JPH0947035A - Inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter in which the heating value is prevented from being differentiated among respective transistors while ensuring smooth rotation of a motor. SOLUTION: The inverter comprises a heat sink, three transistor modules 21-23 each comprising a pair of transistors having having a positive pole side terminal (a), a negative pole side terminal (b), and an output terminal (c), a bus panel 12 connecting the transistor modules 21-23, two cable assemblies 27, 28 connected between the bus panel 12 and a power cable in order to apply a voltage to the transistor, two capacitors 13, 14, and a switching means for turning the transistor on/off. The transistor modules 21-23, two cable assemblies 27, 28 and two capacitors 13, 14 are arranged symmetrically to the center line of central transistor module 22. This arrangement eliminates fluctuation of inductance among the transistors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device.

[0002]

2. Description of the Related Art Conventionally, in an electric vehicle, a battery is mounted and a motor is driven by a current supplied from the battery. The motor is composed of a rotor and a stator coil. Then, a three-phase sine wave signal is generated, the sine wave signal is multiplied by a current command value to generate a pulse width modulation signal, and the pulse width modulation signal selectively turns on / off six transistors. As a result, three phase currents are generated.

By the way, the six transistors form a transistor module by combining them in pairs, and the transistor modules, smoothing capacitors, power cables, etc. are electrically connected to each other via a bus panel. It has become. In this case, when each transistor is turned on and off, an overvoltage ΔV ΔV = Ldi / dt L: wiring inductance component i: phase current is generated between the collector and emitter. Then, the overvoltage ΔV destroys the element of the transistor, increases loss, and becomes a noise source to the outside.

Therefore, the bus bars on the positive electrode side and the negative electrode side are made wide, and an insulator is sandwiched between the bus bars to reduce the inductance of the wiring and prevent the overvoltage ΔV from occurring. FIG. 2 is a perspective view of a conventional inverter device. In the figure, 11 is a control board, 1
Reference numeral 2 is a bus panel formed by sandwiching an insulator between each of the positive and negative side bus bars, 13 and 14 are smoothing capacitors, and 15 is a heat sink. The capacitors 13 and 14 are connected in parallel to increase the capacity. Further, three transistor modules (not shown) are sandwiched between the bus panel 12 and the heat sink 15, and a voltage is applied to each transistor of the transistor module via the bus panel 12. Then, the heat generated by turning on / off each transistor is radiated by the heat sink 15.

FIG. 3 is a conceptual diagram of a conventional inverter device. In the figure, 12 is a bus panel, 13 and 14 are smoothing capacitors, and 21 to 23 are transistor modules. Each of the transistor modules 21 to 23 is composed of a pair of transistors, and has a positive electrode side terminal a, a negative electrode side terminal b, and an output terminal c, respectively.

Then, each transistor module 21-
An output-side bus bar 25 is connected to the output terminal c of 23, and a motor-connecting cable assembly 26 is connected to the bus bar 25. Incidentally, 27 and 28 are cable assemblies for connecting a power cable (not shown), and the cable assemblies 27, 28 and a power source (not shown) can be connected by the power cable.

FIG. 4 is a conceptual diagram of another conventional inverter device. In the figure, 12 is a bus panel, 13 is a capacitor, and 21 to 23 are transistor modules. Each of the transistor modules 21 to 23 is composed of a pair of transistors, and has a positive electrode side terminal a, a negative electrode side terminal b, and an output terminal c, respectively. A condenser (not shown) is arranged on the inner side of the condenser 13.

Then, each of the transistor modules 2
An output side bus bar 25 is connected to the output terminals c of 1 to 23, and a motor connecting cable assembly 26 is connected to the bus bar 25. Incidentally, 27 and 28 are cable assemblies for connecting a power cable (not shown), and the cable assemblies 27, 28 and a power source (not shown) can be connected by the power cable.

In this case, the capacitor 13 can be housed in the inverter device case (not shown).

[0010]

However, in the above-mentioned conventional inverter device, since the inductance of each transistor varies, the overvoltage ΔV differs for each transistor and the loss varies. As a result, the amount of heat generated varies from transistor to transistor, and the motor cannot rotate smoothly.

Further, two or more capacitors 13 and 14
When using, if the balance of the wiring of the capacitors 13 and 14 is poor, the balance of the ripple current becomes poor,
The heat generation amount of only one capacitor may increase. The present invention solves the problems of the conventional inverter device described above, and the amount of heat generated is different for each transistor, the motor cannot be smoothly rotated, and when two or more capacitors are used, An object of the present invention is to provide an inverter device in which the heat generation amount of only one capacitor does not increase.

[0012]

To that end, in the inverter device of the present invention, a heat sink and a 3 mounted on the heat sink, each of which is composed of a pair of transistors, has a positive side terminal, a negative side terminal and an output terminal. Transistor modules, a bus panel connected to each transistor module, and two cable assemblies connected between the bus panel and a power cable for applying a voltage to the transistors via the bus panel, It has two capacitors connected to the cable assembly to smooth the voltage applied to the transistor, and switching means connected to the transistor to turn on / off the transistor.

Then, each of the transistor modules,
The cable assemblies and the capacitors are arranged symmetrically with respect to the central transistor module. In another inverter device of the present invention,
The capacitor is disposed adjacent to the cable assembly. In still another inverter device of the present invention, the bus panel is further bent in an “L” shape, and the capacitor is arranged parallel to the heat sink.

[0014]

As described above, according to the present invention, in the inverter device, the heat sink and the heat sink mounted on the heat sink, each of which is composed of a pair of transistors, are provided with the positive side terminal, the negative side terminal and the output terminal. Three transistor modules, a bus panel connected to each of the transistor modules, and two cable assemblies connected between the bus panel and the power cable and applying a voltage to the transistors via the bus panel. And two capacitors connected to the cable assembly to smooth the voltage applied to the transistor, and switching means connected to the transistor to turn on / off the transistor.

In this case, when the switching means selectively turns on / off the transistors, a phase current is generated in each transistor module and is supplied to the motor. The transistor modules, the cable assemblies, and the capacitors are arranged symmetrically with respect to the central transistor module.

Therefore, there is no variation in the inductance of each transistor, and the flow of direct current can be made equal from the cable assembly to the transistor module. As a result, the overvoltages of the respective transistors become equal, and the loss does not vary. Further, since the amount of heat generated by each transistor is equal, the motor can be smoothly rotated.

Furthermore, since the flow of direct current from the cable assembly to each capacitor can be made equal, the balance of the wiring of each capacitor is improved. Therefore, the balance of the ripple current is improved, and the heat generation amounts of both capacitors can be equalized. In another inverter device of the present invention, the capacitor is further arranged adjacent to the cable assembly.

In this case, since the flow of the direct current from the cable assembly to each capacitor can be shortened, the wiring balance of each capacitor is improved. In still another inverter device of the present invention, further, the bus panel is bent into an “L” shape, and
The capacitor is arranged parallel to the heat sink.

In this case, since the capacitor is arranged parallel to the heat sink, the entire capacitor can be housed in the inverter device case. As a result, the capacitor does not penetrate the heat sink, so that it is not necessary to increase the airtightness between the capacitor and the heat sink.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 5 is a diagram showing a drive system for an electric vehicle according to the first embodiment of the present invention. In the figure, 31 is a motor, and the motor 31 is a motor vehicle
It is arranged in each drive wheel of the wheel and is driven by the current supplied from the DC power supply 33. The motor 31 includes a rotor (not shown) made of permanent magnets having 6 poles, and a stator coil (not shown) made of three-phase windings.

A rotor of the resolver 35 is coaxially coupled to the rotor shaft 34 of the motor 31,
The magnetic pole position of the rotor of the motor 31 can be detected. Further, a resolver circuit 36 is connected to the resolver 35, and the resolver circuit 36 is
AC voltage x (= E _m sin ωt), y is applied to the resolver 35.
(= E _m cos ωt) is applied and the resolver 35
From the resolver signal a (= E _m sin (ωt
+ Θ)), the magnetic pole position of the rotor is detected, and the magnetic pole position signal b is output to the current waveform control circuit 37.

The current waveform control circuit 37 generates a three-phase pulse width modulation signal d consisting of U phase, V phase and W phase having a duty ratio corresponding to the current command value, and outputs the pulse width modulation signal d. Output to the base drive circuit 38. The base drive circuit 38 receives the pulse width modulation signal d output from the current waveform control circuit 37, and
A transistor drive signal c for driving each transistor Tr is generated and output to the inverter 40. The current waveform control circuit 37 and the base drive circuit 38 form a switching means.

The stator coil of the motor 31 is excited by the inverter 40. The inverter 40 includes the six transistors Tr, three snubber circuits 41, and smoothing capacitors 13 and 14, and the transistor drive signal c is input to the base of each transistor Tr. And a pair of transistors T
Transistor modules 21-23 by connecting r in series
Is formed, and the inverter 40 is formed by connecting the transistor modules 21 to 23 in parallel.

Further, 49 is a main computer, 51 is a current sensor for detecting a phase current supplied to the motor 31, 53 is a power supply circuit connected to the DC power supply 33, and the power supply circuit 53 is the inverter 40. Is applied to the current waveform control circuit 37 and the like, and the control power supply voltage r is applied to the current waveform control circuit 37 and the like. By the way, if the inductance of each transistor Tr varies, the overvoltage ΔV differs for each transistor Tr, and the loss varies. As a result, the amount of heat generated varies from transistor to transistor Tr, and the motor 31 cannot rotate smoothly.

Further, two or more capacitors 13 and 14
When using, if the balance of the wiring of the capacitors 13 and 14 is poor, the balance of the ripple current becomes poor,
The amount of heat generated by only one of the capacitors will increase. Therefore, in order to eliminate the variation in the inductance of each transistor Tr, the flow of the DC current supplied from the DC power supply 33 and the flow of the phase current supplied from the inverter 40 to the motor 31 is controlled by the DC power supply 33, the positive electrode side and the negative electrode side. The cable assemblies 27 and 28 (see FIG. 3), the capacitors 13 and 14, the inverter 40, and the motor 31 are arranged in this order, and the cable assemblies 27 and 28 to the respective transistor modules 21 to 23, that is, the cable assemblies 27 and 28 to the respective transistors Tr. Make the length on the wiring up to as short as possible and equal. for that reason,
The respective components such as the transistor modules 21 to 23, the cable assemblies 27 and 28, the capacitors 13 and 14 are arranged symmetrically with respect to the central transistor module 22.

FIG. 1 is a conceptual diagram of an inverter device according to the first embodiment of the present invention, and FIG. 6 is a sectional view of the inverter device according to the first embodiment of the present invention. In the figure, 12
Is a bus panel formed by sandwiching an insulator between the positive and negative side bus bars, 13 and 14 are smoothing capacitors, and 15 is a heat sink. Transistor modules 21 to 23 are sandwiched between the bus panel 12 and the heat sink 15, and a voltage is applied to each transistor Tr (FIG. 5) of each of the transistor modules 21 to 23 via the bus panel 12. Then, the heat generated by turning on / off each transistor Tr is
It is released by the heat sink 15.

Each of the transistor modules 21-23
Respectively have a positive electrode side terminal a, a negative electrode side terminal b, and an output terminal c. The positive electrode side terminal a is a positive electrode side bus bar of the bus panel 12, and the negative electrode side terminal b is a bus panel 12 shown in the figure. The negative side bus bar, the output side bus bar 25 is connected to the output terminal c, and the motor connecting cable assembly 26 is connected to the bus bar 25. The motor connecting cable assembly 26 is connected to the motor 31 via a power cable 63. In addition, 27 and 28 are cable assemblies for connecting the power cables 64, and the cable assemblies 27 and 28 and the DC power source 33 are connected to the power cables 64.
Can be connected by

The bus panel 12 and the transistor modules 2 are formed on the front surface of the heat sink 15.
1 to 23 are mounted, and the bus panel 12 and the transistor modules 21 to 23 are mounted on the inverter device case 6
A waterproof structure is formed by being surrounded by 1. Further, a fin 65 for heat dissipation is formed on the back surface of the heat sink 15 so that the heat generated by turning on / off each transistor Tr of the transistor modules 21-23 can be released. There is.

In this case, the motor connecting cable assembly 26 and the cable assemblies 27, 28 are penetrated from the front side to the back side of the heat sink 15, and the motor connecting cable assembly 26 and the power cable 64 are connected to each other on the back side surface. Two
8 and the power cable 63 are connected.

The bus panel 12 is formed by sandwiching an insulator between two copper flat plates. Since the bus panel 12 is a large flat plate, the transistor modules 21 to 23, the capacitors 13, 14 and the like are fixed from below the bus panel 12 by bolts (not shown). A pair of cable assemblies 27 and 28 are arranged symmetrically in front of the transistor module 22 at the center of the transistor modules 21 to 23, and capacitors 13 and 1 are provided on both sides of the cable assemblies 27 and 28.
4 is provided.

Therefore, there is no variation in the inductance of each transistor Tr, and the cable assemblies 27 and 28 are used to form the transistor modules 21 to 23.
It is possible to equalize the flow of direct current. As a result, the overvoltages .DELTA.V of the respective transistors Tr become equal, and the loss does not vary. Further, since the heat generation amounts of the respective transistors Tr become equal, the motor 31 can be smoothly rotated.

Further, the cable assemblies 27, 28
Since it is possible to equalize the flow of the DC current from the capacitors 13 and 14 to the capacitors 13 and 14, the balance of the wirings of the capacitors 13 and 14 is improved. Therefore, the balance of the ripple current is improved, and the heat generation amounts of both capacitors 13 and 14 become equal. Next, the cable assembly 27 will be described. The cable assembly 28 also has a similar structure, and a description thereof will be omitted.

FIG. 7 is a sectional view of the cable assembly according to the first embodiment of the present invention, and FIG. 8 is a front view of the cable assembly according to the first embodiment of the present invention. In the figure, 27 is a cable assembly, 63 is a power cable, 67 is a bush, 68 is an O-ring which is arranged around the bush 67 and seals the heat sink 15 (FIG. 6), and 69 is the bush 67. Heat sink 1
5, a through hole of a bolt (not shown) for fixing to 5, a bolt for connecting the bus panel 12 and the adapter 71, a bush cover 72, and a filling material.

Next, a second embodiment of the present invention will be described. 9 is a conceptual diagram of an inverter device according to the second embodiment of the present invention, FIG. 10 is a sectional view of the inverter device according to the second embodiment of the present invention, and FIG. 11 is a cable assembly according to the second embodiment of the present invention. It is a figure which shows the adapter of. In the figure, 12 is a bus panel, 13 and 14 are smoothing capacitors, and 21 to 23 are transistor modules. Each of the transistor modules 21 to 23 is composed of a pair of transistors (not shown), and has a positive electrode side terminal a, a negative electrode side terminal b, and an output terminal c, respectively.

Then, each transistor module 2
An output side bus bar 25 is connected to the output terminals c of 1 to 23, and a motor connecting cable assembly 26 is connected to the bus bar 25. The cable assemblies 27, 28 (see FIG. 4) and a power source (not shown) can be connected by the power cable 64. Also,
70 is a bolt for connecting the bus panel 12 and the adapter 27a of the cable assembly 27.

In this case, the bus panel 12 is bent into an "L" shape, and the capacitors 13 and 14 are fixed to the rising wall portion 12a which stands up in a direction perpendicular to the heat sink 15. Therefore, since the capacitors 13 and 14 are arranged parallel to the heat sink 15, the entire capacitors 13 and 14 can be housed in the inverter device case 61. As a result, since the capacitors 13 and 14 do not penetrate the heat sink 15, it is not necessary to increase the airtightness between the capacitors 13 and 14 and the heat sink 15.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and these are not excluded from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an inverter device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a conventional inverter device.

FIG. 3 is a conceptual diagram of a conventional inverter device.

FIG. 4 is a conceptual diagram of another conventional inverter device.

FIG. 5 is a diagram showing a drive device for an electric vehicle according to a first embodiment of the present invention.

FIG. 6 is a cross-sectional view of the inverter device according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view of the cable assembly according to the first embodiment of the present invention.

FIG. 8 is a front view of the cable assembly according to the first embodiment of the present invention.

FIG. 9 is a conceptual diagram of an inverter device according to a second embodiment of the present invention.

FIG. 10 is a sectional view of an inverter device according to a second embodiment of the present invention.

FIG. 11 is a diagram showing an adapter of a cable assembly according to a second embodiment of the present invention.

[Explanation of symbols]

 12 bus panel 13, 14 capacitor 15 heat sink 21-23 transistor module 27, 28 cable assembly 37 current waveform control circuit 38 base drive circuit 63 power cable Tr transistor a positive side terminal b negative side terminal c output terminal

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kimiya Maki Aisin AW Co., Ltd. 10 Takane, Fujii-cho, Anjo City, Aichi Prefecture

Claims (3)

[Claims] 1. A heatsink, three transistor modules mounted on the heatsink, each transistor including a pair of transistors, each having a positive side terminal, a negative side terminal and an output terminal, and a bus connected to each transistor module. A panel, two cable assemblies that are connected between the bus panel and the power cable and apply a voltage to the transistor via the bus panel, and a voltage that is connected to the cable assembly and that is applied to the transistor. The capacitor includes two capacitors for smoothing and switching means connected to the transistor to turn on / off the transistor, and the transistor modules, the cable assemblies, and the capacitors are left and right with a central transistor module as a center. Arranged symmetrically An inverter device characterized in that 2. The inverter device according to claim 1, wherein the capacitor is arranged adjacent to a cable assembly. 3. The inverter device according to claim 1, wherein the bus panel is bent in an “L” shape, and the capacitor is arranged parallel to the heat sink.