cooling structure prevents miniaturization and low capacity. In this cooling structure, heat generated from the element is transmitted to the radiator plate through the board on which the element is mounted, and is radiated by cooling the radiator plate with cooling water. Therefore, in order to improve the cooling efficiency of the element, it is preferable that the substrate is disposed in close contact with the plane of the radiator plate. Is required.
On the other hand, the rotating electrical machine components are shaped to perform rotary motion, so if an inverter with a large cubic shape is installed, the unit shape will be unbalanced and the electrical operation will also be the wiring inductance and resistance. Causes an imbalance. In addition, the capacitor module provided for stabilizing the power supply voltage during the operation of the inverter is required to have a relatively large capacity and a high withstand voltage. Therefore, it is usually arranged separately from the inverter module.
[0004]
As a structure of an inverter module that solves the above-described problem, in the technology described in Patent Document 1, an inverter module incorporating a capacitor module is formed in a ring shape so as to match the cross-sectional shape of a rotor that is a constituent member of a rotating electric machine. There has been proposed a configuration in which an inverter can be compactly built in a rotating electric machine.
In this structure, by forming the heat radiating plate that forms the outer shape of the inverter module in a ring shape, it is possible to secure the planar area of the heat radiating plate and realize compact integration into the rotating electric machine.
[0005]
[Patent Document 1]
JP-A-11-206183
[Problems to be solved by the invention]
The above conventional inverter module structure has room for improvement for further improving the cooling efficiency.
In the present invention, in view of the above-mentioned prior art, by improving the structure of an inverter module built in a vehicle-mounted electric motor, in particular, it facilitates incorporation and arrangement in the electric motor, and furthermore, miniaturization and low capacity by improving the cooling performance of the inverter module. Achieve realization.
[0007]
[Means for Solving the Problems]
The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
[0008]
That is, in claim 1, two sets of semiconductor modules having a power element and a diode element are stacked and arranged, and a terminal plate having an output terminal and a gate signal input terminal is interposed between the two sets of semiconductor modules. , Two sets of semiconductor modules are sandwiched between an arc-shaped positive plate provided with a positive input terminal and an arc-shaped negative plate provided with a negative input terminal from both sides in the stacking direction to form a unit. Are connected annularly, a capacitor module is arranged between each positive electrode plate and the negative electrode plate, and the space between the positive electrode plate and the negative electrode plate is sealed with resin.
[0009]
In claim 2, the power element is an IGBT element.
[0010]
According to a third aspect of the present invention, the elements provided in the inverter module are in the form of a bare chip.
[0011]
According to a fourth aspect of the present invention, in the inverter module, the power element and the diode element included in the two sets of stacked semiconductor modules are intersected with each other via a terminal plate.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the invention will be described.
FIG. 1 is a circuit diagram showing a configuration of an inverter module according to an embodiment of the present invention, FIG. 2 is a diagram showing an inverter module, FIG. 3 is a view showing a semiconductor module as viewed in the direction of arrow X in FIG. 2, and FIG. FIG. 3 is a view as viewed in the direction X in FIG. 2.
FIG. 5 is a cross-sectional view showing an example of a motor in which an inverter module is integrated, and FIG. 6 is a cross-sectional view showing an example of a motor in which an inverter module is integrated.
[0013]
In an electric vehicle, a hybrid system vehicle, or the like, power is supplied from a high-voltage battery, the battery output is converted into AC power by an inverter circuit or the like, and power is supplied to a driving motor.
As shown in the circuit diagram of FIG. 1, in the inverter circuit, the output of the high-voltage battery 25 is input to the inverter module 11 from the P terminal 18 and the N terminal 17 provided in the inverter module 11 and is provided in the inverter module 11. From the output terminals of the U terminal 15u, the V terminal 15v, and the W terminal 15w, a three-phase AC current including a U phase, a V phase, and a W phase is output to the electric motor 27. The inverter circuit controls the torque and the number of revolutions of the electric motor 27.
The inverter circuit includes a capacitor module 26, which functions as a temporary battery that suppresses transient voltage fluctuations during the operation of the inverter module 11.
[0014]
The inverter module 11 is a three-phase bridge type circuit, and is provided with an output circuit for flowing a current to each of the output terminals 15, 15, and 15 of the U terminal 15u, the V terminal 15v, and the W terminal 15w for each phase. . Each output circuit includes two sets each including a power element 22 and a diode element 23 arranged in parallel for protection of element withstand voltage from a flyback voltage applied to the power element 22 and generation of a current path during regenerative operation. They are arranged in series.
In the inverter module 11, by performing the switching operation of the power element 22, the U-phase, V-phase, and W-phase single-phase currents are output from the U terminal 15u, the V terminal 15v, and the W terminal 15w with a phase difference. Converted to current. The timing of the switching operation of the power element 22 is calculated and calculated by an external control unit (ECU), and is input and instructed from the gate terminal 16 as a gate input signal of the power element 22.
[0015]
Here, the structure of the inverter module 11 will be described.
As shown in FIGS. 2 and 3, the inverter module 11 is configured by annularly connecting U-phase, V-phase, and W-phase output units 10 (10u), 10 (10v), and 10 (10w). . Each of the U-phase, V-phase, and W-phase output units 10, 10, and 10 has substantially the same configuration, and has a shape obtained by dividing a ring into three equal parts.
As described above, by making the inverter module 11 divided, the handling is facilitated, mass productivity is enhanced, and the component types are reduced to substantially the same shape to reduce the number of parts, and assembly work is performed. Keep it simple.
[0016]
The U-phase, V-phase, and W-phase output units 10 are laminated in the order of the negative electrode plate 13, the semiconductor module 19, the terminal plate 14, the semiconductor module 19, and the positive electrode plate 12, and these are soldered or bonded to a high heat conductive adhesive. It is formed by making electrical connection.
By connecting the U-phase, V-phase and W-phase output units 10, 10, 10, a ring-shaped inverter module 11 is formed. In the space where the semiconductor module 19 and the terminal board 14 are not arranged in the inverter module 11, the capacitor modules 26 are arranged.
[0017]
The negative electrode plate 13 has a shape obtained by dividing a ring into three equal parts, and electrically connects the negative electrode plates 13, 13, 13 of the U-phase, V-phase, and W-phase output units 10, 10, 10 by resistance bonding or the like. By making the connection and the connection, one annular negative bus bar 13 ′ can be formed. An input portion 13a is integrally formed on one of the negative plates 13, 13, 13 of the U-phase, V-phase, and W-phase output units 10, 10, 10, respectively. Is provided with an N terminal 17.
Further, the positive electrode plate 12 has substantially the same shape as the negative electrode plate 13, and the positive electrode plates 12, 12, 12 of the U-phase, V-phase, and W-phase output units 10, 10, 10 are joined by resistance bonding or the like. By making an electrical connection and connecting, one annular positive bus bar 12 ′ can be formed. An input portion 12a is integrally formed on one of the positive plates 12, 12, 12 of each of the U-phase, V-phase, and W-phase output units 10, 10, 10. A P terminal 18 is provided at 12a.
[0018]
As described above, the positive electrode bus bar 12 ′ is formed from the positive electrode plates 12, 12, and the negative electrode bus bar 12 ′ is also formed from the negative plates 13, 13. The negative electrode bus bar 13 ′ and the positive electrode bus bar 12 ′ are formed. Form the outer shape of the inverter module 11.
In the inverter module 11, a high voltage is applied from the external battery 25 to the inverter module 11 from the input terminals of the P terminal 18 provided on the positive bus bar 12 ′ and the N terminal 17 provided on the negative bus bar 13 ′. Enter The input high voltage is uniformly supplied through the positive bus bar 12 'and the negative bus bar 13'.
[0019]
Further, the positive electrode plate 12 and the negative electrode plate 13 also have a function as a heat sink, and the positive electrode plate 12 and the negative electrode plate 13 are made of a material having high thermal conductivity. As a result, in the inverter module 11, heat generated from elements provided in the semiconductor module 19 is conducted to the positive electrode plate 12 or the negative electrode plate 13 and radiated. When the inverter module 11 is incorporated in the electric motor 27, both the positive electrode plate 12 and the negative electrode plate 13 are arranged at positions where the electric motor 27 is cooled by the cooling system of the electric motor 27. Cooling takes place.
[0020]
The terminal plate 14 includes a gate terminal 16 for inputting a gate signal and an output terminal 15 (any one of a U terminal 15u, a V terminal 15v, and a W terminal 15w). When the V-phase / W-phase output units 10, 10, 10 are connected to form a ring-shaped inverter module 11, the gate terminal 16 is arranged on the inner periphery of the ring, and the output terminal 15 is arranged on the outer periphery of the ring. Thus, the position of each terminal is determined.
The positive electrode plate 12, the negative electrode plate 13, and the terminal plate 14 are made of a metal such as aluminum or Cu-Mo having properties as close as possible to silicon, and are preferably formed with a substrate 21 provided in a semiconductor module 19 described later. And can conduct heat generated from the semiconductor module 19.
[0021]
In the semiconductor module 19, a power element 22 and a diode element 23 are arranged on a substrate 21 made of a material such as high thermal conductive ceramics, and the substrate 21 is further arranged thereon. It is formed by interposing a power element 22 and a diode element 23 therebetween and making an electrical connection with solder or a high heat conductive adhesive.
In this embodiment, a bare chip IGBT element is employed as the power element 22. The diode element 23 also employs a bare chip shape.
The substrate 21 is provided with a through hole and can be electrically connected to the front and back surfaces. At least one of the front and back surfaces is provided with a gate signal as a semiconductor element switching signal from the gate terminal 16 provided on the terminal plate 14 to wire bonding or the like. The pattern which can be drawn out by is drawn.
[0022]
The semiconductor module 19 is provided in two sets in each of the phase output units 10. 10. However, the power elements 22 of each semiconductor module 19 are not overlapped in the stacking direction. Both the diode element 22 and the diode element 23 are arranged crossing via a terminal plate. That is, the power element 22 of one semiconductor module 19 and the diode element 23 of the other semiconductor module 19 are arranged in an overlapping state.
In the operation of the inverter, the heat generation state of the power element 22 and the diode element 23 tends to be biased such that heat generation of one of the power element 22 and the diode element 23 is increased. In order to avoid this uneven heating, the power element 22 and the diode element 23 are arranged crosswise. This makes it possible to suppress a local temperature rise and a change in element characteristics due to the temperature rise.
[0023]
Further, as shown in FIGS. 2 and 4, each of the phase output units 10, 10, 10 is connected in a ring shape, and then the positive electrode plates 12, 12, 12 are connected to each other to form an annular positive bus bar 12 '. The capacitor modules 26, 26, 26 are interposed in a space between the negative electrode plates 13, 13, 13 and an annular negative bus bar 13 'formed by connecting the negative plates 13, 13, and are electrically connected by soldering or the like. I have. Thus, the capacitor modules 26, 26, 26 are built in the inverter module 11.
By arranging the capacitor module 26 in the vicinity of the semiconductor module 19, the wiring between the capacitor module 26 and the semiconductor module 19 can be reduced as much as possible, thereby reducing the wiring inductance and the resistance value. As a result, a reduction in the amount of self-heating due to a reduction in the ripple current value can be expected, and it is possible to reduce the withstand voltage specifications of the terminals and to reduce the size and capacity of the inverter module 11 itself.
[0024]
Each of the phase output units 10 is connected in a ring shape, and the capacitor module 26 is disposed, and the space between the positive bus bar 12 ′ and the negative bus bar 13 ′ is sealed with a protective resin 30 (epoxy resin or the like). . The protection resin 30 ensures that the elements (including the capacitor module 26) provided in the inverter module 11 have moisture resistance.
As described above, by filling the space between the positive bus bar 12 ′ and the negative bus bar 13 ′ with the resin 30 and surrounding the power element 22 and the diode element 23 with the resin 30, it is possible to employ a bare chip as an element. Thus, the size of the inverter module 11 can be reduced. In addition, since the bare chip is used, the heat radiation efficiency is high, and the heat generated by the power element 22 and the diode element 23 is quickly conducted to the positive electrode plate 12 or the negative electrode plate 13 via the substrates 21, and the heat is radiated. Is done.
In addition, as described above, the cooling from both sides of the positive bus bar 12 'and the negative bus bar 13' is expected to greatly improve the cooling efficiency of the element.
[0025]
Further, in the inverter module 11, the wiring length is minimized by being laminated in the order of the positive electrode plate 12, the semiconductor module 19, the terminal plate 14, the semiconductor module 19 and the negative electrode plate 13. Therefore, it is possible to expect a reduction in switching loss, a flyback voltage, a ripple current value, a self-heating amount, and the like in an inverter operation, and to reduce a withstand voltage specification of a terminal to be used and to downsize the inverter module 11 itself by downsizing. The capacity can be reduced.
[0026]
Regarding a rotating electric machine with a built-in inverter including the inverter module 11 configured as described above, a permanent magnet type synchronous motor 27 used in a hybrid system vehicle or an electric vehicle as a kind of the rotating electric machine is shown.
As shown in FIG. 5, the electric motor 27 includes an inverter module 11, a rotor 47 having a rotor core 46 and a permanent magnet 45, a rotation shaft 48 of the rotor 47, a stator core 43 and a stator wound around the stator core 43. It is composed of a stator 44 having a coil 42 and the like, and a housing 41 in which these are installed. Then, by controlling the three-phase voltage and current applied to the stator coil 42, the driving force (torque and rotational speed) of the hybrid system vehicle or the electric vehicle is obtained from the synchronous motor 27.
As a cooling system for the electric motor 27, an internal water passage is formed in the housing 41, and a stator 44 provided inside the housing 41 is cooled by cooling water flowing through the internal water passage.
[0027]
The inverter module 11 is arranged in a relatively vacant space inside the housing 41 of the electric motor 27 and in a place where the direct connection structure between the inverter module 11 and the stator coil 42 can simplify the electrical connection. Is established. That is, the inverter module 11 and the stator coil 42 are arranged close to each other.
[0028]
Then, the terminal plate 14 having the respective output terminals of the U terminal 15u, the V terminal 15v, and the W terminal 15w of the inverter module 11 is directly fastened to the housing 41, and the U terminal 15u, the V terminal 15v, and the W terminal 15w. Each output terminal is directly connected to each input terminal of the U terminal 15u, the V terminal 15v, and the W terminal 15w of the stator coil 42 of the electric motor 27.
Accordingly, in connecting the output terminal on the inverter module 11 side and the input terminal on the electric motor 27 side, connection components such as wires are not required, and the wiring inductance and resistance value are reduced.
Further, as described above, since the housing 41 of the electric motor 27 is cooled by the cooling water in the internal water passage, heat generated by the inverter module 11 can be radiated from the terminal plate 14 to the housing 41.
[0029]
The arrangement of the inverter modules 11 satisfying the above conditions may be, for example, an outer peripheral portion of the stator coil 42 as shown in FIG. 5 or an end portion of the stator coil 42 as shown in FIG.
As described above, by making the shape of the inverter module 11 annular so as to match the shape of the stator 44 of the electric motor 27, it is possible to obtain an arrangement place inside the housing 41 on which the rotating shaft 48 is supported. The wiring length for connecting the output terminal 15 of the module 11 and the input terminal 28 of the electric motor 27 can be minimized. Therefore, the electric motor 27 and the inverter module 11 can be easily integrated, and a good balance can be realized.
[0030]
In addition, the annular inverter module 11 is cooled by using a cooling system provided in the electric motor 27, and is cooled by a cooling water flowing through an internal water passage formed in the housing 41 and a component of the inverter. A certain positive electrode bus bar 12 'and a certain negative electrode bus bar 13' are arranged so as to be in contact with each other, and both outer sides of the positive electrode bus bar 12 'and the negative electrode bus bar 13' are surrounded by portions of the housing cooled by cooling water.
Accordingly, heat generated by the elements provided in the inverter module 11 is conducted to the positive bus bar 12 ′, the negative bus bar 13 ′, and the terminal plate 14, and the positive bus bar 12 ′, the negative bus bar 13 ′, and the terminal plate 14 The heat is dissipated by being cooled using the cooling system provided in the device. Therefore, each of the semiconductor modules 19, 19,... Provided in the inverter module 11 is configured to radiate heat from both the front and back surfaces, and the heat radiation performance is greatly improved. As a result, the size and capacity of the inverter module 11 can be reduced.
[0031]
In order to ensure insulation between the positive electrode plate 12 and the negative electrode plate 13 of the inverter module 11 and the housing 41 of the electric motor 27, when the material of the positive electrode plate 12 and the negative electrode plate 13 is aluminum, aluminum anodic oxidation treatment is performed. When the positive electrode plate 12 and the negative electrode plate 13 are made of another metal, the positive electrode plate 12 and the negative electrode plate 13 are insulated. Is done. Thereby, the insulating property is ensured without substantially decreasing the thermal conductivity of the positive electrode plate 12 and the negative electrode plate 13.
Further, the high heat conductive grease is applied on the surface layer of the insulated positive electrode plate 12 and the negative electrode plate 13 and the motor mounting surface, and then assembled, so that the positive electrode plate 12 and the negative electrode plate 13 are assembled. Thus, the degree of thermal adhesion between the motor 27 and the housing 41 is ensured.
[0032]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
[0033]
That is, as set forth in claim 1, two sets of semiconductor modules each having a power element and a diode element are stacked and arranged, and a terminal plate having an output terminal and a gate signal input terminal is interposed between the two sets of semiconductor modules. Then, the two sets of semiconductor modules are sandwiched between an arc-shaped positive electrode plate having a positive input terminal and an arc-shaped negative electrode plate having a negative input terminal from both sides in the stacking direction to form a unit. The set of units are connected in a ring, a capacitor module is arranged between each positive electrode plate and the negative electrode plate, and the space between the positive electrode plate and the negative electrode plate is sealed with resin. In addition, the performance variation factor can be reduced by shortening the wiring length between the electric motor and the inverter module and between the components of the inverter module.
[0034]
Since the power element is an IGBT element, the inverter module can be made compact.
[0035]
According to a third aspect of the present invention, since the elements included in the inverter module are formed in a bare chip shape, it is possible to contribute to a reduction in size and weight of the inverter module. In addition, heat dissipation is improved, which can contribute to further downsizing of the inverter module.
[0036]
According to a fourth aspect of the present invention, in the inverter module, the power element and the diode element included in the two sets of semiconductor modules to be stacked are arranged to intersect via the terminal plate, respectively, thereby preventing the bias of the heat generation in the inverter module. can do.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a configuration of an inverter module according to an embodiment of the present invention.
FIG. 2 is a diagram showing an inverter module.
FIG. 3 is a view showing the semiconductor module as viewed in the direction of the arrow X in FIG. 2;
FIG. 4 is a view showing the inverter module as viewed in the direction of the arrow X in FIG. 2;
FIG. 5 is a cross-sectional view showing an example of an electric motor in which an inverter module is integrated.
FIG. 6 is a sectional view showing an example of an electric motor in which an inverter module is integrally incorporated.
[Explanation of symbols]
Reference Signs List 10 phase output unit 11 inverter module 12 positive electrode plate 12 'positive electrode bus bar 13 negative electrode plate 13' negative electrode bus bar 14 terminal plate 15 output terminal 16 gate terminal 17 N terminal 18 P terminal 19 semiconductor module 22 power element 23 diode element 26 capacitor module

Claims (4)

Two sets of semiconductor modules including a power element and a diode element are stacked and arranged, and a terminal plate having an output terminal and a gate signal input terminal is interposed between the two sets of semiconductor modules. An arc-shaped positive electrode plate with a positive input terminal and an arc-shaped negative plate with a negative input terminal are sandwiched from both sides in the stacking direction to form a unit,
Three units are connected in a ring,
Place a capacitor module between each positive electrode plate and negative electrode plate,
An inverter module, wherein a space between a positive electrode plate and a negative electrode plate is sealed with a resin. The inverter module according to claim 1, wherein the power element is an IGBT element. The inverter module according to claim 1, wherein an element provided in the inverter module has a bare chip shape. 4. The inverter module according to claim 1, wherein in the inverter module, a power element and a diode element included in the two sets of stacked semiconductor modules are arranged to cross each other via a terminal plate. 5.

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